Biomass resources are gaining increasing importance world over due to their ease of conversion to... more Biomass resources are gaining increasing importance world over due to their ease of conversion to various energy product in the face of depleting fossil fuel store and increasing environmental concerns over their use. The present work elucidates different physico-chemical properties of three biomasses, paddy straw (PS)an agricultural residue, spent paddy straw obtained after mushroom cultivation (SS), and a noxious weed (Parthenium hysterophorus; PR) to understand their properties and to explore the feasibility of using them as feedstocks in different biomass to bioenergy conversion routes. In addition to physico-chemical analysis, biochemical analysis of these biomasses along with XRD, thermogravimetric analysis, FTIR and SEM analysis have been carried out. Present study suggests that PS is a better choice as feedstock compared to both PR and SS. The calorific value to ash content ratio is more in PS (1.13) as compared to PR (1.06) and SS (0.84). Thus, it may be inferred that the b...
Current Developments in Biotechnology and Bioengineering, 2020
Abstract India, being one of the largest producers of many food crops, also turns out with a huge... more Abstract India, being one of the largest producers of many food crops, also turns out with a huge amount of agricultural residues. Because of the bulky nature, lack of a structured market for selling, significant deterioration of quality during storage, immediate need of field preparation for the next crop in the cropping pattern, etc., are some of the reasons of crop residue burning in the field causing excessive emission of particulate matter and greenhouse gases. Crop residue burning has become a serious environmental issue in recent years, having manifold ramifications with regional, national, and international perspectives. Crop residues and bioproducts generated at different stages of agricultural activities have left behind many useful chemical components that necessitate its utilization for the development of various useful products and processes. This is important not only for the generation of additional income but also for the abatement of greenhouse gas emissions from its residue burning, the scope of employment generation at villages, avoiding disposal-related problems and attaining a sustainable environment. This chapter discusses the global and Indian scenario of agriculture residue generation and various processes and products that can be obtained from agricultural residues as a feedstock. The chapter summarizes that proper utilization of agricultural residues and wastes will be beneficial not only for the farming community but will also be a boon for overall agricultural development in the country and circular economy.
Behaviour of Strontium in Plants and the Environment, 2017
Although Strontium (Sr) is a natural and commonly occurring alkaline earth metal, various anthrop... more Although Strontium (Sr) is a natural and commonly occurring alkaline earth metal, various anthropogenic activities including nuclear weapons explosions or wastes from nuclear reactors and their accidental fallouts are responsible for contaminating the environment, especially with its radioactive isotope (90Sr). 90Sr has lasting effect on the human body, as it causes several diseases including cancers. Due to its chemical similarity to calcium, strontium is absorbed readily by plants. Some plants even effectively accumulate 90Sr, which is used for phytoremediation. The efficiency depends on, e.g. soil properties, climate, biosphere, and particular species and populations (subspecies, cultivars). Phytoremediation can either be direct with uptake or absorption by plants, or rhizoremediation where, after transformation, radionuclides are confined to the rhizosphere by enzymatic or root specific microbial actions. The rhizosphere plays an important role in plants’ potential in accumulating 90Sr. This chapter tries to encompass the recent findings on Sr in the environment and its uptake by plants and related phytoremediation capacity.
Mushrooms are macrofungi that serve as a vegetarian source of protein along with various bio-acti... more Mushrooms are macrofungi that serve as a vegetarian source of protein along with various bio-active molecules of primary health importance. The activity of the bio-active molecules range from antioxidant, immunomodulation, hepatoprotection. Cultivated oyster mushrooms are also rich in these components which may be estimated quantitatively by skill intensive ‘destructive’ chemical techniques. Infra Red spectroscopy provides a non-destructive user friendly technique to quickly assess the presence of bio-active compounds in mushroom species to be used as a quality control measure as this non-destructive tool can be used to segregate mushroom harvest according to availability of bioactive compounds. IR spectra based strain classification and taxa delimitation of mushroom samples are also attempted vis a vis DNA sequence based phylogeny analysis of the same, but no correlation is observed between the two types of phylogeny analysis.
International Journal of Renewable Energy Development, 2019
Biomass resources are gaining increasing importance world over due to their ease of conversion to... more Biomass resources are gaining increasing importance world over due to their ease of conversion to various energy product in the face of depleting fossil fuel store and increasing environmental concerns over their use. The present work elucidates different physico-chemical properties of three biomasses, paddy straw (PS)- an agricultural residue, spent paddy straw obtained after mushroom cultivation (SS), and a noxious weed (Parthenium hysterophorus; PR) to understand their properties and to explore the feasibility of using them as feedstocks in different biomass to bioenergy conversion routes. In addition to physico-chemical analysis, biochemical analysis of these biomasses along with XRD, thermogravimetric analysis, FTIR and SEM analysis have been carried out. Present study suggests that PS is a better choice as feedstock compared to both PR and SS. The calorific value to ash content ratio is more in PS (1.13) as compared to PR (1.06) and SS (0.84). Thus, it may be inferred that the...
Abstract Information about the layer wise variation in Municipal Solid Waste (MSW) dumps, their e... more Abstract Information about the layer wise variation in Municipal Solid Waste (MSW) dumps, their environmental consequences, and leaching dynamics are rather scarce. MSW samples were, therefore, collected from three layers of a 30 year old dumping site at Silchar (India). Significant variations in pH, density, and metal toxicity were evidenced in different layers of the MSW pile. Physical characteristics (grain size, porosity etc) noticeably varied along the depth as substantiated by SEM analysis. FTIR analysis further revealed predominance of amines and alkenes in the deeper layers. NPK availability was found to be 1.5–2 folds lower in the deepest layer (L3) than the upper layers (L1 and L2). However, Pb, Cr, and Cd availability was significantly high in the middle layer (L2). Lab scale leaching experiments showed that metals (Fe, Cu, and Pb), phosphates and sulphates can greatly contaminate the soil and aquatic ecosystems in the long run. Visual MINTEQ model predicted possibilities of time dependent long range leaching of Fe, Cu, and Pb. Attributes like pollution index, ecological risk index, and geo-accumulation index also revealed adverse impacts of the deeper landfill layers on the surrounding environment. The potentially toxic MSWs were sanitized via vermitechnology by utilizing the bioaccumulation traits of earthworms (Eisenia fetida). On an average more than 3–5 fold reduction in overall environmental risk could be achieved in the vermicomposted and composted MSW fractions. The N, P, and K levels increased by 85%, 41%, and 68% in the vermicomposted MSW + Cow dung (1:1) feedstock. This also induced greater seed viability than composted mixtures. Finally, the economic evaluation of the treatment technologies was performed to realize their industrial value.
Mushroom is a very popular food that is consumed around the globe yet it finds very limited accep... more Mushroom is a very popular food that is consumed around the globe yet it finds very limited acceptance in India, that too mainly among the elite. Non-availability of mushrooms around the year and its highly perishable nature makes it an expensive commodity for the common people to afford. Hence pickling may be viewed as a method to increase the shelf life of oyster mushrooms from 4-7 days under refrigerated condition to at least up to 12 months at room temperature. Hence a recipe for pickling of mushrooms using Indian spices was formulated so as to suit the Indian palate. The proximate analysis, calorific value, mineral and fatty acid profile along with antioxidant profile of the mushroom pickle was elucidated. Sensory parameters and shelf life and stability determining data like pH, titratable acidity and microbiological profile of the pickle was also performed. Finally it was observed that the mushroom pickle formulation has a shelf life of at least 12 months at room temperature w...
Toxicology in vitro : an international journal published in association with BIBRA, 2008
Abrin is a plant glycoprotein toxin, classified as ribosome inactivating protein (RIP) due to its... more Abrin is a plant glycoprotein toxin, classified as ribosome inactivating protein (RIP) due to its property of damaging ribosomes in an irreversible manner. Many RIPs have direct DNA damaging activity. The objective of the present study was to evaluate the oxidative stress and DNA damaging potential of abrin in U937 human myeloleukemic cells. Cells were treated with abrin at IC50 of 8 ng/ml for 24h. Abrin induced a time dependent increase in reactive oxygen species and levels of antioxidant enzymes. There was significant depletion of reduced glutathione levels. DNA damage was assessed by comet assay in terms of percent head DNA, tail DNA, tail length and Olive tail moment. DNA damage was more pronounced at 4 and 8h at IC50 concentration. Abrin at 4, 8, 16 and 32 ng/ml concentration induced significant DNA damage at 4h. There was time dependent increase in levels of 8-OHdG in abrin treated cells indicating the oxidative stress mediated DNA damage. N-Acetylcysteine pretreatment at 10nM...
ABSTRACT The individual toxic effects of arsenic and organophosphate pesticides are known but the... more ABSTRACT The individual toxic effects of arsenic and organophosphate pesticides are known but there is a lack of data on their combined effects. The present study investigates the toxic effects following combined exposure to organophosphate and arsenic on: (i) alterations in brain biogenic amines, (ii) oxidative stress and its correlation with glutathione linked enzymes, cell death and histopathological observations, and (iii) arsenic concentration in soft tissues. Rats were exposed to arsenic (1 mg kg−1 body weight, orally) and dichlorvos (4 mg kg−1 body weight, subcutaneously) either individually or in combination for 16 weeks. Arsenic alone and in combination with DDVP led to a significant increase in reactive oxygen species (ROS), thiobarbituric acid reactive substance (TBARS), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities accompanied by a decreased glutathione reductase, reduced and oxidized glutathione (GSH and GSSG) levels in tissues. Arsenic and DDVP also produced a significant depletion in brain biogenic amines; however, acetylcholinesterase (AChE) activity increased moderately on arsenic exposure. Arsenic and DDVP co-exposure exhibited synergism in the case of ROS while no such effect was noted in the case of TBARS. Interestingly, combined exposure to arsenic and DDVP resulted in more pronounced toxic effects compared to their individual effects based on various biochemical variables, cell death (TUNEL assay) and histopathological observations. Interestingly, brain arsenic levels decreased on co-exposure to arsenic and DDVP accompanied with prominent elevation of liver arsenic content in co-exposed groups. The present study thus provides some interesting observations on the interaction between arsenic and DDVP including (i) co-exposure to arsenic and DDVP might lead to significant oxidative stress and (ii) their co-exposure produced synergistic effects on some liver variables but some antagonistic effects on the brain.
Sulfur mustard (SM; 2,2'-dichloro diethyl sulfide... more Sulfur mustard (SM; 2,2'-dichloro diethyl sulfide), an alkylating chemical warfare agent, poses a major threat in both military conflict and chemical terrorism situations. 2-chloroethyl ethyl sulfide (CEES) is a monofunctional analogue of SM, frequently used in laboratory settings, therefore increasing chances of its exposure. S-2(ω-aminoalkylamino) alkylaryl sulfide (DRDE-07) is an analogue of amifostine reported to have protective effects against SM but its effect on CEES is largely unexplored. Therefore, this study was planned to explore the effects of DRDE-07 against CEES-induced toxicity. 0.75 LD50 (1068 mg/kg) of CEES was exposed percutaneously in the presence or absence of DRDE-07 (249 mg/kg p.o.) which is given prophylactically (before 30 minute) to male mice. Animals were sacrificed on 24 h, 7th day and 14th day of CEES exposure, and tissues were collected to study oxidative stress and inflammatory markers. CEES exposure depleted intracellular GSH level and activities of GSH-linked enzymes (GR, GPx and GST) which play a major role in GSH metabolism. CEES exposure augmented lipid peroxidation indicating severe oxidative stress. It also initiated inflammation causing an increase in proinflammatory (IL1-α, IL1-β, IL-6, TNF-α and IFN-ϒ) and corresponding decrease in anti-inflammatory cytokines (IL-4 and IL-10). This was also accompanied by neutrophils infiltration indicated by higher than normal myeloperoxidase (MPO) levels. DRDE-07 efficiently reduced the oxidative stress and also facilitated to resolve inflammatory alterations. This study thus evaluated the beneficial role of DRDE-07 in ameliorating the deleterious effects of CEES and can be potentially used against SM/CEES poisoning.
Comparative efficacy as peripheral sensory irritant, oral and inhalation exposure studies were ca... more Comparative efficacy as peripheral sensory irritant, oral and inhalation exposure studies were carried out on oleoresin capsicum (OC) of Capsicum frutescence var. Nagahari containing various percentages of capsaicinoids and two synthetic isomers of capsaicin in Swiss albino male mouse model to come up with a suitable active ingredient from natural source for tear gas munitions. The compounds screened were OC having varying percentages of capsaicinoids (20, 40 and 80%, respectively) and synthetic isomers (E and Z) of capsaicin (8-methyl-N-vanillyl-6-nonenamide). Mice were exposed to pyrotechnically generated smoke of the compounds in an all glass static exposure chamber for 15 min to determine acute inhalation toxicity (LC₅₀) and quantitative sensory irritation potential (RD₅₀). Acute oral median lethal dose (LD₅₀) was also evaluated. Safety index of tear gas (SITG), a ratio of lethal concentration 50% (LC₅₀) and the concentration which depresses respiration by 50% (RD₅₀) due to peripheral sensory irritation is also proposed. The compound having highest SITG is considered as the most suitable to be used for tear gas munitions. The study revealed that oleoresin capsicum containing 40% capsaicinoids had the highest SITG among the compounds studied. The oral dosage versus mortality pattern of some compounds did not follow a true dose-response curve (DRC); however, following inhalation, all the compounds followed DRC. It was concluded that oleoresin capsicum (40% capsaicinoids) may be considered as the most suitable and environmental friendly compound from natural source to be used as an active ingredient for tear gas munitions.
Comparative inhalation toxicity studies of pyrolytic products (smoke) from synthetic polymer, fib... more Comparative inhalation toxicity studies of pyrolytic products (smoke) from synthetic polymer, fiberglass reinforced plastic (FRP) and teak wood shavings were carried out in male Swiss albino mice. The breathing pattern and the respiratory variables were monitored using a computer program that recognizes the modifications of the respiratory pattern. Exposure to the smoke from both the polymers caused a concentration dependent decrease in normal breathing and an increase in sensory irritation measure. The acute lethal concentration 50 values for a 15 min static inhalation exposure to the smoke from FRP and teak wood shavings were found to be > 200.00 and 62.99 g/m(3), respectively. Hence the inhalation toxicity of smoke from FRP sample on a mass basis is approximately one-third that of the smoke from teak wood. The concentration of smoke causing 50% respiratory depression of the exposed animals were found to be 6.877 and 0.106 g/m(3) for FRP and teak wood samples, respectively. Thus the sensory irritancy of the smoke from FRP sample is approximately 65 times lesser than the smoke from teak wood. The higher sensory irritancy potential of wood smoke as compared to FRP smoke may be caused by a greater number of submicron particles (size range of 2 micron and less) and greater percentage of gases present in wood smoke as compared to FRP smoke. Thus in case of accidental fires, synthetic polymers like FRP may be a safer choice for structural parts and interiors than the natural wood.
Comparative inhalation toxicity studies of aerosols of insect repellents N,N-diethylbenzamide (DE... more Comparative inhalation toxicity studies of aerosols of insect repellents N,N-diethylbenzamide (DEB), N,N-diethylphenylacetamide (DEPA), and N,N-diethyl-3-methylbenzamide (DEET) were carried out in mice. The respiratory pattern was monitored using a computer program that recognizes the modifications of the breathing pattern. Exposure to the aerosols caused a dose-dependent decrease in normal breath, with an increase in airway obstruction. All the three insect "sensilla irritants" showed no significant mammalian sensory irritation. The acute LC(50) value for a 4-h exposure of DEB, DEPA, and DEET aerosols in male mice was found to be >2.5 g/m(3), 1714 mg/m(3), and 1369 mg/m(3), respectively. Irreversible depression in respiratory frequency was observed after exposure to DEB aerosol at a concentration of 277 mg/m(3) and above, which did not revert back to normal level even after aerosol exposure was stopped. At a concentration of 156 mg/m(3) of DEB, no respiratory depression was observed. DEPA and DEET caused no depression in respiratory frequency up to a concentration 1292 and 950 mg/m(3), respectively. Hence the two insect repellents DEET and DEPA do not cause any harmful effect to the respiratory parameters in acute exposure, showing that they are more suitable chemicals to be used as insect repellents as compared to DEB.
Inhalation toxicity of silicon dioxide aerosol (150, 300 mg/m(3)) daily over a period of 28 days ... more Inhalation toxicity of silicon dioxide aerosol (150, 300 mg/m(3)) daily over a period of 28 days was carried out in rats. The changes in respiratory variables during the period of exposure were monitored using a computer programme that recognizes the modifications of the breathing pattern. Exposure to the aerosol caused a time dependent decrease in tidal volume, with an increase in respiratory frequency compared to the control. Biochemical variables and histopathological observation were noted at 28th day following the start of exposure. Biochemical markers of silica induced lung injury like plasma alkaline phosphatase, lactate dehydrogenase and angiotensine converting enzyme activities increased in a concentration dependent manner compared to control. Increase in the plasma enzymatic activities indicates endothelial lung damage, increased lung membrane permeability. Histopathological observation of the lungs confirmed concentration dependent granulomatous inflammation, fibrosis and proteinacious degeneration. Aggregates of mononuclear cells with entrapped silica particles circumscribed by fibroblast were observed in 300 mg/m(3) silica aerosol exposed group at higher magnification. Decrease in tidal volume and increase in respiratory frequency might be due to the thickening of the alveolar wall leading to a decreased alveolar volume and lowered elasticity of the lung tissue. The trends in histological and biochemical data are in conformity with the respiratory data in the present study. This study reports for the first time, the changes in respiratory variables during silica aerosol exposure over a period of 28 days.
Biomass resources are gaining increasing importance world over due to their ease of conversion to... more Biomass resources are gaining increasing importance world over due to their ease of conversion to various energy product in the face of depleting fossil fuel store and increasing environmental concerns over their use. The present work elucidates different physico-chemical properties of three biomasses, paddy straw (PS)an agricultural residue, spent paddy straw obtained after mushroom cultivation (SS), and a noxious weed (Parthenium hysterophorus; PR) to understand their properties and to explore the feasibility of using them as feedstocks in different biomass to bioenergy conversion routes. In addition to physico-chemical analysis, biochemical analysis of these biomasses along with XRD, thermogravimetric analysis, FTIR and SEM analysis have been carried out. Present study suggests that PS is a better choice as feedstock compared to both PR and SS. The calorific value to ash content ratio is more in PS (1.13) as compared to PR (1.06) and SS (0.84). Thus, it may be inferred that the b...
Current Developments in Biotechnology and Bioengineering, 2020
Abstract India, being one of the largest producers of many food crops, also turns out with a huge... more Abstract India, being one of the largest producers of many food crops, also turns out with a huge amount of agricultural residues. Because of the bulky nature, lack of a structured market for selling, significant deterioration of quality during storage, immediate need of field preparation for the next crop in the cropping pattern, etc., are some of the reasons of crop residue burning in the field causing excessive emission of particulate matter and greenhouse gases. Crop residue burning has become a serious environmental issue in recent years, having manifold ramifications with regional, national, and international perspectives. Crop residues and bioproducts generated at different stages of agricultural activities have left behind many useful chemical components that necessitate its utilization for the development of various useful products and processes. This is important not only for the generation of additional income but also for the abatement of greenhouse gas emissions from its residue burning, the scope of employment generation at villages, avoiding disposal-related problems and attaining a sustainable environment. This chapter discusses the global and Indian scenario of agriculture residue generation and various processes and products that can be obtained from agricultural residues as a feedstock. The chapter summarizes that proper utilization of agricultural residues and wastes will be beneficial not only for the farming community but will also be a boon for overall agricultural development in the country and circular economy.
Behaviour of Strontium in Plants and the Environment, 2017
Although Strontium (Sr) is a natural and commonly occurring alkaline earth metal, various anthrop... more Although Strontium (Sr) is a natural and commonly occurring alkaline earth metal, various anthropogenic activities including nuclear weapons explosions or wastes from nuclear reactors and their accidental fallouts are responsible for contaminating the environment, especially with its radioactive isotope (90Sr). 90Sr has lasting effect on the human body, as it causes several diseases including cancers. Due to its chemical similarity to calcium, strontium is absorbed readily by plants. Some plants even effectively accumulate 90Sr, which is used for phytoremediation. The efficiency depends on, e.g. soil properties, climate, biosphere, and particular species and populations (subspecies, cultivars). Phytoremediation can either be direct with uptake or absorption by plants, or rhizoremediation where, after transformation, radionuclides are confined to the rhizosphere by enzymatic or root specific microbial actions. The rhizosphere plays an important role in plants’ potential in accumulating 90Sr. This chapter tries to encompass the recent findings on Sr in the environment and its uptake by plants and related phytoremediation capacity.
Mushrooms are macrofungi that serve as a vegetarian source of protein along with various bio-acti... more Mushrooms are macrofungi that serve as a vegetarian source of protein along with various bio-active molecules of primary health importance. The activity of the bio-active molecules range from antioxidant, immunomodulation, hepatoprotection. Cultivated oyster mushrooms are also rich in these components which may be estimated quantitatively by skill intensive ‘destructive’ chemical techniques. Infra Red spectroscopy provides a non-destructive user friendly technique to quickly assess the presence of bio-active compounds in mushroom species to be used as a quality control measure as this non-destructive tool can be used to segregate mushroom harvest according to availability of bioactive compounds. IR spectra based strain classification and taxa delimitation of mushroom samples are also attempted vis a vis DNA sequence based phylogeny analysis of the same, but no correlation is observed between the two types of phylogeny analysis.
International Journal of Renewable Energy Development, 2019
Biomass resources are gaining increasing importance world over due to their ease of conversion to... more Biomass resources are gaining increasing importance world over due to their ease of conversion to various energy product in the face of depleting fossil fuel store and increasing environmental concerns over their use. The present work elucidates different physico-chemical properties of three biomasses, paddy straw (PS)- an agricultural residue, spent paddy straw obtained after mushroom cultivation (SS), and a noxious weed (Parthenium hysterophorus; PR) to understand their properties and to explore the feasibility of using them as feedstocks in different biomass to bioenergy conversion routes. In addition to physico-chemical analysis, biochemical analysis of these biomasses along with XRD, thermogravimetric analysis, FTIR and SEM analysis have been carried out. Present study suggests that PS is a better choice as feedstock compared to both PR and SS. The calorific value to ash content ratio is more in PS (1.13) as compared to PR (1.06) and SS (0.84). Thus, it may be inferred that the...
Abstract Information about the layer wise variation in Municipal Solid Waste (MSW) dumps, their e... more Abstract Information about the layer wise variation in Municipal Solid Waste (MSW) dumps, their environmental consequences, and leaching dynamics are rather scarce. MSW samples were, therefore, collected from three layers of a 30 year old dumping site at Silchar (India). Significant variations in pH, density, and metal toxicity were evidenced in different layers of the MSW pile. Physical characteristics (grain size, porosity etc) noticeably varied along the depth as substantiated by SEM analysis. FTIR analysis further revealed predominance of amines and alkenes in the deeper layers. NPK availability was found to be 1.5–2 folds lower in the deepest layer (L3) than the upper layers (L1 and L2). However, Pb, Cr, and Cd availability was significantly high in the middle layer (L2). Lab scale leaching experiments showed that metals (Fe, Cu, and Pb), phosphates and sulphates can greatly contaminate the soil and aquatic ecosystems in the long run. Visual MINTEQ model predicted possibilities of time dependent long range leaching of Fe, Cu, and Pb. Attributes like pollution index, ecological risk index, and geo-accumulation index also revealed adverse impacts of the deeper landfill layers on the surrounding environment. The potentially toxic MSWs were sanitized via vermitechnology by utilizing the bioaccumulation traits of earthworms (Eisenia fetida). On an average more than 3–5 fold reduction in overall environmental risk could be achieved in the vermicomposted and composted MSW fractions. The N, P, and K levels increased by 85%, 41%, and 68% in the vermicomposted MSW + Cow dung (1:1) feedstock. This also induced greater seed viability than composted mixtures. Finally, the economic evaluation of the treatment technologies was performed to realize their industrial value.
Mushroom is a very popular food that is consumed around the globe yet it finds very limited accep... more Mushroom is a very popular food that is consumed around the globe yet it finds very limited acceptance in India, that too mainly among the elite. Non-availability of mushrooms around the year and its highly perishable nature makes it an expensive commodity for the common people to afford. Hence pickling may be viewed as a method to increase the shelf life of oyster mushrooms from 4-7 days under refrigerated condition to at least up to 12 months at room temperature. Hence a recipe for pickling of mushrooms using Indian spices was formulated so as to suit the Indian palate. The proximate analysis, calorific value, mineral and fatty acid profile along with antioxidant profile of the mushroom pickle was elucidated. Sensory parameters and shelf life and stability determining data like pH, titratable acidity and microbiological profile of the pickle was also performed. Finally it was observed that the mushroom pickle formulation has a shelf life of at least 12 months at room temperature w...
Toxicology in vitro : an international journal published in association with BIBRA, 2008
Abrin is a plant glycoprotein toxin, classified as ribosome inactivating protein (RIP) due to its... more Abrin is a plant glycoprotein toxin, classified as ribosome inactivating protein (RIP) due to its property of damaging ribosomes in an irreversible manner. Many RIPs have direct DNA damaging activity. The objective of the present study was to evaluate the oxidative stress and DNA damaging potential of abrin in U937 human myeloleukemic cells. Cells were treated with abrin at IC50 of 8 ng/ml for 24h. Abrin induced a time dependent increase in reactive oxygen species and levels of antioxidant enzymes. There was significant depletion of reduced glutathione levels. DNA damage was assessed by comet assay in terms of percent head DNA, tail DNA, tail length and Olive tail moment. DNA damage was more pronounced at 4 and 8h at IC50 concentration. Abrin at 4, 8, 16 and 32 ng/ml concentration induced significant DNA damage at 4h. There was time dependent increase in levels of 8-OHdG in abrin treated cells indicating the oxidative stress mediated DNA damage. N-Acetylcysteine pretreatment at 10nM...
ABSTRACT The individual toxic effects of arsenic and organophosphate pesticides are known but the... more ABSTRACT The individual toxic effects of arsenic and organophosphate pesticides are known but there is a lack of data on their combined effects. The present study investigates the toxic effects following combined exposure to organophosphate and arsenic on: (i) alterations in brain biogenic amines, (ii) oxidative stress and its correlation with glutathione linked enzymes, cell death and histopathological observations, and (iii) arsenic concentration in soft tissues. Rats were exposed to arsenic (1 mg kg−1 body weight, orally) and dichlorvos (4 mg kg−1 body weight, subcutaneously) either individually or in combination for 16 weeks. Arsenic alone and in combination with DDVP led to a significant increase in reactive oxygen species (ROS), thiobarbituric acid reactive substance (TBARS), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities accompanied by a decreased glutathione reductase, reduced and oxidized glutathione (GSH and GSSG) levels in tissues. Arsenic and DDVP also produced a significant depletion in brain biogenic amines; however, acetylcholinesterase (AChE) activity increased moderately on arsenic exposure. Arsenic and DDVP co-exposure exhibited synergism in the case of ROS while no such effect was noted in the case of TBARS. Interestingly, combined exposure to arsenic and DDVP resulted in more pronounced toxic effects compared to their individual effects based on various biochemical variables, cell death (TUNEL assay) and histopathological observations. Interestingly, brain arsenic levels decreased on co-exposure to arsenic and DDVP accompanied with prominent elevation of liver arsenic content in co-exposed groups. The present study thus provides some interesting observations on the interaction between arsenic and DDVP including (i) co-exposure to arsenic and DDVP might lead to significant oxidative stress and (ii) their co-exposure produced synergistic effects on some liver variables but some antagonistic effects on the brain.
Sulfur mustard (SM; 2,2'-dichloro diethyl sulfide... more Sulfur mustard (SM; 2,2'-dichloro diethyl sulfide), an alkylating chemical warfare agent, poses a major threat in both military conflict and chemical terrorism situations. 2-chloroethyl ethyl sulfide (CEES) is a monofunctional analogue of SM, frequently used in laboratory settings, therefore increasing chances of its exposure. S-2(ω-aminoalkylamino) alkylaryl sulfide (DRDE-07) is an analogue of amifostine reported to have protective effects against SM but its effect on CEES is largely unexplored. Therefore, this study was planned to explore the effects of DRDE-07 against CEES-induced toxicity. 0.75 LD50 (1068 mg/kg) of CEES was exposed percutaneously in the presence or absence of DRDE-07 (249 mg/kg p.o.) which is given prophylactically (before 30 minute) to male mice. Animals were sacrificed on 24 h, 7th day and 14th day of CEES exposure, and tissues were collected to study oxidative stress and inflammatory markers. CEES exposure depleted intracellular GSH level and activities of GSH-linked enzymes (GR, GPx and GST) which play a major role in GSH metabolism. CEES exposure augmented lipid peroxidation indicating severe oxidative stress. It also initiated inflammation causing an increase in proinflammatory (IL1-α, IL1-β, IL-6, TNF-α and IFN-ϒ) and corresponding decrease in anti-inflammatory cytokines (IL-4 and IL-10). This was also accompanied by neutrophils infiltration indicated by higher than normal myeloperoxidase (MPO) levels. DRDE-07 efficiently reduced the oxidative stress and also facilitated to resolve inflammatory alterations. This study thus evaluated the beneficial role of DRDE-07 in ameliorating the deleterious effects of CEES and can be potentially used against SM/CEES poisoning.
Comparative efficacy as peripheral sensory irritant, oral and inhalation exposure studies were ca... more Comparative efficacy as peripheral sensory irritant, oral and inhalation exposure studies were carried out on oleoresin capsicum (OC) of Capsicum frutescence var. Nagahari containing various percentages of capsaicinoids and two synthetic isomers of capsaicin in Swiss albino male mouse model to come up with a suitable active ingredient from natural source for tear gas munitions. The compounds screened were OC having varying percentages of capsaicinoids (20, 40 and 80%, respectively) and synthetic isomers (E and Z) of capsaicin (8-methyl-N-vanillyl-6-nonenamide). Mice were exposed to pyrotechnically generated smoke of the compounds in an all glass static exposure chamber for 15 min to determine acute inhalation toxicity (LC₅₀) and quantitative sensory irritation potential (RD₅₀). Acute oral median lethal dose (LD₅₀) was also evaluated. Safety index of tear gas (SITG), a ratio of lethal concentration 50% (LC₅₀) and the concentration which depresses respiration by 50% (RD₅₀) due to peripheral sensory irritation is also proposed. The compound having highest SITG is considered as the most suitable to be used for tear gas munitions. The study revealed that oleoresin capsicum containing 40% capsaicinoids had the highest SITG among the compounds studied. The oral dosage versus mortality pattern of some compounds did not follow a true dose-response curve (DRC); however, following inhalation, all the compounds followed DRC. It was concluded that oleoresin capsicum (40% capsaicinoids) may be considered as the most suitable and environmental friendly compound from natural source to be used as an active ingredient for tear gas munitions.
Comparative inhalation toxicity studies of pyrolytic products (smoke) from synthetic polymer, fib... more Comparative inhalation toxicity studies of pyrolytic products (smoke) from synthetic polymer, fiberglass reinforced plastic (FRP) and teak wood shavings were carried out in male Swiss albino mice. The breathing pattern and the respiratory variables were monitored using a computer program that recognizes the modifications of the respiratory pattern. Exposure to the smoke from both the polymers caused a concentration dependent decrease in normal breathing and an increase in sensory irritation measure. The acute lethal concentration 50 values for a 15 min static inhalation exposure to the smoke from FRP and teak wood shavings were found to be > 200.00 and 62.99 g/m(3), respectively. Hence the inhalation toxicity of smoke from FRP sample on a mass basis is approximately one-third that of the smoke from teak wood. The concentration of smoke causing 50% respiratory depression of the exposed animals were found to be 6.877 and 0.106 g/m(3) for FRP and teak wood samples, respectively. Thus the sensory irritancy of the smoke from FRP sample is approximately 65 times lesser than the smoke from teak wood. The higher sensory irritancy potential of wood smoke as compared to FRP smoke may be caused by a greater number of submicron particles (size range of 2 micron and less) and greater percentage of gases present in wood smoke as compared to FRP smoke. Thus in case of accidental fires, synthetic polymers like FRP may be a safer choice for structural parts and interiors than the natural wood.
Comparative inhalation toxicity studies of aerosols of insect repellents N,N-diethylbenzamide (DE... more Comparative inhalation toxicity studies of aerosols of insect repellents N,N-diethylbenzamide (DEB), N,N-diethylphenylacetamide (DEPA), and N,N-diethyl-3-methylbenzamide (DEET) were carried out in mice. The respiratory pattern was monitored using a computer program that recognizes the modifications of the breathing pattern. Exposure to the aerosols caused a dose-dependent decrease in normal breath, with an increase in airway obstruction. All the three insect "sensilla irritants" showed no significant mammalian sensory irritation. The acute LC(50) value for a 4-h exposure of DEB, DEPA, and DEET aerosols in male mice was found to be >2.5 g/m(3), 1714 mg/m(3), and 1369 mg/m(3), respectively. Irreversible depression in respiratory frequency was observed after exposure to DEB aerosol at a concentration of 277 mg/m(3) and above, which did not revert back to normal level even after aerosol exposure was stopped. At a concentration of 156 mg/m(3) of DEB, no respiratory depression was observed. DEPA and DEET caused no depression in respiratory frequency up to a concentration 1292 and 950 mg/m(3), respectively. Hence the two insect repellents DEET and DEPA do not cause any harmful effect to the respiratory parameters in acute exposure, showing that they are more suitable chemicals to be used as insect repellents as compared to DEB.
Inhalation toxicity of silicon dioxide aerosol (150, 300 mg/m(3)) daily over a period of 28 days ... more Inhalation toxicity of silicon dioxide aerosol (150, 300 mg/m(3)) daily over a period of 28 days was carried out in rats. The changes in respiratory variables during the period of exposure were monitored using a computer programme that recognizes the modifications of the breathing pattern. Exposure to the aerosol caused a time dependent decrease in tidal volume, with an increase in respiratory frequency compared to the control. Biochemical variables and histopathological observation were noted at 28th day following the start of exposure. Biochemical markers of silica induced lung injury like plasma alkaline phosphatase, lactate dehydrogenase and angiotensine converting enzyme activities increased in a concentration dependent manner compared to control. Increase in the plasma enzymatic activities indicates endothelial lung damage, increased lung membrane permeability. Histopathological observation of the lungs confirmed concentration dependent granulomatous inflammation, fibrosis and proteinacious degeneration. Aggregates of mononuclear cells with entrapped silica particles circumscribed by fibroblast were observed in 300 mg/m(3) silica aerosol exposed group at higher magnification. Decrease in tidal volume and increase in respiratory frequency might be due to the thickening of the alveolar wall leading to a decreased alveolar volume and lowered elasticity of the lung tissue. The trends in histological and biochemical data are in conformity with the respiratory data in the present study. This study reports for the first time, the changes in respiratory variables during silica aerosol exposure over a period of 28 days.
Uploads