Objective: The present study investigates the modulation of cholestanol glucoside (CG) biosynthes... more Objective: The present study investigates the modulation of cholestanol glucoside (CG) biosynthesis by Lasiodiplodia theobromae in response to oxidative, osmotic and heat shock stresses. Methods: The fungal cultures were subjected to oxidative stress by supplementing the culture media with menadione or H 2O 2
Since the dawn of civilization, natural resources have remained the mainstay of various remedial ... more Since the dawn of civilization, natural resources have remained the mainstay of various remedial approaches of humans vis-à-vis a large number of illnesses. Saraca asoca (Roxb.) de Wilde (Saraca indica L.) belonging to the family Caesalpiniaceae has been regarded as a universal panacea in old Indian Ayurvedic texts and has especially been used to manage gynaecological complications and infections besides treating haem-morhagic dysentery, uterine pain, bacterial infections, skin problems, tumours, worm infestations, cardiac and circulatory problems. Almost all parts of the plant are considered pharmacologically valuable. Extensive folkloric practices and ethnobotanical applications of this plant have even lead to the availability of several commercial S. asoca formulations recommended for different indications though adulteration of these remains a pressing concern. Though a wealth of knowledge on this plant is available in both the classical and modern literature, extensive research on its phytomedicinal worth using state-of-the-art tools and methodologies is lacking. Recent reports on bioprospecting of S. asoca endophytic fungi for industrial bioproducts and useful pharmacologically relevant metabolites provide a silver lining to uncover single molecular bio-effectors from its endophytes. Here, we describe socio-ethnobotanical usage, present the current pharmacological status and discuss potential bottlenecks in harnessing the proclaimed phytomedicinal worth of this prescribed Ayurvedic medicinal plant. Finally, we also look into the possible future of the drug discovery and pharmaceutical R&D efforts directed at exploring its pharma legacy.
Microorganisms have provided mankind with a plethora of small molecule natural products ranging f... more Microorganisms have provided mankind with a plethora of small molecule natural products ranging from industrial enzymes to therapeutic agents. Analyses of microbial genome sequences have revealed the presence of numerous ‘silent’ or ‘cryptic’ biosynthetic gene clusters (BGCs). Activation of these cryptic biosynthetic pathways can pave way to the discovery of novel bioactive secondary metabolites (SMs). This article summarizes various approaches employed to unlock the hidden biosynthetic potential of microbes and methods developed to study their silent gene products.
Since the dawn of civilization, natural resources have remained the mainstay of various remedial ... more Since the dawn of civilization, natural resources have remained the mainstay of various remedial approaches of humans vis-a-vis a large number of illnesses. Saraca asoca (Roxb.) de Wilde (Saraca indica L.) belonging to the family Caesalpiniaceae has been regarded as a universal panacea in old Indian Ayurvedic texts and has especially been used to manage gynaecological complications and infections besides treating haemmorhagic dysentery, uterine pain, bacterial infections, skin problems, tumours, worm infestations, cardiac and circulatory problems. Almost all parts of the plant are considered pharmacologically valuable. Extensive folkloric practices and ethnobotanical applications of this plant have even lead to the availability of several commercial S. asoca formulations recommended for different indications though adulteration of these remains a pressing concern. Though a wealth of knowledge on this plant is available in both the classical and modern literature, extensive research on its phytomedicinal worth using state-of-the-art tools and methodologies is lacking. Recent reports on bioprospecting of S. asoca endophytic fungi for industrial bioproducts and useful pharmacologically relevant metabolites provide a silver lining to uncover single molecular bio-effectors from its endophytes. Here, we describe socio-ethnobotanical usage, present the current pharmacological status and discuss potential bottlenecks in harnessing the proclaimed phytomedicinal worth of this prescribed Ayurvedic medicinal plant. Finally, we also look into the possible future of the drug discovery and pharmaceutical R&D efforts directed at exploring its pharma legacy.
Search for novel anticancer lead molecules continues to be a major focus of cancer research due t... more Search for novel anticancer lead molecules continues to be a major focus of cancer research due to the limitations of existing drugs such as lack of tumor selectivity, narrow therapeutic index and multidrug resistance of cancer types. Natural molecules often possess better pharmacokinetic traits compared to synthetic molecules as they continually evolve by natural selection process to interact with biological macromolecules. Microbial metabolites constitute nearly half of the pharmaceuticals in market today. Endophytic fungi, owing to its rich chemical diversity, are viewed as attractive sources of novel bioactive compounds. In the present study, we report the purification and characterization of a novel steroidal saponin, cholestanol glucoside (CG) from Saraca asoca endophytic fungus Lasiodiplodia theobromae. The compound was assessed for its cytotoxic potentialities in six human cancer cell lines, A549, PC3, HepG2, U251, MCF7 and OVCAR3. CG exhibited significant cytotoxicities towards A549, PC3 and HepG2 among which A549 cells were most vulnerable to CG treatment. However, CG treatment exhibited negligible cytotoxicity in non malignant human lung fibroblast cell line (WI-38). Induction of cell death by CG treatment in A549 cells was further investigated. CG induced the generation of reactive oxygen species (ROS) and mitochondrial membrane permeability loss followed by apoptotic cell death. Mitochondrial membrane depolarization and apoptotic cell death in CG treated A549 cells were completely blocked in presence of an antioxidant, N-acetyl cysteine (NAC). Hence it could be concluded that CG initiates apoptosis in cancer cells by augmenting the basal oxidative stress and that the generation of intracellular ROS is crucial for the induction of apoptosis.
Cancer remains a major health issue worldwide due to the high rate of its morbidity and mortality... more Cancer remains a major health issue worldwide due to the high rate of its morbidity and mortality. Search for tumor selective, novel anticancer compounds with lesser side-effects remains a major focus of cancer research. Endophytic fungi, owing to their chemical diversity, are an attractive source of bioactive metabolites. In the present study, we have explored the endophytic fungal population associated with a traditional Indian medicinal plant, Saraca asoca for their cytotoxic potentialities. Taxonomic identities and phylogenetic relationships of the fungal isolates were investigated using molecular techniques. 37 fungal species obtained from S. asoca were grouped into 22 genera of which the most dominant genus was Camarosporium followed by Pestalotiopsis and Fusarium. Fermentation extracts of all fungal isolates were assessed for their cytotoxic effects towards three human cancer cell lines, HeLa, HepG2 and PC3. 18 fungi exhibited remarkable cytotoxic activities among which Pestalotiopsis sp. 6 exhibited the most significant cytotoxicity towards all three cell lines used. Apoptosis inducing effect of Pestalotiopsis sp. 6 ethyl acetate culture extract (PS6) on HeLa cell line was further assessed by in vitro assays. PS6 induced mitochondria dependent apoptotic cell death in HeLa cells in a dose dependent manner. The study suggests these fungal extracts to be potential sources of secondary metabolites which can serve as promising lead molecules for the development of novel anti-cancer agents.
Tobacco smoking is apparently the major reason for the increasing incidence of lung cancers. Nico... more Tobacco smoking is apparently the major reason for the increasing incidence of lung cancers. Nicotine, an alkaloid in present in tobacco accounts for the addictive nature of tobacco. Nicotine is an exogenous agonist to the nicotinic Acetylcholine Receptors (nAChRs) distributed throughout the central and peripheral nervous system. Upon administration, nicotine binds to the nAChRs and modulates the neurotransmitter release. Studies relate the pleasurable effects of cigarette smoking to the nicotine induced increase in dopamine levels in the mesocorticolimbic system in mammals. Understanding the molecular mechanisms underlying nicotine addiction enables the development of effective strategies for smoking cessation.
Cholestanol and its derivatives are known to possess diverse biological activities. An endophytic... more Cholestanol and its derivatives are known to possess diverse biological activities. An endophytic fungus, Lasiodiplodia theobromae associated with Saraca asoca, was found to produce a novel steroidal glycoside, cholestanol glucoside (CG) which exhibited significant antioxidant and anticancer potentialities. Low cost and sustained production of bioactive compound is a major criterion determining its development as a drug. In the present study, we have attempted to optimize the media components to ensure optimum production of CG by L. theobromae. One factor at a time (OFAT) approach along with response surface methodology (RSM) was employed to investigate the effects of various medium components on the production of CG in submerged cultures of L. theobromae. Carbon and nitrogen sources were optimized by OFAT approach. RSM was further used to determine the optimum values of trace elements for maximum CG production. The fit of the quadratic model was found to be significant. A significant increase in CG production (50 ± 2.7 mg/L) was achieved by optimizing the media components. Our findings support a cost-effective production of CG.
Nature remains to be an attractive source of bioactive compounds and natural compounds are extens... more Nature remains to be an attractive source of bioactive compounds and natural compounds are extensively being explored for their therapeutic applications. Steroidal glycosides are a major group of secondary metabolites that exhibit broad spectrum of biological activities. Several steroidal glycosides have been reported to possess promising anti-oxidant activities. In the present study, we investigate the anti-oxidant potentialities of cholestanol glucoside (CG), a steroidal glycoside produced by Lasiodiplodia theobromae, an endophytic fungus isolated from Saraca asoca, using in vitro assays such as DPPH radical scavenging assay, nitric oxide radical scavenging assay, hydroxyl radical scavenging assay, super oxide radical scavenging assay and hydrogen peroxide scavenging assay. The compound showed significant free radical scavenging capacity with an IC50 value of 16.2 µM. The compound could also effectively scavenge hydrogen peroxide (IC50 value of 7.2 µM) and hydroxyl radicals (IC50 value of 3.6 µM).
Objective:The present study investigates the modulation of cholestanol glucoside (CG) biosynthesi... more Objective:The present study investigates the modulation of cholestanol glucoside (CG) biosynthesis by Lasiodiplodia theobromae in response to oxidative, osmotic and heat shock stresses. Methods: The fungal cultures were subjected to oxidative stress by supplementing the culture media with menadione or H2O2 Results: Oxidative stress enhanced CG yield by the fungus by 1.8-fold (88.3±0.6 mg/l) where as osmotic and heat shock stresses proved to be poor enhancers of CG production. to the desired final concentrations. Osmotic stress was implemented by the addition of the desired concentrations of NaCl or sorbitol. For heat-shock treatments, the fungal cultures were subjected to required temperature variations. Each stress treatment was carried out at different time points so as to include different stages of fungal growth. Conclusions: Our findings enable a cost-effective, large scale production of CG by L. theobromae and more over throws light on the possible antioxidant activity of the compound in the organism.
Objective: The present study investigates the modulation of cholestanol glucoside (CG) biosynthes... more Objective: The present study investigates the modulation of cholestanol glucoside (CG) biosynthesis by Lasiodiplodia theobromae in response to oxidative, osmotic and heat shock stresses. Methods: The fungal cultures were subjected to oxidative stress by supplementing the culture media with menadione or H 2O 2
Since the dawn of civilization, natural resources have remained the mainstay of various remedial ... more Since the dawn of civilization, natural resources have remained the mainstay of various remedial approaches of humans vis-à-vis a large number of illnesses. Saraca asoca (Roxb.) de Wilde (Saraca indica L.) belonging to the family Caesalpiniaceae has been regarded as a universal panacea in old Indian Ayurvedic texts and has especially been used to manage gynaecological complications and infections besides treating haem-morhagic dysentery, uterine pain, bacterial infections, skin problems, tumours, worm infestations, cardiac and circulatory problems. Almost all parts of the plant are considered pharmacologically valuable. Extensive folkloric practices and ethnobotanical applications of this plant have even lead to the availability of several commercial S. asoca formulations recommended for different indications though adulteration of these remains a pressing concern. Though a wealth of knowledge on this plant is available in both the classical and modern literature, extensive research on its phytomedicinal worth using state-of-the-art tools and methodologies is lacking. Recent reports on bioprospecting of S. asoca endophytic fungi for industrial bioproducts and useful pharmacologically relevant metabolites provide a silver lining to uncover single molecular bio-effectors from its endophytes. Here, we describe socio-ethnobotanical usage, present the current pharmacological status and discuss potential bottlenecks in harnessing the proclaimed phytomedicinal worth of this prescribed Ayurvedic medicinal plant. Finally, we also look into the possible future of the drug discovery and pharmaceutical R&D efforts directed at exploring its pharma legacy.
Microorganisms have provided mankind with a plethora of small molecule natural products ranging f... more Microorganisms have provided mankind with a plethora of small molecule natural products ranging from industrial enzymes to therapeutic agents. Analyses of microbial genome sequences have revealed the presence of numerous ‘silent’ or ‘cryptic’ biosynthetic gene clusters (BGCs). Activation of these cryptic biosynthetic pathways can pave way to the discovery of novel bioactive secondary metabolites (SMs). This article summarizes various approaches employed to unlock the hidden biosynthetic potential of microbes and methods developed to study their silent gene products.
Since the dawn of civilization, natural resources have remained the mainstay of various remedial ... more Since the dawn of civilization, natural resources have remained the mainstay of various remedial approaches of humans vis-a-vis a large number of illnesses. Saraca asoca (Roxb.) de Wilde (Saraca indica L.) belonging to the family Caesalpiniaceae has been regarded as a universal panacea in old Indian Ayurvedic texts and has especially been used to manage gynaecological complications and infections besides treating haemmorhagic dysentery, uterine pain, bacterial infections, skin problems, tumours, worm infestations, cardiac and circulatory problems. Almost all parts of the plant are considered pharmacologically valuable. Extensive folkloric practices and ethnobotanical applications of this plant have even lead to the availability of several commercial S. asoca formulations recommended for different indications though adulteration of these remains a pressing concern. Though a wealth of knowledge on this plant is available in both the classical and modern literature, extensive research on its phytomedicinal worth using state-of-the-art tools and methodologies is lacking. Recent reports on bioprospecting of S. asoca endophytic fungi for industrial bioproducts and useful pharmacologically relevant metabolites provide a silver lining to uncover single molecular bio-effectors from its endophytes. Here, we describe socio-ethnobotanical usage, present the current pharmacological status and discuss potential bottlenecks in harnessing the proclaimed phytomedicinal worth of this prescribed Ayurvedic medicinal plant. Finally, we also look into the possible future of the drug discovery and pharmaceutical R&D efforts directed at exploring its pharma legacy.
Search for novel anticancer lead molecules continues to be a major focus of cancer research due t... more Search for novel anticancer lead molecules continues to be a major focus of cancer research due to the limitations of existing drugs such as lack of tumor selectivity, narrow therapeutic index and multidrug resistance of cancer types. Natural molecules often possess better pharmacokinetic traits compared to synthetic molecules as they continually evolve by natural selection process to interact with biological macromolecules. Microbial metabolites constitute nearly half of the pharmaceuticals in market today. Endophytic fungi, owing to its rich chemical diversity, are viewed as attractive sources of novel bioactive compounds. In the present study, we report the purification and characterization of a novel steroidal saponin, cholestanol glucoside (CG) from Saraca asoca endophytic fungus Lasiodiplodia theobromae. The compound was assessed for its cytotoxic potentialities in six human cancer cell lines, A549, PC3, HepG2, U251, MCF7 and OVCAR3. CG exhibited significant cytotoxicities towards A549, PC3 and HepG2 among which A549 cells were most vulnerable to CG treatment. However, CG treatment exhibited negligible cytotoxicity in non malignant human lung fibroblast cell line (WI-38). Induction of cell death by CG treatment in A549 cells was further investigated. CG induced the generation of reactive oxygen species (ROS) and mitochondrial membrane permeability loss followed by apoptotic cell death. Mitochondrial membrane depolarization and apoptotic cell death in CG treated A549 cells were completely blocked in presence of an antioxidant, N-acetyl cysteine (NAC). Hence it could be concluded that CG initiates apoptosis in cancer cells by augmenting the basal oxidative stress and that the generation of intracellular ROS is crucial for the induction of apoptosis.
Cancer remains a major health issue worldwide due to the high rate of its morbidity and mortality... more Cancer remains a major health issue worldwide due to the high rate of its morbidity and mortality. Search for tumor selective, novel anticancer compounds with lesser side-effects remains a major focus of cancer research. Endophytic fungi, owing to their chemical diversity, are an attractive source of bioactive metabolites. In the present study, we have explored the endophytic fungal population associated with a traditional Indian medicinal plant, Saraca asoca for their cytotoxic potentialities. Taxonomic identities and phylogenetic relationships of the fungal isolates were investigated using molecular techniques. 37 fungal species obtained from S. asoca were grouped into 22 genera of which the most dominant genus was Camarosporium followed by Pestalotiopsis and Fusarium. Fermentation extracts of all fungal isolates were assessed for their cytotoxic effects towards three human cancer cell lines, HeLa, HepG2 and PC3. 18 fungi exhibited remarkable cytotoxic activities among which Pestalotiopsis sp. 6 exhibited the most significant cytotoxicity towards all three cell lines used. Apoptosis inducing effect of Pestalotiopsis sp. 6 ethyl acetate culture extract (PS6) on HeLa cell line was further assessed by in vitro assays. PS6 induced mitochondria dependent apoptotic cell death in HeLa cells in a dose dependent manner. The study suggests these fungal extracts to be potential sources of secondary metabolites which can serve as promising lead molecules for the development of novel anti-cancer agents.
Tobacco smoking is apparently the major reason for the increasing incidence of lung cancers. Nico... more Tobacco smoking is apparently the major reason for the increasing incidence of lung cancers. Nicotine, an alkaloid in present in tobacco accounts for the addictive nature of tobacco. Nicotine is an exogenous agonist to the nicotinic Acetylcholine Receptors (nAChRs) distributed throughout the central and peripheral nervous system. Upon administration, nicotine binds to the nAChRs and modulates the neurotransmitter release. Studies relate the pleasurable effects of cigarette smoking to the nicotine induced increase in dopamine levels in the mesocorticolimbic system in mammals. Understanding the molecular mechanisms underlying nicotine addiction enables the development of effective strategies for smoking cessation.
Cholestanol and its derivatives are known to possess diverse biological activities. An endophytic... more Cholestanol and its derivatives are known to possess diverse biological activities. An endophytic fungus, Lasiodiplodia theobromae associated with Saraca asoca, was found to produce a novel steroidal glycoside, cholestanol glucoside (CG) which exhibited significant antioxidant and anticancer potentialities. Low cost and sustained production of bioactive compound is a major criterion determining its development as a drug. In the present study, we have attempted to optimize the media components to ensure optimum production of CG by L. theobromae. One factor at a time (OFAT) approach along with response surface methodology (RSM) was employed to investigate the effects of various medium components on the production of CG in submerged cultures of L. theobromae. Carbon and nitrogen sources were optimized by OFAT approach. RSM was further used to determine the optimum values of trace elements for maximum CG production. The fit of the quadratic model was found to be significant. A significant increase in CG production (50 ± 2.7 mg/L) was achieved by optimizing the media components. Our findings support a cost-effective production of CG.
Nature remains to be an attractive source of bioactive compounds and natural compounds are extens... more Nature remains to be an attractive source of bioactive compounds and natural compounds are extensively being explored for their therapeutic applications. Steroidal glycosides are a major group of secondary metabolites that exhibit broad spectrum of biological activities. Several steroidal glycosides have been reported to possess promising anti-oxidant activities. In the present study, we investigate the anti-oxidant potentialities of cholestanol glucoside (CG), a steroidal glycoside produced by Lasiodiplodia theobromae, an endophytic fungus isolated from Saraca asoca, using in vitro assays such as DPPH radical scavenging assay, nitric oxide radical scavenging assay, hydroxyl radical scavenging assay, super oxide radical scavenging assay and hydrogen peroxide scavenging assay. The compound showed significant free radical scavenging capacity with an IC50 value of 16.2 µM. The compound could also effectively scavenge hydrogen peroxide (IC50 value of 7.2 µM) and hydroxyl radicals (IC50 value of 3.6 µM).
Objective:The present study investigates the modulation of cholestanol glucoside (CG) biosynthesi... more Objective:The present study investigates the modulation of cholestanol glucoside (CG) biosynthesis by Lasiodiplodia theobromae in response to oxidative, osmotic and heat shock stresses. Methods: The fungal cultures were subjected to oxidative stress by supplementing the culture media with menadione or H2O2 Results: Oxidative stress enhanced CG yield by the fungus by 1.8-fold (88.3±0.6 mg/l) where as osmotic and heat shock stresses proved to be poor enhancers of CG production. to the desired final concentrations. Osmotic stress was implemented by the addition of the desired concentrations of NaCl or sorbitol. For heat-shock treatments, the fungal cultures were subjected to required temperature variations. Each stress treatment was carried out at different time points so as to include different stages of fungal growth. Conclusions: Our findings enable a cost-effective, large scale production of CG by L. theobromae and more over throws light on the possible antioxidant activity of the compound in the organism.
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Papers by Jinu Mathew Valayil
Methods: The fungal cultures were subjected to oxidative stress by supplementing the culture media with menadione or H2O2
Results: Oxidative stress enhanced CG yield by the fungus by 1.8-fold (88.3±0.6 mg/l) where as osmotic and heat shock stresses proved to be poor enhancers of CG production. to the desired final concentrations. Osmotic stress was implemented by the addition of the desired concentrations of NaCl or sorbitol. For heat-shock treatments, the fungal cultures were subjected to required temperature variations. Each stress treatment was carried out at different time points so as to include different stages of fungal growth.
Conclusions: Our findings enable a cost-effective, large scale production of CG by L. theobromae and more over throws light on the possible antioxidant activity of the compound in the organism.
Methods: The fungal cultures were subjected to oxidative stress by supplementing the culture media with menadione or H2O2
Results: Oxidative stress enhanced CG yield by the fungus by 1.8-fold (88.3±0.6 mg/l) where as osmotic and heat shock stresses proved to be poor enhancers of CG production. to the desired final concentrations. Osmotic stress was implemented by the addition of the desired concentrations of NaCl or sorbitol. For heat-shock treatments, the fungal cultures were subjected to required temperature variations. Each stress treatment was carried out at different time points so as to include different stages of fungal growth.
Conclusions: Our findings enable a cost-effective, large scale production of CG by L. theobromae and more over throws light on the possible antioxidant activity of the compound in the organism.