Obesity is one of the foremost risk factors in coronavirus infection resulting in severe illness ... more Obesity is one of the foremost risk factors in coronavirus infection resulting in severe illness and mortality as the pandemic progresses. Obesity is a well-known predisposed chronic inflammatory condition. The dynamics of obesity and its impacts on immunity may change the disease severity of pneumonia, especially in acute respiratory distress syndrome, a primary cause of death from SARS-CoV-2 infection. The adipocytes of adipose tissue secret leptin in proportion to individuals’ body fat mass. An increase in circulating plasma leptin is a typical characteristic of obesity and correlates with a leptin-resistant state. Leptin is considered a pleiotropic molecule regulating appetite and immunity. In immunity, leptin functions as a cytokine and coordinates the host’s innate and adaptive responses by promoting the Th1 type of immune response. Leptin induced the proliferation and functions of antigen-presenting cells, monocytes, and T helper cells, subsequently influencing the pro-inflam...
Science of Ashwagandha: Preventive and Therapeutic Potentials, 2017
Withania somnifera (Ashwagandha) is a shrub plant from the family of Solanaceae and widely used b... more Withania somnifera (Ashwagandha) is a shrub plant from the family of Solanaceae and widely used by practitioners in the folk medicines as immune boosting agent. The medicinal properties of plants have been attributed due to the presence of steroidal lactones called as withanolides. Withanolides are a group of highly oxygenated steroids derived from a C28 ergostane skeleton and have attracted significant scientific interest due to their complex structural features and multiple bioactivities. Last one decade’s more than 130 new natural withanolides were isolated from Withania spp., and the scientist from the different field demonstrated that Ashwagandha possesses antioxidant, anti-inflammatory, antitumor, antimicrobial properties. This chapter briefly reviews the drug-likeness activity of withanolides against antibacterial, antifungal, antiparasitic diseases and more focussed on antileishmanial and immunomodulatory activities of withanolides.
The emergence of drug‐resistant Leishmania is the major challenge to management of visceral leish... more The emergence of drug‐resistant Leishmania is the major challenge to management of visceral leishmaniasis (VL) in areas in which this parasite is endemic. Miltefosine has been widely used against VL, but the emergence of resistant strains could impose a significant threat in the near future. The present study used high‐throughput proteomics to determine whether proteins are differentially expressed in miltefosine‐resistant (BHU875) and ‐sensitive (DD8) Leishmania donovani strains. Comparative proteomic analysis revealed up‐regulation of iron superoxide dismutase (FeSODA) in the resistant BHU875 strain compared to the drug‐sensitive DD8 strain. In accordance with the proteomic data, BHU875 showed higher FeSODA enzymatic activity relative to the sensitive strain. Molecular characterization of BHU875 parasites in which the gene encoding FeSODA was silenced demonstrated that drug sensitivity was restored and the intracellular survival of the parasite was lowered. This suggests that FeSODA activity plays a part in miltefosine resistance. Our study provides a drug target that could be used to overcome miltefosine resistance or help in rational redesigning of miltefosine‐based therapy to combat Leishmania infection.
Visceral leishmaniasis (VL) is responsible for several deaths in malnourished children accompanie... more Visceral leishmaniasis (VL) is responsible for several deaths in malnourished children accompanied by diminished circulating leptin and impaired cell-mediated immunity. Typically, leptin deficiency is associated with the Th2 polarization that markedly coincides with the pathogenesis of VL. The aim of the present study was to unravel the prophylactic role of leptin in malnutrition-coupled VL mice. Interestingly, we observed that L. donovani infection itself reduces the serum leptin levels in malnutrition. Exogenous leptin restored severe body weight loss and parasite load in the spleen and liver of malnourished infected mice compared to controls. Leptin increases functional CD8+ T-cell population, Granzyme-A expression down-regulates anergic T-cell markers such as PD-1 and CTLA-4. It was also noticed that, leptin suppresses GM-CSF mRNA expression in parasite favored monocytes and reduced arginase activity in bone marrow derived macrophage indicate macrophages dependent T-cell activat...
Despite the existence of chemotherapy, there is no effective cure for leishmaniasis. In the light... more Despite the existence of chemotherapy, there is no effective cure for leishmaniasis. In the light of recommended therapeutic regimen is attributed for toxicity and development of clinical resistance, exploration of an efficient method of drug delivery could be one of the option in reducing the dosage and toxicity of drugs. This work is aimed in such fashion to study the enhanced antileishmanial activity of miltefosine with silver-nanoparticles (AgNPs) synthesized by using Anethum graveolens (dill) leaf extract as reducing agent. AgNPs were synthesized in a single step process and characterized by UV-visible, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR) to understand the crystal structure and functional groups on their surface. TEM analysis showed that the synthesized AgNPs are of an average size of 35 nm. By performing MTT assay, we found that, AgNPs (between 20 and 100 μM) are biocompatible in nature through pertaining >80% viability of macrophages. F...
The American journal of tropical medicine and hygiene, Jul 25, 2016
Visceral leishmaniasis (VL) is caused by the protozoan parasite Leishmania donovani There are no ... more Visceral leishmaniasis (VL) is caused by the protozoan parasite Leishmania donovani There are no vaccines and available drugs against leishmaniasis are toxic. Immunomodulators that specifically boost the anti-microbial activities of the immune cells could alleviate several of these limitations. Therefore, finding novel immunomodulators for VL therapy is a pressing need. This study is aimed to evaluate the immunomodulatory role of leptin, an adipocyte-derived hormone capable of regulating the immune response, in L. donovani-infected mice. We observed that recombinant leptin treatment reduced splenic parasite burden compared with non-treated infected normal mice. Decrease in parasite burden correlated with an induction of innate immune response in antigen-presenting cells that showed an increase in nitric oxide, enhanced pro-inflammatory cytokine (interferon gamma [IFNγ], interleukin12 [IL]12, and IL1β) response in the splenocytes, indicating host-protecting Th1 response mediated by l...
Visceral leishmaniasis (VL) is an infectious disease responsible for several deaths in malnourish... more Visceral leishmaniasis (VL) is an infectious disease responsible for several deaths in malnourished children due to impaired cell-mediated immunity, which is accompanied by low circulating leptin levels. The cytokine function of leptin is implicated for several immune regulation activities such as hematopoiesis, angiogenesis, innate and adaptive immunity. Its deficiency associated with polarization of Th2 response, which coincides with VL pathogenesis. To determine the cytokine role of leptin in case of experimental VL, we tested the leptin associated Th1/Th2 type cytokine profile at mRNA level from Leishmania donovani infected human monocytic leukemia cell line (THP-1) and peripheral blood mononuclear cells (PBMCs). We also tested the effect of leptin on macrophages activation (viz. studying the phosphorylation of signaling moieties), phagocytic activity and intracellular reactive oxygen species (ROS) production during infection. We observed that leptin induced Th1 specific response by upregulation of IL-1α, IL-1β, IL-8 and TNF-α in THP-1 and IFN-γ, IL-12 and IL-2 in PBMCs. We also observed the downregulation of Th2 type cytokine i.e. IL-10 in THP-1 and unaltered expression of cytokines i.e. TGF-β, IL-10 and IL-4 in PBMCs. In addition, leptin stimulates the macrophages by inducing phosphorylation of Erk1/2 and Akt which are usually dephosphorylated in L. donovani infection. In concordance, leptin also induces the macrophage phagocytic activity by enhancing the intracellular ROS generation which helps in phagolysosome formation and oxidative killing of the parasite. In compilation, leptin is able to maintain the defensive environment against L. donovani infection through the classical macrophage activity.
Reineckia carnea has been used to treat several diseases in folk remedies. RCE-4 has been isolate... more Reineckia carnea has been used to treat several diseases in folk remedies. RCE-4 has been isolated from several plants of the family Liliaceae, but its biological activity has not yet been reported. In the present study, we found that RCE-4 exhibited potent cytotoxicity to the tested human cancer cell lines, and the CaSki cell line was the most sensitive with an IC50 of 3.37 µM. Thus, we presented the apoptosis-inducing effect of RCE-4 on CaSki cervical cancer cells and investigated the relevant mechanisms. Based on observations using transmission electron microscopy, RCE-4-treated cells manifested nuclear shrinkage, condensation and fragmentation. Annexin V/PI dual staining flow cytometry assay further confirmed that RCE-4 caused a dose-dependent early apoptotic effect. Prior to these events, RCE-4 triggered a rapid decrease of the mitochondrial membrane potential and caused the release of cytochrome c from the mitochondria into the cytoplasm. RCE-4 increased the expression of Bax ...
A number of methods have been described for the isolation of genomic DNA from whole blood. Howeve... more A number of methods have been described for the isolation of genomic DNA from whole blood. However, these described methods are either unreliable or too expensive to be used routinely in small diagnostic laboratories of developing countries. We have evaluated the slightly modified salt-out method for DNA isolation so that it can be applied on whole blood samples using a three step procedure: (1) lysis of RBC; (2) removal of protein; and (3) precipitation of DNA. We compared the yield of DNA per mL of blood using our modified salt-out DNA extraction method, (40.8 ± 4.3 g) with Phenol-chloroform extraction (38.5 ±7.3 g) or QIAamp DNA Mini kits (35. 3± 5.4 g). The described method allows simple, fast and cost efficient DNA extraction with qualitative parameters maintained and comparable to those of other extraction method described.
Superoxide dismutase (SOD) is a crucial enzyme required to maintain the redox potential of the ce... more Superoxide dismutase (SOD) is a crucial enzyme required to maintain the redox potential of the cells. It plays a vital role in protecting normal cells from reactive oxygen species (ROS) produced during many intracellular pathogens infections. SOD removes excess superoxide radicals (O2−) by converting them to hydrogen peroxide (H2O2) and molecular oxygen (O2). Several superoxide dismutase enzymes have been identified based on the metal ion as a cofactor. Human SOD differs from the intracellular pathogens in having Cu/Zn and Mn as metal cofactors. However, SOD of intracellular pathogens such as Trypanosoma, Leishmania, Plasmodium, and Mycobacterium have iron (Fe) as metal cofactors. Iron Superoxide Dismutase (FeSOD) is an essential enzyme in these pathogens that neutralizes the free radical of oxygen (O−) and prevents the formation of Peroxynitrite anion (ONOO−), helping the pathogens escape from redox-based cytotoxic killing. Moreover, most intracellular bacteria hold MnSOD or FeSOD ...
In order to understand the mechanism of molecular interactions at the active site of Tryparedoxin... more In order to understand the mechanism of molecular interactions at the active site of Tryparedoxin Peroxidase (Try P), homology modeling and docking studies were performed. We generated a Three-Dimensional (3D) model of target protein based on the Crystal structure of Leishmania Major Try PI (PDB ID: 3TUE) using modeler software. Docking analysis was carried out to study the effects of methotrexate on Tryparedoxin Peroxidase (Try P). Inhibition of the Tryparedoxin peroxidase interaction has become a new therapeutic strategy in treating leishmaniasis. Docking analysis was carried out to study the effects of methotrexate on Tryparedoxin Peroxidase (TryP). Tryparedoxin peroxidase of Trypanosomatidae family functions as antioxidant through their peroxidase and peroxynitrite reductase activities. The theoretical docking study, conducted on a sample previously reported for anti-cancer properties of Methotrexate at the binding site of 3D models of Tryparedoxin Peroxidase of Leishmania braziliensis (L. braziliensis Try P) examine interaction energy. Our studies indicate that Methotrexate displays potent activity against Try P with lowest binding energy and RMSD values to be-14.5879 Kcal/Mol and 2.0 A. The results of the present study clearly demonstrated the Tryparedoxin Peroxidase inhibitory activity by methotrexate in in silico docking analysis and in vitro assay which contributes towards understanding the mechanism of antileishmanial activity.
Obesity is one of the foremost risk factors in coronavirus infection resulting in severe illness ... more Obesity is one of the foremost risk factors in coronavirus infection resulting in severe illness and mortality as the pandemic progresses. Obesity is a well-known predisposed chronic inflammatory condition. The dynamics of obesity and its impacts on immunity may change the disease severity of pneumonia, especially in acute respiratory distress syndrome, a primary cause of death from SARS-CoV-2 infection. The adipocytes of adipose tissue secret leptin in proportion to individuals’ body fat mass. An increase in circulating plasma leptin is a typical characteristic of obesity and correlates with a leptin-resistant state. Leptin is considered a pleiotropic molecule regulating appetite and immunity. In immunity, leptin functions as a cytokine and coordinates the host’s innate and adaptive responses by promoting the Th1 type of immune response. Leptin induced the proliferation and functions of antigen-presenting cells, monocytes, and T helper cells, subsequently influencing the pro-inflam...
Science of Ashwagandha: Preventive and Therapeutic Potentials, 2017
Withania somnifera (Ashwagandha) is a shrub plant from the family of Solanaceae and widely used b... more Withania somnifera (Ashwagandha) is a shrub plant from the family of Solanaceae and widely used by practitioners in the folk medicines as immune boosting agent. The medicinal properties of plants have been attributed due to the presence of steroidal lactones called as withanolides. Withanolides are a group of highly oxygenated steroids derived from a C28 ergostane skeleton and have attracted significant scientific interest due to their complex structural features and multiple bioactivities. Last one decade’s more than 130 new natural withanolides were isolated from Withania spp., and the scientist from the different field demonstrated that Ashwagandha possesses antioxidant, anti-inflammatory, antitumor, antimicrobial properties. This chapter briefly reviews the drug-likeness activity of withanolides against antibacterial, antifungal, antiparasitic diseases and more focussed on antileishmanial and immunomodulatory activities of withanolides.
The emergence of drug‐resistant Leishmania is the major challenge to management of visceral leish... more The emergence of drug‐resistant Leishmania is the major challenge to management of visceral leishmaniasis (VL) in areas in which this parasite is endemic. Miltefosine has been widely used against VL, but the emergence of resistant strains could impose a significant threat in the near future. The present study used high‐throughput proteomics to determine whether proteins are differentially expressed in miltefosine‐resistant (BHU875) and ‐sensitive (DD8) Leishmania donovani strains. Comparative proteomic analysis revealed up‐regulation of iron superoxide dismutase (FeSODA) in the resistant BHU875 strain compared to the drug‐sensitive DD8 strain. In accordance with the proteomic data, BHU875 showed higher FeSODA enzymatic activity relative to the sensitive strain. Molecular characterization of BHU875 parasites in which the gene encoding FeSODA was silenced demonstrated that drug sensitivity was restored and the intracellular survival of the parasite was lowered. This suggests that FeSODA activity plays a part in miltefosine resistance. Our study provides a drug target that could be used to overcome miltefosine resistance or help in rational redesigning of miltefosine‐based therapy to combat Leishmania infection.
Visceral leishmaniasis (VL) is responsible for several deaths in malnourished children accompanie... more Visceral leishmaniasis (VL) is responsible for several deaths in malnourished children accompanied by diminished circulating leptin and impaired cell-mediated immunity. Typically, leptin deficiency is associated with the Th2 polarization that markedly coincides with the pathogenesis of VL. The aim of the present study was to unravel the prophylactic role of leptin in malnutrition-coupled VL mice. Interestingly, we observed that L. donovani infection itself reduces the serum leptin levels in malnutrition. Exogenous leptin restored severe body weight loss and parasite load in the spleen and liver of malnourished infected mice compared to controls. Leptin increases functional CD8+ T-cell population, Granzyme-A expression down-regulates anergic T-cell markers such as PD-1 and CTLA-4. It was also noticed that, leptin suppresses GM-CSF mRNA expression in parasite favored monocytes and reduced arginase activity in bone marrow derived macrophage indicate macrophages dependent T-cell activat...
Despite the existence of chemotherapy, there is no effective cure for leishmaniasis. In the light... more Despite the existence of chemotherapy, there is no effective cure for leishmaniasis. In the light of recommended therapeutic regimen is attributed for toxicity and development of clinical resistance, exploration of an efficient method of drug delivery could be one of the option in reducing the dosage and toxicity of drugs. This work is aimed in such fashion to study the enhanced antileishmanial activity of miltefosine with silver-nanoparticles (AgNPs) synthesized by using Anethum graveolens (dill) leaf extract as reducing agent. AgNPs were synthesized in a single step process and characterized by UV-visible, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FTIR) to understand the crystal structure and functional groups on their surface. TEM analysis showed that the synthesized AgNPs are of an average size of 35 nm. By performing MTT assay, we found that, AgNPs (between 20 and 100 μM) are biocompatible in nature through pertaining >80% viability of macrophages. F...
The American journal of tropical medicine and hygiene, Jul 25, 2016
Visceral leishmaniasis (VL) is caused by the protozoan parasite Leishmania donovani There are no ... more Visceral leishmaniasis (VL) is caused by the protozoan parasite Leishmania donovani There are no vaccines and available drugs against leishmaniasis are toxic. Immunomodulators that specifically boost the anti-microbial activities of the immune cells could alleviate several of these limitations. Therefore, finding novel immunomodulators for VL therapy is a pressing need. This study is aimed to evaluate the immunomodulatory role of leptin, an adipocyte-derived hormone capable of regulating the immune response, in L. donovani-infected mice. We observed that recombinant leptin treatment reduced splenic parasite burden compared with non-treated infected normal mice. Decrease in parasite burden correlated with an induction of innate immune response in antigen-presenting cells that showed an increase in nitric oxide, enhanced pro-inflammatory cytokine (interferon gamma [IFNγ], interleukin12 [IL]12, and IL1β) response in the splenocytes, indicating host-protecting Th1 response mediated by l...
Visceral leishmaniasis (VL) is an infectious disease responsible for several deaths in malnourish... more Visceral leishmaniasis (VL) is an infectious disease responsible for several deaths in malnourished children due to impaired cell-mediated immunity, which is accompanied by low circulating leptin levels. The cytokine function of leptin is implicated for several immune regulation activities such as hematopoiesis, angiogenesis, innate and adaptive immunity. Its deficiency associated with polarization of Th2 response, which coincides with VL pathogenesis. To determine the cytokine role of leptin in case of experimental VL, we tested the leptin associated Th1/Th2 type cytokine profile at mRNA level from Leishmania donovani infected human monocytic leukemia cell line (THP-1) and peripheral blood mononuclear cells (PBMCs). We also tested the effect of leptin on macrophages activation (viz. studying the phosphorylation of signaling moieties), phagocytic activity and intracellular reactive oxygen species (ROS) production during infection. We observed that leptin induced Th1 specific response by upregulation of IL-1α, IL-1β, IL-8 and TNF-α in THP-1 and IFN-γ, IL-12 and IL-2 in PBMCs. We also observed the downregulation of Th2 type cytokine i.e. IL-10 in THP-1 and unaltered expression of cytokines i.e. TGF-β, IL-10 and IL-4 in PBMCs. In addition, leptin stimulates the macrophages by inducing phosphorylation of Erk1/2 and Akt which are usually dephosphorylated in L. donovani infection. In concordance, leptin also induces the macrophage phagocytic activity by enhancing the intracellular ROS generation which helps in phagolysosome formation and oxidative killing of the parasite. In compilation, leptin is able to maintain the defensive environment against L. donovani infection through the classical macrophage activity.
Reineckia carnea has been used to treat several diseases in folk remedies. RCE-4 has been isolate... more Reineckia carnea has been used to treat several diseases in folk remedies. RCE-4 has been isolated from several plants of the family Liliaceae, but its biological activity has not yet been reported. In the present study, we found that RCE-4 exhibited potent cytotoxicity to the tested human cancer cell lines, and the CaSki cell line was the most sensitive with an IC50 of 3.37 µM. Thus, we presented the apoptosis-inducing effect of RCE-4 on CaSki cervical cancer cells and investigated the relevant mechanisms. Based on observations using transmission electron microscopy, RCE-4-treated cells manifested nuclear shrinkage, condensation and fragmentation. Annexin V/PI dual staining flow cytometry assay further confirmed that RCE-4 caused a dose-dependent early apoptotic effect. Prior to these events, RCE-4 triggered a rapid decrease of the mitochondrial membrane potential and caused the release of cytochrome c from the mitochondria into the cytoplasm. RCE-4 increased the expression of Bax ...
A number of methods have been described for the isolation of genomic DNA from whole blood. Howeve... more A number of methods have been described for the isolation of genomic DNA from whole blood. However, these described methods are either unreliable or too expensive to be used routinely in small diagnostic laboratories of developing countries. We have evaluated the slightly modified salt-out method for DNA isolation so that it can be applied on whole blood samples using a three step procedure: (1) lysis of RBC; (2) removal of protein; and (3) precipitation of DNA. We compared the yield of DNA per mL of blood using our modified salt-out DNA extraction method, (40.8 ± 4.3 g) with Phenol-chloroform extraction (38.5 ±7.3 g) or QIAamp DNA Mini kits (35. 3± 5.4 g). The described method allows simple, fast and cost efficient DNA extraction with qualitative parameters maintained and comparable to those of other extraction method described.
Superoxide dismutase (SOD) is a crucial enzyme required to maintain the redox potential of the ce... more Superoxide dismutase (SOD) is a crucial enzyme required to maintain the redox potential of the cells. It plays a vital role in protecting normal cells from reactive oxygen species (ROS) produced during many intracellular pathogens infections. SOD removes excess superoxide radicals (O2−) by converting them to hydrogen peroxide (H2O2) and molecular oxygen (O2). Several superoxide dismutase enzymes have been identified based on the metal ion as a cofactor. Human SOD differs from the intracellular pathogens in having Cu/Zn and Mn as metal cofactors. However, SOD of intracellular pathogens such as Trypanosoma, Leishmania, Plasmodium, and Mycobacterium have iron (Fe) as metal cofactors. Iron Superoxide Dismutase (FeSOD) is an essential enzyme in these pathogens that neutralizes the free radical of oxygen (O−) and prevents the formation of Peroxynitrite anion (ONOO−), helping the pathogens escape from redox-based cytotoxic killing. Moreover, most intracellular bacteria hold MnSOD or FeSOD ...
In order to understand the mechanism of molecular interactions at the active site of Tryparedoxin... more In order to understand the mechanism of molecular interactions at the active site of Tryparedoxin Peroxidase (Try P), homology modeling and docking studies were performed. We generated a Three-Dimensional (3D) model of target protein based on the Crystal structure of Leishmania Major Try PI (PDB ID: 3TUE) using modeler software. Docking analysis was carried out to study the effects of methotrexate on Tryparedoxin Peroxidase (Try P). Inhibition of the Tryparedoxin peroxidase interaction has become a new therapeutic strategy in treating leishmaniasis. Docking analysis was carried out to study the effects of methotrexate on Tryparedoxin Peroxidase (TryP). Tryparedoxin peroxidase of Trypanosomatidae family functions as antioxidant through their peroxidase and peroxynitrite reductase activities. The theoretical docking study, conducted on a sample previously reported for anti-cancer properties of Methotrexate at the binding site of 3D models of Tryparedoxin Peroxidase of Leishmania braziliensis (L. braziliensis Try P) examine interaction energy. Our studies indicate that Methotrexate displays potent activity against Try P with lowest binding energy and RMSD values to be-14.5879 Kcal/Mol and 2.0 A. The results of the present study clearly demonstrated the Tryparedoxin Peroxidase inhibitory activity by methotrexate in in silico docking analysis and in vitro assay which contributes towards understanding the mechanism of antileishmanial activity.
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Papers by Radheshyam Maurya