Biophysical and in-silico studies on the structure-function relationship of Brugia malayi protein disulfide isomerase.

Human Lymphatic filariasis is caused by parasitic nematodes Wuchereria bancrofti, Brugia malayi, and Brugia timori. Protein disulfide isomerase (PDI), a redox-active enzyme, helps to form and isomerize the disulfide bonds, thereby acting as a chaperone. Such activity is essential for activating many essential enzymes and functional proteins. Brugia malayi protein disulfide isomerase (BmPDI) is crucial for parasite survival and an important drug target. Here, we used a combination of spectroscopic and computational analysis to study the structural and functional changes in the BmPDI during unfolding. Tryptophan fluorescence data revealed two well-separated transitions during the unfolding process, suggesting that the unfolding of the BmPDI is non-cooperative. The binding of the fluorescence probe 8-anilino-1-naphthalene sulfonic acid dye (ANS) validated the results obtained by the pH unfolding. The dynamics of molecular simulation performed at different pH conditions revealed the structural basis of BmPDI unfolding. Detailed analysis suggested that under different pH, both the global structure and the conformational dynamics of the active site residues were differentially altered. Our multiparametric study reveals the differential dynamics and collective motions of BmPDI unfolding, providing insights into its structure-function relationship.Communicated by Ramaswamy H. Sarma.

Phytochemical Profiling of Microalgae Euglena tuba and Its Anticancer Activity in Dalton's Lymphoma Cells.

INTRODUCTION: Natural phytochemicals are considered safe to use as therapeutic agents. There is a growing trend toward exploring anticancer effects of crude algal extracts or their active ingredients. Euglena tuba, a microalga, contains excellent antioxidant potential. However, the anticancer property of E. tuba has not been explored. This study investigates the chemical profiling as well as antitumor property of methanolic extract of E. tuba (ETME) against Dalton's lymphoma (DL) cells. MATERIALS AND METHODS: E. tuba, procured from northern part of India, was extracted in 70% methanol, dried at room temperature, and stored at -20 ∘C for future use. A freshly prepared aqueous solution of ETME of different concentrations was employed into each experiment. The ETME mediated anti-tumor response in Dalton's lymphoma was evaluated in the inbred populations of BALB/c (H2d) strain of mice of either sex at 8-12 weeks of age. The cytotoxicity of ETME in cancer cells, effects on morphology of cell and nucleus, alteration in the mitochondrial membrane potential, and level of expression of proapoptotic proteins (Bcl-2, cyt C, Bax and p53) were done using known procedures. RESULTS: The ETME contained high content of total alkaloids (96.02 ± 3.30 mg/100 mg), flavonoids (15.77 ± 2.38 mg/100 mg), carbohydrate (12.71 ± 0.59 mg/100 mg), ascorbic acid (12.48 ± 2.59 mg/100 mg), and phenolics (0.94 ± 0.05 mg/100 mg). Gas chromatography-mass spectrometry (GC-MS) analysis indicated the presence of 23 phytochemicals with known anticancer properties. DL cells treated with ETME exhibited significant and concentration dependent cytotoxicity. Florescent microscopy and flow cytometry of ETME treated DL cells indicated significant repair in cellular morphology and decreased mitochondrial potential, respectively. Western blot analysis displayed up-regulation of proapoptotic proteins (Bax, Cyt-c, p53) and down regulation of anti-apoptotic protein (Bcl2) in DL cells treated with ETME. CONCLUSIONS: The findings of this study clearly indicated that the anticancer property of ETME was mediated via reduction in mitochondrial potential and induction of apoptotic mechanism. Further studies are warranted to explore the anticancer activities of active ingredients present in this microalga of pharmaceutical importance.

Pharmacological Chemistry and Biomedical Implications of Chemical Ingredients from Parthenium hysterophorus.

Parthenium hysterophorus L. belonging to the family Asteraceae is a noxious weed infestation with allelopathic effects with its lower economic value. It poses a serious risk to its surroundings. The presence of oils, polyphenols, flavones, flavonoids, alkaloids, terpenes, pseudoguaianolides, and histamines in P. hysterophorus makes it important and beneficial due to its medicinal properties. This review article is focused on the history, geographical distribution, chemical composition, and molecular structure of some phytochemicals and ethanopharmacological aspects of P. hysterophorus. The harmful effects of this weed have also been included. The information available from the existing literature revealed that P. hysterophorus is rich in various phytochemicals with different pharmacological activities. However, the complete analysis of different phytoconstituents isolated from P. hysterophorus and their specific properties are not fully understood. The sporadic information published in some journals suggests that this plant could be exploited to develop new drugs against certain diseases, including cancer, HIV-1 infection, and immunological disorders. The structure and mode of action of some compounds such as parthenin and stigmasterol were also discussed. Though the current information on P. hysterophorus indicates the ethnopharmacological implications of extracts of this plant, more systematic and extensive studies are still required to properly understand the contribution of its specific chemical constituents responsible for their various medicinal properties.

Features, Pharmacological Chemistry, Molecular Mechanism and Health Benefits of Lemon.

BACKGROUND: Citrus limon, a Mediterranean-grown citrus species of plants belonging to the Rutaceae family, occupies a place of an impressive range of food and medicinal uses with considerable value in the economy of the fruit of the country. Citrus fruits are economically important with large-scale production of both the fresh fruits and industrially processed products. The extracts and phytochemicals obtained from all parts of C. limon have shown immense therapeutic potential because of their anticancer, anti-tumor and anti-inflammatory nature, and also serve as an important ingredient in the formulation of several ethnic herbal medicines. These properties are mediated by the presence of different phytochemicals, vitamins and nutrients in the citrus fruits. MATERIAL AND METHODS: The methods involved in the preparation of the present article included the collection of information from various scientific databases, indexed periodicals, and search engines such as Medline Scopus google scholar PubMed, PubMed central web of science, and science direct. RESULTS: This communication presents an updated account of different pharmacological aspects of C. limon associated with its anti-oxidative, antiulcer, antihelmintic, insecticidal, anticancer, cytotoxic, and estrogenic activities. In addition, C. limon extracts possess hepatoprotective, anti-hyperglycemic, and antimicrobial properties. The present article includes the structure and function of different key chemical constituents from different parts of C. limon. Also, the possible molecular mechanisms of actions of bioactive compounds from C. limon are displayed. CONCLUSION: The traditional and ethno-medicinal literature revealed that C. limon is very effective in different pathologies. Most of these compounds possessing antioxidant properties would be implicated in offering health benefits by acting as potential nutraceuticals to humans with special reference to disease management of health and disease.

Anti-Inflammatory and Antioxidative Potential of Aloe vera on the Cartap and Malathion Mediated Toxicity in Wistar Rats.

Aloe vera has been the most useful medicinal herb in the world since ancient times due to its vast biological effects. The presence of high content of bioactive compounds make Aloe vera a promising complementary and alternative agent in disease prevention. The effectiveness of A. vera-based medicines against pesticide toxicity has never been evaluated. It was therefore envisaged to develop an A. vera-based strategy to protect the non-target animals from adverse effects of the pesticides. This article illustrates the ameliorating effect of aqueous extract (AE) of A. vera leaves against the cartap and malathion toxicity. To evaluate the protective impact of A. vera against cartap (Ctp), malathion (Mtn) and a mixture of both pesticides, the animals were divided in eight groups, each containing six rats: Group 1- C (control), Group 2- AE + C, Group 3- Ctp, Group 4- Mtn, Group 5- Ctp + Mtn, Group 6- AE + Ctp, Group 7- AE + Mtn, Group 8- AE + Ctp + Mtn. Wistar rats exposed to Ctp, Mtn and Ctp + Mtn, displayed significant change in body weight. It was observed that the WBC level increased significantly in Mtn and Ctp + Mtn challenged groups. The contents of TNF-α and IL-6 in serum increased expressively in the Ctp, Mtn and Ctp + Mtn challenged groups. Rats treated with Ctp, Mtn and Ctp + Mtn displayed significant alterations in the levels of antioxidative indices (MDA, GSH, GST, GPx, SOD and CAT). Significant alterations were recorded in the activities of AST, ALT, ACP and ALP in Ctp, Mtn and Ctp + Mtn challenged groups. The histopathological results of liver supported the biochemical data. The pre-treatment of rats with the aqueous extract of A. vera leaves significantly protected them from the toxicity of pesticides. These results suggested that A. vera extract may be used as a promising natural agent for the management of pesticide induced toxicity.

Studies on the ameliorative effect of curcumin on carbofuran induced perturbations in the activity of lactate dehydrogenase in wistar rats.

Carbofuran is known to inhibit neurotransmission system of insects. The present study was undertaken to evaluate the possible ameliorative effect of curcumin on carbofuran induced alterations in energy metabolism in brain and liver of rats. The results demonstrate that carbofuran caused a significant inhibition of lactate dehydrogenase (LDH) activity in rat liver but an increase in LDH activity in the brain. Increased LDH activity was also observed in the serum indicating organ damage in treated animals. Carbofuran caused an increase in level of pyruvic acid in rat liver but a decrease in the brain. A decrease in the level of soluble protein was also observed in the tissues studied. Pretreatment of animals with curcumin resulted in significant amelioration of the altered indices. These results indicate that carbofuran at sub lethal concentrations may adversely alter energy metabolism in brain and liver of non-target mammalian systems. Pretreatment of animals with curcumin may exhibit a potential to mitigate the carbofuran induced toxicity.

Synergistic Effect of Quercetin and α-Lipoic Acid on Aluminium Chloride Induced Neurotoxicity in Rats.

OBJECTIVES: The present study was carried out to study the protective effects of quercetin and α-lipoic acid alone and in combination against aluminum chloride induced neurotoxicity in rats. MATERIALS AND METHODS: The study consisted of eight groups, namely, Group 1: control rats, Group 2: rats receiving aluminium chloride 7 mg/kg body weight intraperitoneal route (i.p) for two weeks, Group 3: rats receiving quercetin 50 mg/kg body weight i.p. for two weeks, Group 4: rats receiving quercetin 50 mg/kg body weight followed by aluminium chloride 7 mg/kg body weight i.p. for two weeks, Group 5: rats receiving α-lipoic acid 20 mg/kg body weight i.p. for two weeks, Group 6: rats receiving lipoic acid 20 mg/kg body weight followed by aluminium chloride 7 mg/kg body weight i.p. for two weeks, Group 7: rats receiving α-lipoic acid 20 mg/kg body weight and quercetin 50 mg/kg body weight i.p. for two weeks, and Group 8: rats receiving α-lipoic acid 20 mg/kg body weight and quercetin 50 mg/kg body weight followed by aluminium chloride 7 mg/kg body weight i.p. for two weeks. The animals were killed after 24 hours of the last dose by cervical dislocation. RESULTS: Aluminium chloride treatment of rats resulted in significant increases in lipid peroxidation, protein carbonyl levels, and acetylcholine esterase activity in the brain. This was accompanied with significant decreases in reduced glutathione, activities of the glutathione reductase, and superoxide dismutase. Pretreatment of AlCl3 exposed rats to either quercetin or α-lipoic acid also restored altered lipid peroxidation and superoxide dismutase to near normal levels. Quercetin or α-lipoic acid pretreatment of AlCl3 exposed rats improved the protein carbonyl and reduced glutathione, glutathione reductase, and acetylcholine esterase activities in rat brains towards normal levels. Combined pretreatment of AlCl3 exposed rats with quercetin and α-lipoic acid resulted in a tendency towards normalization of most of the parameters. CONCLUSIONS: Quercetin and α-lipoic acid complemented each other in protecting the rat brain against oxidative stress induced by aluminium chloride.

Hepatoprotective effect of Quercetin supplementation against Acrylamide-induced DNA damage in wistar rats.

BACKGROUND: Quercetin (QR), is a polyphenolic flavonoid compound which is found in large amounts in certain foods, and protects against oxidative stress. The current study was conducted to determine whether Quercetin can possibly exert hepatoprotective and antioxidant activity against acrylamide (ACR) induced toxicity in rats. METHODS: Four groups of Wistar rats consisting of six rats each: (i) control group; (ii) ACR treated group (50 mg/kg bw); (iii) QR group: rats were treated with QR (10 mg/kg bw); (iv) QR (10 mg/kg bw) was given i.p. for 5 days followed by ACR (50 mg/kg bw) on 5th day (single dose). RESULTS: ACR caused an elevation in 8-OH guanosine level and a reduction in Glutahione S-transferase (GST) activity. Administration of QR significantly protected liver tissue against hepatotoxic effect of acrylamide from amelioration of the marker enzyme (p < 0.05) and DNA damage (p < 0.01) as evident by comet assay and, besides some indices of histopathological alterations. CONCLUSION: It is concluded that QR could protect the liver against DNA damage induced by ACR probably is thus capable of ameliorating ACR-induced changes in the rat livers.

Therapeutic role of quercetin on oxidative damage induced by acrylamide in rat brain.

Context Quercetin (QE), a bioflavonoid present abundantly in fruits and vegetables, has been reported to possess antioxidant properties. Acrylamide (ACR) is formed in foods during cooking and is known to be neurotoxic. Objective The present study was designed to evaluate the protective effect of QE against neurotoxicity induced by ACR. Materials and methods Four groups of Wistar rats consisting of six rats each: (i) control group; (ii) acrylamide treated group (50 mg/kg body weight as single dose); (iii) quercetin group: rats were treated intraperitoneally (i.p.) with QE (10 mg/kg body weight alone every day for 5 d); (iv) quercetin + acrylamide group: quercetin (10 mg/kg bw) was given i.p. every day for 5 d followed by acrylamide i.p. injection (50 mg/kg bw) on fifth day (single dose). Rats were killed after 48 h. Results Administration of ACR (50 mg/kg bw) in Wistar rats resulted in significant increase of dopamine, interferon-γ and 8-hydroxyguanosine with concomitant decrease of serotonin (p < 0.001) in the rat brain. Treatment of rats with QE intraperitonealy (10 mg/kg body weight) before ACR assault resulted in the diminution of ACR-mediated neurotoxicity as evident from decreased levels of dopamine, interferon-γ (p < 0.001) and 8-hydroxyguanosine with concomitant restoration of serotonin levels (p < 0.001). Discussion and conclusion On the basis of the above results, the present study suggests that quercetin may be a potential therapeutic agent for restoration of oxidative damage to neurons.

Phytochemicals Mediated Remediation of Neurotoxicity Induced by Heavy Metals.

Almost all the environmental components including both the abiotic and biotic factors have been consistently threatened by excessive contamination of heavy metals continuously released from various sources. Different heavy metals have been reported to generate adverse effects in many ways. Heavy metals induced neurotoxicity and impairment in signalling cascade leading to cell death (apoptosis) has been indicated by several workers. On one hand, these metals are required by the cellular systems to regulate various biological functions of normal cells, while on the other their biomagnification in the cellular systems produces adverse effects. The mechanism by which the heavy metals induce neurotoxicity follows free radicals production pathway(s) specially the generation of reactive oxygen species and reactive nitrogen species. These free radicals produced in excess have been shown to create an imbalance between the oxidative and antioxidative systems leading to emergence of oxidative stress, which may cause necrosis, DNA damage, and many neurodegenerative disorders. This mini review summarizes the current knowledge available on the protective role of varied natural products isolated from different herbs/plants in imparting protection against heavy metals (cadmium, lead, arsenic, and mercury) mediated neurotoxicity.

Acetylcholinesterase from Human Erythrocytes as a Surrogate Biomarker of Lead Induced Neurotoxicity.

Lead induced neurotoxicity in the people engaged in different occupations has received wide attention but very little studies have been carried out to monitor occupational neurotoxicity directly due to lead exposure using biochemical methods. In the present paper an endeavour has been made in order to assess the lead mediated neurotoxicity by in vitro assay of the activity of acetylcholinesterase (AChE) from human erythrocytes in presence of different concentrations of lead. The results suggested that the activity of this enzyme was localized in membrane bound fraction and it was found to be highly stable up to 30 days when stored at -20°C in phosphate buffer (50 mM, pH 7.4) containing 0.2% Triton X-100. The erythrocyte's AChE exhibited K m for acetylcholinesterase to be 0.1 mM. Lead caused sharp inhibition of the enzyme and its IC50 value was computed to be 1.34 mM. The inhibition of the enzyme by lead was found to be of uncompetitive type (K i value, 3.6 mM) which negatively influenced both the V max and the enzyme-substrate binding affinity. Taken together, these results indicate that AChE from human erythrocytes could be exploited as a surrogate biomarker of lead induced neurotoxicity particularly in the people occupationally exposed to lead.

Protective effects of quercetin on cadmium fluoride induced oxidative stress at different intervals of time in mouse liver.

Quercetin, a member of the flavonoid family is a major antioxidant acquired in humans by food consumption, while Cadmium fluoride (CdF2) is one of the naturally occurring chemicals having adverse effects. The protective effect of quercetin on time dependent oxidative damage induced in mice liver by CdF2 was studied in the following groups of mice consisting of six mice each: (i) control group; (ii) mice treated with single i.p injection of 2 mg/kg bw CdF2 for 24 h; (iii) mice treated with single i.p injection of 2 mg/kg bw CdF2 for 48 h; (iv) mice treated with single i.p injection of quercetin (100 mg/kg bw); (v) mice treated with i.p injection of 100 mg/kg bw of quercetin followed by i.p injection of CdF2 (2 mg/kg bw) for 24 h; and (vi) mice treated with i.p injection of 100mg/kg bw of quercetin followed by CdF2 (2 mg/kg bw) for 48 h. Administration of quercetin two hours before CdF2 significantly reduced the biochemical alterations in reduced glutathione, ascorbic acid, lipid peroxidation, super oxide dismutase, catalase and total protein (p<0.05). Histopathology also showed the protective effect of quercetin. The livers treated with CdF2 were atrophic, markedly nodular, inflamed and necrotic. However, this effect was reduced to a minimum in the mice pre-treated for two hours with quercetin.

A novel promising strain of Trichoderma evansii (WF-3) for extracellular α-galactosidase production by utilizing different carbon sources under optimized culture conditions.

A potential fungal strain of Trichoderma sp. (WF-3) was isolated and selected for the production of α-galactosidase. Optimum conditions for mycelial growth and enzyme induction were determined. Basal media selected for the growth of fungal isolate containing different carbon sources like guar gum (GG), soya bean meal (SM), and wheat straw (WS) and combinations of these carbon substrates with basic sugars like galactose and sucrose were used to monitor their effects on α-galactosidase production. The results of this study indicated that galactose and sucrose enhanced the enzyme activity in guar gum (GG) and wheat straw (WS). Maximum α-galactosidase production (213.63 U mL(-1)) was obtained when the basic medium containing GG is supplemented with galactose (5 mg/mL). However, the presence of galactose and sucrose alone in the growth media shows no effect. Soya meal alone was able to support T. evansii to produce maximum enzyme activity (170.36 U mL(-1)). The incubation time, temperature, and pH for the maximum enzyme synthesis were found to be 120 h (5 days), 28°C, and 4.5-5.5, respectively. All the carbon sources tested exhibited maximum enzyme production at 10 mg/mL concentration. Among the metal ions tested, Hg was found to be the strongest inhibitor of the enzyme. Among the chelators, EDTA acted as stronger inhibitor than succinic acid.

Carbofuran induced oxidative stress mediated alterations in Na⁺-K⁺-ATPase activity in rat brain: amelioration by vitamin E.

Pesticides cause oxidative stress and adversely influence Na(+)-K(+)-ATPase activity in animals. Since impact of carbofuran has not been properly studied in the mammalian brain, the ability of carbofuran to induce oxidative stress and modulation in Na(+)-K(+)-ATPase activity and its amelioration by vitamin E was performed. The rats divided into six groups received two different doses of carbofuran (15% and 30% LD50) for 15 days. The results suggested that the carbofuran treatment caused a significant elevation in levels of malonaldehyde and reduced glutathione and sharp inhibition in the activities of super oxide dismutase, catalase, and glutathione-S-transferase; the effect being dose dependent. Carbofuran at different doses also caused sharp reduction in the activity of Na(+)-K(+)-ATPase. The pretreatment of vitamin E, however, showed a significant recovery in these indices. The pretreatment of rats with vitamin E offered protection from carbofuran-induced oxidative stress.

Effect of mercuric chloride on urinary excretion of free hydroxyproline.

BACKGROUND: The present study was undertaken to study the effect of mercuric chloride (HgCl2) on the collagen metabolism in rats and the protective effect of 2, 3-dimercapto-1-propane sulfonic acid (DMPS) in HgCl2-treated rats. MATERIAL/METHODS: The experimental groups studied were (i) a control group (ii) rats injected with a single intraperitoneal (ip) dose of 2 mg of HgCl2/kg body weight (HgCl2-treated group, n=10 rats), (iii) Rats injected with a single dose (ip) of 100 mg of DMPS/kg body weight (DMPS group, n=10 rats), (iv) rats injected with a single dose (ip) of 100 mg of DMPS/kg body weight followed by a single dose (ip) of 2 mg of HgCl2/kg body weight 1 hour after a 100-mg DMPS injection (DMPS + HgCl2-treated group, n=10 rats). Half of the rats from each group were sacrificed after 24 hours and the other half after 48 hours of treatment. RESULTS: A dose of 2.0 mg HgCl2/kg body weight caused an impairment of glomerular function, which was reflected by significant increases in the levels of serum creatinine and serum urea nitrogen in HgCl2-treated rats compared with control rats. Administration of 2.0 mg of HgCl2/kg body weight significantly increased urinary excretion of free hydroxyproline in HgCI2-treated rats compared with the control rats, reflecting increased collagen breakdown. CONCLUSIONS: Administration of DMPS one hour before HgCl2 treatment caused the restoration of altered parameters to near normal levels.