Chemomodulatory effect of Ficus racemosa extract against chemically induced renal carcinogenesis and oxidative damage response in Wistar rats

Ferric nitrilotriacetate (Fe-NTA) is a well-known renal carcinogen. In this communication, we show the chemopreventive effect of Ficus racemosa extract against Fe-NTA-induced renal oxidative stress, hyperproliferative response and renal carcinogenesis in rats. Fe-NTA (9 mg Fe/kg body weight, intraperitoneally) enhances renal lipid peroxidation, xanthine oxidase, gamma-glutamyl transpeptidase and hydrogen peroxide (H(2)O(2)) generation with reduction in renal glutathione content, antioxidant enzymes, viz., glutathione peroxidase, glutathione reductase, catalase, glucose-6-phosphate dehydrogenase and phase-II metabolising enzymes such as glutathione-S-transferase and quinone reductase. It also enhances blood urea nitrogen, serum creatinine, ornithine decarboxylase (ODC) activity and thymidine [(3)H] incorporation into renal DNA. It also enhances DEN (N-diethylnitrosamine) initiated renal carcinogenesis by increasing the percentage incidence of tumors. Treatment of rats orally with F. racemosa extract (200 and 400 mg/kg body weight) resulted in significant decrease in gamma-glutamyl transpeptidase, lipid peroxidation, xanthine oxidase, H(2)O(2) generation, blood urea nitrogen, serum creatinine, renal ODC activity, DNA synthesis (P<0.001) and incidence of tumors. Renal glutathione content (P<0.01), glutathione metabolizing enzymes (P<0.001) and antioxidant enzymes were also recovered to significant level (P<0.001). Thus, our data suggests that F. racemosa extract is a potent chemopreventive agent and suppresses Fe-NTA-induced renal carcinogenesis and oxidative damage response in Wistar rats.     

Induction of renal oxidative stress and cell proliferation response by ferric nitrilotriacetate (Fe-NTA): diminution by soy isoflavones

Ferric nitrilotriacetate (Fe-NTA) is a known potent nephrotoxic agent. In this communication, we report the chemopreventive effect of soy isoflavones on renal oxidative stress, toxicity and cell proliferation response in Wistar rats. Fe-NTA (9 mg Fe/kg body weight, intraperitoneally) enhances gamma-glutamyl transpeptidase, renal lipid peroxidation, xanthine oxidase and hydrogen peroxide (H2O2) generation with reduction in renal glutathione content, antioxidant enzymes, viz., glutathione peroxidase, glutathione reductase, catalase, glucose-6-phosphate dehydrogenase and phase-II metabolising enzymes such as glutathione-S-transferase and quinone reductase. Fe-NTA treatment also induced tumor promotion markers, viz., ornithine decarboxylase (ODC) activity and thymidine [3H] incorporation into renal DNA. A sharp elevation in the levels of blood urea nitrogen and serum creatinine has also been observed. Treatment of rats orally with soy isoflavones (5 mg/kg body weight and 10 mg/kg body weight) resulted in significant decreases in gamma-glutamyl transpeptidase, lipid peroxidation, xanthine oxidase, H2O2 generation, blood urea nitrogen, serum creatinine, renal ODC activity and DNA synthesis (P < 0.001). Renal glutathione content (P < 0.01), glutathione metabolizing enzymes (P < 0.001) and antioxidant enzymes were also returned to normal levels (P < 0.001). Thus, our data suggest that soy isoflavones may be used as an effective chemopreventive agent against Fe-NTA-mediated renal oxidative stress, toxicity and cell proliferation response in Wistar rats.     

Attenuation of oxidative stress, inflammation and early markers of tumor promotion by caffeic acid in Fe-NTA exposed kidneys of Wistar rats

Iron nitrilotriacetate (Fe-NTA), a chief environmental pollutant, is known for its extensive toxic manifestations on renal system. In the present study, caffeic acid, one of the most frequently occurring phenolic acids in fruits, grains, and dietary supplements was evaluated for its shielding effect against the Fe-NTA-induced oxidative, inflammatory, and pathological damage in kidney. Fe-NTA was administered (9 mg Fe/kg body weight) intraperitoneally to the Wistar male rats on 20th day while caffeic acid was administered orally (20 and 40 mg/kg body weight) before administration of Fe-NTA. The intraperitoneal administration of Fe-NTA-enhanced lipid peroxidation, xanthine oxidase, and hydrogen peroxide generation with reduction in renal glutathione content, antioxidant enzymes, viz., catalase, glutathione peroxidase, and glutathione reductase. A sharp elevation in the levels of myloperoxidase, blood urea nitrogen (BUN), and serum creatinine has also been observed. Tumor promotion markers viz., ornithine decarboxylase (ODC) and [(3)H] thymidine incorporation into renal DNA were also significantly increased. Treatment of rats orally with caffeic acid (20 and 40 mg/kg body weight) resulted in a significant decrease in xanthine oxidase (P < 0.001), lipid peroxidation (P < 0.001), γ-glutamyl transpeptidase (P < 0.01), and H(2)O(2) (P < 0.01). There was significant recovery of renal glutathione content (P < 0.001) and antioxidant enzymes (P < 0.001). There was also a reversal in the enhancement of renal ODC activity, DNA synthesis, BUN, and serum creatinine (P < 0.001). All these changes were supported by histological observations. The results indicate that caffeic acid may be beneficial in ameliorating the Fe-NTA-induced oxidative damage and tumor promotion in the kidney of rats.     

Acorus calamus extracts and nickel chloride

Nickel, a major environmental pollutant, is known for its clastogenic, toxic, and carcinogenic potential. In this article, we report the effect of Acorus calamus on nickel chloride (NiCl₂)-induced renal oxidative stress, toxicity, and cell proliferation response in male Wistar rats. NiCl₂ (250 μmol/kg body weight/mL) enhanced reduced renal glutathione content (GSH) glutathione-S-transferase (GST), glutathione reductase (GR), lipid peroxidation (LPO), H₂O₂ generation, blood urea nitrogen (BUN), and serum creatinine with a concomitant decrease in the activity of glutathione peroxidase (GPx) (p<0.001). NiCl₂ administration also dose-dependently induced the renal ornithine decarboxylase (ODC) activity several-fold as compared to salinetreated control rats. Similarly, renal DNA synthesis, which is measured in terms of [³H] thymidine incorporation in DNA, was elevated following NiCl₂ treatment. Prophylactic treatment of rats with A. calamus (100 and 200 mg/kg body weight po) daily for 1 wk resulted in the diminution of NiCl₂-mediated damage, as evident from the downregulation of glutathione content, GST, GR, LPO, H₂O₂ generation, BUN, serum creatinine, DNA synthesis (p<0.001), and ODC activity (p<0.01) with concomitant restoration of GPx activity. These results clearly demonstrate the role of oxidative stress and its relation to renal disfunctioning and suggest a protective effect of A. calamus on NiCl₂-induced nephrotoxicity in a rat experimental model.     

Inhibition of potassium bromate-induced renal oxidative stress and hyperproliferative response by Nymphaea alba in Wistar rats

KBrO3-mediated renal injury and hyperproliferative response in Wistar rats. In this communication, we report the efficacy of Nymphaea alba on KBrO3 (125 mg/kg body weight, intraperitoneally) caused reduction in renal glutathione content, renal antioxidant enzymes and phase-II metabolising enzymes with enhancement in xanthine oxidase, lipid peroxidation, gamma-glutamyl transpeptidase and hydrogen peroxide (H202). It also induced blood urea nitrogen, serum creatinine and tumor promotion markers, viz., ornithine decarboxylase (ODC) activity and DNA synthesis. Treatment of rats with Nymphaea alba (100 and 200 mg/kg body weight) one hour before KBrO3 (125 mg/kg body weight, i.p.) resulted in significant decreases in xanthine oxidase (P < 0.05), lipid peroxidation, gamma-glutamyl transpeptidase, H202 generation, blood urea nitrogen, serum creatinine, renal ODC activity and DNA synthesis (P < 0.001). Renal glutathione content, glutathione metabolizing enzymes and antioxidant enzymes were also recovered to significant levels (P < 0.001). These results show that Nymphaea alba acts as chemopreventive agent against KBrO3-mediated renal injury and hyperproliferative response.     

Antioxidant and hepatoprotective potential of Aegle marmelos Correa. against CCl4-induced oxidative stress and early tumor events

The antioxidant properties and inhibitory effect on early tumor promoter markers of A. marmelos (25 and 50 mg/Kg b. wt. orally) have been evaluated. Male Wistar rats were pre-treated for seven consecutive days with A. marmelos prior to CCl₄ (1 mL Kg^{? 1} body weight p. o., in corn oil [1:1 v/v]) treatment. Pre-treatment with A. marmelos suppressed lipid peroxidation (LPO), xanthine oxidase (XO) and release of serum toxicity marker enzymes viz, SGOT, LDH, SGPT dose-dependently and significantly (p < 0.001). Hepatic antioxidant status viz, reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx), quinone reductase (QR), catalase (CAT) were concomitantly restored in A. marmelos-treated groups (p < 0.001). In addition, A. marmelos pretreatment also prevented the CCl₄-enhanced ornithine decarboxylase (ODC) and hepatic DNA synthesis significantly (p < 0.001). In conclusion, carbon tetrachloride-induced liver toxicity was strikingly attenuated by A. marmelos treatment and the study gives some insight into the mechanisms involved in diminution of free radical generating toxicants and enhancement of the antioxidant armory, hence preventing further tissue damage, injury and hyperproliferation.

Thus, these findings indicate that A. marmelos attenuates CCl₄-mediated hepatic oxidative stress, toxicity, tumor promotion and subsequent cell proliferation response in Wistar rats.     

Glyceryl trinitrate,a nitric oxide donor,abrogates ferric nitrilotriacetate-induced oxidative stress and renal damage

Ferric nitrilotriacetate (Fe-NTA), a common water pollutant and a known renal carcinogen, acts through the generation of oxidative stress and hyperproliferative response. In the present study, we show that the nitric oxide (NO) generated by the administration of glyceryl trinitrate (GTN) affords protection against Fe-NTA-induced oxidative stress and proliferative response. Administration of Fe-NTA resulted in a significant (P<0.001) depletion of renal glutathione (GSH) content with concomitant increase in lipid peroxidation and elevated tissue damage marker release in serum. Parallel to these changes, Fe-NTA also caused down-regulation of GSH metabolizing enzymes including glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase and several fold induction in ornithine decarboxylase (ODC) activity and rate of DNA synthesis. Subsequent exogenous administration of GTN at doses of 3 and 6mg/kg body weight resulted in significant (P<0.001) recovery of GSH metabolizing enzymes and amelioration of tissue GSH content, in a dose-dependent manner. GTN administration also inhibited malondialdehyde (MDA) formation, induction of ODC activity, enhanced rate of DNA synthesis, and pathological deterioration in a dose-dependent fashion. Further, administration of NO inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), exacerbated Fe-NTA-induced oxidative tissue injury, hyperproliferative response, and pathological damage. Overall, the study suggests that NO administration subsequent to Fe-NTA affords protection against ROS-mediated damage induced by Fe-NTA.     

Reversal of cadmium chloride-induced oxidative stress and genotoxicity by Adhatoda vasica extract in Swiss albino mice

Adhatoda vasica Nees (Acanthaceae) that is used by Ayurvedic physicians possesses some established medicinal properties. Environmental and occupational exposure with cadmium affects the renal system adversely. Cadmium is an established genotoxic agent. In the present study, we evaluated the antioxidant and anticlastogenic efficacy of A. vasica against cadmium chloride (CdCl₂)-induced renal oxidative stress and genotoxicity in Swiss albino mice. A single intraperitoneal dose of CdCl₂ (5 mg/kg BW) resulted in significant (p<0.001) increase in chromosomal aberration and micronuclei formation. Oral administration of A. vasica at two doses (50 and 100 mg/kg BW) for seven consecutive days showed significant (p<0.001) suppression of mutagenic effects of CdCl₂ in plant-pretreated groups. To study the mechanism by which A. vasica exerts its antimutagenic potential, enzymes involved in metabolism and detoxification were also estimated. Cadmium intoxication altered the antioxidant levels and enhanced MDA formation significantly (p<0.001). A. vasica showed significant (p<0.001) recovery in antioxidant status, viz., GSH content, its dependent enzymes, and catalase activity. Prophylactic pretreatment of A. vasica extract in cadmium-intoxicated mice showed marked (p<0.001) inhibition of lipid peroxidation (LPO) and xanthine oxidase (XO) activity. The present findings support that antimutagenic efficacy of A. vasica can be attributed to its restoring effects on antioxidant status and suppression of MDA level formation.     

Probucol modulates iron nitrilotriacetate (Fe-NTA)-dependent renal carcinogenesis and hyperproliferative response: diminution of oxidative stress

Probucol is a clinically used cholesterol-lowering drug, with pronounced antioxidant properties. We have reported previously, that dietary supplementation of probucol enhances NAD(P)H:quinone reductase (Iqbal M, Okada S (2003) Pharmacol Toxicol 93:259–263) and inhibits Fe-NTA induced lipid peroxidation and DNA damage in vitro (Iqbal M, Sharma SD, Oakada (2004) Redox Rep 9:167–172). Further to this, in the present study, we evaluated the modulatory effect of probucol on iron nitrilotriacetae (Fe-NTA) dependent renal carcinogenesis, hyperproliferative response and oxidative stress. In Fe-NTA alone treated group, a 20% renal cell tumor incidence was recorded whereas, in N-diethylnitrosamine (DEN)-initiated and Fe-NTA promoted animals, the percentage tumor incidence was increased to 70% as compared with untreated controls. No tumor incidence was recorded in DEN-initiated, nonpromoted group. Diet supplemented with 1.0% probucol fed prior to, during and after Fe-NTA treatment in DEN-initiated animals afforded >65% protection in renal cell tumor incidence. Probucol fed diet pretreatment also resulted a significant and dose dependent inhibition of Fe-NTA induced renal ornithine decarboxylase (ODC) activity. In oxidative stress studies, Fe-NTA alone treatment enhanced lipid peroxidation, accompanied by a decrease in the level of GSH, activities of antioxidants and phase II metabolizing enzymes in kidney concomitant with histolopathological changes. These changes were significantly and dose-dependently alleviated by probucol fed diet. From this data, it can be concluded that probucol can modulates toxic and tumor promoting effects of Fe-NTA and can serve as a potent chemopreventive agent to suppress oxidant induced tissue injury and carcinogenesis, in addition to being a cholesterol lowering and anti-atherogenic drug.     

Nutraceutical Activity of Anthocyanins from the Edible Berries of Rhamnus pompana

We present the inhibitory properties of the R. pompana anthocyanin fraction (RPAF) and its major constituents on alpha-glucosidase (AG), pancreatic lipase (PL), HMG-CoA reductase, and ornithine decarboxylase (ODC). The effect of RPAF was also evaluated in ICR male mice subjected to oral glucose tolerance test (OGTT) and hypercaloric/atherogenic diet for 30 days. RP-HPLC/MS profiling revealed that RPAF contained five major anthocyanins and induced slight inhibition on PL and HMG-CoA reductase (IC₅₀, 245–338 μg mL⁻¹) whereas strong activity on AG and ODC (IC₅₀, 130–133 μg mL⁻¹) was observed. Kinetic studies and molecular docking with pelargonidin-3-O-rutinoside (P3R) on ODC, revealed changes in K_m (0.9514–0.9746 mM) and V_max (1.96–2.32 μmol mg⁻¹ min⁻¹) suggesting mixed inhibition and molecular interaction with two active sites of ODC. P3R showed antiproliferative activity (IC_50, 46.5 μM) and decreased polyamine accumulation in DLD-1 cells. The results of OGTT confirmed that RPAF regulates postprandial glucose levels in diabetic animals which experienced a significant glucose depletion (30 %; p<0.001) from 30 to 120 min post-treatment. Prolonged supplementation of RPAF caused significant decrease (p<0.001) in plasma glucose, total cholesterol, LDL-c and triglycerides as well as significant increase (p<0.001) of HDL-c compared with normoglycemic untreated animals.     

Protective effect of Didymocarpus pedicellata on ferric nitrilotriacetate (Fe-NTA) induced renal oxidative stress and hyperproliferative response

Didymocarpus pedicellata R. Br. (Gesneriaceae) is widely used in traditional Indian medicines against renal afflictions. In the present study, we have revealed ethanolic extract of aerial parts of D. pedicellata to possess significant antioxidant activity and protect against ferric nitrilotriacetate (Fe-NTA) mediated renal oxidative stress, nephrotoxicity and tumor promotion response. D. pedicellata extract was found to possess a high content of total polyphenolics, exhibit potent reducing power and significantly scavenge free radicals including several reactive oxygen species (ROS) and reactive nitrogen species (RNS). The extract also significantly and dose-dependently protected against Fe-NTA plus H(2)O(2)-mediated damage to lipids and DNA. Protective efficacy of the extract was also tested in vivo against Fe-NTA mediated nephrotoxicity and tumor promotion response. Administration of Fe-NTA (9 mg/kg body weight, i.p.) to Swiss albino mice depleted renal glutathione content and activities of antioxidant and phase II metabolizing enzymes with concomitant induction of oxidative damage. Fe-NTA also incited hyperproliferation response elevating ornithine decarboxylase activity and [(3)H]-thymidine incorporation into DNA. Elevation in serum creatinine (SCr) and blood urea nitrogen (BUN), and histopathological changes were also evident and suggested Fe-NTA to afflict damage to kidney. Pretreatment of mice with D. pedicellata extract (100-200 mg/kg body weight) for 7 days not only restored antioxidant armory near normal values but also significantly protected against renal oxidative stress and damage restoring normal renal architecture and levels of renal damage markers, viz., BUN and SCr. The results of the present study indicate D. pedicellata to possess potent antioxidant and free radical scavenging activities and preclude oxidative damage and hyperproliferation in renal tissues.     

Acorus calamus extracts and nickel chloride: prevention of oxidative damage and hyperproliferation response in rat kidney

Nickel, a major environmental pollutant, is known for its clastogenic, toxic, and carcinogenic potential. In this article, we report the effect of Acorus calamus on nickel chloride (NiCl2)-induced renal oxidative stress, toxicity, and cell proliferation response in male Wistar rats. NiCl2 (250 micromol/kg body weight/mL) enhanced reduced renal glutathione content (GSH), glutathione- S-transferase (GST), glutathione reductase (GR), lipid peroxidation (LPO), H2O2 generation, blood urea nitrogen (BUN), and serum creatinine with a concomitant decrease in the activity of glutathione peroxidase (GPx) (p < 0.001). NiCl2 administration also dose-dependently induced the renal ornithine decarboxylase (ODC) activity several-fold as compared to salinetreated control rats. Similarly, renal DNA synthesis, which is measured in terms of [3H] thymidine incorporation in DNA, was elevated following NiCl2 treatment. Prophylactic treatment of rats with A. calamus (100 and 200 mg/kg body weight po) daily for 1 wk resulted in the diminution of NiCl2- mediated damage, as evident from the downregulation of glutathione content, GST, GR, LPO, H2O2 generation, BUN, serum creatinine, DNA synthesis (p < 0.001), and ODC activity (p < 0.01) with concomitant restoration of GPx activity. These results clearly demonstrate the role of oxidative stress and its relation to renal disfunctioning and suggest a protective effect of A. calamus on NiCl2-induced nephrotoxicity in a rat experimental model.     

Suppressive effects of dietary curcumin on the increased activity of renal ornithine decarboxylase in mice treated with a renal carcinogen, ferric nitrilotriacetate

Curcumin, a natural, biologically active compound extracted from rhizomes of Curcuma species, has been shown to act as a biological response modifier in various disorders. We have reported previously that the dietary supplementation of curcumin enhances the activities of antioxidant and phase II metabolizing enzymes in mice (M. Iqbal, S.D. Sharma, Y. Okazaki, M. Fujisawa, S. Okada, Dietary supplementation of curcumin enhances antioxidant and phase II metabolizing enzymes in ddY mice: possible role in protection against chemical carcinogenesis and toxicity, Pharmacol and Toxicol. 92 (2003) 33_38.) and inhibits ferric nitrilotriacetate (Fe-NTA) induced oxidative injury of lipids and DNA in vitro (M. Iqbal, Y. Okazaki, S. Okada, In vitro curcumin modulates Ferric Nitrilotriacetate (Fe-NTA) and hydrogen peroxide (H(2)O(2))-induced peroxidation of microsomal membrane lipids and DNA damage, Teratogenesis Carcinogenesis and Mutagenesis Supplement 23 (2003) 151-160.). In our present study, Fe-NTA, a known complete renal carcinogen, which generate ROS in vivo, was given intraperitoneally to mice and curcumin was tested for its ability to inhibits oxidative stress and the activity of ornithine decarboxylase (ODC) as well as histopathological changes in the kidney. Substantial changes in glutathione, antioxidant enzymes as well as changes in phase II metabolizing enzymes were observed in the kidney at 12 h after treatment with Fe-NTA (9.0 mg Fe/kg body weight). Effect of oxidative stress induced by Fe-NTA were also demonstrated by the increase in lipid peroxidation as monitored by formation of thiobarbituric acid-reactive substances and 4-hydroxy-2-nonenal (HNE)-modified proteins in kidney. Likewise, the level of protein carbonyl contents, an indicator of protein oxidation was also increased after Fe-NTA administration. However, the changes in these parameters were restored to normal in curcumin-pretreated mice. The ODC activity in the kidney was significantly increased by Fe-NTA, while the increased ODC activity induced by Fe-NTA was normalized in curcumin-pretreated mice. In addition, curcumin pretreatment almost completely prevented kidney biomolecules from oxidative damage and protected the tissue against observed histopathological alterations.     

Glutathione metabolizing enzymes and oxidative stress in ferric nitrilotriacetate mediated hepatic injury

Summary

Glutathione (GSH) plays several important roles in the protection of cells against oxidative damage, particularly following exposure to xenobiotics. Ferric nitrilotriacetate (Fe-NTA) is a potent depletor of GSH and also enhances tissue lipid peroxidation. In this study, we show the effect of Fe-NTA treatment on hepatic GSH and some of the glutathione metabolizing enzymes, oxidant generation and liver damage. The level of hepatic GSH and the activities of glutathione reductase, glutathione S-transferase, glutathione peroxidase, and glucose 6-phosphate dehydrogenase all decrease following Fe-NTA administration. In these parameters the maximum decrease occurred at 12 h following Fe-NTA treatment. In contrast, γ-glutamyl transpeptidase was increased at this time. Not surprisingly, the increase in the activity of γ-glutamyl transpeptidase and decreases in GSH, glutathione peroxidase, glutathione reductase, glucose 6-phosphate dehydrogenase and glutathione S-transferase were found to be dependent on the dose of Fe-NTA administered. Fe-NTA administration also enhances the production of H₂O₂ and increases hepatic lipid peroxidation. Parallel to these changes, Fe-NTA enhances liver damage as evidenced by increases in serum transaminases. Once again, the liver damage is dependent on the dose of Fe-NTA and is maximal at 12 h. Pretreatment of animals with antioxidant, butylated hydroxy anisole (BHA), protects against Fe-NTA-mediated hepatotoxicity further supporting the involvement of oxidative stress in Fe-NTA-mediated hepatic damage. In aggregate, our results indicate that Fe-NTA administration eventuates in decreased hepatic GSH, a fall in the activities of glutathione metabolizing enzymes and excessive production of oxidants, all of which are involved in the cascade of events leading to iron-mediated hepatic injury.     

Thiamine deficiency induces oxidative stress in brain mitochondria of Mus musculus

The present investigation evaluates the changes in the levels of antioxidant enzymes, lipid peroxidation (LPO), and protein carbonyl content (PCC) in brain mitochondria following thiamine deficiency (TD). The study was carried out on Mus musculus allocated into three groups, namely control and thiamine-deficient group for 8 (TD 8) and 10 (TD 10) days. The LPO was measured in terms of reduced glutathione (GSH) and thiobarbituric acid reactive substance (TBARS). Antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were measured biochemically. A significant increase in the TBARS (p?<?0.0001) and PCC (p?<?0.001) levels in group II (TD 8) and group III (TD 10) animals was observed in comparison to controls. The GSH levels were found to be reduced in both the treated groups compared to the control. A significant reduction in the activities of SOD was also observed in group II (p?<?0.01) and group III (p?<?0.0001) animals in comparison to the control. Enzymatic activities of CAT (p?<?0.001) and GPx (p?<?0.05) were found to be significantly reduced in group III (TD 10) in comparison to the control. In conclusion, reduction in the activities of antioxidant enzymes as well as an increase in LPO and PCC following TD implies oxidative stress in brain mitochondria that may further leads to neurodegeneration.     

Vanadium(III)-L-cysteine protects cisplatin-induced nephropathy through activation of Nrf2/HO-1 pathway

Cisplatin (CDDP) is one of the first-line anticancer drugs; however, the major limitation of CDDP therapy is development of nephrotoxicity (25–35% cases), whose precise mechanism mainly involves oxidative stress, inflammation and cell death. Therefore, in search of a potential chemoprotectant, an organovanadium complex, viz., vanadium(III)-L-cysteine (VC-III) was evaluated against CDDP-induced nephropathy in mice. CDDP was administered intraperitoneally (5?mg/kg b.w.) and VC-III was given by oral gavage (1?mg/kg b.w.) in concomitant and pre-treatment schedule. The results showed that VC-III administration reduced (p?<?0.001) serum creatinine and blood urea nitrogen levels, suggesting amelioration of renal dysfunction. VC-III treatment also significantly (p?<?0.001) prevented CDDP-induced generation of reactive oxygen species, reactive nitrogen species, and onset of lipid peroxidation in kidney tissues of the experimental mice. In addition, VC-III also substantially (p?<?0.001) restored CDDP-induced depleted activities of the renal antioxidant enzymes such as, superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, and glutathione (reduced) level. Furthermore, histopathological study also confirmed the renoprotective efficacy of VC-III. Western blotting analysis appended by immunohistochemical data showed that VC-III treatment quite effectively reduced the expression of proinflammatory mediators such as, NFκβ, COX-2 and IL-6. VC-III administration also stimulated Nrf2-mediated antioxidant defense system by promotion of downstream antioxidant enzymes, such as HO-1. Moreover, treatment with VC-III significantly (p?<?0.001) enhanced CDDP-mediated cytotoxicity in MCF-7 and NCI-H520 human cancer cell lines. Thus, VC-III can serve as a suitable chemoprotectant and increase the therapeutic window of CDDP in cancer patients.     

Antioxidant and hepatoprotective potential of Aegle marmelos Correa. against CCl4-induced oxidative stress and early tumor events

The antioxidant properties and inhibitory effect on early tumor promoter markers of A. marmelos (25 and 50 mg/Kg b. wt. orally) have been evaluated. Male Wistar rats were pre-treated for seven consecutive days with A. marmelos prior to CCl4 (1 mL Kg(- 1) body weight p. o., in corn oil [1:1 v/v]) treatment. Pre-treatment with A. marmelos suppressed lipid peroxidation (LPO), xanthine oxidase (XO) and release of serum toxicity marker enzymes viz, SGOT, LDH, SGPT dose-dependently and significantly (p < 0.001). Hepatic antioxidant status viz, reduced glutathione (GSH), glutathione reductase (GR), glutathione peroxidase (GPx), quinone reductase (QR), catalase (CAT) were concomitantly restored in A. marmelos-treated groups (p < 0.001). In addition, A. marmelos pretreatment also prevented the CCl4-enhanced ornithine decarboxylase (ODC) and hepatic DNA synthesis significantly (p < 0.001). In conclusion, carbon tetrachloride-induced liver toxicity was strikingly attenuated by A. marmelos treatment and the study gives some insight into the mechanisms involved in diminution of free radical generating toxicants and enhancement of the antioxidant armory, hence preventing further tissue damage, injury and hyperproliferation. Thus, these findings indicate that A. marmelos attenuates CCl4-mediated hepatic oxidative stress, toxicity, tumor promotion and subsequent cell proliferation response in Wistar rats.     

Attenuation of potassium bromate-induced nephrotoxicity by coumarin (1,2-benzopyrone) in Wistar rats: chemoprevention against free radical-mediated renal oxidative stress and tumor promotion response

We report the modulatory effect of coumarin (1,2-benzopyrone) on potassium bromate (KBrO(3)) mediated nephrotoxicity in Wistar rats. KBrO(3) (125 mg/kg body weight, i.p.) enhances gamma-glutamyl transpeptidase, renal lipid peroxidation, xanthine oxidase and hydrogen peroxide (H(2)O(2)) generation with reduction in renal glutathione content and antioxidant enzymes. It also enhances blood urea nitrogen, serum creatinine, ornithine decarboxylase (ODC) activity and [(3)H]-thymidine incorporation into renal DNA. Treatment of rats orally with coumarin (10 mg/kg body weight and 20 mg/kg body weight) resulted in a significant decrease in gamma-glutamyl transpeptidase, lipid peroxidation, xanthine oxidase, H(2)O(2) generation, blood urea nitrogen, serum creatinine, renal ODC activity and DNA synthesis (P < 0.001). Renal glutathione content (P < 0.01) and antioxidant enzymes were also recovered to significant level (P < 0.001). These results show that coumarin may be used as an effective chemopreventive agent against KBrO(3)-mediated renal oxidative stress, toxicity and tumor promotion response in Wistar rats.     

Tamarix gallica ameliorates thioacetamide–induced hepatic oxidative stress and hyperproliferative response in Wistar rats

Tamarix gallica, a hepatic stimulant and tonic, was examined for its ability to inhibit thioacetamide (TAA)-induced hepatic oxidative stress, toxicity and early tumor promotion response in male Wistar rats. TAA (6.6 mmol/kg body wt. i.p) enhanced lipid peroxidation, hydrogen peroxide content, glutathione S-transferase and xanthine oxidase with reduction in the activities of hepatic antioxidant enzymes viz., glutathione peroxidase, superoxide dismutase and caused depletion in the level of hepatic glutathione content. A marked increase in liver damage markers was also observed. TAA treatment also enhanced tumor promotion markers, ornithine decarboxylase (ODC) activity and [³H] thymidine incorporation into hepatic DNA. Pretreatment of rats orally with Tamarix gallica extract (25 and 50 mg/kg body weight) prevented TAA-promoted oxidative stress and toxicity. Prophylaxis with Tamarix gallica significantly reduced the susceptibility of the hepatic microsomal membrane for iron-ascorbate induced lipid peroxidation, H₂O₂ content, glutathione S-transferase and xanthine oxidase activities. There was also reversal of the elevated levels of liver marker parameters and tumor promotion markers. Our data suggests that Tamarix gallica is a potent chemopreventive agent and may suppress TAA-mediated hepatic oxidative stress, toxicity, and tumor promotion response in rats.     

Analyses of impact of metal ion contamination on carp (Cyprinus carpio L.) gill cell suspensions

The decline in fish population because of water contamination is problem. As a result of direct exposure in water, it has been readily accepted that the gills are the main site of water contamination and toxicity (e.g., metal ions). In the present study, we investigated metal ion contamination on the functional capacity of carp gill cells with antioxidant interactions in an in vitro study. The extent of cellular membrane damage, lipid peroxidation (LPO) (as TBARS levels), and glutathione (GSH) content were investigated after the addition of two metal ion compounds (viz., CuSO₄ and HgCl₂) in various concentrations (300, 500, 700, 1000, and 3000 μM) to gill cell preparation of the freshwater fish carp (Cyprinus carpio L.) with modulations by bovine serum albumin (BSA) (0.5% and 1.0%) and dimethyl sulfoxide (DMSO) (0.5%) as free-radical scavengers. The Comet assay technique was also performed for the highest concentrations of the two mentioned metal ions as an index of DNA breaks. The outcomes were as follows: (1) Copper and mercury increased the rate of LPO dose dependently (r=+0.995 and r=+0.993, respectively; p<0.001), but the GSH content was only marginally affected (r=−0.787 and r=−0.844, respectively; p<0.05). (2) Depletion of GSH molecules by copper had a wider range than mercury. (3) In the highest concentration of metal ions (3000 μM), both DMSO and 1.0% BSA showed a pro-oxidative potential to elevate the levels of TBARS (p<0.001), but for other concentrations when supplemented with three scavengers, a fall in the levels of the latter was found. (4) The addition of 1.0% BSA to medium containing 3000 μM of metal ions caused a significant decline in GSH content (p<0.01). (5) Copper and mercury could cause a high rate of DNA breaks (single stranded) in carp gill cell suspensions as a Comet appearance. These findings indicate that copper and mercury have a deleterious influence on membrane integrity and GSH content in a relatively dose-dependent manner. The complexes of metal ions and thiol (−SH) residues of cell proteins could also act as a potential cell toxicant leading to disturbances in cell functions causing cell death. DNA fragmentation is frequent in metal ion contamination.