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Nephrotoxicity is a dose-limiting factor in clinical use of cisplatin. The changes in renal haemodynamics were suggested to play a role in cisplatin-induced nephrotoxicity. The aim of the present study was to investigate the effect of modulation of nitric oxide on the severity of cisplatin-induced nephrotoxicity using an experimental rat model. A nitric oxide precursor, L-arginine and an inhibitor of nitric oxide synthase, L-NAME were used. After six days of cisplatin injection, acute nephrotoxicity was demonstrated by a marked increase in serum creatinine and blood urea nitrogen. Histological examination of the kidneys confirmed the occurrence of renal damage. Moreover, cisplatin induced an increase in the level of lipid peroxides and oxidized glutathione and a depletion of reduced glutathione. The activities of the antioxidant enzymes glutathione peroxidase and superoxide dismutase were also lowered. Besides, there was a reduction in the kidney total nitrate/nitrite levels. L-arginine significantly attenuated the oxidative stress and nephrotoxic effect of cisplatin. On the other hand, L-NAME was found to aggravate cisplatin nephrotoxicity. In conclusion, the decrease in the kidney nitric oxide level contributes, at least in part, in the mechanism underlying the nephrotoxicity of cisplatin. Furthermore, L-arginine shows nephroprotective effects and might be useful in improving the therapeutic index of cisplatin

Background: In the present study, we investigated the possible modulatory effect of losartan, an angiotensin receptor blocker, on oxidative stress induced by cisplatin (CDDP) as well as on CDDP uptake by the kidney. Methods: Rats were injected with a single dose of CDDP (7 mg/kg) and/or losartan (in either a single dose of 60 mg/kg or divided doses (10 mg/kg daily for 6 days), starting 1 h before CDDP injection. In addition, rat renal cortical slices were incubated with CDDP (2 mM) and/or losartan (2 mM) for 4 h. Nephrotoxicity was evaluated by measuring serum creatinine and blood urea nitrogen (BUN) in vivo and lactate dehydrogenase (LDH) leakage in vitro; histopathological examination of kidney tissue was also done. Oxidative stress markers including reduced glutathione (GSH) and lipid peroxides were also assessed. Furthermore, CDDP uptake by renal cortical slices was determined. Results: Losartan has protective effects against CDDP-induced nephrotoxicity as evidenced by restoration of normal serum levels of creatinine and BUN, and LDH leakage. Histopathological examination of the kidney confirmed these results. Also, losartan significantly counteracted CDDP-induced lipid peroxidation and GSH depletion. However, losartan did not affect CDDP uptake by the kidney. Conclusion: Our results indicate that losartan has proved to be a promising drug for clinical use as a nephroprotectant against CDDP-induced nephrotoxicity.

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Low dose methotrexate is the cornerstone for the treatment of rheumatoid arthritis. One of its major drawbacks is hepatotoxicity, resulting in poor compliance of therapy. Dissatisfied arthritis patients are likely to seek the option of complementary and alternative medicine such as bee venom. The combination of natural products with modern medicine poses the possibility of potential interaction between the two groups and needs investigation. The present study was aimed to investigate the modulatory effect of bee venom acupuncture on efficacy, toxicity, and pharmacokinetics and tissue disposition of methotrexate. Complete Freund's adjuvant induced arthritic rats were treated for 3 weeks with methotrexate and/or bee venom. Arthritic score, ankle diameter, paw volume and tissue expression of NF-κB and TNF-α were determined to assess anti-arthritic effects, while anti-nociceptive effects were assessed by gait score and thermal hyperalgesia. Methotrexate toxicity was assessed by measuring serum TNF-α, liver enzymes and expression of NF-κB in liver. Combination therapy of bee venom with methotrexate significantly improved arthritic parameters and analgesic effect as compared to methotrexate alone. Bee venom ameliorated serum TNF-α and liver enzymes elevations as well as over expression of NF-κB in liver induced by methotrexate. Histological examination supported the results. And for the first time bee venom acupuncture was approved to increase methotrexate bioavailability with a significant decrease in its elimination. Conclusion: bee venom potentiates the anti-arthritic effects of methotrexate, possibly by increasing its bioavailability. Also, it provides a potent anti-nociceptive effect. Furthermore, bee venom protects against methotrexate induced hepatotoxicity mostly due to its inhibitory effect on TNF-α and NF-κB.

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