Although cisplatin is an effective anti-cancer agent that is widely used for treating various types of malignant solid tumors, the nephrotoxicity induced by cisplatin severely limits its clinical application. The present study was designed to explore the potential protective effect of ginsenoside Rg5, a rare ginsenoside generated during steaming ginseng, on cisplatin-induced nephrotoxicity in a mouse experimental model. The possible mechanisms underlying this nephroprotective effect were also investigated for the first time. Rg5 was given at doses of 10 and 20 mg/kg for 10 consecutive days. On Day 7, a single nephrotoxic dose of cisplatin (25 mg/kg) was injected to mice. Cisplatin administration resulted in renal dysfunction as evidenced by increase in serum creatinine (CRE) and blood urea nitrogen (BUN) levels. In addition, cisplatin increased the level of malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), the makers of lipid peroxidation, and depleted glutathione (GSH) content and superoxide dismutase (SOD) activity in renal tissues. These effects were associated with the significantly increased levels of cytochrome P450 E1 (CYP2E1), 4-hydroxynonenal (4-HNE), tumor necrosis factor (TNF)-α, interleukin (IL)-1β, nuclear factor-kappa B (NF-κB) p65, and cyclooxygenase-2 (COX-2) in renal tissues. However, pretreatment with ginsenoside Rg5 significantly attenuated the renal dysfunction, oxidative stress and inflammation response induced by cisplatin. Furthermore, ginsenoside Rg5 supplementation inhibited activation of apoptotic pathways through increasing Bcl-2 and decreasing Bax expression levels. Histopathological examination further confirmed the nephroprotective effect of Rg5. Collectively, these results clearly suggest that Rg5-mediated alleviation of cisplatin-induced nephrotoxicity may be related to its anti-oxidant, anti-apoptotic and anti-inflammatory effects.

Frequent overdose of acetaminophen (APAP) is one of the most common and important incentives of acute hepatotoxicity. Prior to this work, our research group confirmed that black ginseng (Panax ginseng, BG) showed powerful protective effects on APAP-induced ALI. However, it is not clear which kind of individual ginsenoside from BG plays such a liver protection effect. The objective of the current investigation was to evaluate whether ginsenoside Rg5 (G-Rg5) protected against APAP-induced hepatotoxicity and the involved action mechanisms. Mice were administrated with G-Rg5 at two dosages of 10 or 20 mg/kg for 7 consecutive days. After the last treatment, all of the animals that received a single intraperitoneal injection of APAP (250 mg/kg) showed severe liver toxicity after 24 h, and the liver protection effects of G-Rg5 were examined. The results clearly indicated that pretreatment with G-Rg5 remarkably inhibited the production of serum tumor necrosis factor (TNF-α) and interleukin-1β (IL-1β) compared with the APAP group. Meanwhile, G-Rg5 decreased the hepatic malondialdehyde (MDA) content, the protein expression levels of 4-hydroxynonenal (4-HNE) and cytochrome P450 2E1 (CYP2E1) in the liver tissues. G-Rg5 decreased APAP caused the hepatic overexpression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Furthermore, analysis of immunohistochemistry and Western blotting also indicated that G-Rg5 pretreatment inhibited activation of apoptotic pathways mainly via increasing the expression of Bcl-2 protein, decreasing the expression of Bax protein, proliferating cell nuclear antigen (PCNA), cytochrome c, caspase-3, caspase-8, and caspase-9. Liver histopathological observation provided further evidence that pretreatment with G-Rg5 could significantly inhibit hepatocyte necrosis, inflammatory cell infiltration, and apoptosis caused by APAP. In conclusion, the present study clearly demonstrates that G-Rg5 exerts a liver protection effect against APAP-induced acute hepatotoxicity mainly via a caspase-mediated anti-apoptotic effect.