BackgroundFrequent overdose of paracetamol (APAP) has become the major cause of acute liver injury. The present study was designed to evaluate the potential protective effects of ginsenoside Rk1 on APAP-induced hepatotoxicity and investigate the underlying mechanisms for the first time.MethodsMice were treated with Rk1 (10 mg/kg or 20 mg/kg) by oral gavage once per d for 7 d. On the 7th d, all mice treated with 250 mg/kg APAP exhibited severe liver injury after 24 h, and hepatotoxicity was assessed.ResultsOur results showed that pretreatment with Rk1 significantly decreased the levels of serum alanine aminotransferase, aspartate aminotransferase, tumor necrosis factor, and interleukin-1β compared with the APAP group. Meanwhile, hepatic antioxidants, including superoxide dismutase and glutathione, were elevated compared with the APAP group. In contrast, a significant decrease in levels of the lipid peroxidation product malondialdehyde was observed in the ginsenoside Rk1-treated group compared with the APAP group. These effects were associated with a significant increase of cytochrome P450 E1 and 4-hydroxynonenal levels in liver tissues. Moreover, ginsenoside Rk1 supplementation suppressed activation of apoptotic pathways by increasing Bcl-2 and decreasing Bax protein expression levels, which was shown using western blotting analysis. Histopathological observation also revealed that ginsenoside Rk1 pretreatment significantly reversed APAP-induced necrosis and inflammatory infiltration in liver tissues. Biological indicators of nitrative stress, such as 3-nitrotyrosine, were also inhibited after pretreatment with Rk1 compared with the APAP group.ConclusionThe results clearly suggest that the underlying molecular mechanisms in the hepatoprotection of ginsenoside Rk1 in APAP-induced hepatotoxicity may be due to its antioxidation, antiapoptosis, anti-inflammation, and antinitrative effects.

Acetaminophen (APAP) overdose is one of the most common inducements of drug-induced liver injury (DILI) in the world. The main purpose of this paper was to investigate the liver protection activity of saponins (ginsenosides) from the leaves of Panax quinquefolius (PQS) against APAP-induced hepatotoxicity, and the involved mechanisms were demonstrated for the first time. Mice were pretreated with PQS (150 and 300 mg/kg) by oral gavage for 7 days before being treated with 250 mg/kg APAP. Severe liver injury was exerted at 24 h post-APAP, and hepatotoxicity was assessed. Our results showed that pretreatment with PQS significantly decreased the serum alanine aminotransferase (ALT), aspartate transaminase (AST), tumor necrosis factor (TNF-α), and interleukin-1β (IL-1β) levels in a dose-dependent manner as compared to the APAP administration. Meanwhile, compared with that in the APAP group, PQS decreased hepatic malondialdehyde (MDA) contents and 4-hydroxynonenal (4-HNE) expression and restored reduced glutathione (GSH) content and superoxide dismutase (SOD) activity in livers of mice. PQS inhibited the overexpression of pro-inflammatory factors cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in the liver tissues. Furthermore, Western blotting analysis revealed that PQS pretreatment inhibited the activation of apoptotic signaling pathways via increase of Bcl-2 and decrease of Bax and caspase-3 protein expression levels. Liver histopathological observation provided further evidence that PQS pretreatment significantly inhibited APAP-induced hepatocyte necrosis, inflammatory cell infiltration, and congestion. Biological indicators of nitrative stress such as 3-nitrotyrosine (3-NT) were inhibited after PQS pretreatment, compared to the APAP group. The present study clearly demonstrates that PQS exerts a protective effect against APAP-induced hepatic injury because of its antioxidant, anti-apoptotic, and anti-inflammatory activities. The findings from the present investigation show that PQS might be a promising candidate treatment agent against drug-induced ALI.

Although growing evidence has shown that ginseng (Panax ginseng C.A. Meyer.) exerts strong protective and preventive effects on cisplatin-induced side effects, the ameliorative effects of ginseng on intestinal damage caused by cisplatin are unknown to date.

Acute liver injury (ALI) induced by acetaminophen (APAP) is the main cause of drug-induced liver injury. Previous reports indicated liver failure could be alleviated by saponins (ginsenosides) from Panax ginseng against APAP-induced inflammatory responses in vivo. However, validation towards ginsenoside Rb1 as a major and marker saponin may protect liver from APAP-induced ALI and its mechanisms are poorly elucidated. In this study, the protective effects and the latent mechanisms of Rb1 action against APAP-induced hepatotoxicity were investigated. Rb1 was administered orally with 10[Formula: see text]mg/kg and 20[Formula: see text]mg/kg daily for 1 week before a single injection of APAP (250[Formula: see text]mg/kg, i.p.) 1[Formula: see text]h after the last treatment of Rb1. Serum alanine/aspartate aminotransferases (ALT/AST), liver glutathione (GSH) depletion, as well as the inflammatory cytokines, such as tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text]), interleukin-1[Formula: see text] (IL-1[Formula: see text]), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2), were analyzed to indicate the underlying protective effects of Rb1 against APAP-induced hepatotoxicity with significant inflammatory responses. Histological examination further proved Rb1’s protective effects. Importantly, Rb1 mitigated the changes in the phosphorylation of MAPK and PI3K/Akt, as well as its downstream factor NF-[Formula: see text]B. In conclusion, experimental data clearly demonstrated that Rb1 exhibited a remarkable liver protective effect against APAP-induced ALI, partly through regulating MAPK and PI3K/Akt signaling pathways-mediated inflammatory responses.