Ciliary neurotrophic factor analogue aggravates CCl4-induced acute hepatic injury in rats.

Ciliary neurotrophic factor (CNTF) and CNTF analogs were reported to have hepatoprotective effect and ameliorate hepatic steatosis in db/db or high-fat-diet-fed mice. Because hepatic steatosis and injury are also commonly induced by hepatotoxin, the aim of the present study is to clarify whether CNTF could alleviate hepatic steatosis and injury induced by carbon tetrachloride (CCl4). Unexpectedly, when combined with CCl4, CNTF aggravated hepatic steatosis and liver injury. The mechanism is associated with effects of CNTF that inhibited lipoprotein secretion and drastically impaired the ability of lipoproteins to act as transport vehicles for lipids from the liver to the circulation. While injected after CCl4 cessation, CNTF could improve liver function. These data suggest that CNTF could be a potential hepatoprotective agent against CCl4-induced hepatic injury after the cessation of CCl4 exposure. However, it is forbidden to combine recombinant mutant of human CNTF treatment with CCl4.

Ginsenoside-Rd exhibits anti-inflammatory activities through elevation of antioxidant enzyme activities and inhibition of JNK and ERK activation in vivo.

Our previous study has reported that ginsenoside-Rd significantly inhibited the production of pro-inflammatory cytokines and mediators in carrageenan (Carr)-induced rat paw edema, which might be due to its blocking of the nuclear factor-κB (NF-κB) signaling pathway. The aim of the present study was to clarify the more detailed mechanisms of anti-inflammatory activity of ginsenoside-Rd in Carr-induced rat paw edema model. Rats were pretreated with dexamethasone or ginsenoside-Rd 1 h before the Carr injection. Six hours after Carr injection, the malondialdehyde (MDA) level and myeloperoxidase (MPO), superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) activities in inflamed paw tissues were determined. The levels of nitric oxide (NO) and prostaglandin E2 (PGE2) in serum were measured. The expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and NF-κB were detected by western blot. In addition, the extent of phosphorylation of extracellular signal-regulated protein kinase (ERK), p38 and c-Jun NH2-terminal kinase (JNK) was analyzed by western blot. The results showed that ginsenoside-Rd significantly attenuated MPO activity and MDA level, increased the activities of SOD, GPx and CAT, lowered the levels of NO and PGE2, down-regulated the expressions of iNOS, COX-2 and NF-κB, and suppressed the phosphorylation of ERK and JNK. Taken together, the possible mechanisms of anti-inflammatory activity of ginsenoside-Rd were: it could reduce the inflammatory cell infiltration into inflammatory sites, inhibit the tissue lipid peroxidation, increase the antioxidant enzyme activities, and suppress the proinflammatory enzyme expressions through the downregulation of NF-κB activation via suppression of ERK and JNK phosphorylation.