Panaxatriol saponin ameliorated liver injury by acetaminophen via restoring thioredoxin-1 and pro-caspase-12

Panaxatriol Saponins Promote M2 Polarization of BV2 Cells to Reduce Inflammation and Apoptosis after Glucose/Oxygen Deprivation by Activating STAT3

Panaxatriol saponins (PTS) have a long history in the treatment of stroke. In our previous experiments, PTS has been found to alleviate ischemic stroke and play a role through regulating the inflammatory response, but the specific mechanism of its regulation is still unclear. Cell viability was determined by MTT assay. Expressions of polarization-related proteins CD16, CD68, ARG1 and CD206; inflammatory factors interleukin-1β (IL-1β); inducible nitric oxide synthase (iNOS); monocyte chemotactic protein 1(MCP-1) and cyclooxygenase-2 (COX-2); apoptosis-related proteins pro-caspase3; bax; caspase3 and bcl-2; and STAT3 and p-STAT3 were detected by western blot. ELISA was used to detect the expression of inflammatory-related factors in cells. The apoptosis rate was detected by flow cytometry. We found that the survival rate of oxygen sugar deprivation/reoxygenation (OGD/R) cells increased obviously after PTS treatment in a dose-dependent manner. PTS can promote M2 polarization of microglial cells (BV2) and inhibit inflammatory response of OGD/R cells, accompanied by decreased expression of inflammatory factors IL-1β, iNOS, MCP-1, and COX-2. PTS inhibited apoptosis of OGD/R cells and was accompanied by decreased expression of apoptotic proteins Bax and caspase3 and increased expression of Bcl-2. We also found that PTS activated STAT3 levels in BV2 cells. After the addition of STAT3 inhibitor Stattic, it was found that PTS could promote M2 polarization of BV2 cells by activating the STAT3 pathway, thus inhibiting cell inflammation and apoptosis. PTS promoted M2 polarization in microglia cells by activating the STAT3 pathway, thereby reducing cell inflammation and apoptosis after glucose/oxygen deprivation.

Caspase-Mediated Anti-Apoptotic Effect of Ginsenoside Rg5, a Main Rare Ginsenoside, on Acetaminophen-Induced Hepatotoxicity in Mice

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.