Sodium arsenite (NaAsO₂) has been recognized as a worldwide health concern. Hydrangea macrophylla (HM) is used as traditional Chinese medicine possessing antioxidant activities. The study was performed to investigate the therapeutic role and underlying molecular mechanism of HM on NaAsO₂-induced toxicity in human liver cancer (HepG2) cells and liver in mice. The hepatoprotective role of HM in HepG2 cells was assessed by using 3-(4,5-dimethylthiazol-2-Yl)-2,5-diphenyltetrazolium bromide (MTT), reactive oxygen species (ROS), and lactate dehydrogenase (LDH) assays. Histopathology, lipid peroxidation, serum biochemistry, quantitative real-time polymerase chain reaction (qPCR) and Western blot analyses were performed to determine the protective role of HM against NaAsO₂ intoxication in liver tissue. In this study, we found that co-treatment with HM significantly attenuated the NaAsO₂-induced cell viability loss, intracellular ROS, and LDH release in HepG2 cells in a dose-dependent manner. Hepatic histopathology, lipid peroxidation, and the serum biochemical parameters alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were notably improved by HM. HM effectively downregulated the both gene and protein expression level of the mitogen-activated protein kinase (MAPK) cascade. Moreover, HM well-regulated the Bcl-2-associated X protein (Bax)/B-cell lymphoma-2 (Bcl-2) ratio, remarkably suppressed the release of cytochrome c, and blocked the expression of the post-apoptotic transcription factor caspase-3. Therefore, our study provides new insights into the hepatoprotective role of HM through its reduction in apoptosis, which likely involves in the modulation of MAPK/caspase-3 signaling pathways.

Stress can lead to inflammation, accelerated aging, and some chronic diseases condition. Mentha arvensis (MA) is a traditional medicine having antioxidant and anti-inflammatory activities. The present study investigated the anti-stress role of MA and fermented MA (FMA) extract in immobilized rats. We studied the lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 cells and rats were immobilized for 2 h per day for 14 days using a restraining cage. MA (100 mg/kg) and FMA (100 mg/kg) were orally administered to rats 1 h prior to immobilization. Using high-performance liquid chromatography (HPLC) analysis, we determined the rosmarinic acid content of MA and FMA. The generation of malondialdehyde (MDA) and nitric oxide (NO) in RAW 246.7 cells were suppressed by both MA and FMA. In rats, MA and FMA notably improved the body weight, daily food intake, and duodenum histology. MDA and NO level were gradually decreased by MA and FMA treatment. MA and FMA significantly controlled the stress-related hormones by decreasing corticosterone and β-endorphin and increasing serotonin level. Moreover, protein expression levels of mitogen activated protein kinases (MAPK) and cyclooxygenase-2 (COX-2) were markedly downregulated by MA and FMA. Taken together, MA and FMA could ameliorate immobilized-stress by reducing oxidative stress, regulating stress-related hormones, and MAPK/COX-2 signaling pathways in rats. Particularly, FMA has shown greater anti-stress activities than MA.