[6-Gingerol ameliorates adipose tissue insulin resistance in aging rats].

This study investigated the effects and mechanisms of 6-gingerol on adipose tissue insulin resistance in naturally aging rats with glycolipid metabolism disorders. Twenty-seven aging male SD rats were randomly divided into a model group(aged, n=9) and two groups treated with 6-gingerol at 0.05 mg·kg~(-1)(G-L, n=9) and 0.2 mg·kg~(-1)(G-H, n=9). Six young rats were randomly assigned to a normal control group(NC). Rats were treated for seven weeks by gavage. Non-esterified fatty acid(NEFA) and insulin content was determined by enzyme-linked immunosorbent assay(ELISA), and adipose tissue insulin resistance index(Adipo-IR) was calculated. HE staining was used to observe the size of adipocytes in epididymal white adipose tissue(eWAT). The gene and protein expression levels of adiponectin receptor 1(AdipoR1), AMP-activated protein kinase α(AMPKα), phosphorylated AMPK(p-AMPKα~(Thr172)), peroxisome proliferator-activated receptor-γ coactivator-1α(PGC-1α), phosphatidylinositol 3-kinase(PI3 K), protein kinase B(Akt), phosphorylated Akt(p-Akt~(Ser473)), tumor necrosis factor-α(TNF-α), c-Jun N-terminal kinase 1/2(JNK1/2), phosphorylated JNK1/2(p-JNK~(Thr183/Tyr185)), interleukin-1ß(IL-1ß), and interleukin-6(IL-6) in adiponectin(APN), insulin, and inflammatory factor signaling pathways were detected by Western blot and real-time RCR, respectively. The results showed that 6-gingerol at a high dose could significantly decrease the fasting plasma content of NEFA and insulin and reduce Adipo-IR. Additionally, 6-gingerol at a high dose significantly increased the protein and mRNA expression of APN, AdipoR1, PGC-1α, and PI3 K in eWAT, elevated the relative expression of p-AMPK~(Thr172) and p-Akt~(Ser 473), reduced the protein and mRNA expression of TNF-α, IL-1, and IL-6 in eWAT, and decreased the relative expression of p-JNK1 and p-JNK2. This study reveals that 6-gingerol can improve insulin sensitivity of adipose tissues in aging rats with glycolipid metabolism disorders, and this effect is presumedly achieved by enhancing the PI3 K/Akt signaling pathway, inhibiting adipose tissue inflammation, increasing APN synthesis, enhancing AdipoR1 expression, and activating its downstream AMPK/PGC-1α signaling pathway.

Astragaloside IV Blunts Epithelial-Mesenchymal Transition and G2/M Arrest to Alleviate Renal Fibrosis via Regulating ALDH2-Mediated Autophagy.

Previous studies show that astragaloside IV (ASIV) has anti-renal fibrosis effects. However, its mechanism remains elusive. In this study, we investigated the anti-fibrosis mechanisms of ASIV on chronic kidney disease (CKD) in vivo and in vitro. A CKD model was induced in rats with adenine (200 mg/kg/d, i.g.), and an in vitro renal fibrosis model was induced in human kidney-2 (HK-2) cells treated with TGF-ß1. We revealed that ASIV significantly alleviated renal fibrosis by suppressing the expressions of epithelial-mesenchymal transition (EMT)-related proteins, including fibronectin, vimentin, and alpha-smooth muscle actin (α-SMA), and G2/M arrest-related proteins, including phosphorylated p53 (p-p53), p21, phosphorylated histone H3 (p-H3), and Ki67 in both of the in vivo and in vitro models. Transcriptomic analysis and subsequent validation showed that ASIV rescued ALDH2 expression and inhibited AKT/mTOR-mediated autophagy. Furthermore, in ALDH2-knockdown HK-2 cells, ASIV failed to inhibit AKT/mTOR-mediated autophagy and could not blunt EMT and G2/M arrest. In addition, we further demonstrated that rapamycin, an autophagy inducer, reversed the treatment of ASIV by promoting autophagy in TGF-ß1-treated HK-2 cells. A dual-luciferase report assay indicated that ASIV enhanced the transcriptional activity of the ALDH2 promoter. In addition, a further molecular docking analysis showed the potential interaction of ALDH2 and ASIV. Collectively, our data indicate that ALDH2-mediated autophagy may be a novel target in treating renal fibrosis in CKD models, and ASIV may be an effective targeted drug for ALDH2, which illuminate a new insight into the treatment of renal fibrosis and provide new evidence of pharmacology to elucidate the anti-fibrosis mechanism of ASIV in treating renal fibrosis.