Astragaloside IV inhibits protein tyrosine phosphatase 1B and improves insulin resistance in insulin-resistant HepG2 cells and triglyceride accumulation in oleic acid (OA)-treated HepG2 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Astragaloside IV (AST IV) is the active component of Astragalus membranaceus (Fisch.) Bunge, which regulates lipid and carbohydrate metabolism and improves insulin resistance. In this study, we investigated the effects of AST IV on insulin resistant cells and a non-alcoholic fatty liver disease (NAFLD) model induced by high-concentration insulin or oleic acid (OA) in HepG2 cells, as well as the associated regulatory markers. METHODS: First, the target of AST IV was predicted via pharmacophore model matching and molecular docking. Then, enzyme kinetics experiments were conducted in vitro to determine the effect of AST IV on the target protein. Next, AST IV's toxicity was tested on HepG2 cells in vitro, through an insulin resistance model and an NAFLD model, by high-concentration insulin or OA, respectively. To explore the effects of AST IV on insulin resistance and lipid metabolism, we detected the related indexes of glucose and lipid metabolism through commercially available kits. Relevant proteins were also detected by Western blot to provide future direction for study. RESULTS: Our preliminary results of pharmacophore model matching and molecular docking suggested that AST IV and protein tyrosine phosphatase 1B (PTP1B) can be well-combined through hydrogen bonding. Further, the enzyme kinetics experiment showed that AST IV was an effective and specific inhibitor to PTP1B. We found that the protein level of PTP1B in HepG2 cells was significantly increased after treating with high-concentration insulin or OA. Additionally, the intervention of AST IV significantly increased glucose consumption in an insulin resistance model and reduced the content of triglyceride (TG), total cholesterol (TC), and free fatty acid (FFA) in the NAFLD model. Moreover, the 2-N-(7-nitrobenze-2-oxa-1, 3 diazol-4-yl) (2-NBDG) uptake rate in the NAFLD model was also greatly improved. These results validated the effects of AST IV on improving insulin resistance and lipid accumulation. Furthermore, Western blot results illustrated that AST IV suppressed PTP1B and increased levels of phosphorylated insulin receptor (p-IR) and phosphorylated insulin receptor substrate-1 (p-IRS-1) in insulin-resistant HepG2 cells, while also decreasing protein levels of PTP1B and sterol element regulatory binding protein-1c (SREBP-1c) in the NAFLD model. CONCLUSION: This study demonstrated that AST IV inhibited PTP1B and effectively improved insulin resistance in insulin-resistant HepG2 cells and triglyceride accumulation in OA-treated HepG2 cells.

[Effect of acupoint catgut embedding on levels of PG-related factors and NF-κB proteins in ute-rine tissues of rats with primary dysmenorrhea].

OBJECTIVE: To observe the effect of acupoint catgut embedding on levels of prostaglandin F2α(PGF2α), cyclooxygenase-2(COX-2) and nuclear factor kappa B(NF-κB) in the uteruses of rats with primary dysmenorrhea (PD), so as to explore its mechanisms underlying improvement of PD. METHODS: Forty female SD rats were randomly divided into normal, model, acupoint catgut embedment and medication groups, with 10 rats in each group. The PD model was established by subcutaneous injection of estradiol benzoate (0.5 mg on the 1st day, and 0.2 mg thereafter) once daily for 10 days, followed by i．p. of oxytocin 2 U(0.5 mg•5 U－1•mL－1) on the 11th day. Catgut embedment was applied to "Guanyuan"(CV4) and "Sanyinjiao"(SP6) on day 1 and 5 while modeling, and rats of the medication group received gavage of ibuprofen (1.25 mg/mL, 0.8 mL/rat) once daily for 10 d. The level of PGF2αin the uterus tissuewas assayed by ELISA, and the expression levels of uterine COX-2, phospho (p)-NF-κB p65, NF-κB p65 proteins were detected by Western blot. RESULTS: Compared with the normal group, the levels of PGF2α， COX-2, p-NF-κB p65 and NF-κB p65 in the uterine tissues were significantly increased in the model group (P<0.05). Compared with the model group, the levels of PGF2α and COX-2 in both catgut embedment and medication groups as well as p-NF-κB p65 in the catgut embedment group were significantly decreased (P<0.05). Compared with the medication group, the level of p-NF-κB 65 in the catgut embedment group was significantly decreased (P<0.05). CONCLUSION: The analgesic effect of acupoint catgut embedding may be related to its effects in down-regulating the expression of p-NF-κB and the levels of COX-2 and PGF2αin uteruses of PD rats.

Cornel Iridoid Glycoside Improves Locomotor Impairment and Decreases Spinal Cord Damage in Rats.

Purpose. This study was to investigate the effects of cornel iridoid glycoside (CIG) on spinal cord injury (SCI) in rats. Methods. The thoracic cord (at T9) of rats was injured by clip compression for 30 sec. Locomotor function was assessed using the Basso, Beattie, and Bresnahan (BBB) rating scale. Neuroanatomic stereological parameters as well as Nogo-A, p75 neurotrophin receptor (p75NTR), and ROCKII expression were measured by histological processing, immunohistochemistry, and stereological analyses. The axons passing through the lesion site were detected by BDA tracing. Results. Intragastric administration of CIG (60 and 180 mg/kg) improved the locomotor impairment at 10, 17, 24, and 31 days post-injury (dpi) compared with untreated SCI model rats. CIG treatment decreased the volume of the lesion epicenter (LEp) and increased the volume of spared tissue and the number of surviving neurons in the injured spinal cord at 31 dpi. CIG promoted the growth of BDA-positive axons and their passage through the lesion site and decreased the expression of Nogo-A, p75NTR, and ROCKII both in and around the LEp. Conclusion. CIG improved the locomotor impairment, decreased tissue damage, and downregulated the myelin-associated inhibition signaling pathway in SCI rats. The results suggest that CIG may be beneficial for SCI therapy.