ABSTRACT
Aim To evaluate the antioxidant effect of tetrahydrocurcuminoids(THC)and its effect on melanin production,and to explore its mechanism of inhibiting melanin production.Methods Human immortalized epidermal cell(HaCaT cell)model was used to evaluate the antioxidant activity.The activities of superoxide dismutase(SOD),glutathione peroxidase(GSH-PX)and lactate dehydrogenase(LDH)in HaCaT cells were detected by ELISA.Total antioxidant activity of THC was detected by DPPH and T-AOC methods.Mouse melanoma cell model B16F10 was used on the experiment of inhibition of melanin production.The effect of THC on the proliferation activity of mouse B16F10 cells was determined by CCK8 assay.The content of melanin and tyrosinase activity in B16F10 cells were determined by NaOH lysis assay and dopamine oxidation assay,respectively.The effect of THC on B16F10 cell migration was investigated by scratch assay,and the expression of melanin production-related protein MITF was determined by Western blot.Results THC could increase the levels of SOD and GSH-Px in HaCaT cells,reduce the content of LDH,and increase the scavenging rate of DPPH free radical and the reducing ability of Fe3+.THC could inhibit the proliferation and migration of mouse B16F10 cells,reduce the content of melanin in B16F10 cells,reduce the activity of tyrosinase,and inhibit the expression of MITF.Conclusions Tetrahydrocurcumin has antioxidant effect and can inhibit melanin production,and its mechanism is related to inhibiting MITF expression.
ABSTRACT
Aim To evaluate the effect of E-se extract on insulin resistance in KK-Ay mice with spontaneous type 2 diabetes anrl explore its mechanism.Methods Ten C57/6J mice were assigned to a normal control group.Fifty KK-Ay model mice were randomly divided into model group, positive control group ( rosiglita- zone, 2.67 mg • kg 1 ), and low- ( 0.75 g • kg 1 ) , medium- ( 1.50 g • kg 1 ) , and high-dose ( 3.00 g • kg ') E-se groups, with 10 mice in each group.All mice were measured for body weight and fasting blood glucose weekly, insulin tolerance on the 32nd day, and insulin after the last administration on the 35th day, and the insulin resistance/sensitivity indexes were calculated.The pancreas was stained by hematoxylin- eosin ( HE ).Islet cell apoptosis was detected by TUNEL staining.Glucagon-like peptide-1 ( GLP-1 ) was detected by immunohistochemistry.Results j j Compared with the model group, the E-se groups showed reduced body weight, fasting blood glucose, serum insulin concentration, and insulin resistance in¬dex, elevated insulin sensitivity index, decreased le¬sion grading score of pancreatic tissues and apoptosis percentage of islet cells, and increased content of GLP- 1 protein in pancreatic tissues.Conclusions E-se ex¬tract can improve insulin resistance by reducing serum insulin level, inhibiting islet cell apoptosis, and in¬creasing the sensitivity of the body to insulin.
ABSTRACT
The aim of this paper was to observe the anti-inflammatory action and mechanism of Lonicerae Japonicae Flos extract and Lonicerae Flos extract in xylene-induced ear swelling experiment and lipopolysaccharide(LPS)-induced RAW264.7 cell inflammatory model. In vivo, xylene-induced mouse auricle swelling model was used to detect the auricle swelling degree and swelling inhibition rate of Lonicerae Japonicae Flos extract and Lonicerae Flos extract; the pathological changes of mice auricle were observed by hematoxylin eosin(HE) staining. In vitro, RAW264.7 inflammatory cell model was induced by LPS, where the cytotoxic effects of Lonicerae Japonicae Flos extract and Lonicerae Flos extract on RAW264.7 cells were detected by CCK-8 method; Griess method was used to detect the effect of Lonicerae Japonicae Flos extract and Lonicerae Flos extract on nitric oxide(NO) production, and ELISA method was used to detect the content of inflammatory factors interleukin-6(IL-6), IL-1β, and tumor necrosis factor-α(TNF-α). At last, Western blot was used to detect the protein changes of cyclooxygenase 1(COX1), COX2 and inducible nitric oxide synthetase(iNOS) for RAW264.7 cells. The results showed that both Lonicerae Japonicae Flos extract and Lonicerae Flos extract could significantly inhibit the degree of auricle swelling caused by xylene in mice and the inhibition rate was positively correlated with the drug dose. Furthermore, both of them could reduce the infiltration of lymphocytes and neutrophils in mouse ear tissues. For in vitro experiments, both Lonicerae Japonicae Flos extract and Lonicerae Flos extract inhibited NO secretion in RAW264.7 cells, down-regulated the release of IL-1β, IL-6 and TNF-α, and down-regulated iNOS protein and COX2, NF-κB p65 protein content. In conclusion, both Lonicerae Japonicae Flos extract and Lonicerae Flos extract have good anti-inflammatory effect, and the mechanism may be related with the inhibition of NF-κB signaling pathway.