Glycosylated piericidins from an endophytic streptomyces with cytotoxicity and antimicrobial activity.

Two new glycosylated piericidins, glucopiericidinol A3 (1) and 7-demethyl-glucopiericidin A (2), along with four known analogs were isolated from the culture broth of Streptomyces sp. KIB-H1083. The chemical structures of new compounds were elucidated by spectroscopic analyses. Their cytotoxicity on HL-60, SMMC-772, A-549, MCF-7, and SW480 cell lines, as well as antimicrobial activities was evaluated. The results showed that glucopiericidin A (4) has potent cytotoxicity against HL-60, SMMC-772, A-549, and MCF-7 cell lines with IC50 values of 0.34, 0.65, 0.60, and 0.50 µM, respectively. For the antimicrobial activity, piericidin A (6) showed most powerful inhibitory activities against Xanthomonas oryzae pv. oryzicola, and Penicillium decumbens.

Moderate intensity treadmill exercise alters food preference via dopaminergic plasticity of ventral tegmental area-nucleus accumbens in obese mice.

Obesity has been associated with the excessive intake of palatable food as well as physical inactivity. To investigate the neurobiological mechanism underlying the exercised-induced prevention and treatment of obesity, the present study examined the effect of treadmill exercise on the preference for palatable food in mice. Levels of tyrosine hydroxylase (TH) in the ventral tegmental area-nucleus accumbens system were also analysed, as well as levels of dopamine, dopamine transporter, and D2 receptors in the nucleus accumbens. Forty C57BL/6J mice were randomly divided into a control group (CG, n=10) and a high-fat diet group (HG, N=30). Mice of the HG group were fed a high-fat diet for 12 weeks in order to induce a model of obesity, following which the obese mice were randomly divided into an obese control group (OG, n=11) and an obese+exercise group (OEG, n=12). OEG mice received 8 weeks of treadmill exercise intervention. Our results indicate that, relative to animals in the OG group, OEG mice exhibited significant decreases in the preference for high-fat diets and insulin resistance, along with increases in the preference for sucrose and milk, TH and D2 receptor expression, and levels of dopamine in the ventral tegmental area-nucleus accumbens system. These results suggest that moderate-intensity treadmill exercise can alter food preference in obese mice, which may be mediated by dopaminergic plasticity of the ventral tegmental area-nucleus accumbens and enhanced insulin sensitivity.