Study on neoflavonoids from heartwood of Dalbergia latifolia / 中国中药杂志

Dalbergiae Odoriferae Lignum is derived from heartwood of Dalbergia odorifera,which is national Ⅱ level of rare and endangered protective plants in China. Its resources are scarce and its price is high. In order to find substitutes of D. odorifera,the chemical constituents of 70% ethanol extract of heartwood of D. catifolia were systematically studied by using silica gel,Sephadex LH-20 column chromatography,and semi-preparative HPLC. Sixteen neoflavanoids were isolated and identified as eight dalbergiphenols( 1-8),three dalbergiones( 9-11),two dalbergins( 12,13),two benzophenones( 14,15) and one other type neoflavanoids( 16) based on spectroscopic data analyses and/or comparing the spectroscopic data with those in literature. Among them,compounds 3,7 and 11 were isolated from the genus Dalbergia for the first time,and compounds 2,4-6,8,14 and 15 were isolated from the D. latifolia for the first time. Ten neoflavonoids were both discovered from D. latifolia and D. odorifera.

Effect of neoflavonoid latifolin isolated from Dalbergia odorifera on acute myocardial ischemia in rats and its mechanism of Nrf2 signaling pathway / 中国中药杂志

The present study was designed to evaluate the cardioprotective effect of latifolin on pituitrin(Pit) or isoproterenol(ISO)-induced myocardial injury in rats, and further investigate its underlying mechanisms. Rats were administrated sublingually with pituitrin or subcutaneously with isoproterenol to induce acute myocardial ischemia in rats, and lead II electrocardiograph was recorded. In rats with isoproterenol, ELISA assay or colorimetric method was used to detect the content or activity of myocardial injury markers in serum, and the SOD activity and MDA content in myocardium were detected by colorimetric assay; histopathological examination was conducted by HE staining; the frozen section of myocardial tissues was used for DCFH-DA fluorescent staining to detect the content of ROS in myocardium; Western blot was used to detect the protein expression levels of Nrf2, Keap1, HO-1 and NQO1 in myocardium. Results showed that latifolin significantly inhibited ST-segment changes induced by pituitrin or isoproterenol, and increased heart rate. Further mechanism study showed that latifolin reduced cardiac troponin I(cTnI) level, aspartate transaminase(AST) and lactate dehydrogenase(LDH) activities in serum, increased myocardial superoxide dismutase(SOD) activity and reduced myocardial malondialdehyde(MDA) level, and protected myocardium with less necrosis, infiltration of inflammatory cells and fracture of myocardial fibers. Furthermore, latifolin obviously reduced ROS level in myocardium, inhibited the expression of Kelch-like ECH-associated protein-1(Keap1), increased the nuclear translocation of nuclear factor erythroid 2 related factor 2(Nrf2), and promoted the expression of Heme oxygenase-1(HO-1) and NAD(P)H quinone oxidoreductase-1 (NQO1) in myocardial tissues. Our data suggest that latifolin has a potent protective effect against pituitrin or isoproterenol-induced myocardial injury, which may be related to inhibition of oxidative stress by activating Nrf2 signaling pathway.