Six undescribed derivatives of stilbene isolated from Lindera reflexa Hemsl. and their anti-tumor and anti-inflammatory activities.

Six undescribed stilbene derivatives Reflexanbene DH (1-4, 6) and Reflexanbene J (5), as well as one known stilbene 3,5-dimethoxystilbene (7), were isolated from the dried roots of Lindera reflexa Hemsl. Their structures and absolute configurations were elucidated using spectroscopy and electronic circular dichroism (ECD) analysis. In cytotoxic assays, moderately inhibitory activities of Reflexanbene F (3) against MGC80-3 and A549 cell lines were observed, with IC50 values of 15.42 and 5.09 µM, respectively. The IC50 value of Reflexanbene E (2) on A549 cell lines was 19.78 µM. The isolated compounds were also tested for their inhibitory effect against LPS-induced NO and IL-6 production in RAW 264.7 cells. In particular, Reflexanbene J (5) and Reflexanbene H (6) showed significant inhibition of NO production in LPS-stimulated macrophage RAW 264.7 cells at the concentration of 20 µM. Furthermore, the expression of IL-6 protein in the LPS-induced RAW 264.7 cells can also be significantly inhibited by different concentrations (5, 10 and 20 µM, p < 0.05 or p < 0.01) of compounds 1-7.

Gastroprotective effect of an active ingredients group of Lindera reflexa Hemsl. On Ethanol-Induced gastric ulcers in Rats: Involvement of VEGFR2/ERK and TLR-2/Myd88 signaling pathway.

Lindera reflexa Hemsl. (LR) has been used for the treatment of gastrointestinal disorders. The present study was carried out to investigate the gastroprotective effect of an active ingredients group of Lindera reflexa Hemsl. (LRG) on ethanol-induced gastric ulcer in rats and its possible mechanisms. The ulcer area was measured, and samples of gastric tissue were taken for histochemical, pathological, and biochemical analyses. Pretreatment with LRG protected the gastric mucosa as seen by reduction the GUI and gastric juice volume, regulated gastric acid secretion. LRG counteracted the ethanol-induced oxidative stress by increasing the levels of depleted SOD and CAT as well as significantly attenuating the lipid peroxidation by reducing the levels of MDA and MPO. LRG also reduced release of inflammatory mediator TNF-α, increased the content of PGE2 and inhibited MTL secretion. Immunofluorescence and Western blot analyses confirmed that the co-localization of TLR-2 and MyD88 protein in the gastric mucosa of LRG-treated rats was significantly lower than that of rats with gastric ulcers. Furthermore, LRG also modulated the expression of Ki-67 antigens. LRG markedly increased the expression of phosphorylated form of extracellular signal-regulated kinaseVEGFR2, ERK1/2, AKT and p38, thereby protecting the gastric mucosa. These findings indicated that the gastroprotective effect of LRG is attributable to its antioxidant, anti-inflammatory, and antisecretory properties. In addition, LRG can ameliorate ethanol-induced gastric ulcers in rats by regulating the VEGFR2/ERK and TLR-2/MyD88 signaling pathways.

Chemical constituents of the antiulcer purified fractions of Lindera reflexa Hemsl. and its quantitative analysis.

The root of Lindera reflexa Hemsl. (LR) is a folk Chinses herbal medicine that has been used to treat gastritis and peptic ulcers. In this study, three new stilbenes (1-3) and two known flavonoids (4 and 5) were isolated from the antiulcer purified fractions of LR. The chemical structures of the isolated compounds were characterized comprehensively based on the basis of extensive spectroscopic data. Absolute configurations of compounds 1, 2, and 3 were determined by ECD calculations. The cytotoxic activities of compounds 1-5 were evaluated by MTT assay. Compound 4 showed the strongest inhibitory effect on the proliferation of tumor cells lines MGC803 and SMMC-7721, with IC50 values of 2.65 and 4.13 µM, respectively. The quantitative analysis of 12 compounds of the antiulcer purified fractions of LR were carried out by using the reversed-phase high-performance liquid chromatography (HPLC) method. Within the test range, all calibration curves showed good linearity (R2 > 0.9993). The LOD, LOQ, specificity, precision, and accuracy of the method were verified. Therefore, the present study may provide a valuable method for quality control the antiulcer purified fractions of LR.