Gastroprotective activity of (E)-ethyl-12-cyclohexyl-4,5-dihydroxydodec-2-enoate, a compound isolated from Heliotropium indicum: role of nitric oxide, prostaglandins, and sulfhydryls in its mechanism of action.

CONTEXT: The gastroprotective effect of Heliotropium indicum L. (Boraginaceae), a plant traditionally used in Mexico to treat gastric ulcers, has been previously reported. However, no active compound was identified. OBJECTIVE: The current contribution aimed to isolate, through a bioassay-guided study, at least one compound from H. indicum with considerable gastroprotective activity, examine its effect on ethanol-induced gastric lesions in mice, and explore possible mechanisms of action. MATERIALS AND METHODS: Three extracts (hexane, dichloromethane, and methanol) were obtained from H. indicum leaves. Their 30 and 100 mg/kg doses were assessed on ethanol-induced gastric lesions in male CD1 mice. Since the dichloromethane extract was the most active, successive chromatographies were carried out leading to the identification of the most active compound. This compound (at 3-100 mg/kg) was compared to carbenoxolone (at 10-100 mg/kg) in biological evaluations in mice. Pre-treatments with indomethacin (10 mg/kg, s.c.), L-NAME (70 mg/kg, i.p.), and NEM (10 mg/kg, s.c.) were performed independently to determine the participation of prostaglandins, nitric oxide, and/or sulfhydryl groups, respectively, in the mechanism of action of the compound. RESULTS: (E)-Ethyl-12-cyclohexyl-4,5-dihydroxydodec-2-enoate, a compound isolated from H. indicum, afforded dose-dependent gastroprotective activity. The maximum effect was observed at 100 mg/kg (90.13 ± 3.08%), with an ED50 of 5.92 ± 2.48 mg/kg. Gastroprotection was not modified by pre-treatment with indomethacin, L-NAME, or NEM. CONCLUSIONS: (E)-Ethyl-12-cyclohexyl-4,5-dihydroxydodec-2-enoate, isolated from H. indicum, was found to produce a substantial gastroprotective effect. Prostaglandins, nitric oxide, and non-protein sulfhydryl groups are not involved in its mechanism of action.

Apoptosis Induced by (-)-Epicatechin in Human Breast Cancer Cells is Mediated by Reactive Oxygen Species.

(-)-Epicatechin is a phenolic compound with antioxidant activity that is present in natural food and drinks, such as cocoa and red wine. Evidence suggests that (-)-epicatechin exhibits anticancer activity; however, its mechanism of action is poorly understood. Here, we investigated the anticancer effects of (-)-epicatechin and its mechanism of action in breast cancer cells. We assessed the anticancer activity by cell proliferation assays, apoptosis by DNA fragmentation and flow cytometry. The expression of proteins associated with apoptosis was analyzed by the human apoptosis array. MitoSOXTM Red and biomarkers of oxidative damage were used to measure the effect of (-)-epicatechin on mitochondrial reactive oxygen species (ROS) and cellular damage, respectively. (-)-Epicatechin treatment caused a decreasing in the viability of MDA-MB-231 and MCF-7 cells. This cell death was associated with DNA fragmentation and an apoptotic proteomic profile. Further, (-)-epicatechin in MDA-MB-231 cells upregulated death receptor (DR4/DR5), increased the ROS production, and modulated pro-apoptotic proteins. In MCF-7 cells, (-)-epicatechin did not involve death receptor; however, an increase in ROS and the upregulation of pro-apoptotic proteins (Bad and Bax) were observed. These changes were associated with the apoptosis activation through the intrinsic pathway. In conclusion, this study shows that (-)-epicatechin has anticancer activity in breast cancer cells and provides novel insight into the molecular mechanism of (-)-epicatechin to induce apoptosis.

Lecithin-chitosan-TPGS nanoparticles as nanocarriers of (-)-epicatechin enhanced its anticancer activity in breast cancer cells.

Natural compounds such as (-)-epicatechin show a variety of biological properties including anticancer activity. Nonetheless, (-)-epicatechin's therapeutic application is limited due to its low water solubility and sensitivity to oxygen and light. Additionally, previous studies have reported that the encapsulation of flavonoids in nanoparticles might generate stable deliverable forms, which improves the availability and solubility of the bioactive compounds. The aims of this study were to generate (-)-epicatechin-loaded lecithin-chitosan nanoparticles (EC-LCT-NPs) by molecular self-assembly and to assess their cytotoxic potential against breast cancer cells. Various parameters were measured to characterize the EC-LCT-NPs including size, polydispersity index (PdI), zeta potential, morphology and entrapment efficiency. The results showed that the mean particle size of the EC-CLT-NPs was 159 ± 2.23 nm (PdI, 0.189), and the loading and entrapment efficiencies of (-)-epicatechin were 3.42 ± 0.85% and 56.1 ± 3.9%, respectively. The cytotoxic effect of the EC-CLT-NPs was greater than that of free (-)-epicatechin on breast cancer cell lines (MCF-7, MDA-MB-231, MDA-MB-436 and SK-Br3). Indeed, EC-LCT-NPs showed an IC50 that was four-fold lower (85 µM) than free (-)-epicatechin (350 µM) and showed selectivity to cancerous cells. This study demonstrated that encapsulating (-)-epicatechin into lecithin-chitosan nanoparticles opens new options for breast cancer treatment.