Small inhibitor of Bcl-2, HA14-1, selectively enhanced the apoptotic effect of cisplatin by modulating Bcl-2 family members in MDA-MB-231 breast cancer cells

Inhibition or downregulation of Bcl-2 represents a new therapeutic approach to by-pass chemoresistance in cancer cells. Therefore, we explored the potential of this approach in breast cancer cells. Cisplatin and paclitaxel induced apoptosis in a dose-dependent manner in MCF-7 (drug-sensitive) and MDA-MB-231 (drug-insensitive) cells. Furthermore, when we transiently silenced Bcl-2, both cisplatin and paclitaxel induced apoptosis more than parental cells. Dose dependent induction of apoptosis by drugs was enhanced by the pre-treatment of these cells with HA14-1, a Bcl-2 inhibitor. Although the effect of cisplatin was significant on both cell lines, the effect of paclitaxel was much less potent only in MDA-MB-231 cells. To further understand the distinct role of drugs in MDA-MB-231 cells pretreated with HA14-1, caspases and Bcl-2 family proteins were studied. The apoptotic effect of cisplatin with or without HA14-1 pre-treatment is shown to be caspase-dependent. Among pro-apoptotic Bcl-2 proteins, Bax and Puma were found to be up-regulated whereas Bcl-2 and Bcl-x(L) were down-regulated when cells were pretreated with HA14-1 followed by paclitaxel or cisplatin. Enforced Bcl-2 expression in MDA-MB-231 cells abrogated the sensitizing effect of HA14-1 in cisplatin induced apoptosis. These results suggest that the potentiating effect of HA14-1 is drug and cell type specific and may not only depend on the inhibition of Bcl-2. Importantly, alteration of other pro-apoptotic or anti-apoptotic Bcl-2 family members may dictate the apoptotic response when HA14-1 is combined with chemotherapeutic drugs

Isolation of anti-inflammatory compounds from Sambucus ebulus leaves through in vitro activity-guided fractionation

63rd International Congress and Annual Meeting of the Society-for-Medicinal-Plant-and-Natural-Product-Research (GA) -- August 23-27, 2015 -- Budapest, HungaryWOS: 000367558100418The in vitro anti-inflammatory effects of subextracts (n-hexane, chloroform, ethyl acetate, n-butanol, remaining water) of the methanol extract of the leaves of Sambucus ebulus L. (Adoxaceae) were investigated for their inhibitory activities on the activation of Nuclear factor kappa B (NF-κB) on lipopolysaccharide induced Raw 264.7 cells. The n-hexane, chloroform and ethyl acetate subextracts inhibited NF-κB activation at 50, 100 and 100 µg/mL concentrations, respectively. Two flavonoid mixtures [quercetin-3-O-β-D- glucopyranoside, quercetin-3-O-β-D-galactopyranoside], two flavonoids [isorhamnetin-3-O- β-D-glucopyranoside (1), isorhamnetin-3-O-rutinoside (2)] were isolated from ethyl acetate subextract. 10-O-acetylpatrinoside (3) and a new iridoid [Sambulin B (4)] was obtained from chloroform and n-hexane subextracts respectively. Structures were elucidated by NMR and MS. The compounds exerted inhibitions between 30 – 80% on NF-κB. Flavonoids were applied to cells at 25, 50, 75 and 100 µg/mL concentrations. Sambulin B was applied at 6,25, 12,5, 25 and Sambulin A applied at 12,5, 25 and 50 µg/mL concentrations