Identification and Quantification of Quercetin, A Major Constituent ofArtocarpus altilisby Targeting Related Genes of Apoptosis and Cell Cycle: In Vitro Cytotoxic Activity Against Human Lung Carcinoma Cell Lines

Antibacterial and antioxidant activities in various parts of Artocarpus lacucha Buch. Ham. ethanolic extract

Artocarpus lacucha is an endemic plant to North Sumatera, Indonesia. This plant has pharmacological activities, including acting as an antioxidant and antibacterial. The aim of the present study was to analyze the antibacterial and antioxidant activities, and determine the flavonoid compounds from four parts of A. lachuca, namely leaves, barks, twigs and fruits. Antioxidant activity was investigated using the 2,2-diphenyl 1-picrylhydrazyl (DPPH) and cupric reducing antioxidant capacity (CUPRAC) methods. Antibacterial activity was analyzed using disk diffusion and microdilution methods. Several flavonoids, such as luteolin-7-O-glucoside, rutin, quercetin, kaempferol and apigenin, were determined using high performance liquid chromatography. Based on the antioxidant activity test results using the DPPH method, the bark ethanolic extract provided the highest antioxidant capacity, while the CUPRAC method indicated that the twig ethanolic extract had the highest antioxidant capacity. The antibacterial activity test results demonstrated that at a low concentration of 750 µg/disk the bark ethanolic extract obtained the highest inhibition zone and minimum inhibitory concentration level against six of nine pathogenic bacteria. Therefore, A. lachuca bark ethanolic extract could be potentially developed as antioxidant and antibacterial agents.

Protein from Hylocereus polyrhizus protects MRC-5 cells against hydrogen peroxide (H2O2)-induced damage

The cytoprotective and potential molecular mechanisms of Hylocereus polyrhizus protein (RFPP) were investigated on the hydrogen peroxide (H2O2)-triggered damage in normal human embryonic lung (MRC-5) cells. An MTT assay was conducted to assess the MRC-5 cell viability after exposure to H2O2 or RFPP. Cell cycle distribution and apoptosis were explored via flow cytometry. The contents of related proteins were assessed via western blot. MRC-5 cells exhibited markedly decreased cellular viability after treatment with H2O2; however, treatment with RFPP suppressed this decrease. Additionally, RFPP interference dampened H2O2-triggered intracellular apoptosis levels and increased H2O2-triggered intracellular S phase. In these processes, the contents of phosphorylated (p)-AKT along with p-mTOR proteins were downregulated in 120 µM H2O2-treated cells compared with vehicle-treated cells. Nevertheless, in MRC-5 cells inoculated with RFPP, the levels expression of these proteins were reversed. To conclude, RFPP protected MRC-5 cells from H2O2-triggered damage via activation of the PI3K/AKT/mTOR cascade.

Effect of Sargassum fusiforme polysaccharide on apoptosis and its possible mechanism in human erythroleukemia cells

This study aimed to investigate the effects of Sargassum fusiforme polysaccharide (SFPS I, II, and III) on the apoptosis and regulation of human erythroleukemia (HEL) cells. The effect of different doses of SFPS on HEL cell growth was detected using the Cell Counting Kit-8 method, and apoptosis was detected by Hoechst staining. Cell cycle distribution and apoptosis were detected using flow cytometry. Expression of the cell cycle gene, p53, antiapoptotic genes, Bcl-xL and Bcl-2, and pro-apoptotic genes, Bax, Bad, and Caspase-3, as well as the expression of the corresponding proteins, were detected using real-time quantitative polymerase chain reaction (qPCR) and Western blot. The results showed that SFPS II and III decreased HEL cell viability and induced HEL cell apoptosis. Different concentrations of SFPS (I, II, and III) were detected that induced much less toxic effect in normal human embryonic lung (MRC-5) cells, and SFPS I increased cell proliferation, indicating its favorable selectivity towards cancer cells. The mechanism by which SFPS induced apoptosis was also found to be related to the induction of cell cycle arrest in the G0/G1 phase and the increased expression of apoptosis-related genes and proteins. We concluded that SFPS induces HEL cell apoptosis, possibly via activation of the Caspase pathway, providing the theoretical basis for the development of SFPS-based anti-tumor drug products.