The effect of hesperidin and luteolin isolated from Eriocephalus africanus on apoptosis, cell cycle and miRNA expression in MCF-7.

This study investigates the molecular mechanisms underlying the anticancer activity of hesperidin and luteolin, isolated from Eriocephalus africanus, in the human breast carcinoma cell line (MCF-7). The viability of MCF-7 cells, upon treatment with hesperidin and luteolin, was evaluated using the 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay; apoptotic activity and effect on cell cycle progression were analysed by flow cytometry; effect on expression of key apoptotic regulatory genes (caspase-3, -8, -9, Bcl-2 and Bax) and apoptotic microRNAs (-16, -21 and -34a) were evaluated using quantitative real-time PCR. Hesperidin and luteolin reduced cell viability in a dose and time-dependent manner, caused a significant accumulation of apoptotic cells into the G0/G1 and sub-G1 cell cycle phases, induced apoptosis through the intrinsic and extrinsic pathways, down-regulated anti-apoptotic, Bcl-2, and upregulated pro-apoptotic, Bax. In addition, hesperidin and luteolin significantly downregulated the expression of miR-21 and upregulated that of miR-16 and -34a in MCF-7. Spearman`s rank analysis revealed a positive correlation between Bcl-2 and miR-21 and negative correlation between Bcl-2, miR-16 and -34a. Findings from this study provide new evidence on the molecular basis of the anticancer activity of luteolin and hesperidin in breast cancer cell lines.Communicated by Ramaswamy H. Sarma.

Hesperidin-loaded nanoemulsions improve cytotoxicity, induce apoptosis, and downregulate miR-21 and miR-155 expression in MCF-7.

Hesperidin, a ubiquitous plant-based flavanone, was encapsulated into nanoemulsions (HP-NEM) using a spontaneous emulsification method to improve its solubility and enhance bioavailability and efficacy in breast cancer treatment using MCF-7 cell lines. The cytotoxic and apoptotic effects of HP-NEM against MCF-7 and its impact on oncomiRs, microRNA-21, and microRNA-155 expression were also assessed. The optimised HP-NEM displayed a spherical shape with 305 ± 40.8 nm, 0.308 ± 0.04, and -11.6 ± 3.30 mV and 93 ± 0.45% for particle size, polydispersity index (PDI), zeta-potential (ζ), and encapsulation efficiency, respectively. Cytotoxicity studies using MTT assay showed selective toxicity of the HP-NEM against MCF-7 without affecting normal cells (HEK 293). Treatment with the HP-NEM induced cell death through apoptosis, cell cycle arrest in the G2/M phase, and downregulated miR-21 and miR-155 expression in MCF-7. This study supports the use of HP-NEM as a potential therapeutic agent in breast cancer treatment.

Phytochemical constituents and in vitro anticancer screening of isolated compounds from Eriocephalus africanus‡.

This study investigated the in vitro anticancer potential of phytochemical constituents isolated from the methanolic extract of Eriocephalus africanus. One flavanone (hesperidin) and two flavones (luteolin and apigenin) were isolated for the first time from the plant using column chromatography. Standard MTT assay was used to evaluate the effect of the constituents on cell viability in MCF-7, A549, HepG2 and normal HEK 293 cell lines. The flavonoids decreased cell viability in a dose dependent manner in all tested cell lines. Hesperidin and luteolin were more sensitive against MCF-7, with EC50 values of 62.57 µg/mL and 70.34 µg/mL, respectively and apigenin showed the most potent activity against HepG2 (EC50 = 11.93 µg/mL). The results revealed E. africanus to be a rich source of flavonoids and natural anticancer agents, which could potentially be used in the development of new therapeutics for cancer treatment.

Toxic metals (As and Pb) in Sargassum elegans Suhr (1840) and its bioactive compounds.

Sargassum elegans Suhr 1840 (Phaeophyta) is a brown marine macro alga, which is used both nutritionally and medicinally in the coastal areas of Southern Africa. Consequently, we conducted a phytochemical and analytical investigation on samples of this species collected from seven sites along the coast of KwaZulu-Natal, South Africa. Sargassum elegans was found to be rich in ß-sitosterol, fucosterol and phaeophytin a as confirmed by spectroscopic techniques. Concentrations of essential and toxic elements varied significantly with location and were in the order of Ca > Mg> Fe > As > Cu > Zn > Mn > Ni > Pb > Co > Se > Cr > Cd. The accumulation of As by S. elegans was also evident as concentrations ranged from 42 to 105 mg kg-1, of which, 21 to 53 mg kg-1 was in inorganic form; consumption of this species may therefore increase dietary exposure to inorganic arsenic. Abbreviation: CRM: Certified reference material; NMR: Nuclear magnetic resonance; ICP - OES: Inductively coupled plasma - optical emission spectroscopy; PCA: Principal component analysis.

Chemical composition of selected seaweeds from the Indian Ocean, KwaZulu-Natal coast, South Africa.

The chemical composition of three edible seaweeds (Codium capitatum, Hypnea spicifera and Sargassum elegans) and two inedible seaweeds (Halimeda cuneata and Spyridia hypnoides) from the Indian Ocean along the KwaZulu-Natal East Coast, South Africa were investigated as a function of seasonal variation. The proximate compositions of the edible seaweeds were determined. In edible seaweeds, the moisture level ranged from 85.4 to 89.5%, protein from 6.1 to 11.8%, lipids from 7.5 to 13.1% and carbohydrates from 37.8 to 71.9%. Elemental concentrations in the five studied seaweeds varied significantly with season (P < 0.05) with mean elemental concentrations (in µg g(-1), dry weight) being: Ca (29 260), Mg (6 279), Fe (1 086), Cu (145.9), Mn (48.32), As (24.29), Zn (15.65), Ni (9.83), Cr (5.78), Pb (4.84), Co (0.87) and Se (0.86). The concentrations of As were particularly high in S. elegans, ranging from 94.70 ± 6.6 µg g(-1) in winter to 65.10 ± 2.3 µg g(-1) in summer. Hierarchical cluster analysis showed similar distribution of elements in edible seaweeds which was dissimilar to that in inedible seaweeds. This study suggests that edible macro alga, C. capitatum and H. spicifera, could be potential sources of most essential nutrients and may contribute positively to the diet without posing the risk of adverse health effects due to low concentrations of toxic elements. However, due to high levels of As in S. elegans, its consumption should be moderated to reduce dietary exposure to this toxic element.