Research Article Anticancer and antimicrobial activities of diosmin

Flavonoids are a group of natural polyphenols that are typically present in many higher plants as secondary metabolites with low molecular weight.Diosmin (3′,5,7-trihydroxy-4′methoxyflavone-7-ramnoglucoside) is a naturally occurring flavonoid found in relatively large quantities in citrus fruits.We examined the cytotoxic, antiangiogenic and antimicrobial activity of diosmin.The cytotoxic effect was assessed by the WST-1 test.Cellular DNA fragmentation was determined by measuring BrdU-labeled DNA fragments.The mRNA and protein levels were assessed by qRT-PCR and Western blot.The minimal inhibitory concentrations (MIC) of diosmin for six Gram-positive and nine Gram-negative bacteria were determined by using a microdilution method.Diosmin significantly and selectively inhibited proliferation depending on concentration and exposure time.Following diosmin treatment of MDA-MB-231 cells, a concentration-dependent and time-dependent increase in the number of apoptotic BrdU-labeled DNA fragments was observed.Exposure of MDA-MB-231 breast cancer cells to diosmin for 24 h markedly increased the mRNA expression of Bax and caspase-3, whereas the expressions of Bcl-2 and Bcl-XL were decreased.Furthermore, Western blotting demonstrated that protein expression of Bcl-2 and Bcl-XL was downregulated, while the expression of Bax and caspase-3 proteins was upregulated.Based on the MICs, significant activity was only seen against Gram-positive bacteria.We conclude that diosmin is a potential candidate for use in the treatment of breast cancer and for controlling infection.