Antiproliferative and Antimigratory Activity of Poly-gallic Acid in Cancer Cell Lines

BACKGROUND/AIM

Enzyme-mediated grafting of poly (gallic acid) (PGAL) and L-arginine and a-L-lysine onto PGAL produces reactive oxygen species (ROS)-suppressor multiradical molecules with low cytotoxicity, high thermostability and water solubility with cancer treatment potential. This study examined the anticancer effects of these molecules in hepatic (HepG2, ATCC HB-8065), breast (MCF7, ATCC HTB-22), and prostate (PC-3, ATCC CRL-1435 and DU 145, ATCC HTB-81) cancer cell lines, as well as in fibroblasts from healthy human skin as control cells.

MATERIALS AND METHODS

PGAL was synthesized by the oxidative polymerization of the naturally abundant GA using laccase from Trametes versicolor. Insertions of amino acids L-arginine and α-L-lysine on the PGAL chain were carried out by microwave. The cells of dermal fibroblast (Fb) were obtained from primary skin cultures and isolated from skin biopsies. The cancer cells lines of hepatic (HepG2), breast (MCF7), and prostate (PC-3, DU 145) were obtained from ATCC. The viability of the cancer cells and the primary culture was obtained by the MTT assay. Proliferation was demonstrated by crystal violet assay. Cell migration was determined by Wound healing assay. Finally, cell cycle analysis was carried out with cells.

RESULTS

The results show that 200 μg/ml of PGAL cultured in vitro with prostate cancer cells decreased viability, proliferation, and migration, as well as arrested cells in the G1 and S phases of the cell cycle. In contrast, the dermal fibroblasts and the hepatic line remained unaffected. The random grafting of L-Arg and a-L-Lys onto the PGAL chain also decreased the viability of prostate cancer cells.

CONCLUSION

PGAL and PGAL-grafted amino acids are potential adjuvants for prostate cancer treatment, with improved physicochemical characteristics compared to GA.

The enzymatic poly(gallic acid) reduces pro-inflammatory cytokines in vitro, a potential application in inflammatory diseases

Cytokines like IL-6, TNF-α, and IL-1β are important mediators of inflammation in many inflammatory diseases, as well as in cellular processes like cell proliferation and cell adhesion. Finding new molecules that decrease cell proliferation, adhesion (inflammatory infiltrate), and pro-inflammatory cytokine release could help in the treatment of many inflammatory diseases. The naturally derived poly(gallic acid) (PGAL), produced enzymatically from gallic acid in aqueous medium, is a non-toxic, thermostable multiradical polyanion that is antioxidant and has potential biomedical uses. Experimental evidence has demonstrated that PGAL reduces pro-inflammatory cytokines, which are the target of some inflammatory diseases. PGAL decreased IL-6, TNF-α, and IL-1β production in human monocytes exposed to PMA without affecting cell viability. Additionally, PGAL reduced cell proliferation by affecting the transition from the S phase to the G2 phase of the cell cycle. Cell adhesion experiments showed that PMA-induced cell adhesion was diminished with the presence of PGAL, particularly at a concentration of 200 μg/mL. These properties of PGAL show a potential use for treating inflammatory diseases, such as psoriasis or arthritis.