Evaluation of Mangrove (Rhizophora mangle L.) products as coloring, antimicrobial and antioxidant agents

Abstract

Mangrove populations were selected in Multiple Use Natural Reserve of Monterrico, Guatemala, for the chemical characterization and biological evaluation of leaves, roots and bark. Ethanol extract were prepared and secondary metabolites identified by macro and semi-micro tests. The antioxidant activity was determined by ABTS and DPPH tests and antibacterial activity by a microdilution test. The best extraction yields of leaves was obtained with ethanol (43%), most common secondary metabolites were identified as flavonoids and tannins. Leaf samples demonstrated the greatest number of flavonoids expressed as chlorogenic acid; in the bark and roots, the most common secondary metabolites were tannins. Ethanol extracts of root and leaf showed the highest antioxidant activity by DPPH and ABTS tests (IC50 0.21 and 0.15 mg/mL, respectively). The extracts showed moderate antibacterial activity against Escherichia coli and Salmonella typhi at 1 mg/ml. The tests showed a possible cosmetics use as coloring extracts; it can be used at concentrations of 1, 3 and 5%, which had coloration from yellow to orange as possible substitutes for artificial yellow dyes such as No. 5 and 6. Tinctures showed good stability a different pH (3, 4, 5 and 7), especially leaves tinctures at pH 5 such as Red No. 40. Phytochemical analysis showed the presence of various metabolites of therapeutic and cosmetic significance. This paper demonstrates that Mangrove products could be used as coloring and antioxidant agents in the cosmetic, pharmaceutical and food industry. Utilization of these products might help in preserving Mangrove from depredation and sustainable exploitation in ecological reserve areas.