Screening of the antioxidant properties of the leaf extracts of Philippine medicinal plants Ficus nota (Blanco) Merr., Metroxylon sagu Rottb., Mussaenda philippica A. Rich., Inocarpus fagifer, and Cinnamomum mercadoi Vidal.

In our continued searched for natural antioxidants from Philippine medicinal plants, decoction and ethanol extracts of the leaves of Ficus nota (Blanco) Merr., Metroxylon sagu Rottb., Mussaenda philippica A. Rich, Inocarpus fagifer, and Cinnamomum mercadoi Vidal were investigated for their antioxidant potentials. The C. mercadoi ethanolic (CmE) extract demonstrated the highest amount of total phenolics (570.58 mg GAE) and it correlates well to its strong radical scavenging activity (91.97% at 500 ppm) against 1,1Diphenyl-2-picrylhydrazyl (DPPH) and high antioxidant capacities (149.91 AAE, 209.98 BHTE). The M. sagu decoction (MsD), (403.00 mg GAE, 96.39 AAE, 139.61 BHTE) and ethanolic (MsE), (310.58 mg GAE/g, 73.49 AAE, 102.36 BHTE) extracts are the second and third that showed high amount of phenolics, strong free radical scavenging against DPPH and high antioxidant capacities, respectively. These are followed by decoction extracts of F. nota (FnD) (88.19% at 500 ppm against DPPH, 216.64 mg GAE, 55.52 AAE, 77.05 BHTE), I. fagifer (IfD) (83.64% at 500 ppm against DPPH, 194.48 mg GAE, 63.13 AAE, 88.89 BHTE), C. mercadoi (CmD) (83.64% at 500 ppm against DPPH, 166.03 mg GAE, 80.88 AAE, 88.31 BHTE), and ethanolic extract of I. fagifer (IfE) (89.76% at 500 ppm against DPPH, 131.48 mg GAE, 59.48 AAE, 82.63 BHTE). These findings may support their traditional/ethnomedicinal claims. This study further indicates that the extracts from C. mercadoi, M. sagu, F. nota, and I. fagifer can be used as important sources of natural antioxidants that may offer protection from the harmful effects caused by overproduction of radicals in the body.