Free radical scavenging activity of Pluchea indica, Rhizophora mucronata and Rhizophora apiculata edible leaf extracts

Mangrove forest is valuable resource for food and herb. Pluchea indica Less, Rhizophora mucronata Lam. and Rhizophora apiculata Blume are wetland plants and have been used as vegetable, medicine and also applied as herbal tea for nutraceutical purpose. Thus, the study investigated the aqueous leaf extracts of these herbs on free radical scavenging activity. Total phenolic content, ferric reducing antioxidant power assay (FRAP), DPPH and ABTS scavenging assay were determined. All extracts exhibited free radical scavenging activity. P. indica extract demonstrated the strongest activity on every assay; 38.61 ± 0.62 g gallic acid equivalent/100 g extract for total phenolic content, 89.12 ± 3.37 mmol FeSO₄ equivalent/100 g extract for FRAP assay, IC₅₀ 21.03 ± 2.76 and 53.24 ± 2.16 µg/mL, for DPPH and ABTS assay, respectively. From chemical fingerprint of P. indica aqueous extract, the present of abundant flavonoids and phenolics was possibly responsible for free radical scavenging activity.