Phytochemical Analysis and Antioxidant Activities of Hot and Cold Water Extracts of Mango (Mangifera indica L.) Leaf and Stem Bark

Abstract

Background: Mango (Mangifera indica L.) contains various classes of polyphenols, carotenoids and ascorbic acid which demonstrate different health-promoting properties, mainly due to their antioxidant activities.

Objective: To evaluate the effects of hot water treatment on the phytochemicals and antioxidant properties of mango leaf and stem bark.

Materials and Methods: The fresh leaves (250 g) and fresh stem bark (250 g) of mango were rinsed in water separately, dried on paper towel and were chopped into small pieces. Tengrams (lOg) were taken and extracted using 100ml distilled water (cold water and hot water) separately. The cold water and hot water extracts of the leaves and the stem bark were centrifuged separately. Supernatants were filtered using Whatman No I filter paper and used for the determination of the phytochemicals and antioxidant properties.

Results: There was a significant (P<0.05) decrease in the ascorbic acid content ofthe hot water extracts while the total phenol of hot water extracts ofmango leaf and stem bark were significantly (P<0.05) higher than the corresponding cold water extracts. The flavonoid content ofmango stem bark ofboth cold and hot water extracts was significantly (P<0.05) higher than that of the leaves. The cold water extract of mango leaf (CL) had the lowest reducing power of 28.1 mgAAEIlOO g and hydroxyl radical (OHo) scavenging ability (10.3% at 2.5 mg/ml and 14.2% at 5 mg/ml). The mango stem bark of both cold and hot water extracts exhibited a higher reducing power.

Conclusion: The results of this study demonstrated that both cold and hot water extracts of mango leaves and stem bark have potent antioxidant activity. However, hot water caused a marked increase in the antioxidant ability ofthe mango leaves and stem bark extracts.