In vitro free radical scavenging and in vivo antioxidant potential of mulberry (Morus indica L.) leaves

The leaves of mulberry (Morus indica L.) of Moraceae, possess a number of bioactive compounds that fight against various ailments. In vitro free radical scavenging and in vivo antioxidant potential of mulberry leaves were investigated. Ethanolic extract of mulberry leaves was tested for antioxidant activity in vitro using butylated hydroxy toluene as a positive control. Erythrocyte membrane was used as peroxidation model system in vitro while elderly human volunteers who received mulberry leaf powder (5 g/day) for 60 days served as subjects for in vivo assessment. Mulberry leaf extract scavenged DPPH, nitric oxide and superoxide radicals in a concentration dependent manner and inhibited FeSO4-induced lipid peroxidation and hydroperoxides in the erythrocyte membrane model. This was supported by significantly (p < 0.01) decreased lipid peroxidation in plasma (23%) and erythrocytes (49%), significantly (p < 0.01) elevated levels of non enzymatic antioxidants viz. β carotene (116%), vitamin A (69%), vitamin C (23%), vitamin E (55%) and ceruloplasmin (26%); decreased nitrite (43%) in serum and significantly elevated activity of superoxide dismutase (47%) and glutathione-S-transferase (72%) and reduced glutathione (21%, p < 0.05) in erythrocytes from elderly subjects treated with mulberry leaf powder. Mulberry leaves exhibited antioxidant properties postulated to be as a result of the synergistic action of free radical scavenging compounds such as carotenoids, flavonoids, moracins and others present in the leaves.