antioxidant activity

This work is devoted to phytochemical study of tannic extracts from the leaves of Combretum paniculatum (CP), Mallotus oppositifolius (MO) and Ximenia americana (XA), three medicinal plants of Ivorian flora, used in traditional medicine against certain types of cancer. Qualitative analysis by phytochemical screening of these extracts, performed by means of TLC, revealed in addition to hydrolysable and condensed tannins, the presence of phenolic acids and flavonoids. Total tannin contents determined by permanganometry and spectrophotometry are respectively 41.03 ± 0.77% and 12.3648 ± 0.0004% for MO; 20.03 ± 0.44% and 11.7974 ± 0.0001% for XA; 18.76 ± 0.89% and 11.6026 ± 0.0008% for CP. Condensed tannin content in XA leaves (234.135 ± 0.003 µg ECT/mg) is considerably higher than in CP (37.731 ± 0.001 µg ECT/mg) and MO (19.082 ± 0.001 µg ECT/mg). All XA extracts (aqueous and ethyl acetate) have shown good antioxidant activity with CR50s which are lower than that of vitamin C (reference antioxidant). A correlative relationship was found between tannin content and antioxidant activity.

Last few decades, research data has prompted a passionate debate as to whether oxidation, or specifically, oxidative stress mediated by free radicals/reactive oxygen species (ROS)/reactive nitrogen species (RNS), is a primary or secondary cause of many chronic diseases. Lagenaria siceraria is fair source of ascorbic acid, beta carotene and different phytochemicals to heal many disorders. It shows ribonucleolytic, antihyperlipidemic, hepatoprotective, antioxidant, immunomodulatory, cardiotonic activity. The collection and identification of juice of Lgenaria siceraria and preparation of four fractions of concentrated juice were carried out and preliminary phytochemical and pharmacological screening of same fractions was done. Preliminary pharmacological screening of each fraction was investigated to find out desired in-vitro antioxidant activity. Aqueous fraction showed better yield because of polarity of compound. Preliminary phytochemical screening of four different fractions had various phytochemicals like steroids, flavonids, glycosides, saponins, etc. As we had followed the biological activity guided isolation of active constituents, the fractions were evaluated for antioxidant activity. Isolated aliphatic and saponins moiety may be responsible for the antioxidant activity.

The present study was to evaluate antioxidant activity of ethanolic and aqueous extract of Benincasa hispida (Thunb.) Cogn. fruit for their therapeutic potential. In vitro antioxidant activity was performed by 1, 1- diphenyl-2-picrylhydrazyl (DPPH) and Hydrogen peroxide (H2O2). For aqueous extract the scavenging activity of DPPH is 59.7% at the concentration of 200 µg/ml and the activity of H2O2 is 20.5% at concentration of 1000 µg/ml. For ethanolic extract The scavenging activity of DPPH is 77.4% at the concentration of 250 µg/ml and the activity of H2O2 is 21.3% at concentration of 1000 µg/ml. The method is compared to standard (ascorbic acid). Presence of phytochemicals like carbohydrates, proteins and amino acids, flavonoids, phenolic compounds might contribute to observed antioxidant activity. Benincasa hispida fruits are potential source of natural antioxidant compounds to replace synthetic antioxidants.