Chemical constituents and in vivo preliminary evaluation of the toxicological activity of Ouratea spectabilis (OCHNACEAE) and Clitoria guianensis (Fabaceae) leaves

Clitoria guianensis and Ouratea spectabilis, found in the Brazilian Cerrado, are used in folk medicine, despite the few chemical and biological studies reported in the literature. The present study aims to investigate the toxicity and effect of extracts from both species on the microcrustacean Artemia salina, and to determine the chemical composition of the hexane extract of O. spectabilis leaves and the EtOAc fraction of C. guianensis leaves. Kaempferitrin, a flavonoid isolated from of the EtOAc fraction of C. guianensis leaves, was identified by chemical analysis. Analysis of the hexane extract of O. spectabilis leaves using gas chromatography-mass spectrometry (GC-MS) suggested the presence of twenty-five known substances. The Hex, EtOAc, and EtOH crude extracts of C. guianensis leaves exhibited high and moderate toxicity against Artemia salina, with median lethal dose values (LD50) of 43.7, 25.4, and 233.4 mg.L−1, respectively. The acetone extract of O. spectabilis leaves showed moderate toxicity against Artemia salina with an LD50 value of 115.13 mg.L−1.

Evaluation of antioxidant potential of Clitoria ternata L. and Eclipta prostrata L.

Free radical-mediated oxidative stress is believed to be the primary cause of many disorders, such as cardiovascular diseases, brain dysfunction, cataract, diabetes mellitus, arthritis, cancer, ageing etc. In treatment of these diseases, antioxidant therapy has gained an utmost importance in the recent years. Current research is now directed towards finding naturally occurring antioxidants of plant origin. In Indian system of medicine, Clitoria ternata L. and Eclipta prostrata L. are the important medicinal plants, which have a wide range of applications. In the present study, the antioxidant potential of aqueous extracts of C. ternata and E. prostrata was evaluated by determining the levels of enzymatic and non-enzymatic antioxidants. In vitro antioxidant capacity was also determined using different assays and the results were compared with standard antioxidants such as butylated hydroxy toluene (BHT), ascorbic acid and rutin. Our results showed that both plant extracts possessed significant levels of enzymatic and non-enzymatic antioxidants and also exhibited antioxidant capacity. However, C. ternata showed higher levels of enzymatic and non-enzymatic antioxidants, as compared to E. prostrata. In addition, the antioxidant capacity of C. ternata was observed to be significant as compared to E. prostrata.