Antioxidant Activity, Phenolic Content and Hematoprotective Effects of Cleome arabica Polyphenolic Leaf Extract

In this study a polyphenolic extract from Cleome arabica leaves (CALE) was investigated for its antioxidant activity in vitro using DPPH•, metal chelating and reducing power methods and for its protective effects against AraC-induced hematological toxicity in vivo using Balb C mice. Results indicated that CALE exhibited a strong and dose-dependent scavenging activity against the DPPH• free radical (IC50 = 4.88 μg/ml) and a high reducing power activity (EC50 = 4.85 μg/ml). Furthermore, it showed a good chelating effects against ferrous ions (IC50 = 377.75 μg/ml). The analysis of blood showed that subcutaneous injection of AraC (50 mg/kg) to mice during three consecutive days caused a significant myelosupression (P < 0.05). The combination of CALE and AraC protected blood cells from a veritable toxicity. Where, the number of the red cells, the amount of hemoglobin and the percentage of the hematocrite were significantly high. On the other hand, AraC cause an elevation of body temperature (39 °C) in mice. However, the temperature of the group treated with CALE and AraC remained normal and did not exceed 37.5 °C. The observed biological effects of CALE, in vitro as well as in vivo, could be due to the high polyphenol and flavonoid contents. In addition, the antioxidant activity of CALE suggested to be responsible for its hematoprotective effect.