Antioxidant activity of some Jordanian medicinal plants used traditionally for treatment of diabetes.

Medicinal plants are being used extensively in Jordanian traditional medicinal system for the treatment of diabetes symptoms. Twenty one plant samples were collected from different Jordanian locations and used for antioxidant evaluation. The level of antioxidant activity was determined by DPPH and ABTS assays in relation to the total phenolic contents of the medically used parts. The most frequently used plant parts as medicines were fruit, shoot and leaves. The total phenolic contents of methanol and aqueous extracts, from plants parts, ranged from 6.6 to 103.0 and 3.0 to 98.6 GAE mg g(-1) of plant part dry weight, respectively. DPPH-TEAC of the methanol extracts of plants parts were varied from 4.1 to 365.0 mg g(-1) of plant dry weight versus 0.6 to 267.0 mg g(-1) in aqueous extracts. Moreover, the mean values of ABTS*- (IC50) varied from 6.9 to 400.0 microg dry weight mL(-1) ABTS in methanol extracts versus 9.8 to 580.5 microg mL(-1) in aqueous extracts. According to their antioxidant capacity, the plants were divided into three categories: high (DPPH-TEAC > or = 80 mg g(-1) ), (i.e., Punica granatum peel, Quercus calliprinos leave, Quercus calliprinos fruit, Cinchona ledgeriana and Juniperus communis leave), moderate (DPPH-TEAC range 20-80 mg g(-1)) (i.e., Salvia fruticosa shoot, Crataegus azarolus stem, Crataegus azarolus leave, Varthemia iphionoides shoot, Artemisia herba-alba shoot, Thymus capitatus shoot, Morus nigra leaves and Arum palaestinum leaves) and low antioxidant plants (DPPH-TEAC < 20 mg g(-1)), (i.e., Matricaria aurea shoot, Artemisia judaica shoot, Teucrium polium shoot, Pinus halepenss pollen grains, Sarcopoterium spinosum root, Crataegus azarolus fruit, Inula viscose shoot and Achillea fragrantissima shoot). The antioxidant activity of these plant's extracts and their potential rule in radical scavenging agreed with their potential use by Jordanian population as a traditional anti-diabetic agents.