Antioxidant, hypoglycemic and anti-diabetic activities of Ziziphus spina-christi (L) Willd (Rhamnacae) leaf extract

Purpose: To investigate the antioxidant, hypoglycemic and antidiabetic activities as well as the phenolic composition of Ziziphus spina-christi (ZSC) Methods: Eighty percent methanol extract (ZSC-1), as well as ethyl acetate (ZSC-2), n-butanol (ZSC-3) and aqueous (ZSC-4) fractions were administered orally to mice at doses of 250 and 500 mg/kg of body weight. The hypoglycemic and anti-diabetic activities of these fractions in the treated mice were evaluated after 7 and 15 days, using glibenclamide as a standard. Antioxidant activities in vitro were determined using stable free radical DPPH and ABTS radical scavenging techniques. Results: The strongest (p < 0.001) anti-diabetic activity (25.59 and 39.48 % after 7 and 15 days, respectively) was found following treatment with 500 mg/kg ZSC-3 fraction. Similarly, the highest (p > 0.001) hypoglycemic effect was achieved with 500 mg/kg ZSC-3 treatment (29.07 and 35.56 % after 7 and 15 days, respectively). ZSC-1 possessed the highest content of total flavonoids (36.2 mg/g) and total polyphenol (82.3 mg/g). Conclusion: Fraction ZSC-3 displayed potential hypoglycemic activity while ZSC-1, ZSC-2 and ZSC-3 possess remarkable DPPH scavenging ability equivalent to 89, 96 and 80.3 % of the activity of the standard drug respectively.