ABSTRACT
ABSTRACT The protective activity of methanolic (Met E) and aqueous (Aq E) extracts of Globularia alypum L. (G. alypum) against DNA, lipid and protein oxidative damage was investigated. Moreover, the scavenging, chelating, and reducing power activities of the extracts were also evaluated. Phytochemical analysis was performed to determine phenolic compounds. Results showed that Met E and Aq E were rich in phenolic compounds, and were able to scavenge DPPH˙ with IC50 values of 48.61 µg/mL and 51.97 µg/mL, respectively. In addition, both extracts were able to chelate ferrous ions. At 300 μg/mL, the chelating activity was 97.53% and 91.02%, respectively. The reducing power of these extracts was also remarkable and concentration dependent. At 100 µg/mL, both extracts inhibited lipid peroxidatin by only 42.45% and 4.03%. However, the DNA oxidation damage was inhibited dose-dependently in the presence of G. alypum extracts. At 1 mg/mL, both extracts suppressed DNA cleavage by 83%-84%. The protein oxidation was also inhibited by G. alypum extracts. At 1 mg/mL, Aq E and Met E protected BSA fragmentation by 77%-99%. The overall results suggest that G. alypum extracts exerted antioxidant activity and protect biomolecules against oxidative damage; hence it may serve as a potential source of natural antioxidants.
ABSTRACT
In the present study, Globularia alypum (GA) was extracted with solvent of varying polarity allowed its separation into four subtractions: crude extract (CrE) chloroform extract (ChE), ethyl acetate extract (AcE) and aqueous extracts (AqE). The results showed that AcE had the highest content of phenolic compounds. The inhibitory activity of the extracts on xanthine oxidase (XO) was evaluated, the results obtained showed that the inhibition is dose-dependent and the AcE had a very significant inhibitory effect (0.069 ± 0.003 mg/ml) followed by CrE and AqE (0.081 ± 0.000 et 0.088 ± 0.002 mg/ml, respectively). The CrE, ChE and AqE inhibit competitively XO, whereas AcE is a non-competitive inhibitor. Hyperuricemia was induced by intraperitoneally injection of potassium oxonate, the uric acid, urea and creatinine were measured in serum and liver supernatant. The ChE, AcE, and AqE extracts had reduced significantly the plasma and liver uric acid levels (decreased 44.76%, 43.03% and 31.31%, respectively). Comparing these results with those obtained in vitro, the ChE extract with the lowest inhibitory effect in vitro (IC50 = 0,123 mg / ml) was the most effective extract in vivo. In summary, there was a contradiction between inhibition in vitro and in vivo, this inconsistency or difference may be due to the difference in the bioavailability of flavonoids or natural substances and their extensive metabolism in mice.
ABSTRACT
The present study investigates the effect of intraperitoneal administration of Globularin on blood glucose levels in normal and streptozotocin diabetic rats. Globularin was an iridoid glucoside which was isolated from the leaves of Globularia alypum (3.4 %). This compound was identified by means of physical constants and spectral data UV, IR, MS, 1H-NMR, 13C-NMR, DEPT, COSY, HMBC. The acute toxicity test demonstrated that Globularin is not lethal up to dose of 1000 mg/kg body weight after intraperitoneal injection. In normal and streptozotocin diabetic rats, single intraperitoneal administration of Globularin at a dose 100 mg/kg body weight produced significant decrease of blood glucose levels. However, in prolonged treatment study, the repeated intraperitoneal administration of Globularin (2 x 100 mg/kg body weight) decreased significantly the blood glucose levels when compared to the diabetic control rats. In addition, daily injection of Globularin (2 x 100 mg/kg body weight) reduced significantly serum levels of total cholesterol (varied from 0.53 to 0.41 g/L) and triglycerides (varied from 1.71 to 0.79 g/L) in the diabetic rats.