Résumé
The present study describes the free radical scavenging activity and reducing power of methanolic leaf extract of Gnidia glauca (Fresen.) Gilg.using ABTS [2, 2' azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)], FRAP (Ferric reducing antioxidant power) and nitric oxide scavenging assays. Total antioxidants were determined by phosphomolybdenum method. The results have indicated that the total phenolic content of the extract was 203.3 GAE/g and showed significant antioxidant activity with an IC50 value of 16.3μg/mL in ABTS and 360.8μg/mL in nitric oxide scavenging assays respectively. A FRAP value of 993.7 μm TE/mg of leaf extract was recorded at 30 minutes. The total antioxidant activity was 142.5 mg AAE/g of extract. The results strongly establish the significant antioxidant property of G. glauca owing to its high phenolic content.
Résumé
The present study was conducted to estimate total phenolic and flavonoid content and to determine anticariogenic efficacy of methanol extract of Gnidia glauca (Fresen.) Gilg (Thymelaeaceae), Pothos scandens L. (Araceae) and Elaegnus kologa Schlecht (Elaeagnaceae) leaves. Total phenolic and flavonoid content of leaf extracts was determined by Folin-Ciocalteau method and Aluminium chloride colorimetric estimation method respectively. Anticariogenic activity of leaf extracts was assessed against 13 clinical isolates of Streptococcus mutans by Agar well diffusion technique. The contents of total phenolics and flavonoids were higher in G. glauca followed by P. scandens and E. kologa. The extract of G. glauca showed greater inhibition of cariogenic isolates than P. scandens and E. kologa as revealed by wider inhibition zones. The study revealed a correlation between the amount of phenolics and flavonoids present in the extracts and the anticariogenic activity of the extracts. The plants used in this study could be used against dental caries.