Antioxidant activity and phenolic compounds identification of Micromeria inodora (Desf.) Benth. from Western Algeria.

Micromeria inodora (Desf.) Benth. is most studied for the antimicrobial activity of their essential oils; nevertheless there are no reports on the phenolic compounds of this species and their antioxidant activity. In this study, aqueous and organic extracts were assayed for their antioxidant activity. The polyphenol and total flavonoid content, varied between 175.50 and 332.62 mg GAE/g extract and 65.38-86.30 mg catechin equivalent/g extract, respectively. The results of antioxidant activity have shown that all extracts reported an important activity and the ethyl acetate extract showed the stronger effect, higher than some standards molecules. Its IC50 value of scavenging DPPH is 1.5 ± 0.001 µg/mL; ß-Carotene Bleaching assay (BCB) IC50 = 28.1 ± 0.001 µg/mL and the Ferric Reducing Antioxidant Power (FRAP) IC50 = 6.96 ± 0.05 µg/mL. RP-HPLCPDA analysis of phenolic compounds revealed the presence of phenolic acids and flavonoids as: gallic acid, quercetin, rutin, vanillin and naringenin.

In silico evaluation of phenolic compounds as inhibitors of Α-amylase and Α-glucosidase.

The aim of the present study focuses on the molecular docking approach to screen alternative drug that can regulate the hyperglycemia by down-regulating α-glucosidase and α-amylase activity using phenolic compounds: tannic acid (L1), catechin (L2), gallic acid (L3), quercetin (L5) and epicatechin (L6). L1 gives the best docking scores, its interaction with α-amylase and α-glucosidase has the lowest energy score compared to the other complexes and to the acarbose (L4). L1 forms strong five H-donor interactions with residues of active site of α-amylase and three H-donor interactions with α-glucosidase. The in silico evaluation of the unfavorable absorption, distribution, metabolism, and elimination (ADME) properties and drug-likeness revealed that L5 has high absorption compared to tannic acid and to the other compounds. This study revealed for the first time that tannic acid is a functional inhibitor of α-glucosidase and α-amylase activities and can be used as alternative for the regulation of post-prandial hyperglycaemia. Communicated by Ramaswamy Sarma.