Moss Octoblepharum albidum Hedw.: Isolation, characterization, in vitro and in vivo antidiabetic activities

In India’s folklore, extracts of moss Octoblepharum albidum used in the treatment of fever, bacterial infections, and diabetes. The present study aimed to establish the chemical and pharmacological profile of the ethanolic extract of O. albidum (OA-Et). By using column chromatography, OA-Et yielded three known metabolites, namely 6-hydroxy-4,4,7a-trimethyl-5,6,7,7a-tetrahydrobenzofuran-2(4H)-one(1), 4,4,7a-trimethyl-2-(prop-1-en-2-yl)-2,4,5,6,7,7a-hexahydrobenzofuran-6-ol(2) and 1-(6-hydroxy-2-(2-hydroxypropan-2-yl)-4-methoxy-2,3-dihydrobenzofuran-7-yl)-ethan-1-one(3), which were reported for the first time from this species. The isolated metabolites(1–3) and OA-Et were screened against ferric ions, DPPH free-radicals, superoxide free-radicals, α-glucosidase, α-amylase and aldose-reductase assays, and particularly OA-Et subjected to glycemia activities in albino rats. Among all, 3 and OA-Et depicted significant inhibitory profiles against free-radicals. Particularly, 3 and OA-Et depicted better IC50 values on α-glucosidase and α-amylase, rather than aldose-reductase. Also, the OA-Et (200 mg/kg b.w) treated group revealed significant drop-in body weight (p > 0.001), plasma glucose (p > 0.001), total cholesterol (p > 0.005), total glycerides (p > 0.005), and LDL levels (p > 0.005) in STZ-induced diabetic rats. The HDL levels were markedly augmented in OA-Et (p > 0.005) treated diabetic rats when related to controlled rats. OA-Et abolished increased lipid peroxidation content (p > 0.001) in the pancreas, liver, and kidneys. Histopathological examination of the pancreas of the OA-Et treated group protected the Langerhans islets with the number of islet cells found statistically significant (p > 0.05) compared to diabetic control pancreas. Thus, O. albidum has an aptitude to acts against diabetes by particularly acting against digestive enzymes, i.e., α-glucosidase and α-amylase.