Chemical Constituents and Antidiabetic Activities of The Aerial Parts Of Tiliacora triandra

Abstract

Initial investigations revealed that the ethanol extract of the whole aerial part, n-hexane (TT-001) and ethyl acetate (TT-002) fractions of the leaves as well as the n-hexane (TT-004) and ethyl acetate (TT-005) fractions of the twigs of Tiliacora triandra exhibited potent alpha-glucosidase and alpha-amylase inhibitory activities. Further investigations led to the isolation of 5,7-dihydroxyl-6-oxoheptadecanoic acid (1), 5,7-dihydroxyl-6-oxooctadecanoate (2), ethyl(9Z,127,15Z)-octadeca-9,12,15- trienoate (3) and ethyl(9Z,12Z)-octadeca-9,12-dienoate (4) from the leaves and twigs of T. triandra. Compounds 1 and 2 are new compounds while 3 and 4 were isolated from T. triandra for the first time. Compounds 1, 2, 3 and 4 showed potent inhibitory activity against alpha-glucosidase enzyme while only compound 1 showed alpha- amylase inhibitory activity. Furthermore, the antidiabetic effect of the ethanol extract of the aerial part of T. triandra and compound 1 on high-fat diet/streptozotocin induced diabetic rats was evaluated. Treatment with 100 mg/kg and 400 mg/kg of T. triandra extract and 25 mg/kg of compound 1 markedly suppressed insulin resistance, hyperglycemia, polydipsia, polyphagia, lipid profile and liver function enzymes. Furthermore, the extract of T. triandra and compound 1 enhanced glucose tolerance, improved body weight, haematological parameters, and reversed damages to the pancreas and displayed protective effects against diabetes induced liver, kidney and testicular damage. Findings from this study revealed that T. Triandra and its' constituents demonstrated good in vitro and in vivo antidiabetic properties and are potential sources of alternative or complementary therapy for the treatment of diabetes and its' complications.