Evaluation of antithyroid potential of Luffa acutangula peel extract and its chemical constituents as identified by HR-LC/MS

Although some reports are there indicating the medicinal values of fruit peels, on vegetable peels investigations are meager. The present study is an attempt to explore the hitherto unknown potential of Luffa acutangula peel extract in T₄-induced hyperthyroid female mice. Animals were made hyperthyroid by administering pre-standardized dose of l-thyroxin (l-T₄ at 0.5 mg/kg/day) for 12 consecutive days and then the effects of the test peel extract at 25 and 50 mg/kg for 15 days were studied on the changes in serum thyroid hormones, glucose, different lipids; hepatic lipid peroxidation (LPO); enzymatic antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, and in reduced glutathione. The main chemical constituents of the extract were identified by high resolution liquid chromatography mass spectrometry. Administration of the test peel extract to the hyperthyroid mice at both the test doses decreased the levels of serum thyroid hormones, glucose and tissue LPO suggesting its antithyroid, antihyperglycemic and antiperoxidative potential. These positive effects were also supported by an improved lipid profile as well as liver histology. LC-MS analyses revealed the presence of kaempferol-3-O-rutinoside, kameferol-O-neohesporoside, quercetin, cinnamic acid ethyl ester, caffeic acid derivatives such as 4-O-caffeyol quinic acid, 3-sinapoylquinic acid and 4,5-dihydroxyprenyl caffeate, orientin and sinapic acid. It is presumed that the antithyroid and anti-hyperglycemic actions of the test plant extract could be the result of antioxidative properties of these phytochemicals.

Keywords: Catalase; Hyperglycemia; Lipid peroxidation; Liver histology; Superoxide dismutase; Thyrotoxicosis.