In vitro validation of anti-diabetic and free radical scavenging property of Naaval Kottai Mathirai, a promising Siddha drug for the management of Diabetes mellitus

Abstract

The World Health Organization (WHO) reported 422 million total Diabetic population worldwide and about 1.5 million death rates caused due to it. Diabetes Mellitus (Madhumegam) is a disease classified under Neerinai Perkukkal Noi (diseases causing excessive urination) caused due to increased kapam humour. Naaval Kottai Mathirai (NKM) is a unique herbal Siddha drug prepared from Aristolochia bracteolata which has bitter taste and Syzygium cumini which has astringent taste. The herbal formulation NKM neutralizes kapam and hence effective in Madhumegam. In vitro studies like alpha-amylase, alpha-glucosidase inhibitory assays were performed to prove the anti diabetic effect of the drug NKM. DPPH (2,2- Diphenyl 1-2 picrylhydrazyl) assay, hydrogen peroxide scavenging assay (H₂O₂) and nitric oxide radical scavenging assay were done to evaluate its antioxidant potency. The results showed that minimum alpha amylase inhibitory activity ranged from 19.42±5.92 to 60.92±3.98%, with an IC₅₀ value 70.9±12.37 μg/mL, when it is compared with standard drug acarbose, which showed inhibition ranged from 39.83±2.18 to 91.08±5.43 with an IC₅₀ value 13.29±1.95 μg/mL in various concentration levels of NKM. The IC₅₀ value of Butylated Hydroxyanisole (BHA) was noted as 48.61±1.69 μg/mL and NKM as 67.19±7.81 μg/mL for the H₂O₂ scavenging antioxidant activity. In nitrogen scavenging antioxidant activity, it was observed that IC₅₀ value of gallic acid was 23.02 μg/mL and NKM was 79.13 μg/mL. In DPPH scavenging activity, for ascorbic acid, the standard showed its IC₅₀ value as 13.36 μg/mL and NKM as 53.39 μg/mL. The phytoconstituents present in NKM may enrich the antidiabetic and antioxidant properties of the drug.