Assessment of in vitro antioxidant, antidiabetic, anti-inflammatory, and cytotoxicity properties and HPTLC-EDA based phytochemical screening of Macropanax undulatus leaves: An ethnomedicinal plant of Darjeeling Himalayan region

Abstract

Macropanax undulatus, a plant indigenous to the Eastern Himalayan region has not been studied yet, although the locals claim it to be a valuable medicinal plant. The research focuses on its in vitro pharmacological activities, including antioxidant, antidiabetic, anti-inflammatory, and cytotoxic properties of various extracts from leafy parts. Antioxidant was done by using DPPH, metal chelating, and reducing power assays. α-Amylase and α-glucosidase inhibition assays were used to evaluate antidiabetic potential of the plant extracts. Protein denaturation assay was used to perform anti-inflammatory activity. MTT assay was employed to evaluate the cytotoxicity activity. HPTLC based effected directed analysis (EDA) was used to identify antioxidant and antidiabetic agents. Extracts, other than pet. ether and n-hexane extracts, showed high TPC where all extracts showed better TFC. Methanolic (IC₅₀:77.22 ± 0.53 µg/mL) and hydroalcoholic extracts (IC₅₀:75.94 ± 5.82 µg/mL) were observed to possess prominent antioxidant property. The plant also exhibited significant antidiabetic (hydroalcoholic, IC₅₀: 181.90 ± 15.44 µg/mL), as well as anti-inflammatory properties (aqueous, IC₅₀: 91.96 ± 6.03 µg/mL). Aqueous extract showed highest cytotoxicity properties among the other extracts. Further, the chemical composition of those extracts was evaluated with HPTLC based EDA which revealed the presence of stigmasterol and gallic acid in leaves extracts in qualitative as well as in quantitative manner. These results suggest that M. undulatus may have therapeutic potential for the treatment of oxidative damage, diabetes, anti-cancer and inflammatory illnesses. Presence of gallic acid and stigmasterol may be responsible for the therapeutical properties of the plant.