Pharmacological Evaluation and Phytochemical Profiling of Dioscorea Bulbifera L. Tuber

Abstract

Introduction: Dioscorea bulbifera L. (D. bulbifera) (Family: Dioscoreaceae), locally known as ‘Baonla,’ is naturally grown in the forest-encircled area of Nayagram, Jhargram, India. There is no previously published report on the phytochemical and pharmacological potential of D. bulbifera tuber.

Objective: The present experimental study was performed to evaluate the phytochemical and pharmacological investigation of the D. bulbifera tuber.

Methods: Gas-chromatography-Mass-spectroscopy (GC-MS) and high-performance thin-layer chromatography (HPTLC) were used for phytochemical screening, The antioxidant potential of the tuber-extracts was examined by using assays such as DPPH, metal chelating, and reducing power assay. Furthermore, the anti-diabetic efficacy was tested by targeting the carbohydrate-hydrolyzing enzymes α-amylase and α-glucosidase. The protein denaturation assay was utilized to assess the plant's anti-inflammatory properties.

Results: D. bulbifera tuber methanolic extract showed a significantly higher total phenolic content of 105.58±123 mg GAE/g, and the aqueous extract was found to have appreciably higher total flavonoid content of 306.85±20.10 mg QRE/g. Among all the tuber-extracts, the methanolic extract has shown good antioxidant activity by different assays such as DPPH ((IC₅₀: 36.97±1.74 µg/ml), metal chelating (IC₅₀: 97.32±7.9 µg/ml), and reducing power assay, maximum antidiabetic (α-amylase: IC₅₀: 81.75±4.5 µg/mL and α-glucosidase: IC₅₀: 168.17±7.27 µg/mL), and anti-inflammatory (IC₅₀:149.33±4.94 µg/mL) potential as compared to their respective standard. Numerous biologically active substances were found by GC-MS analysis; among the most abundant ones were 2-hydroxy-gamma-butyrolactone (19.9%) and 13(Z)-Docosenoic acid methyl ester (20.22%) in the methanolic extract of D. bulbifera tuber. HPTLC analysis identified and quantified four phenolic acids (gallic acid, caffeic acid, 4-hydroxybenzoic acid, and t-cinnamic acid) and two flavonoids (quercetin and myricetin) with the validated method.

Conclusion: D. bulbifera tuber has the potential to be used therapeutically to treat oxidative stress, diabetes, and inflammatory diseases.