HPLC Standardization and Comparative in Vitro α-Amylase and α-Glucosidase Inhibitory Activity of Katakakhadiradi Kashayam

Katakakhadiradi Kashayam is a classical Ayurvedic polyherbal decoction traditionally used in the management of metabolic disorders. The present study aimed to establish an HPLC-based marker profile of Katakakhadiradi Kashayam and evaluate its in vitro α-amylase and α-glucosidase inhibitory activities in comparison with a marketed formulation and acarbose. HPLC analysis was performed using gallic acid as the reference marker. The method showed good linearity (R² = 0.998), with gallic acid detected at a retention time of 8.445 min. The gallic acid content of the formulation was 0.47 mg/g with a %RSD of 1.08, supporting the reproducibility of the analytical determination. Antidiabetic potential was assessed using α-amylase and α-glucosidase inhibition assays over a concentration range of 10–500 µg/mL. Katakakhadiradi Kashayam showed concentration-dependent inhibition of both enzymes. At 500 µg/mL, α-amylase inhibition was 78.80 ± 2.36%, compared with 77.60 ± 2.33% for the marketed formulation and 85.30 ± 2.56% for acarbose. The approximate IC50 values were 253 µg/mL for the Kashayam and 103 µg/mL for acarbose. Similarly, α-glucosidase inhibition reached 72.40 ± 1.45% at 500 µg/mL, compared with 71.80 ± 1.44% for the marketed formulation and 88.60 ± 1.77% for acarbose. The corresponding approximate IC50 values were 227 and 92 µg/mL for the Kashayam and acarbose, respectively. Overall, the laboratory-prepared Katakakhadiradi Kashayam showed enzyme-inhibitory activity comparable to the marketed formulation, although lower than acarbose. The findings support its in vitro antidiabetic potential and provide a quantitative HPLC marker for its analytical standardization.