In-vitro static digestion and bio-accessibility analysis of selected Ayurvedic Drugs for the assessment of their Guru-Laghu gunas (heaviness and lightness) in terms of digestibility properties- An exploratory study

Introduction: In Ayurveda Guna forms the basis for selecting drugs for treatment. Drugs possessing Guru guna are nourishing but require longer digestion whereas those with Laghu guna are lighter and digest faster. This exploratory study evaluated these traditional classifications using modern digestive parameters and bio accessibility. Material & Methods: An in-vitro static digestion model simulating oral, gastric and intestinal phases was used. Two representative drugs from each category were selected: Shatavari (Asparagus racemosus Willd.) and Chandrashura (Lepidium sativum L.) for Guru guna; Amalaki (Phyllanthus emblica L.) and Usheera (Vetiveria zizanioides (L.) Nash) for Laghu Guna. Carbohydrates and protein bio-accessibility were measured at defined intervals (G-60, G-120, I-60, and I-120 minutes). Results: Shatavari (Guru) demonstrated sustained and increased carbohydrate bio-accessibility with a moderate biphasic protein release- oral phase (139.56%) and intestinal phase at I-60 (87.73%) reinforcing its nourishing role. Chandrashura (Guru) showed delayed and limited carbohydrate bio-accessibility but markedly high intestinal protein bio-accessibility (802.05 % at I-60 and 1214.97 % at I-120) consistent with Guru characteristics. In contrast Amalaki (Laghu) exhibited sustained carbohydrate release with rapid, high gastric protein bio-accessibility (416.68%). Usheera (Laghu) showed consistently low carbohydrate availability and a poor gastric protein bio-accessibility (negative values), followed by mild intestinal increase (up to 497.93 %) aligning with its Laghu classification. Conclusion: The findings suggest that Ayurvedic Guna based drug classification has a measurable biochemical basis. The study highlights the potential of integrating feasible scientific models to interpret and validate traditional Ayurvedic pharmacological concepts.