Ethnobotanical Significance, Phytochemistry, and Antimicrobial Properties of Sal (Shorea robusta): A Comprehensive Review

Abstract

Shorea robusta Gaertn. (family Dipterocarpaceae), commonly known as Sal, stands among the most ecologically, economically, and medicinally significant tree species of the Indian subcontinent. Revered across Hindu and Buddhist traditions and extensively utilised by indigenous tribal communities spanning multiple ecological zones, Sal has accumulated a rich ethnobotanical legacy spanning several millennia. This narrative review comprehensively synthesises the current state of knowledge pertaining to the ethnobotanical significance, phytochemical composition, and antimicrobial properties of S. robusta, while contextualising these within the broader pharmacological and ecological profile of the species. The plant elaborates a chemically diverse array of secondary metabolites, with resveratrol oligomers (including hopeaphenol, α-viniferin, and vaticanol series), triterpene acids (ursolic acid, bergenin), condensed tannins, flavonoids, and diterpene resins representing the principal bioactive phytochemical classes. Antimicrobial investigations have demonstrated significant inhibitory activity of various plant-part extracts and isolated compounds against a range of clinically important pathogenic bacteria and fungi, with aqueous and methanolic resin extracts exhibiting the broadest spectrum of antibacterial efficacy. The mechanisms of antimicrobial action—encompassing membrane disruption, inhibition of bacterial type III secretion systems, reactive oxygen species-mediated oxidative damage, and immunostimulatory enhancement of host defence—are discussed in detail. Evidence for anti-inflammatory, wound-healing, antioxidant, hepatoprotective, and preliminary anticancer properties is also synthesised. The ecological importance of Sal forests for carbon sequestration and biodiversity conservation, alongside the challenges to sustainable management of the species, is examined. Despite the substantial body of in vitro and animal-model evidence supporting multiple pharmacological claims, significant knowledge gaps persist regarding clinical validation, bioavailability and pharmacokinetics, structure–activity relationships of key bioactive compounds, and molecular target characterisation. Future research should prioritise rigorous preclinical mechanistic studies, clinical investigations, and sustainable bioprospecting frameworks that respect indigenous knowledge and biodiversity obligations.