Ocimum sanctum L.-Nature’s Polypharmacological Shield: A Comprehensive Review of Phytochemistry, Bioactivity, and Biomedical Potential

Abstract

Ocimum sanctum L. (Tulsi) has gained significant scientific attention as a versatile medicinal plant with exceptional therapeutic breadth, integrating traditional ethnomedicinal wisdom with modern biomedical potential. This review provides a comprehensive synthesis of its phytochemical diversity, pharmacological activities, and mechanistic insights, emphasizing its relevance as a natural, polypharmacological defense system against contemporary diseases. Tulsi exhibits an extraordinary phytochemical repertoire comprising terpenoids, flavonoids, phenolics, alkaloids, sterols, fatty acids, and vitamins, many of which are responsible for its potent antioxidant, antimicrobial, and anti-inflammatory actions. The essential oil fraction-rich in eugenol, β-caryophyllene, and methyl eugenol-imparts remarkable pharmacodynamic efficacy through free-radical scavenging, enzyme modulation, and immune regulation. Experimental findings demonstrate strong hepatoprotective, hypolipidemic, antidiabetic, and neuroprotective effects, mediated by improved oxidative homeostasis and metabolic balance. The immunomodulatory and anticancer potential of Tulsi extracts further underscores its role in cellular protection and apoptosis regulation. Environmental and extraction-related factors, including solvent polarity and post-harvest conditions, significantly influence the metabolite profile, necessitating process standardization for reproducible outcomes. Collectively, the diverse biochemical interactions of Ocimum sanctum position it as a model medicinal plant for developing phytotherapeutics that complement synthetic drugs in managing oxidative, inflammatory, and degenerative disorders. Future translational research should focus on clinical validation, nanocarrier formulations, and molecular docking studies to unlock its full therapeutic potential.