Phytochemical Profile and Evaluation of Biological Properties of Plectranthus vettiveroides Root Extract – (Vilamichai Root) An Extensive in vitro Study
Background: Plectranthus vettiveroides is an aromatic medicinal herb traditionally used in Ayurvedic and Siddha medicine. Although previous studies have reported its antioxidant, antidiabetic, and anticancer properties, its phytochemical profile and broad biological activities remain incompletely characterised. In parts of South Asia, the roots (Vilamichai root) are traditionally soaked in drinking water for health benefits, but scientific evidence supporting this practice is limited. Objectives: This study aimed to characterise the phytochemical constituents of Plectranthus vettiveroides roots and evaluate their biological activities using multiple in vitro assays. Methods: Ethanolic root extracts were subjected to qualitative and quantitative phytochemical analyses. Their antidiabetic, anti-inflammatory, antilipidemic, antioxidant, antiurolithiatic, immunomodulatory, cytotoxic, and antibacterial activities were assessed using established in vitro methods. Results: Qualitative analysis demonstrated tannins, saponins, flavonoids, steroids, alkaloids, and anthraquinones. The extract contained high total phenolic (223.57 mg GAE/g) and flavonoid (173.19 mg QE/g) contents. It inhibited α-amylase (87.66%) and α-glucosidase (85.75%) activities, suppressed protein denaturation (88.22%), and exhibited strong antioxidant activity across multiple assays. The extract also inhibited calcium oxalate crystallisation, enhanced phagocytic activity, showed cytotoxicity against HeLa cells (IC₅₀ 267.44 µg/mL), and demonstrated antibacterial activity against Vibrio parahaemolyticus and Vibrio harveyi. Conclusion: Plectranthus vettiveroides root extract possesses diverse bioactive phytochemicals with promising antidiabetic, antioxidant, anti-inflammatory, antiurolithiatic, immunomodulatory, cytotoxic, and antibacterial properties. These findings support its traditional use as a health-promoting herbal preparation and warrant further in vivo and clinical studies to validate its therapeutic potential.