Unlocking the phytochemical and pharmacological potential of Ocimum sanctum L. and Plectranthus amboinicus (Lour.) Spreng. toward developing novel evidence-based herbal products in Sri Lanka: A comprehensive review

Ocimum sanctum L. (Heen Maduruthala) and Plectranthus amboinicus (Lour.) Spreng. (Kapparawalliya) are two highly abundant medicinal plants belonging to the family Lamiaceae. Despite their widespread availability and documented ethnomedicinal uses, their phytopharmacological potential remains underexplored in Sri Lanka. Consequently, their utilization of herbal products remains limited. The present review investigates the scientific evidence on phytochemical constituents, pharmacological potential, and safety data of those species and evaluates the research gap regarding their potential for novel herbal product development in Sri Lanka. The scientific data were collected via PubMed, Scopus, ScienceDirect, Web of Science, and Google Scholar databases on both plants from the past 30 years, and they were critically analyzed to evaluate phytopharmacological potential and limitations on developing novel herbal products in Sri Lanka. Based on the available data, O. sanctum contains various bioactive flavonoids, terpenoids, and phenolic compounds. It could be a renewable source of valuable phytochemicals, including eugenol, methyl eugenol, β-caryophyllene, rosmarinic acid, and apigenin, with high potential to be utilized in various herbal products, including antifungal and anti-inflammatory topical applications and anti-aging cosmeceuticals. P. amboinicus contains phenolics (thymol and carvacrol), flavonoids, and abietene diterpenoids as its predominant phytochemicals. These phytochemicals possess a wide range of biological properties and have high potential in developing novel herbal products related to treating and preventing a wide range of health conditions. The data suggest that both species have substantial potential for inclusion in novel evidence-based herbal products. Both plants exhibit rapid growth and can be easily cultivated, making them ideal candidates for cost-effective and scalable herbal product development. However, challenges related to standardization, quality control, and market acceptance have been identified in Sri Lanka. To overcome these challenges, efforts focused on enhancing research, acknowledgment programs, and commercialization strategies in the herbal product sector are recommended. By utilizing the medicinal properties of O. sanctum and P. amboinicus , Sri Lanka can emerge as a global leader with evidence-based phytomedicine research and present a sustainable economic development.