Bridging Indigenous Knowledge and Scientific Evidence for Pharmacological Studies of Phaleria macrocarpa: A Systematic Review

Abstract

Background: Phaleria macrocarpa (Scheff.) Boerl. (Thymelaeaceae), usually referred to as God’s crown, Mahkota dewa, Pau, grows all the year in tropical countries including Malaysia, Indonesia, Papua New Guinea and Australia. It is traditionally used to treat haemorrhoids, stroke, heart disease, tumour, impotence, diabetes, allergies, kidney and liver disorders, migraine, acne and skin ailments. Objective: The purpose of this systematic review is to provide important insight on P. macrocarpa’s traditional use, toxicity, classification of compounds, and pharmacological activities thus identifying the gap in scientific analysis and potential analytical opportunities for future directions on this herb. Method: The related data for this systematic review were collected from renowned online databases, namely Wiley Online Library, Web of Science, Springer Link, PubMed, Science Direct, Scopus, and Google scholar. Results: Around 48 compounds, including benzophenone, xanthonoids, norcucurbitacin derivatives, flavonoids, lignans, fatty acids and esters, phytosterols, aromatic acids and so on were identified from different parts. These constituents and different solvent extracts using various identification techniques have been reported to show a broad range of pharmacological activities. Besides various traditional claims and pharmacological functions, scientific evidence on its ethnopharmacological aspects has been well-documented. Studies found that the plant demonstrates antidiabetic, antioxidant, antimicrobial, anticancer, anti-hypercholesterolemia and antihypertensive. Conclusion: Despite various claims, there is still inadequate scientific evidence particularly on P. macrocarpa’s benefit in the management of dysentery, asthma, skin diseases and rheumatoid arthritis, necessitates future studies. There is also a need to test its pharmacokinetics and toxicological data on humans to verify its potential bioactive properties.