Cleistocalyx operculatus (Roxb.) Merr. & Perry: Phytochemistry, biological activities, and potential applications

Abstract

Cleistocalyx operculatus (Roxb.) Merr. & Perry is a medicinal plant widely distributed in Vietnam and several Asian countries, traditionally used in herbal tea and folk medicine. Owing to the growing scientific interest in this species, this study combines bibliometric analysis and a comprehensive literature review to evaluate research trends, phytochemical constituents, biological activities, and potential applications of C. operculatus. Bibliometric analysis of scientific publications revealed a marked increase in research output during the last decade, with phytochemistry, antioxidant activity, antimicrobial effects, and bioactive compounds emerging as major research themes. Published studies have identified a wide range of phytochemicals, including flavonoids, chalcones, terpenoids, phenolic compounds, phloroglucinol derivatives, and essential oils. Among them, 2′,4′-dihydroxy-6′-methoxy-3′,5′-dimethylchalcone (DMC) has been recognized as a key bioactive compound responsible for several pharmacological effects. Extracts and isolated compounds from C. operculatus exhibit diverse biological activities, including antioxidant, antimicrobial, antiviral, anti-inflammatory, antidiabetic, anti-obesity, anticancer, hepatoprotective, nephroprotective, and neuroprotective properties in both in vitro and in vivo studies. Furthermore, the plant shows promising applications in functional foods, edible coatings, green synthesis of nanoparticles, wastewater treatment, and biomedical materials. Despite these advances, further studies on standardization, toxicity, clinical validation, and large-scale cultivation are required to facilitate industrial and pharmaceutical applications. Overall, C. operculatus represents a valuable natural resource and an emerging research subject with considerable potential for future development in food, pharmaceutical, and biotechnological sectors.