Anti-obesity activity of Cymbopogon citratus (lemongrass): A systematic review

Context: Obesity represents a significant global health challenge. The limited efficacy and possible side effects of available anti-obesity agents highlight the need to find new, effective, and safe agents. Lemongrass (Cymbopogon citratus) is an aromatic herbal plant traditionally used as an anti-obesity agent, but previous review studies did not explain the mechanism in detail. Aims: To evaluate the anti-obesity activity of C. citratus in vitro, in vivo, and in humans. Methods: Full-text relevant articles published between 2003 and 2023 were searched through Google Scholar, PubMed, and Scopus. The American Dietetic Association (ADA) quality criteria checklist was used to assess the risk of bias. Data were systematically analysed and presented in tables and flowcharts. Results: Eighteen articles met the inclusion criteria. The anti-obesity activity of C. citratus could come from various parts of the plant (leaves, stalks, roots, or whole plant). Its hydroalcoholic-based extract was rich in polyphenols, which had anti-obesity activity through inhibiting digestive enzymes, appetite suppression, modulation of lipid metabolism, and adipogenesis inhibition. Its essential oil and citral had anti-obesity activity through energy expenditure stimulation, lipid metabolism modulation, and adipogenesis inhibition. Dietary fibre from C. citratus had anti-obesity activity by inhibiting digestive enzymes and modulating lipid metabolism. Conclusions: The anti-obesity activity of C. citratus could come from its polyphenol content, essential oil, or fibre through the same or different mechanisms, namely inhibition of digestive enzymes, suppression of appetite, modulation of lipid metabolism, inhibition of adipogenesis, and stimulation of energy expenditure.