Botanical Characteristics and in Vitro Pancreatic Lipase Inhibitory Activity of Ixora coccinea L. Flowers
Nguyen Duc Hoai Nam
Faculty of Pharmacy, Nguyen Tat Thanh University, 298A–300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City, Vietnam.
Le Thi Thu Trang *
Faculty of Pharmacy, Nguyen Tat Thanh University, 298A–300A Nguyen Tat Thanh Street, District 4, Ho Chi Minh City, Vietnam.
*Author to whom correspondence should be addressed.
Abstract
Aims: To characterise the flowers of Ixora coccinea L. botanically, screen their phytochemical constituents, and evaluate the in vitro pancreatic lipase inhibitory activity of their extracts.
Study Design: Laboratory experimental study combining descriptive botanical characterisation (morphology, anatomy and powder microscopy) with an in vitro enzyme inhibition assay. No physicochemical standardisation parameters were determined.
Place and Duration of Study: Faculty of Pharmacy, Nguyen Tat Thanh University, Ho Chi Minh City, Vietnam, between April and June 2026.
Methodology: Flowers collected in Vinh Huu commune, Dong Thap province, in April 2026 were examined by light microscopy for morphology, the anatomy of the root, stem, leaf and corolla tube after carmine red – iodine green double staining, and the powder elements. A total extract from 500 g of powdered flowers, obtained by cold maceration with ethanol 96 %, was partitioned with n–hexane, dichloromethane, ethyl acetate and n–butanol. Constituents were identified by specific colour reactions; lipase inhibition was measured by the p–nitrophenyl palmitate assay at 405 nm in triplicate, with orlistat as a positive control.
Results: The morphology agreed with the published descriptions of the species, and the anatomy and diagnostic elements of the flower powder were established. The flowers contained flavonoids, tannins, polyphenols, anthocyanosides, proanthocyanidins, coumarins, anthraquinones and alkaloids. Maceration yielded 62.42 g of total extract, corresponding to a yield of 12.34 %. The total extract was the most active (IC50 83.98 ± 4.38 µg/mL), followed by the ethyl acetate (123.88 ± 3.25), dichloromethane (259.07 ± 27.81) and n–butanol (275.33 ± 10.27 µg/mL) fractions; orlistat gave 1.45 ± 0.22 µg/mL.
Conclusion: The study provides part of the botanical data required for standardising this herbal material and shows that extracts of the flowers of I. coccinea inhibit pancreatic lipase in vitro. Whether this translates into an anti-obesity effect in vivo remains to be established.
Keywords: Ixora coccinea L., Rubiaceae, plant anatomy, powder microscopy, phytochemical screening, flavonoids, pancreatic lipase inhibition, anti-obesity, orlistat