Toxicological, Antidiarrhoeal and Antispasmodic Activities of Syzygium myrtifolium

Syzygium myrtifolium Walp. (Syzygium campanulatum Korth), Myrtaceae, is locally known as “Kelat paya” in Malaysia. Traditionally, it is used as a remedy for stomach pain. The goal of the present study was to investigate the toxicological potential as well as the antidiarrhoeal and antispasmodic activities of betulinic acid, dimethyl cardamonin and standardized non-formulated and nano-formulated ethanol and supercritical fluid extracts prepared from leaves of S. myrtifolium. The standardized extracts did not produce in vivo toxicity. Both the compounds and standardized extracts showed dose-dependent antidiarrhoeal activity by examining changes in the percentage of liquid stools and percentage of defecation frequency. Dimethyl cardamonin and standardized extracts showed antispasmodic activity on the isolated ileum of guinea pigs. Compared with hyoscine-N-butylbromide, dimethyl cardamonin and standardized extracts produced significant, potent antagonizing activity in ileum contractions induced with acetylcholine. Furthermore, the antagonistic potential of S. myrtifolium active markers against muscarinic type M2 and M3 receptors was investigated by molecular docking.