In vitro and in vivo anthelmintic and chemical studies of Cyperus rotundus L. extracts 

BACKGROUND: Trichinellosis, a zoonosis caused by the genus Trichinella, is a widespread foodborne disease. Albendazole, one of the benzimidazole derivatives, is used for treating human trichinellosis, but with limited efficacy in killing the encysted larvae and numerous adverse effects. Cyperus rotundus L. is a herbal plant with a wide range of medicinal uses, including antiparasitic, and is frequently used in traditional medicine to treat various illnesses. METHODS: LC-ESI-MS was used to identify the active phytoconstituents in the methanol extract (MeOH ext.) of the aerial parts of C. rotundus and its derivate fractions ethyl acetate (EtOAc fr.), petroleum ether (pet-ether fr.), and normal butanol (n-BuOH fr.). The in vivo therapeutic effects of C. rotundus fractions of the extracts were evaluated using the fraction that showed the most promising effect after detecting their in vitro anti-Trichinella spiralis potential. RESULTS: C. rotundus extracts are rich in different phytochemicals, and the LC-ESI-MS of the 90% methanol extract identified 26 phenolic compounds classified as phenolic acids, flavonoids, and organic acids. The in vitro studies showed that C. rotundus extracts had a lethal effect on T. spiralis adults, and the LC(50) were 156.12 µg/ml, 294.67 µg/ml, 82.09 µg/ml, and 73.16 µg/ml in 90% MeOH ext., EtOAc fr., pet-ether fr. and n-BuOH fr., respectively. The n-BuOH fr. was shown to have the most promising effects in the in vitro studies, which was confirmed by scanning electron microscopy. The in vivo effects of n-BuOH fr. alone and in combination with albendazole using a mouse model were evaluated by counting adults in the small intestine and larvae in the muscles, in addition to the histopathological changes in the small intestine and the muscles. In the treated groups, there was a significant decrease in the number of adults and larvae compared to the control group. Histopathologically, treated groups showed a remarkable improvement in the small intestine and muscle changes. Remarkably, maximal therapeutic effects were detected in the combination therapy compared to each monotherapy. CONCLUSION: Accordingly, C. rotundus extracts may have anti-T. spiralis potential, particularly when combined with albendazole, and they may be used as synergistic to anti-T. spiralis medication therapy. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12906-023-03839-7.