Chemical profile and alpha-glucosidase inhibitory, cytotoxic, and anti-inflammatory properties of (E)-anethole-rich essential oil from Limnophila rugosa cultivated in Vietnam

Essential oils extracted from the leaves and stems of Limnophila rugosa, collected in Aluoi district, Hue city, Vietnam, were analyzed for their chemical composition and evaluated for -glucosidase inhibitory, cytotoxic, and anti-inflammatory activities.The oils, with yields of 0.6 0.02% (leaves) and 0.4 0.01% (stems) (w/w, fresh weight), were characterized as milky white liquids with a distinct aromatic odor and lower density than water.GC-MS analysis identified 14 volatile compounds in the leaf oil (99.83% of total content) and seven in the stem oil (99.03% of total content), with (E)-anethole as the predominant constituent (77.53% in leaf oil, 94.30% in stem oil).Other notable compounds in the leaf oil included 1-octen-3-ol (8.19%) and 2-octanol (7.94%), which were less abundant in the stem oil (1.93% and 1.24%, respectively).The stem oil exhibited moderate -glucosidase inhibitory activity (IC = 322.26 15.16 g/mL), while the leaf oil showed negligible activity (IC50 > 500.00g/mL), compared to acarbose (IC50 = 117.84 7.25 g/mL).Both oils demonstrated moderate cytotoxicity against HEK-293A, HepG2, and SK-LU-1 cell lines, with IC50 values ranging from 35.56 2.04 to 60.47 2.53 g/mL, compared to ellipticine (IC50 = 0.34-0.38g/mL).Anti-inflammatory activity was assessed via nitric oxide (NO) production inhibition in RAW 264.7 macrophages, with both oils showing significant NO inhibition but IC values exceeding 100 g/mL, compared to dexamethasone (IC = 13.55 1.26 g/mL).The high (E)anethole content likely contributes to these bioactivities, though the presence of 1-octen-3-ol and 2-octanol in the leaf oil may reduce its -glucosidase inhibitory efficacy.This study establishes the foundation for future investigations into the medicinal potential of L. rugosa essential oils from Hue city, Vietnam, by being the first to report their chemical composition and -glucosidase inhibitory, cytotoxic, and anti-inflammatory actions.