Antiallergic Activity of Ethanol Extract from Petiveria alliacea

Objetive: To screen the antiallergic effects of different extracts of the leaves of Petiveria alliacea in two experimental models in vitro assay of antiallergic activity in the RBL cell line and antagonism study of guinea pig ileum to LTD₄. Materials and methods: Crude extract of the leaves of P. alliacea obtained by successive extraction with hexane, chloroform and ethanol, were screened for antiallergic properties in the RBL cell line by measuring the inhibitory effects on release of β-hexosaminidase from RBL-2H3 (rat basophil leukemia) cells and also were evaluated by measuring the inhibitory effects on LTD₄-induced contraction of guinea-pig ileum. Results: β-hexosaminidase release induced by antigen (DNP-HAS) was strongly inhibited by ethanol extract; its IC₅₀ was 0.032mg/mL. Chloroform extract was moderately active. The hexane extract had no activity in the test. The ethanol extract showed a significant antihistamine action (91.1%) at a dose of 50μg/mL compared to control. The chloroform extract was found to have little activity (9.1%) and hexane extract did not show a significant antihistamine activity. The disodium cromoglycate (DSCG) one of the commercial antiallergic drugs was used as positive control. All the extracts were less active than DSCG at doses test. At 50μg/mL the ethanol extract of P. alliacea was the most potent antagonist of LTD₄-induced contractions of guinea pig ileum (91.1%). Chloroform and hexane extracts were less active in the test. Conclusion: From the results obtained, it can be observed that ethanol extract of leaves of Petiveria alliacea have significant antiallergic property. It also provides a rationale for their use in the Mexican traditional system of medicine.