Volatile compounds and bioactivities properties of Opuntia microdasys (Lehm.) and Opuntia macrorhiza (Engelm.) seeds

The seeds of Opuntia sp. require additional investigations because they could contain several active molecules. Therefore, the present study analyzed the chemical composition and biological activities of Opuntia microdasys and that of Opuntia macrorhiza using in vitro and in vivo models.  The headspace of the powders of the seeds of Opuntia have been analyzed by gas chromatography–mass spectrometry (GC–MS). The analgesic activity was assessed using the acetic acid-induced abdominal constriction response on mouse. Chemical analyses showed that the powders of the seeds of O. microdasys and O. macrorhiza were rich in nonanal and camphor. Also, the O. macrorhiza seeds has a high antioxidant activity (EC50 =0.12 mg/ml). The results showed that the ethanolic extracts, at a dose of 200 mg/kg of body weight, caused a significant (P< 0.05) inhibition of the abdominal constriction response (75.17% and 56.22% for O. microdasys and O. microdasys). The microdilution assay revealed that ethanolic extract of O. macrorhiza seeds is more active and could inhibit the growth of almost all the evaluated bacterial and fungal strains, with the minimal bactericidal concentration values (MIC) ranging from 0.039 to 2.50 mg/mL. The overall results highlighted the potential of the tested Opuntia seeds that can be used as a source of bioactive compounds that confer various important biological activities to it, which could imply other pharmacological applications.