Phytochemical screening, antioxidant and antimicrobial activities ofOpuntia streptacanthafruit skin

Opuntiaspecies are utilized as local medicinal interventions for chronic diseases and as food sources mainly because they possess nutritional properties and biological activities. This study aimed to disclose the phytochemical composition, antioxidant potential, and antimicrobial activity of two extracts recovered fromOpuntia streptacanthafruit skin collected from Kasserine region in Tunisia using ethanol (EFSE) and water (AFSE). The results revealed that the phytochemical contents are higher in the EFSE. The major phenolic compounds of this extract were quinic acid, trans ferrelic acid and hyperoside. Also, EFSE was shown to exhibit the highest free radical scavenging by DPPH assay with a half-maximally effective concentration (IC50) of 0.22 +/- 0.006 mg/ml, while AFSE was less active and it's IC50(effective concentration at which DPPH radical was scavenged by 50%) were above 0.61 +/- 0.002 mg/ml. Moreover, the extracts were screened for antimicrobial activity against 7 bacteria and 3 fungal strains and the results showed that the extracts exhibited the strongest activity againstStaphylococcus aureusand that theMicrococcus luteusstrain was the most sensitive to the EFSE, with minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations values of 4.75 mg/ml and 36.5 mg/ml respectively. For fungal strains,Fusarium oxysporumwas the most sensitive for both extracts and exhibited the lowest MIC and minimum fungicidal concentrations compared to other strains. These findings reveal that the EFSE have strong bioactive compounds and hence support its ethnomedicinal application.