Opuntia species 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 from Opuntia streptacantha fruit 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 against Staphylococcus aureus and that the Micrococcus luteus strain 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 oxysporum was 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.

中文翻译：

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仙人掌果果实皮肤的植物化学筛选，抗氧化和抗菌活性

仙人掌物种被用作慢性疾病的当地医学干预手段和食物来源，主要是因为它们具有营养特性和生物活性。这项研究旨在揭示使用乙醇（EFSE）和水（AFSE）从突尼斯卡塞林地区收集的从链霉仙人掌属水果皮中回收的两种提取物的植物化学组成，抗氧化潜力和抗菌活性。结果表明，EFSE中的植物化学含量较高。该提取物中的主要酚类化合物是奎尼酸，反式阿魏酸和高丝苷。同样，通过DPPH分析，EFSE表现出最高的自由基清除率，其有效浓度为一半（IC ₅₀）为0.22±0.006 mg / ml，而AFSE的活性较低，其IC ₅₀（有效清除DPPH自由基的浓度为50％）大于0.61±0.002 mg / ml。此外，将提取物筛选的抗微生物活性对7种细菌和3个真菌菌株，并表明，该提取物表现出对活性最强的结果的金黄色葡萄球菌和该藤黄微球菌菌株的EFSE最敏感的，以最小抑制浓度（MIC ）和最低杀菌浓度值分别为4.75 mg / ml和36.5 mg / ml。对于真菌菌株，尖孢镰刀菌与其他菌株相比，对两种提取物最敏感，并且MIC最低，杀真菌浓度最低。这些发现表明，EFSE具有很强的生物活性化合物，因此支持其种族医学应用。