Salem Mohamed A, El-Shiekh Riham A, Hashem Rasha A, Hassan Mariam
Department of Pharmacognosy, Faculty of Pharmacy, Menoufia University, Menoufia, Egypt.
Department of Pharmacognosy, Faculty of Pharmacy, Cairo University, Cairo, Egypt.
Infect Drug Resist. 2021 Jan 6;14:33-48. doi: 10.2147/IDR.S285940. eCollection 2021.
Star anise fruits ( Hook.) have been used as an important treatment in traditional Chinese medicine. The previous studies reported the activity of the non-polar fractions as potential sources of antibacterial metabolites, and little was done concerning the polar fractions of star anise.
The antibacterial activity of the star anise aqueous methanolic (50%) extract against multidrug-resistant AB5057 and methicillin-resistant (MRSA USA300) was investigated in vitro (disc diffusion assay, minimum bactericidal concentration determination, anti-biofilm activity and biofilm detachment activity). The antibacterial activity was further tested in vivo using a murine model of MRSA skin infection. Ultra-performance liquid chromatography coupled to high-resolution mass spectrometry (UPLC/HRMS) approach was applied for the identification of the metabolites responsible for the antibacterial activity. The antioxidant potential was evaluated using five in vitro assays: TAC (total antioxidant capacity), DPPH, ABTS, FRAP (ferric reducing antioxidant power) and iron-reducing power.
In vitro, star anise aqueous methanolic extract showed significant inhibition and detachment activity against biofilm formation by the multidrug-resistant and highly virulent AB5057 and MRSA USA300. The topical application of the extract in vivo significantly reduced the bacterial load in MRSA-infected skin lesions. The extract showed strong antioxidant activity using five different complementary methods. More than seventy metabolites from different classes were identified: phenolic acids, phenylpropanoids, sesquiterpenes, tannins, lignans and flavonoids.
This study proposes the potential use of star anise polar fraction in anti-virulence strategies against persistent infections and for the treatment of staphylococcal skin infections as a topical antimicrobial agent. To our knowledge, our research is the first to provide the complete polar metabolome list of star anise in an approach to understand the relationship between the chemistry of these metabolites and the proposed antibacterial activity.
八角茴香果实（八角茴香）在中国传统医学中一直被用作重要的治疗药物。先前的研究报道了非极性馏分作为抗菌代谢物潜在来源的活性，而关于八角茴香极性馏分的研究较少。
研究了八角茴香甲醇水溶液（50%）提取物对多重耐药AB5057和耐甲氧西林金黄色葡萄球菌（MRSA USA300）的体外抗菌活性（纸片扩散法、最低杀菌浓度测定、抗生物膜活性和生物膜清除活性）。使用MRSA皮肤感染小鼠模型在体内进一步测试抗菌活性。采用超高效液相色谱-高分辨率质谱联用（UPLC/HRMS）方法鉴定具有抗菌活性的代谢物。使用五种体外试验评估抗氧化潜力：总抗氧化能力（TAC）、二苯基苦味酰基自由基（DPPH）、2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸（ABTS）、铁还原抗氧化能力（FRAP）和铁还原能力。
在体外，八角茴香甲醇水溶液提取物对多重耐药且高毒力的AB5057和MRSA USA300形成的生物膜表现出显著的抑制和清除活性。该提取物在体内局部应用显著降低了MRSA感染皮肤损伤处的细菌载量。使用五种不同的互补方法，该提取物表现出较强的抗氧化活性。鉴定出了七十多种不同类别的代谢物：酚酸、苯丙素、倍半萜、单宁、木脂素和黄酮类化合物。
本研究提出八角茴香极性馏分在针对持续性感染的抗毒力策略中以及作为局部抗菌剂治疗葡萄球菌皮肤感染方面具有潜在用途。据我们所知，我们的研究首次提供了八角茴香完整的极性代谢组清单，以了解这些代谢物的化学性质与所提出的抗菌活性之间的关系。
