Sharma Richa, Kishore Navneet, Hussein Ahmed, Lall Namrita
Department of Plant Science, Faculty of Agricultural and Biological Science, University of Pretoria, Pretoria 0002 South Africa.
BMC Complement Altern Med. 2013 Oct 29;13:292. doi: 10.1186/1472-6882-13-292.
Acne vulgaris is a chronic skin disorder leading to inflammation as a result of the production of reactive oxygen species due to the active involvement of Propionibacterium acnes (P. acnes) in the infection site of the skin. The current study was designed to assess the potential of the leaf extract of Syzygium jambos L. (Alston) and its compounds for antibacterial and anti-inflammatory activity against the pathogenic P. acnes.
The broth dilution method was used to assess the antibacterial activity. The cytotoxicity investigation on mouse melanocyte (B16-F10) and human leukemic monocyte lymphoma (U937) cells was done using sodium 3'-[1-(phenyl amino-carbonyl)-3,4-tetrazolium]-bis-[4-methoxy-6-nitrobenzene sulfonic acid hydrate (XTT) reagent. The non-toxic concentrations of the samples was investigated for the suppression of cytokines interleukin 8 (IL 8) and tumour necrosis factor (TNF α) by testing the supernatants in the co-culture of the human U937 cells and heat killed P. acnes using enzyme immunoassay kits (ELISA). The statistical analysis was done using the Graph Pad Prism 4 program.
Bioassay guided isolation of ethanol extract of the leaves of S. jambos led to the isolation of three known compounds namely; squalene, an anacardic acid analogue and ursolic acid which are reported for the first time from this plant. The ethanol extract of S. jambos and one of the isolated compound namely, anacardic acid analogue were able to inhibit the growth of P. acnes with a noteworthy minimum inhibitory concentration (MIC) value of 31.3 and 7.9 μg/ml, respectively. The ethanol extract and three commercially acquired compounds namely; myricetin, myricitrin, gallic acid exhibited significant antioxidant activity with fifty percent inhibitory concentration (IC50) ranging between 0.8-1.9 μg/ml which was comparable to that of vitamin C, the reference antioxidant agent. The plant extract, compounds ursolic acid and myricitrin (commercially acquired) significantly inhibited the release of inflammatory cytokines IL 8 and TNF α by suppressing them by 74 - 99%. TEM micrographs showed the lethal effects of selected samples against P. acnes.
The interesting antibacterial, antioxidant and anti-inflammatory effects of S. jambos shown in the present study warrant its further investigation in clinical studies for a possible alternative anti-acne agent.
寻常痤疮是一种慢性皮肤疾病，由于痤疮丙酸杆菌（P. acnes）在皮肤感染部位的活跃参与，产生活性氧导致炎症。本研究旨在评估蒲桃叶提取物及其化合物对致病性痤疮丙酸杆菌的抗菌和抗炎活性。
采用肉汤稀释法评估抗菌活性。使用3'-[1-(苯基氨基羰基)-3,4-四氮唑]-双-[4-甲氧基-6-硝基苯磺酸水合物（XTT）试剂对小鼠黑素细胞（B16-F10）和人白血病单核细胞淋巴瘤（U937）细胞进行细胞毒性研究。通过使用酶免疫分析试剂盒（ELISA）检测人U937细胞与热灭活的痤疮丙酸杆菌共培养上清液，研究样品的无毒浓度对细胞因子白细胞介素8（IL 8）和肿瘤坏死因子（TNFα）的抑制作用。使用Graph Pad Prism 4程序进行统计分析。
生物活性导向分离蒲桃叶乙醇提取物，得到三种已知化合物，即角鲨烯、一种腰果酸类似物和熊果酸，这是首次从该植物中报道。蒲桃叶乙醇提取物和其中一种分离化合物，即腰果酸类似物能够抑制痤疮丙酸杆菌的生长，其最低抑菌浓度（MIC）值分别为31.3和7.9μg/ml，值得关注。乙醇提取物和三种商业获得的化合物，即杨梅素、杨梅苷、没食子酸表现出显著的抗氧化活性，半数抑制浓度（IC50）在0.8 - 1.9μg/ml之间，与参考抗氧化剂维生素C相当。植物提取物、熊果酸和杨梅苷（商业获得）通过抑制74 - 99%显著抑制炎症细胞因子IL 8和TNFα的释放。透射电子显微镜图像显示所选样品对痤疮丙酸杆菌的致死作用。
本研究中蒲桃叶显示出的有趣的抗菌、抗氧化和抗炎作用，使其有必要在临床研究中进一步研究，以作为一种可能的抗痤疮替代药物。
