Teethaisong Yothin, Win Htun Htun, Thummavongsa Theera, Eumkeb Griangsak, Dunkhunthod Benjawan, Posoongnoen Saijai, Santhi Maniganda, Gorantla Jaggaiah N, Ketudat-Cairns Mariena, Ketudat-Cairns James R
Department of Medical Sciences, Faculty of Allied Health Sciences, Burapha University, Chon Buri, 20131, Thailand.
Center for Biomolecular Structure, Function and Application, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand.
Sci Rep. 2025 Jul 1;15(1):21151. doi: 10.1038/s41598-025-07396-6.
Acne vulgaris is the most common dermatological problem among adolescents and young adults. Acne-associated pathogens, including Cutibacterium acnes and Staphylococcus epidermidis, and inflammation are among predominant etiologies of acne. Drugs targeting pathogens and inflammation response are an effective avenue to treat acne vulgaris. Rice bran has high pharmacological value, but its therapeutic potential for the treatment of acne remains unexplored. This study, therefore, aimed to purify and identify an anti-acne component from the ethanolic extract of Thai black rice (Oryza sativa cv. Neow Dam 3) bran and to investigate its underlying mechanisms of action. Protocatechuic acid (PA) was purified by bio-guided extraction and identified by a nuclear magnetic resonance. The antibacterial action was elucidated by minimum inhibitory concentration (MIC) determination and electron microscopy. PA cytotoxicity in HaCaT keratinocytes was assessed by an MTT assay, expression of inflammatory-associated genes and proteins by RT-qPCR, western blotting, and ELISA, and the nuclear translocation of NF-κB by immunofluorescence. The MIC of PA against C. acnes DMST 14,916 and S. epidermidis ATCC 12,228 and DMST 14,932 was 2048 µg/mL, which was similar to ferulic acid. Scanning and transmission electron microscopy demonstrated C. acnes and S. epidermidis treated with PA had unambiguous membrane damage and abnormal morphology. C. acnes lysate induced the expression of IL-6, IL-8, IL-1β, iNOS, TNF-α, and COX-2 genes, increased phosphorylated NF-κB, IL-6, and TNF-α protein levels, and caused translocation of NF-κB into the nucleus, while noncytotoxic levels of PA suppressed these effects. In summary, PA had anti-acne activity by inhibiting acne-associated pathogens, possibly through cell membrane damage, and suppressed inflammation induced by C. acnes via the NF-κB pathway suggesting that it may have therapeutic use for treating acne in the future.
寻常痤疮是青少年和青年成年人中最常见的皮肤问题。痤疮相关病原体，包括痤疮丙酸杆菌和表皮葡萄球菌，以及炎症是痤疮的主要病因。针对病原体和炎症反应的药物是治疗寻常痤疮的有效途径。米糠具有很高的药理价值，但其治疗痤疮的潜力仍未得到探索。因此，本研究旨在从泰国黑米（Oryza sativa cv. Neow Dam 3）麸皮的乙醇提取物中纯化和鉴定一种抗痤疮成分，并研究其潜在的作用机制。原儿茶酸（PA）通过生物导向提取进行纯化，并通过核磁共振进行鉴定。通过最低抑菌浓度（MIC）测定和电子显微镜阐明抗菌作用。通过MTT法评估PA在HaCaT角质形成细胞中的细胞毒性，通过RT-qPCR、蛋白质印迹和ELISA评估炎症相关基因和蛋白质的表达，通过免疫荧光评估NF-κB的核转位。PA对痤疮丙酸杆菌DMST 14916和表皮葡萄球菌ATCC 12228及DMST 14932的MIC为2048 μg/mL，与阿魏酸相似。扫描电子显微镜和透射电子显微镜显示，用PA处理的痤疮丙酸杆菌和表皮葡萄球菌有明确的膜损伤和形态异常。痤疮丙酸杆菌裂解物诱导IL-6、IL-8、IL-1β、iNOS、TNF-α和COX-2基因的表达，增加磷酸化NF-κB、IL-6和TNF-α蛋白水平，并导致NF-κB转位到细胞核，而非细胞毒性水平 的PA抑制了这些作用。总之，PA通过抑制痤疮相关病原体具有抗痤疮活性，可能是通过细胞膜损伤，并通过NF-κB途径抑制痤疮丙酸杆菌诱导的炎症，这表明它未来可能具有治疗痤疮的用途。
