Immunology and Immunopharmacology Laboratory, College of Pharmacy, Chungnam National University, 99 Daekak-ro Yuseong-gu, Daejeon 34134, Republic of Korea.
Natural Products and Pharmaceutical Analysis Laboratory, College of Pharmacy, Chungnam National University, 99 Daekak-ro Yuseong-gu, Daejeon 34134, Republic of Korea.
J Ethnopharmacol. 2018 Jan 30;211:171-179. doi: 10.1016/j.jep.2017.09.026. Epub 2017 Sep 21.
As documented in a Vietnamese traditional medical encyclopedia, Syzygium formosum (Wall.) Masam leaves have been routinely used among indigenous Vietnamese people for treatment of various allergy-like symptoms including dermatitis and rhinitis.
Anti-allergic activity of S. formosum leaves was examined with a mouse model of chicken ovalbumin (cOVA)-induced food allergy, and mechanisms underlying the anti-allergic effect were explored.
BALB/c mice were administered i.p. cOVA (20μg) plus alum (2mg) twice on day 0 and 14 for sensitization (immunization). Two weeks after the second immunization, the mice were administered cOVA (50mg) p.o. 5 times every 3 days to induce food allergy symptoms (i.e., anaphylaxis, diarrhea, and drop in the body temperature). Ethanol extract of dried leaves of S. formosum (80mg/kg or 200mg/kg body weight) was administered p.o. daily during the induction (challenge) period.
Treatment with the S. formosum leaves ethanol extract ameliorated the allergic symptoms to a significant extent and in a dose-dependent manner. The treatment also resulted in a significant improvement in the inflammatory lesion in the small intestine and reduction in the numbers of mast cells and eosinophils recruited to the lesion. The treatment also brought about a significant reduction in the levels of Th2 cytokines produced by the mesenteric lymph node cells cultured ex vivo with cOVA. The passive anaphylaxis experiment also showed that the extract treatment impaired the mast cell function.
Our study provides a scientific basis for the traditional (indigenous) use of the S. formosum leaves extract for the treatment of various allergy symptoms in Vietnam. In addition, the results show that the extract has activities to suppress antigen-specific Th2 T cell immune responses and the mast cell function, which are directly related with its anti-allergic effect.
正如越南传统医学百科全书中所记载的那样，桃金娘科植物（Wall.）Masam 的叶子在越南原住民中被常规用于治疗各种过敏样症状，包括皮炎和鼻炎。
使用鸡卵清蛋白（cOVA）诱导的食物过敏小鼠模型检查桃金娘叶的抗过敏活性，并探讨其抗过敏作用的机制。
BALB/c 小鼠在第 0 天和第 14 天两次通过腹腔注射 cOVA（20μg）加明矾（2mg）进行致敏（免疫）。第二次免疫后两周，小鼠通过口服给予 cOVA（50mg），每 3 天 5 次诱导食物过敏症状（即过敏反应、腹泻和体温下降）。在诱导（挑战）期间，桃金娘叶干浸膏（80mg/kg 或 200mg/kg 体重）以口服方式每天给药。
桃金娘叶乙醇提取物的治疗在很大程度上和剂量依赖性地改善了过敏症状。该治疗还显著改善了小肠的炎症病变，并减少了募集到病变的肥大细胞和嗜酸性粒细胞的数量。该治疗还导致体外用 cOVA 培养的肠系膜淋巴结细胞产生的 Th2 细胞因子水平显著降低。被动过敏实验也表明，提取物处理损害了肥大细胞功能。
我们的研究为桃金娘叶提取物在越南治疗各种过敏症状的传统（本土）用途提供了科学依据。此外，结果表明该提取物具有抑制抗原特异性 Th2 T 细胞免疫反应和肥大细胞功能的活性，这与其抗过敏作用直接相关。
