Jine Y, Lis M, Szczypka M, Obmińska-Mrukowicz B
College of Veterinary Medicine, Hunan Agricultural University, Changsha 410128, PR China.
Pol J Vet Sci. 2012;15(2):305-13. doi: 10.2478/v10181-011-0148-y.
Betulinic acid is a pentacyclic triterpene found in many plant species, among others, in the bark of white birch Betula alba. Betulinic acid was reported to display a wide range of biological effects, including antiviral, antiparasitic, antibacterial, anticancer and anti-inflammatory activities. The effects of betulinic acid (50, 5, 0.5 mg/kg) administered orally five times at 24 hours intervals to non-immunized and red blood cells (SRBC)-immunized mice were determined. The present study examined the total number of lymphocytes in the thymus, spleen and mesenteric lymph nodes, and the percentage of subsets of T cells (CD4+CD8+, CD4CD8, CD4+, CD8+) in thymus,T (CD3+, CD4+, CD8+) and B (CD19+) lymphocytes in the spleen and mesenteric lymph nodes, as well as white blood cell (WBC) and differential leukocyte counts in non-immunized mice, and humoral immune response in SRBC-immunized mice. SRBC was injected 24 hours after administration of the last dose of betulinic acid. It was found that betulinic acid administered orally five times at the dose of 0.5 mg/kg increased the total number of thymocytes, splenocytes, lymphocytes of mesenteric lymph node cells, and the weight ratio of the spleen and mesenteric lymph nodes in non-immunized mice. Betulinic acid also changed the percentage of T cell subsets in the thymus and T and B lymphocytes in peripheral lymphatic organs. The effects of betulinic acid on T and B cell subpopulations depended on the dose applied. The strongest stimulating effect of betulinic acid was observed when the drug was administered at the dose of 0.5 mg/kg. Five exposures to betulinic acid (0.5 mg/kg) decreased the percentage of immature CD4+CD8+ thymic cells with corresponding increases in the percentage and absolute count of mature, single-positive CD4+ thymocytes and decreased the percentage and total count of CD3+ splenocytes and mesenteric lymph node cells with corresponding decreases in the percentage and absolute count of CD4+ and CD8+ cells. Multiple administration of betulinic acid at the investigated doses augmented the percentage and absolute count of CD19+ cells in the peripheral lymphatic organs. Moreover, betulinic acid at the dose of 5 mg/kg administered prior to SRBC immunization increased the number of plaque forming cells (PFC) but decreased the production of anti-SRBC antibodies on day 4 after priming. Thus, betulinic acid is a potential biological response modifier and may strengthen the immune response of its host.
桦木酸是一种五环三萜，存在于许多植物物种中，尤其是白桦（Betula alba）的树皮中。据报道，桦木酸具有广泛的生物学效应，包括抗病毒、抗寄生虫、抗菌、抗癌和抗炎活性。测定了以24小时间隔口服给予非免疫和红细胞（SRBC）免疫小鼠五次的桦木酸（50、5、0.5mg/kg）的效果。本研究检测了胸腺、脾脏和肠系膜淋巴结中的淋巴细胞总数，以及胸腺中T细胞亚群（CD4+CD8+、CD4CD8、CD4+、CD8+）的百分比，脾脏和肠系膜淋巴结中T（CD3+、CD4+、CD8+）和B（CD19+）淋巴细胞的百分比，以及非免疫小鼠的白细胞（WBC）和白细胞分类计数，以及SRBC免疫小鼠的体液免疫反应。在最后一剂桦木酸给药后24小时注射SRBC。结果发现，以0.5mg/kg的剂量口服五次桦木酸可增加非免疫小鼠的胸腺细胞、脾细胞、肠系膜淋巴结细胞的淋巴细胞总数，以及脾脏和肠系膜淋巴结的重量比。桦木酸还改变了胸腺中T细胞亚群以及外周淋巴器官中T和B淋巴细胞的百分比。桦木酸对T和B细胞亚群的影响取决于所用剂量。当以0.5mg/kg的剂量给药时，观察到桦木酸的刺激作用最强。五次给予桦木酸（0.5mg/kg）可降低未成熟CD4+CD8+胸腺细胞的百分比，同时成熟单阳性CD4+胸腺细胞的百分比和绝对计数相应增加，并降低CD3+脾细胞和肠系膜淋巴结细胞的百分比和总数，同时CD4+和CD8+细胞的百分比和绝对计数相应降低。在所研究的剂量下多次给予桦木酸可增加外周淋巴器官中CD19+细胞的百分比和绝对计数。此外，在SRBC免疫前以5mg/kg的剂量给予桦木酸可增加初次免疫后第4天的空斑形成细胞（PFC）数量，但降低抗SRBC抗体的产生。因此，桦木酸是一种潜在的生物反应调节剂，可能会增强其宿主的免疫反应。
