Levin Robert M, Kawashima Yoshihito, Leggett Robert E, Whitbeck Catherine, Horan Patrick, Mizutani Kenji
Albany College of Pharmacy, Albany Medical College and Stratton Veterans Affairs Medical Center, Albany, New York, and Maruzen Pharmaceuticals, Onomichi City, Japan.
J Urol. 2002 May;167(5):2260-6.
Extracts of the leaves of Engelhardtia chrysolepis, a subtropical plant that grows wild in southern China, have been used medicinally in east Asia for hundreds of years. A standard extract named Kohki tea (Maruzen Pharmaceuticals, Onomichi City, Japan) is sold over the counter in Japan as a sweet tea shown to confer many beneficial effects on general health and well-being. The tea contains strong antioxidants, including several dihydroflavonol glycosides. The results of previous studies show that natural products with antioxidant activities provide protective effects on the bladder of rabbits with partial outlet obstruction. We determined in vivo and in vitro whether oral pretreatment of rabbits with Kohki tea protects the bladder from dysfunction induced by partial outlet obstruction.
A total of 28 New Zealand White rabbits were separated into 4 groups of 7 each. Rabbits in groups 1 and 2 were treated by gavage with 100 mg./kg. Kohki tea daily in distilled water, while those in groups 3 and 4 were given distilled water. After 4 weeks of daily oral administration each rabbit was sedated, the bladder was catheterized and cystometry was performed at a filling rate of 1 ml. per minute. At the completion of cystometry the rabbits were immediately anesthetized. Moderate outlet obstruction was created in groups 1 and 3, and sham surgery was performed in groups 2 and 4. Treatment was continued for an additional 4 weeks, when each rabbit was sedated and cystometry was repeated. After cystometry the bladder was exposed through a midline incision, excised, weighed and 4 strips of bladder body were cut for contractility studies. The balance of the bladder was separated between smooth muscle and mucosa by blunt dissection, frozen in liquid nitrogen and stored at -70C for biochemical analyses.
Partial outlet obstruction stimulated similar increases in the bladder weight of all obstructed rabbits. Partial outlet obstruction resulted in a significant decrease in bladder compliance in all obstructed animals. However, the bladder of obstructed rabbits given Kohki tea were significantly more compliant than those given water. Voiding pressures in the control group and the obstructed group given distilled water were approximately equal, while obstructed rabbits given Kohki tea showed significantly higher maximal voiding pressure. The contractile responses to all forms of stimulation were reduced by obstruction to a significantly greater degree in the rabbits not given tea than in those given tea. Sarcoplasmic reticulum Ca2+-adenosine triphosphatase enzyme activity of the bladder was significantly reduced in obstructed rabbits given vehicle but activity was not reduced in obstructed rabbits given Kohki tea.
Kohki tea had a significant protective effect on bladder function, contractile responses and bladder biochemistry in rabbits with moderate to severe partial outlet obstruction.
黄杞是一种生长在中国南方的亚热带野生植物，其叶提取物在东亚已药用数百年。一种名为Kohki茶（日本丸善制药，尾道市）的标准提取物在日本作为甜茶在柜台销售，已证明对总体健康有益。该茶含有强效抗氧化剂，包括几种二氢黄酮醇糖苷。先前的研究结果表明，具有抗氧化活性的天然产物对部分出口梗阻的兔子膀胱具有保护作用。我们在体内和体外确定，用Kohki茶对兔子进行口服预处理是否能保护膀胱免受部分出口梗阻引起的功能障碍。
将28只新西兰白兔分为4组，每组7只。第1组和第2组的兔子每天用蒸馏水灌胃100mg/kg的Kohki茶，而第3组和第4组的兔子给予蒸馏水。每天口服给药4周后，将每只兔子麻醉，插入膀胱导管，并以每分钟1ml的充盈速率进行膀胱测压。膀胱测压完成后，立即对兔子进行麻醉。第1组和第3组造成中度出口梗阻，第2组和第4组进行假手术。继续治疗4周，然后将每只兔子麻醉并重复膀胱测压。膀胱测压后，通过中线切口暴露膀胱，切除，称重，并切下4条膀胱体条进行收缩性研究。通过钝性解剖将膀胱其余部分分离为平滑肌和黏膜，在液氮中冷冻并储存在-70℃用于生化分析。
部分出口梗阻刺激所有梗阻兔子的膀胱重量出现类似增加。部分出口梗阻导致所有梗阻动物的膀胱顺应性显著降低。然而，给予Kohki茶的梗阻兔子的膀胱顺应性明显高于给予水的兔子。对照组和给予蒸馏水的梗阻组的排尿压力大致相等，而给予Kohki茶的梗阻兔子的最大排尿压力明显更高。与给予茶的兔子相比，未给予茶的兔子对所有形式刺激的收缩反应因梗阻而降低的程度明显更大。给予赋形剂的梗阻兔子膀胱的肌浆网Ca2+ - 三磷酸腺苷酶活性显著降低，但给予Kohki茶的梗阻兔子的活性未降低。
Kohki茶对中度至重度部分出口梗阻的兔子的膀胱功能、收缩反应和膀胱生物化学具有显著的保护作用。
