Yoshihito Kawashima

Effect of Oral Kohki Tea on Bladder Dysfunction Induced by Severe Partial Outlet Obstruction

PURPOSE 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. MATERIALS AND METHODS 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. RESULTS 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. CONCLUSIONS Kohki tea had a significant protective effect on bladder function, contractile responses and bladder biochemistry in rabbits with moderate to severe partial outlet obstruction.

Abstracts: The effects of licorice leaf extract on ceramide and hyaluronan synthesis

pp.267–273 Both water-holding and permeability barrier function in the stratum corneum (SC) are essential for keeping skin moisture. Intercellular lipids in SC, which are composed mainly of cholesterol, fatty acids, and ceramides, play a crucial role for maintaining the function in SC. The object of our study is to find active ingredients from plant extracts for enhancing the abilities of skin hydration and barrier repair by focusing on the synthesis of ceramides. As a result, we found that licorice leaf extract is a promising ingredient showing not only an increase of mRNA expression levels of serine palmytoyltransferase (SPT) and sphingomyelinase related to ceramide biosynthesis in keratinocytes but also syntheses of ceramides in a 3D skin model and in human skin. Furthermore, licorice leaf extract showed an increase of mRNA expression levels of HMG-CoA reductase (HMGCR) related to cholesterol biosynthesis and an increase of hyaluronan (HA) production in in vitro tests. One of the principles isolated from licorice leaf extract, 6-prenyl-naringenin, was thought to be one of the active components. These results suggested that licorice leaf extract may be a useful ingredient for skin care due to the synthesis of intercellular lipids and HA