从herbmed上面摘抄了一些:
Slimming liposomes i.e., esculoside and Centella asiatica extracts containing 2 micro-circulation activators, i.e., caffeine, and L-carnitine were developed and found to antagonize the alpha(2)-adrenergic receptor and in vivo studies revealed slimming effect on human volunteers. Tholon 2002
Treatment of 100 women with a cream containing Centella asiatica extract, alpha tocopherol and collagen-elastin hydrolysates, help to prevent the development of stretch marks in pregnancy (odds ratio 0.41, 95% confidence interval 0.17 to 0.99). Young 2000
The study of nutritional support for wound healing reveals that Centella asiatica and Aloe vera have been used for decades, both topically and internally, to enhance wound repair. MacKay 2003
基本上就是临床试验证明积雪草中含咖啡因和肉碱帮助体内微循环所以能瘦身。还可以帮助治疗妊娠纹和修复伤口。但是这些试验都是用的提取物并非油。
还有下面这个link里说,
http://www.holistic-online.com/Herbal-Med/_Herbs/h18.htm
Active Compounds:
The primary active constituent is triterpenoid compounds. Saponins (also called triterpenoids) known as asiaticoside, madecassoside, and madasiatic acid are the primary active constituents. These saponins beneficially affect collagen (the material that makes up connective tissue), for example, inhibiting its production in hyperactive scar tissue.
Also contains a green, strongly volatile oil composed of an unidentified terpene acetate, camphor, cineole, and other essential oils. Cintella oil also contains glycerides of fatty acids, various plant sterols such as campesterol, stigmasterol, and sitosterol, and various polyacetylene compounds
我觉得,油的提取应该是从叶子,但是不是通过浸泡的方式就不知道了。