Zhou Z. et al. Effect of gynostemma pentaphyllum mak on carcinomatous conversions of golden hamster cheek pouches induced by dimethylbenzanthracene: a histological study.The Journal of Chinese Medicine 1998.

Dr. Zhou at Shanghai Medical University gave hamsters a known carcinogen. A control group did not receive Jiaogulan and developed cancer as predicted. Two other groups were given Jiaogulan orally. Both groups showed remarked slowing of the cancerous growth. The inhibitory effects were directly correlated with the dosage amounts of Jiaogulan.