An herbal mixture, called “Huang Qin Tang” in China, has been used for about 1800 years to treat gastrointestinal problems like diarrhea. A new pharmaceutical company, PhytoCeutica, in collaboration with Yale University, showed in initial clinical trials that Huang Qin Tang, now called PHY906, prevents the severe diarrhea caused by chemotherapy in colon and rectal cancer patients. Experiments in mice showed how these herbs accomplish intestinal healing.
Mice with colon cancer were treated with a chemotherapeutic drug to shrink their tumors. The tumors receded, but treatment caused extensive damage to the lining of the intestine. Mice with tumors were divided into two groups; one group received only the therapeutic drug, while the other group received the drug plus the PHY906 herbal preparation. The group receiving PHY906 lost less body weight and after only four days of treatment with PHY906, the normal intestinal architecture was restored. The researchers showed that PHY906 blocked the migration of inflammatory cells into the intestine and blocked other pro-inflammatory enzymes and factors. The herbal mixture did not stop the action of the chemotherapeutic drugs, cells were damaged, but it restored the proliferation and function of normal intestinal cells.
Huang Qui Tang (PHY906) consists of four herbs: Chinese licorice (Glycyrrhiza), Chinese skullcap (Scutellaria baicalensis, Chinese peony (Paeonia lactiflora), and the fruit of the Chinese date tree (Zizphus jujuba). Chinese skullcap and licorice are widely used herbs. Chinese skullcap is known to be anti-inflammatory and combats anxiety and high blood pressure. Licorice is also anti-inflammatory and has been used for sore throats, cough, heartburn and gastritis. Scientific studies have demonstrated that both herbs have anti-cancer activity in cells in tissue culture. The effects of peony and Chinese date fruit are less well studied and known.
Problems with herbal remedies
Herbal remedies are big business and are widely used. The power of herbs may be due to the multitude of substances or chemicals that they contain. Many herbalists believe that it is the totality of substances that account for the beneficial effects. But the many chemicals, known and unknown, in herbs make it difficult to study herbal remedies. How do you ensure consistent potency? In the case of Huang Qui Tang, the researchers have identified some, but not all of the active substances using modern technology. Another problem is quality control. Whereas synthetic drugs undergo strict quality control and are FDA regulated, herbal preparations may vary from source to source and due to growing and environmental conditions. They may be contaminated with toxins depending on the source or preparation. Some herbs, like drugs, can also have side effects and when used together with a synthetic drug may increase or decrease the potency of the synthetic drug.
Lam, W. et al. The Four-Herb Chinese Medicine PHY906 Reduces Chemotherapy-Induced Gastrointestinal Toxicity. Science Translational Medicine (2010) 2: 45ra69
Eng, C. Are Herbal Medicines Ripe for the Cancer Clinic? Science Translational Medicine (2010) 2: 45ps41