Ferid Murad, chair of the Department of Integrative Biology, Pharmacology and Physiology at the University of Texas, won the Nobel Prize for physiology in 1998 for his discovery of new properties of nitric oxide.

A colorless, odorless gas, nitric oxide acts as a messenger to tell blood vessels to relax and widen, thereby lowering blood pressure.

The application of his findings later resulted in the invention of the acclaimed impotency drug, Viagra.

Since 2003, Murad has paid several visits a year to China to work with Chinese scientists studying the biological properties of traditional Chinese medicine (TCM).

Currently, 15 native researchers are engaged at the Murad Research Center for Traditional Chinese Medicine with Shanghai University of Traditional Chinese Medicine.

Their aim is to make extracts from natural herbs, and then test their biological properties, said Ke Yan, the center's assistant director.

"We analyze various components of Chinese herbs and try to understand the mechanism of how they work pharmacologically," explains Murad, who closely follows the lab's progress and offers advice, ideas and guidance during his visits.

All the research work is based on Murad's findings concerning the function of nitric oxide in various cellular signaling processes.

Present in most living creatures, nitric oxide is a signal molecule of key importance for the cardiovascular system, immune system and inflammation. It controls blood pressure and its distribution and modulates many functions, from behavior to gastrointestinal motility. High quantities in white cells are toxic to invading bacteria and parasites.

"Murad is highly interested in TCM compound prescriptions. Our research work focuses on exploring their physiological action within a bioinformatics system of nitric oxide," said Ke.

Murad began to take an interest in TCM in the 1980s. At that time, the wife of one of his colleagues had developed breast cancer. She tried numerous Western medicinal therapies, but her condition did not seem to improve. She later went to Hong Kong where she underwent a course of TCM treatment after which the cancer went into complete remission.

This experience, combined with what he learnt whilst giving lectures in the Chinese University of Hong Kong, increased Murad's interest. "There must be something working in TCM," he said.

TCM vs systems biology

The experience of working with Murad has been enjoyable and instructive for Ke and her colleagues.

Like most other traditional Chinese medicine researchers, Ke often felt at a loss as to how to bridge traditional TCM theory, which is empirically based with modern Western evidence-based medicine.

"TCM is directed to the symptoms, rather than the disease. The doctors may write out different prescriptions of herbal medicines for patients with the same disease. Even the medicine prescribed for the same patient may also vary at different stages of the disease," explained Ke.

There remains, for the most part, no scientific evidence to demonstrate the curative effects of TCM.

"The classic theory of TCM is being viewed by more and more scientists as a kind of culture. It is divorced from basic science," said Ke.

And she believes that too many riddles in TCM treatment prevent its efficacy from gaining worldwide recognition.

Notwithstanding its empirical basis, Ke does not suggest TCM researchers totally discard the TCM philosophy as they screen millions of compounds in Chinese herbs in search of single bioactive constituents to make a new drug. With the growing popularity of systems biology nowadays, a group of TCM researchers like Ke have begun to rethink their research strategy.

"The holistic healthcare philosophy of TCM actually accords with the concept of systems biology," she said.

The goal of modern systems biology is to understand physiology and disease from the level of molecular pathways, regulatory networks, cells, tissues, organs and ultimately the whole organism.

Similarly, TCM, boasting a history of 5,000 years, has always focused on a multi-factorial concept. It takes the holistic approach and focuses on functional analysis of the entire body.

Therefore, each herbal mixture TCM doctors prescribe has a polyvalent activity, an interaction with more than one kind of antigen, antibody, toxin, or micro-organism.

So when Ke and her colleagues are analyzing the biological properties of Chinese herbal medicine under the direction of Murad, they seek to integrate the fundamental principles of TCM as being a holistic form of medicine.

They try to measure the synergetic effects in the human body when exposed to complex mixtures of Chinese herbs.

"TCM generally acts on multiple molecular targets in the body. What we want to do is to identify these targets and determine if they work in co-ordination with each other to modulate the physiological pathways," explains Ke.

She believes it could be a considerable advance for TCM if their work could explain how Chinese herbal mixtures work during the disease-fighting process. The researchers are also trying to screen various categories of constituents in Chinese herbs, such as those in the categories of flavones and alkaloids.

"Grasping the most effective part of Chinese herbal medicine will benefit considerably our future new drug development," Ke added.

(China Daily May 18, 2005)