Two research labs 6,000 miles away from each other are studying how herbal remedies work at the molecular level, which would pave the way for a new era of more personalized therapeutics to treat complex human diseases.   Fu-Shuang Li, a Chinese medicinal chemist, summits a mountain in the Guangxi province in south China, and kneels to identify a plant with hollow stems and oval, creamy white flowers. The plant’s name is Japanese Knotweed (Polygonum cuspidatum), and, like all plants, contains thousands of small molecules known as metabolites, which are responsible for qualities such as color, flavor and fragrances. For two thousand years, species of Japanese Knotweed have been used medically for treating Lyme disease, joint pain, bronchitis, jaundice, amenorrhea and hypertension. In traditional Chinese medicine (TCM), a broad…