New research offers insights into BaiJi Traditional Chinese Medicine molecular mechanisms
09 Jul 2024 --- BaiJi, also known as Bletilla striata (B. striata) or Chinese ground orchid, is commonly used in Traditional Chinese Medicine (TCM) for its medicinal polysaccharides, a type of carbohydrate found in its pseudobulbs storage organs. A new study of the plant reveals previously unknown insights about its polysaccharide content, composition and distribution.
Despite BaiJi’s popularity in TCM, much remains unknown about the cellular distribution and molecular mechanisms behind its polysaccharides’ biosynthesis. Scientific research into this process is needed to improve the ingredient’s safety.
Dr. Qiong Liang, the lead researcher, states: “Our findings provide cytological evidence and characterize the key genes involved in glucomannan biosynthesis in B. striata. This study lays a solid foundation for further research on the regulation mechanisms and genetic engineering of B. striata to enhance its medicinal properties.”
BaiJi has been used in TCM, as well as in traditional Korean medicine, to treat hematemesis, hemoptysis and traumatic bleeding due to its arresting bleeding properties. It has also been used to treat tuberculosis, whooping cough, stomach bleeding, ulcers, abscesses, swellings and parasitic diseases.
Biosynthesis of glucomannan
The research conducted by scientists at the China-based Wuhan Botanical Garden of the Chinese Academy of Sciences and Hubei Normal University and published in Horticulture Research reveals molecular mechanisms underlying the biosynthesis of glucomannan, a water-soluble polysaccharide and a dietary fiber, within B. striata.
The research team investigated B. striata’s pseudobulbs and found that the primary polysaccharide is glucomannan with a mannose ratio of approximately 3:2. Mannose is a monosaccharide with diverse properties and applications, including to support the immune system, and address metabolic syndrome, diabetes, intestinal diseases, urinary tract infections and other conditions.
The study was conducted through chemical and immunologic analyses, which allowed the researchers to map the biosynthetic pathway from sucrose sugar to glucomannan and to then identify key genes such as BsGPI, BsmanA and BsCSLAs.
The new insights about B. striata open the door to further genetic engineering and select breeding.
Yeast two-hybrid screening, a technique used in molecular biology to detect protein-protein interactions and luciferase (oxidative enzymes) complementation assay tests confirmed that these genes can form homodimers, formed by two of the same proteins, or heterodimers, formed by two different proteins.
The formation of both homo- or heterodimers suggests the formation of a complex that is essential for glucomannan biosynthesis.
TCM applications
The research paper’s findings offer a new comprehensive understanding of molecular mechanisms behind glucomannan production in B. striata.
These new insights further open the door to novel genetic engineering and selecting breeding. Manipulating the genes now identified as important to the molecular mechanisms, researchers may soon enhance the medicinal properties and polysaccharide content of B. striata. This, in turn, may increase its value in TCM, as well as in pharmaceuticals.
The recently launched three-year public health campaign in China, which aims to improve weight management and ameliorate the rise in obesity in the country, encourages the implementation of TCM solutions in tackling the issue.
By Milana Nikolova
