November 22, 2004, Minneapolis – The health benefits of tea continue to accumulate, with novel benefits being uncovered on an almost weekly basis. New research findings with Suntheanine, a pure source of L-theanine, an abundant amino acid in tea, indicate a protective effect against the cellular side effects that accompany chemotherapy and prevention of nerve cell degeneration.
In the journal Cancer Letters (212:177–184, 2004), Japanese researchers evaluated the effects of injections of Suntheanine into healthy animals and those with transplanted tumors, and in tumor bearing animals injected with the anticancer antibiotic doxorubicin. “Our previous animal studies have shown Suntheanine to increase the efficacy of various anticancer agents,” offered Dr. Yasuyuki Sadzuka of the University of Shizuoka, one of the two investigators of the study. “Our current study indicates that Suntheanine can prevent the doxorubicin-induced fall in glutathione concentrations within heart and liver tissue,” he added.
Previous animal and human studies have linked some of the side effects associated with cancer chemotherapy to a decline in glutathione (GSH), with glutathione administration imparting significant clinical benefit. “We believe that Suntheanine may act as a GSH modulator by supplying glutamate to cells, thereby increasing the cellular synthesis of GSH. This may explain the observed protection against chemotherapeutic toxicity while enhancing chemotherapeutic efficacy,” Dr. Sadzuka added.
The manipulation of glutamate concentrations in the nervous system may influence the dynamics of nerve cell degeneration. Glutamate is used as a neurotransmitter in many nerve cells but its excess accumulation is linked to nerve cell death, as seen in Alzheimer’s and Parkinson’s diseases. A recent study appearing in the journal Biochemical and Biophysical Research Communications (320:116–122, 2004) exposed cultured nerve cells to excess glutamate and found the resultant nerve cell death to be prevented by concurrent exposure to Suntheanine. “Indirect or direct blockade of glutamate neurotoxicity is a very active pursuit in the pharmaceutical industry,” offered Dr. Kazuki Nagasawa of Kyoto Pharmaceutical University, a co-investigator in the study. “Our findings of Suntheanine reversing nerve cell death possibly mediated by preventing glutamate-triggered oxidative stress are very encouraging.”
These studies add to the diverse evidence base supporting the broad spectrum of health applications for Suntheanine. Its primary application has been for promoting relaxation, based upon the findings of several clinical trials. “The breadth of biological activities displayed by Suntheanine continue to intrigue and excite us,” said Scott Smith, Vice President of Taiyo in Minneapolis. “We continue to actively support and foster both preclinical and clinical research, in a variety of areas.”
Taiyo International is the North American sales office for Taiyo Kagaku Japan, a leading manufacturer of functional ingredients for the food, beverage and dietary supplement industries. Taiyo focuses on the development of innovative ingredients, derived from natural sources, to further develop the body’s ability to protect and manage one’s health.
Suntheanine is Taiyo’s exclusive brand of pure L-theanine, supported by extensive clinical trials. Suntheanine is protected by over 40 U.S. and international patents for its various physiological efficacies and L-isomer-specific production processes.