Suntheanine® Protects Against Chemo Side Effects, May PreventNerve Cell Degeneration

Suntheanine® Protects Against Chemo Side Effects, May PreventNerve Cell Degeneration

TOKYO & KYOTO, JapanIn astudy published in Cancer Letters (212,2:177-184, 2004), Japanese researchers evaluated the effects of injections oftheanine (as Suntheanine®, supplied by Taiyo International, a division of TaiyoKagaku Japan) into healthy animals and those with transplanted tumors, and intumor-bearing animals injected with the anticancer antibiotic doxorubicin.Japanese researchers found theanine, a specific glutamate derivative in greentea, decreased doxorubicin (DOX)- induced adverse reactions such as theinduction of the lipid peroxide level and the reduction of glutathioneperoxidase activity in normal tissues. In order to clarify how theanineattenuates the adverse reactions of DOX, the scientists focused on the effectsof theanine on glutamate and glutathione (GSH) levels in normal tissues. Theadministration of theanine to mice increased the glutamate concentration in theliver and heart, and not in tumors. In vitro examinations indicated theanine wasmetabolized to glutamate mainly in the liver. Moreover, theanine inhibited GSHreduction induced by DOX in the liver and heart. The results suggest, accordingto the researchers, that theanine attenuated the DOX-induced adverse reactionsinvolved in oxidative damage, due to increase in glutamate and the recovery ofGSH levels in normal tissues.

Our previous animal studies have shown Suntheanine toincrease the efficacy of various anticancer agents, said Yasuyuki Sadzuka,Ph.D., of the University of Shizuoka, one of the two investigators of the study.Our current study indicates that Suntheanine can prevent the DOX-induced fallin glutathione concentrations within heart and liver tissue.

Previous animal and human studies have linked some of the sideeffects 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 bysupplying glutamate to cells, thereby increasing the cellular synthesis of GSH.This may explain the observed protection against chemotherapeutic toxicity whileenhancing chemotherapeutic efficacy, Sadzuka added.

In another study, published in Biochemicaland Biophysical Research Communications (320,1:116-122, 2004), scientists investigated the molecular mechanism underlying theneuroprotective effect of theanine. The study exposed cultured nerve cells to excess glutamate andfound the resultant nerve cell death to be prevented by concurrent exposure toSuntheanine. Our findings of Suntheanine reversing nerve cell death possiblymediated by preventing glutamate-triggered oxidative stress are veryencouraging, said Kazuki Nagasawa, Ph.D., of Kyoto Pharmaceutical University,co-investigator of the study. Indirect or direct blockade of glutamateneurotoxicity is a very active pursuit in the pharmaceutical industry.

The breadth of biological activities displayed bySuntheanine continues to intrigue and excite us, said Scott Smith, vicepresident of Minneapolis-based Taiyo.We continue to actively support andfoster both preclinical and clinical research, in a variety of areas.Suntheanine holds over 40 U.S. and international patents for its variousphysiological efficacies and L-isomer-specific production processes.