Impact of Goreisan components on rat mesenteric collecting lymphatic vessel pumping

Background Goreisan is a traditional herbal formulation with diuretic properties tested as a clinical therapeutic to alleviate lymphedema in Japan. The present study aimed to determine how Goreisan and its five different components affect lymphatic pump function. Methods Mesenteric collecting lymphatics were isolated from anesthetized Sprague-Dawley rats and mounted on resistance-matched glass micropipettes in a 37 degrees C physiological salt solution bath for studies. Diameter was continuously measured to obtain the following lymphatic pump parameters: contraction frequency (CF), end diastolic diameter (EDD), and end systolic diameter (ESD), contraction amplitude (AMP), ejection fraction (EF), and fractional pump flow (FPF). Goreisan and each of its components (Cinnamomi Cortex, Atractylodis Rhizoma, Alismatis Rhizoma, Polyporus, and Poria) were applied to the bath at concentrations of 1-30 mu g/mL. Results The results show that while Goreisan causes no significant changes to lymphatic pumping, Alismatis Rhizoma and Polyporus each significantly reduce CF and FPF. In addition, rats that received oral administration of Goreisan and Alismatis Rhizoma for 1 week had elevated expression of VEGFR-3 in their mesenteric collecting lymphatics. Conclusions Collectively, the results suggest that some components of Goreisan have a direct, rapid impact on lymphatic pumping. These findings provide new insights but also raise new questions about the therapeutic potential of Goreisan in patients with secondary lymphedema.

Automated summary

This study aimed to evaluate the effects of Goreisan and its five components on lymphatic pump function. The results showed that Alismatis Rhizoma and Polyporus significantly reduced the contraction frequency and fractional pump flow of the lymphatic pump. Additionally, oral administration of Goreisan and Alismatis Rhizoma increased the expression of VEGFR-3 in mesenteric collecting lymphatics.