Studies on the treatment for intractable asthma Part 2. Evaluation of the pharmacological action of various Kampo Medicines on lymphocyte and neutrophil functions in intractable asthmatics

The pharmacological action of Sho-saiko-to and Hange-koboku-to, components of Saiboku-to, as well as that of Sho-seiryu-to were compared with that of Saiboku-to and examined in intractable asthmatics with respect to both lymphocyte functions, including interleukin 2 (IL-2) production and IL-2 receptor expression in peripheral blood lymphocytes stimulated by Candida, and on neutrophil functions, including leukotriene C(4) (LTC(4)) and superoxide (O(2)(-)) production by peripheral blood neutrophils. The results revealed, first, that, Sho-saiko-to, Hange-koboku-to, and Sho-seiryu-to did not have significant suppressive effects on IL-2 production and IL-2 receptor expression by Candia, though Saiboku-to caused significant suppression of these same parameters. Second, after 2 or 3 months oral administration to intractable asthmatics Saiboku-to (TJ-96) suppressed LTC(4) production by peripheral blood neutrophils in response to Candida and Ca-ionophore. Third, in vitro, Saiboku-to caused dose-dependent suppression of both LTC(4) and O(2)(-) production by peripheral blood neutrophils. Sho-saiko-to and Sho-seiryu-to also had suppressive effects on both LTC(4) and O(2)(-) production, with Sho-saiko-to causing the strongest suppression among these drugs. These results indicate that Saiboku-to might be useful in the treatment of intractable asthma due to its suppressive effect on type IV allergy caused by lymphocyte activation by Candida. Moreover, its inhibitory effect of LTC(4) and O(2)(-) production by neutrophils prevents prolonged broncho-constriction and irreversible changes in small airways.