KMRC011, an agonist of toll-like receptor 5, mitigates irradiation-induced tissue damage and mortality in cynomolgus monkeys.

In the study here, the potential applicability of KMRC011 - an agonist of toll-like receptor-5 - as a countermeasure for radiation toxicities was evaluated. Following a single 5.5 Gy total body irradiation (TBI, surface absorbed dose = 7 Gy) of Co60 γ-rays, mortality rates and degrees of pathological lesions that developed over 80 days were compared in monkeys that received TBI only and a group that was injected once with KMRC011 (10 µg/kg) after TBI. Compared to the TBI-only hosts (80%), the death rate was significantly improved by the use of KMRC011 (40%), all deaths in both groups occurred in the period from Days 19-24 post-TBI. Further analysis of monkeys that survived until the end of the experiment showed that AST and ALT levels were elevated only in the TBI group, and that radiation-induced tissue damage was alleviated by the KMRC011 injection. Additionally, expression of cell death-related proteins was lower in tissues from the KMRC011-treated hosts than in those in the TBI-only group. Other measured parameters, including body weight, food uptake, and hematological values did not significantly differ between the two groups over the entire period. The results of this study, thus demonstrate that KMRC011 could potentially be used as a medical countermeasure for the treatment of acute radiation exposure.

Platycodin D and D3 increase airway mucin release in vivo and in vitro in rats and hamsters.

The root of Platycodon grandiflorum has been widely used for the treatment of various chronic inflammatory diseases including airway disease in oriental medicine. The root extract of the plant has been known to be effective in the expectoration of sputum or mucus, thereby improving airway respiratory function and preventing secondary airway inflammation. In this study, we investigated the effect of platycodin D and D3, the saponin components that are anti-inflammatory components in Platycodon grandiflorum. Platycodin D and D3 increased mucin release from rat and hamster tracheal surface epithelial cell culture and also from intact rat trachea upon nebulization. The effect of platycodin D3 was stronger than that of ATP, a potent mucin secretagogue and also of ambroxole, a mucolytic drug. The results from the present study suggest that platycodin D and D3 are useful as expectorant agents in the treatment of various airway diseases.