Radiation effects and radioprotection by Thai medicinal plants in mouse macrophage cell line

Objective To investigate the effects of radiation on growth-arrested (GA) and micronucleus-production (MP) rates, and the radioprotective properties of Thai medicinal plants in mouse macrophage cell line RAW264. 7 in vitro. Methods Mouse macrophage cell line (RAW264. 7) was cultured in vitro. Various radiation exposures, growth-arrested rate assay, micronucleus production assay, and radioprotection by Thai medicinal plants were performed. Results The results showed that GA and MP rates for gamma-rays and UV were dose-dependent. The 50% -affected dose of gamma and UV radiation for the GA rate was 10 Gy and 159 microwatt/cm(2) for 0.5 seconds, respectively. After X-ray exposure, there was no apparent effect on RAW264. 7 cells, even with a fortyfold human diagnostic dose. Two exposures to gamma radiation at 20 Gy resulted in a significantly higher MP rate than 20 Gy single exposure or control (P < 0.05). The Thai medicinal plants (Kamin-chun capsules, Curcuma longa Linn; Hed lingeu, Ganoderma lucidum; Ya Pakking capsule, Murdannia loriformis) could not prevent cell damage, but epigallocatechin gallate and L-cysteine could provide protection from 2 Gy gamma-ray exposure. Conclusion gamma radiation caused chromosomal damage during cell division and UV caused cell death, while X-ray radiation was safe. The radioprotective effects of Thai medicinal plants, Kamin-chun, Hed lingeu, and Ya Pakking, could not prevent cell damage in this study.