Protection against radiation-induced conditioned taste aversion by Centella asiatica.

Radiations are known to cause behavioural perturbations like conditioned taste aversion (CTA), performance decrement, learning, etc., even at very low doses. The manifestation of radiation-induced behavioural degradation has not been understood well and requires further studies. Therefore, the effects of low-dose whole-body 60Co gamma-irradiation in male rats were studied in terms of body weight and CTA learning. For CTA, the consumption of saccharin solution was considered as a parameter. To protect against the adverse effects of radiation, Centella asiatica (aqueous extract) was tested and compared with ondansetron, a standard antiemetic drug. A dose of 2 Gy incurred significant body weight loss [t(9)=9.00, P<.05] and induced CTA in rats [t(26)=9.344, P<.01]. Administration of C. asiatica (100 mg/kg bw ip, 2 Gy, -1 h) rendered significant radioprotection against radiation-induced body weight loss and CTA that became evident on the second postirradiation day [t(7)=0.917, P>>.05; t(7)=4.016, P>.05]. Ondansetron (1 mg/kg bw) elicited higher degree of protection against CTA [t(7)=3.641, P>.05] than C. asiatica [t(7)=7.196, P>.05] on the first postirradiation day, but on the second postirradiation day, both were equally effective [t(7)=3.38, P>.05; t(7)=4.01, P>.05]. In case of C. asiatica-treated animals, however, there was a consistently declining CTA from the second to the fifth postirradiation day whereas in ondansetron-treated animals it was inconsistent. Present investigation suggests that C. asiatica could be useful in preventing radiation-induced behavioural changes during clinical radiotherapy.