Effects of high intensity interval training and curcumin consumption on brain lipid peroxidation, homocysteine and caspase activation in rats exposed to arsenic

Little is known about the concomitant effects of high intensity interval training (HIIT) and curcumin on arsenic toxicity in the brain. The aim of the present study was to evaluate the effects of HIIT and curcumin supplementation on cerebral malondialdehyde (MDA), nitrite, homocysteine and also expression of caspase3, caspae-8 and caspase-9 protein in rats exposed to arsenic.

In this experimental study, 48 male rats were randomly divided into six groups: arsenic+training, arsenic+curcumin, arsenic+training+curcumin (concomitant), arsenic, ethanol-control and normal-control. Arsenic five mg/kg/day and curcumin 15 mg/kg/day were consumed orally (gavaged) for six weeks. HIIT were conducted for six weeks (five sessions/week, each session lasted 60 min) consisted of four min running bouts at 85-90% of vVO2max with two min recovery intervals at 50-60% of vVO2max. Elisa, Western blot and also TBARS as well as Grace reaction methods were used to quantify cerebral homocysteine, caspase expression, MDA and nitrite levels respectively. Data were analyzed by one-way analysis of variance and Tukey post hoc tests at the p<0.05 level.

Arsenic exposure significantly elevated brain caspase-3, -8 and -9 expression, as well as MDA and homocysteine levels (p<0.05). All of three interventions including HIIT, curcumin and their concomitance obviated arsenic induced cerebral MDA elevation compared to normal control group (p<0.05), however; it could not fully corrected homocysteine levels (p>0.05). Caspae-8 and -9 protein expression levels were restored to normal control group level, just in concomitant group (p<0.05).

Arsenic exposure leads to an increased rat cerebral homocysteine, lipid peroxidation as well as intrinsic and extrinsic apoptotic pathways activation. While HIIT, curcumin and their concomitance prevented arsenic induced cerebral lipid peroxidation, only with curcumin supplementation remarkable benefits were observed for rest of variables. Further, only in the concomitant group, the arsenic induced elevations in the activity of both the intrinsic and extrinsic apoptotic pathways were fully prevented. However, more researches should to be done because of the study limitations and lack of similar evidence in human population.