Efficacy of neuroprotection from curcumin through heat shock protein 70 induction in traumatic brain injury – rat model

Abstract

BACKGROUND: Traumatic brain injury (TBI) is the most common problem that caused morbidity and mortality in the world. Secondary brain injury is a complex cascade that causes brain cell apoptosis. Curcumin is a natural product that has neuroprotective properties. AIM: This study aimed to investigate the effect of curcumin toward heat shock protein 70 (HSP 70) expression against the expression apoptosis marker (apoptosis-inducing factor [AIF], caspase-3, and TUNEL assay) in brain tissue after TBI. METHODS: Thirty-three Sprague Dawley rats were randomized into three treatment groups, that is, sham-operated controls, closed head trauma (CHT), and CHT with curcumin extract (treatment group). In the treatment group, curcumin was given 500 mg/kg per oral for 7 days, then brain tissues were investigated (marker AIF, caspase-3, TUNEL assay, and HSP 70) through immunohistochemistry. Statistical test using one-way ANOVA test and Tukey honestly significant difference as post hoc test. RESULTS: The mean of positive AIF stained cells in Group A was 5.36 ± 2.11, Group B was 12.82 ± 1.40, and Group C was 3.82 ± 1.40, with a significant difference of AIF expression between Groups C and B (p < 0.05). Mean of positive caspase-3 stained cells in Group A was 5.45 ± 2.30, Group B was 13.82 ± 2.44, and Group C was 3.82 ± 1.54, with a significant difference of caspase-3 expression between Groups C and B (p < 0.05). Mean of positive TUNEL assay stained cells in Group A was 4.82 ± 2.04, Group B was 11.55 ± 1.51, and Group C was 3.55 ± 1.70, with a significant difference between Groups C and B (p < 0.05). Mean of positive HSP 70 stained cells in Group A was 6.82 ± 2.14, Group B was 3.91 ± 2.26, and Group C was 10.27 ± 2.45 with a significant difference of HSP 70 expression distribution within groups (p < 0.05). CONCLUSION: Curcumin may protect brain cells from apoptosis after close head trauma by upregulated HSP 70 expression.