Introduction:
Multiple sclerosis (MS) is a disease of the central nervous system that causes disorders in the nervous system, especially in young people. Increased inflammatory factors are major complications of MS disease. Aloe vera plant has known antioxidant and anti-inflammatory properties. The purpose of this study is to investigate the effect of Aloe vera extract on the serum levels of certain inflammatory cytokines in ethidium bromide (EB)-induced MS models in rats.

Methods:
In this experimental study, 30 adult female Wistar rats were divided into 6 groups of 5 each, including control, sham, experimental 1 (received 14 μl EB solution), and experimental 2, experimental 3 and experimental 4 groups which received EB solution associated with 300, 600 and 1200 mg/kg Aloe vera alcoholic extract gel, respectively. EB was administered into the lateral ventricles and the extract was given by gavage. On day 35th, blood serum levels of TGF-β, interleukin-1 and interferon gamma were measured by blood sampling from the animals. The results were analyzed by ANOVA and Duncan tests at 5% level of significance (p≤0.05).

Results:
The results showed that EB increased the mean serum concentrations of TGF-β, interleukin 1 and interferon gamma, while simultaneous administration of EB with 1200 mg/kg of the Aloe vera alcoholic extract gel significantly reduced the above factors at level of P≤0.05 as compared with EB group.

Conclusions:
The results of this study showed that the Aloe vera alcoholic extract gel in a dose-dependent manner can reduce EB effects on serum levels of TGF-β, interleukin-1 and interferon gamma in the rats with MS.