Immunoreactivity of arcuate nucleus astrocytes in rats after intragastric administration of habanero peppers (Capsicum Chinese Jacq.)

Abstract

Habanero pepper fruits contain capsaicin (CAP) characterised by a spicy taste. Astrocytes express vanilloid receptor (TRPV1), which interacts with cannabinoids including CAP. Only a few studies revealed that CAP leads to alterations of the arcuate nucleus (ARC) structures. The aim of this study was to analyse the GFAP (GFAP-IR) and S100β (S100β-IR) immunoreactive astrocytes of ARC in adult rats after intragastric administration of habanero pepper fruits. Adult, Wistar rats received a peanut oil -control group (C) -and oil suspension of habanero pepper fruits at a dose of 0.08 g dm/kg b.w. for 7 days -E1 group -and 28 days -E2 group. After euthanasia, the brains were embedded in paraffin blocks using a routine histological technique. Frontal slices of ARC were immunohistochemically stained for GFAP and S100β using specific antibodies in the peroxidase-antiperoxidase method. Astrocytes of ARC were morphologically and morphometrically analysed under a light microscope. The results of the study did not reveal statistically significant changes in the density of GFAP-IR cells in E1 and E2 groups of rats in comparison with group C. A statistically significant increase in the density of S100β-IR astrocytes was observed in the E1 group and a decrease in the E2 group. Astrocytes with expression of both studied proteins were characterised by morphological alterations in ARC in the E2 group. The obtained results suggest an influence of CAP contained in habanero pepper fruits on the reactivity of astroglia, which may have an impact on the astrocyte-neuron interactions in order to maintain a proper activity of nervous cells in ARC.

Evaluation of immunoreactive for glial fibrillary acidic protein astrocytes in the periaqueductal gray matter of rats treated with monosodium glutamate.

“…A negative control for the primary antibody bypass reaction was performed simultaneously. In our earlier studies the specificity of the primary antibody was confirmed using the rat brain sections (24).…”

Reactivity of astrocytes in hippocampal CA1 area in rats after administration of habanero peppers

“…CAP binds to neuronal receptors and astrocytic vanilloid 1 receptor (TRPV1). Some authors suggested that TRPV1 affects the synaptic plasticity in the hippocampal CA1 area [10][11][12][13]. Furthermore, it was found that the stimulation of TRPV1 receptor can lead to excessive activity of pyramidal neurons and the induction of seizures.…”