Antistressor Effect of Costus Speciosus on Noise Induced Immunological and Neurological Changes in Rats

Abstract

The negative impact of noise, the environmental pollutant is increasing day by day. Apart from its direct effects on the auditory system, acute and subacute noise exposure causes mental stress leading to dangerous cardiovascular, endocrinal, and neurological complications. The use of herbal medicines in the management of stress has shown promising results. The present study was conducted to assess the effectiveness of ethanolic extract of Costus speciosus rhizomes (CSE) on noise-induced immunological and neurological changes in rats. Phytochemical analysis of CSE using preliminary phytochemical assays, gas chromatography mass spectrometry (GC MS), and highperformance thin-layer chromatography (HPTLC) fingerprint analysis for flavonoids were performed. In vitro antioxidant activity of CSE was studied in comparison with ascorbic acid standard and its IC50 values were measured. Wistar strain albino rats were used for in vivo study which were divided into 2 sets of 4 groups, each containing 9 animals and used for acute and subacute noise stress studies. Rats were subjected to acute noise stress and subacute noise stress and then the effect of ethanolic Costus speciosus rhizome extract (250 mg/kg and 500 mg/kg) on immunological parameters such as phagocytic index, avidity index, neutrophil adherence test, total and differential leucocyte count were studied. The efficacy of the extract on acute and subacute noise stress induced changes in serum corticosterone levels, lymphoid organ weight to body weight ratio, levels of monoaminergic neurotransmitters, their metabolites and their turnover, enzymatic and non-enzymatic antioxidant activity and 4-HNE lipid peroxidative marker immunoexpression in cerebral cortex and hippocampus of brain were studied. Preliminary phytochemical analysis of the plant extract affirmed the presence of carbohydrates, proteins and amino acids, glycosides, alkaloids, phytosterols, flavonoids, saponins, tannins, and phenolic compounds. The GC MS analysis showed six major peaks which were later iden