Ginkgo modulates noise-induced hippocampal damage in male albino rats: a light and electron microscopic study

Ocimum basilicum (Basil) Modulates Apoptosis and Neurogenesis in Olfactory Pulp of Mice Exposed to Chronic Unpredictable Mild Stress

BACKGROUND

Ocimum basilicum (O. basilicum) was described to have antidepressant and anxiolytic activities. Although the relationship between the main olfactory bulb (MOB) and depression was recently reported, the chronic stress-induced dysfunction of the MOB is not clearly described.

OBJECTIVES

This study aimed to assess the efficacy of inhalation of O. basilicum essential oils in improving chronic unpredictable mild stress (CUMS)-induced changes in MOB of mice and understand the mechanism underlying such effect.

MATERIALS AND METHODS

Adult male mice (n=40) were assigned into four groups included the control, CUMS-exposed, CUMS + fluoxetine (FLU), CUMS + O. basilicum. Behavioral changes, serum corticosterone level, and gene expression of GFAP, Ki 67, and caspase-3 were assessed using real-time PCR (RT-PCR). Histopathological and immunochemical examination of the MOB was performed.

RESULTS

FLU and O. basilicum significantly down-regulated (p = 0.002, p<0.001) caspase-3 gene expression indicating reduced apoptosis and up-regulated (p = 0.002, p < 0.001) Ki67 gene expression indicating enhanced neurogenesis in MOB, respectively. FLU and O. basilicum-treated mice markedly improved MOB mitral cell layer distortion and shrinkage induced by CUMS.

CONCLUSION

O. basilicum relieved both biochemically and histopathological chronic stress-induced changes in the main olfactory bulb possibly through up-regulation of gene expression of GFAP and Ki67 and down-regulation of caspase-3 in the MOB.

Ocimum basilicum improve chronic stress-induced neurodegenerative changes in mice hippocampus

Alzheimer's disease (AD), one of the progressive neurodegenerative diseases might be associated with exposure to stress and altered living conditions. This study aimed to evaluate the effectiveness of Ocimum basilicum (OB) essential oils in improving the neurodegenerative-like changes induced in mice after exposed to chronic unpredictable mild stress (CUMS). Forty male Swiss albino mice divided into four groups (n = 10); the control, CUMS, CUMS + Fluoxetine, CUMS + OB were used. Behavioral tests, serum corticosterone level, hippocampus protein level of the glucocorticoid receptors (GRs) and brain-dreived neurotropic factor (BDNF) were determined after exposure to CUMS. Hippocampus was histopathologically examined. Data were analyzed using statistical package for the social sciences (SPSS) and P value of less than 0.05 was considered significant. OB diminished the depression manifestation as well as impaired short term memory observed in the mice after exposure to the CUMS as evidenced by the forced swimming and elevated plus maze test. OB also up-regulated the serum corticosterone level, hippocampal protein level of the glucocorticoid receptor and the brain-derived neurotropic factor and reduced the neurodegenerative and atrophic changes induced in the hippocampus after exposure to CUMS. Essential oils of OB alleviated the memory impairment and hippocampal neurodegenerative changes induced by exposure to the chronic unpredictable stress indicating that it is the time to test its effectiveness on patients suffering from Alzheimer disease.

The Role of Musk in Relieving the Neurodegenerative Changes Induced After Exposure to Chronic Stress

OBJECTIVE

This study aimed to evaluate the effect induced by musk on Alzheimer's disease-such as neurodegenerative changes in mice exposed to chronic unpredictable mild stress (CUMS).

MATERIAL AND METHODS

Forty male Swiss albino mice were divided into 4 groups (n = 10); control, CUMS, CUMS + fluoxetine, CUMS + musk. At the end of the experiment, behavior of the mice was assessed. Serum corticosterone level, hippocampal protein level of the glucocorticoid receptors, and brain-derived neurotropic factor were also assessed. Hippocampus was histopathologically examined.

RESULTS

Musk improved depressive status induced after exposure to CUMS as evidenced by the forced swimming and open field tests and improved the short-term memory as evidenced by the elevated plus maze test. Musk reduced both corticosterone levels and the hippocampal neurodegenerative changes observed after exposure to CUMS. These improvements were comparable to those induced by fluoxetine.

CONCLUSION

Musk alleviated the memory impairment and neurodegenerative changes induced after exposure to the chronic stress.

Evaluation of the antidepressant-like effect of musk in an animal model of depression: how it works

Depression has become a common public health problem that is showing increasing prevalence. Slow onset of action, low response rates and drug resistance are potential limitations of the current antidepressant drugs. Alternative therapy using natural substances, specifically aromatherapy, is currently tried to treat depression. This work aimed to assess the efficacy of musk in relieving the behavioral, biochemical and hippocampal histopathological changes induced by exposure to chronic mild stress in mice and explore the possible mechanism behind this antidepressant-like effect. Forty male albino mice were divided into four groups (n = 10): control, a group exposed to chronic unpredictable mild stress (CUMS) and two groups exposed to CUMS and then treated with fluoxetine or musk. Behavioral changes and serum corticosterone levels were assessed at the end of the experiment. Protein and gene expressions of brain-derived neurotropic factor (BDNF) and glucocorticoid receptors (GRs) in the hippocampus were assessed using ELISA and real-time RT-PCR, respectively. Histopathological examination of the hippocampus and immunohistochemical techniques using glial fibrillary acidic protein (GFAP), Ki67, caspase-3, BDNF and GR were performed. Inhalation of musk had an antidepressant-like effect in an animal model of depression. Musk alleviated the behavioral changes and elevated serum corticosterone levels induced by exposure to chronic stress. It reduced the hippocampal neuronal apoptosis and stimulated neurogenesis in the dentate gyrus. Musk's action may be related to the upregulation of hippocampal GR and BDNF expressions. Musk is considered a potential antidepressant so it is advisable to assess its efficacy in treating depressed patient.