Understanding the basal gut bacterial community structure and the host metabolic composition is pivotal for the interpretation of laboratory treatments designed to answer questions pertinent to host-microbe interactions. In this study, we report for the first time the underlying gut microbiota and systemic metabolic composition in BALB/c mice during the acclimatisation period. Our results showed that stress levels were reduced in the first three days of the study when the animals were subjected to repetitive handling daily but the stress levels were increased when handling was carried out at lower frequencies (weekly). We also observed a strong influence of stress on the host metabolism and commensal compositional variability. In addition, temporal biological compartmental variations in the responses were observed. Based on these results, we suggest that consistency in the frequency and duration of laboratory handling is crucial in murine models to minimise the impact of stress levels on the commensal and host metabolism dynamics. Furthermore, caution is advised in consideration of the temporal delay effect when integrating metagenomics and metabonomics data across different biological matrices (i.e. faeces and urine).
Environmental stressors may influence chicken performance and susceptibility to pathogens, such as Salmonella enteritidis. This study was conducted to determine the effects of heat shock protein (Hsp)70 expression on resistance to Salmonella enteritidis infection in broiler chickens subjected to heat exposure. Chicks were divided into 3 feeding regimens: ad libitum feeding (control); 60% feed restriction on d 4, 5, and 6 (FR60); and 60% feed restriction on d 4, 5, and 6 plus 1,500 mg/kg of quercetin (FR60Q). On d 35, all of the chickens were individually inoculated with 1 mL of Salmonella enteritidis (1.5 × 10(8) cfu/bird) and exposed to an ambient temperature of 37 ± 1°C and 70% RH for 3 h/d. The FR60 and FR60Q chickens had significantly lower Salmonella enteritidis colonization and lower Hsp70 expression than that of the control chickens following the heat exposure period. The least colonization was observed in the FR60Q group (1.38 log(10) cfu/g in the spleen and 1.96 log(10) cfu/g in the cecal content) and the highest was in the control group (2.1 log(10) cfu/g in the spleen and 4.42 log(10) cfu/g in the cecal content). It appears that neonatal feed restriction can enhance resistance to Salmonella enteritidis colonization in heat-stressed broiler chicks, and the underlying mechanism could be associated with the lower expression of Hsp70.
Postpartum depression (PPD) is a psychiatric disorder that occurs in 10-15% of childbearing women. It is hypothesized that omega-3 fatty acids, which are components of fish oil, may attenuate depression symptoms. In order to examine this hypothesis, the animal model of postpartum depression was established in the present study. Ovariectomized female rats underwent hormone-simulated pregnancy (HSP) regimen and received progesterone and estradiol benzoate or vehicle for 23 days, mimicking the actual rat's pregnancy. The days after hormone termination were considered as the postpartum period. Forced feeding of menhaden fish oil, as a source of omega-3, with three doses of 1, 3, and 9g/kg/d, fluoxetine 15mg/kg/d, and distilled water 2ml/d per rat started in five postpartum-induced and one vehicle group on postpartum day 1 and continued for 15 consecutive days. On postpartum day 15, all groups were tested in the forced swimming test (FST) and open field test (OFT), followed by a biochemical assay. Results showed that the postpartum-induced rats not treated with menhaden fish oil, exhibited an increase in immobility time seen in FST, hippocampal concentration of corticosterone and plasmatic level of corticosterone, and pro-inflammatory cytokines. These depression-related effects were attenuated by supplementation of menhaden fish oil with doses of 3 and 9g/kg. Moreover, results of rats supplemented with menhaden fish oil were comparable to rats treated with the clinically effective antidepressant, fluoxetine. Taken together, these results suggest that menhaden fish oil, rich in omega-3, exerts beneficial effect on postpartum depression and decreases the biomarkers related to depression such as corticosterone and pro-inflammatory cytokines.
The progressive accumulation of amyloid beta (Aβ) peptide is neurotoxic and leads to Alzheimer's type dementia. Accumulation of Aβ has been associated with dysfunction of hypothalamic-pituitary-adrenal (HPA) axis and elevated pro-inflammatory cytokines. In this study, we investigated the effect of 1`δ-1`-acetoxyeugenol acetate (DAEA), isolated from Alpinia galanga (L.), on Aβ(25-35) induced neurodegeneration in mice. Mice were treated with three different doses of DAEA (12.5 mg/kg, 25 mg/kg and 50 mg/kg) for 28 days. Aβ(25-35) was injected by intracerebroventricular (i.c.v.) injection on the 15th day of 28 days. Open field, water maze and step-down inhibitory tests were performed on the 27th day to determine the habituation memory, spatial learning, and short- and long-term memory, respectively. Acetylcholinesterase (AChE), Corticosterone, biogenic amines (serotonin and dopamine), tumour necrosis factor-α (TNF-α), and antioxidant parameters such as superoxide dismutase, catalase, glutathione peroxidase and vitamin C were evaluated in brain homogenates after behavioural tests to ascertain the cognitive improvement through neuro-immune-endocrine modulation. The DAEA treatment with 25 mg/kg and 50 mg/kg resulted in significant (p < 0.001) improvement of habituation memory and step-down inhibitory avoidance task. In spatial learning, the cognitive improvement was significantly improved (p < 0.001) by reduction in escape latency. In the biochemical study, the significant (p < 0.001) reduction of AChE indicates the preeminent neuroprotection. Corticosterone and TNF-α were significantly (p < 0.01) reduced and biogenic amines were increased with antioxidant markers, which signify the potential influence of DAEA on neuroprotection. Our investigation revealed that the drug DAEA attenuates stress mediated through the HPA axis and regulates the neuroendocrine and neuroimmune function to improve the cognition. DAEA could be a potential lead candidate for the treatment of neurodegeneration.
Glucocorticoid-induced osteoporosis is one of the common causes of secondary osteoporosis. Piper sarmentosum (Ps) extract possesses antioxidant and anti-inflammatory activities. In this study, we determined the correlation between the effects of Ps leaf water extract with the regulation of 11β-hydroxysteroid dehydrogenase (HSD) type 1 enzyme activity in serum and bone of glucocorticoid-induced osteoporotic rats. Twenty-four Sprague-Dawley rats were grouped into following: G1: sham-operated group administered with intramuscular vehicle olive oil and vehicle normal saline orally; G2: adrenalectomized (adrx) control group given intramuscular dexamethasone (120 μg/kg/day) and vehicle normal saline orally; G3: adrx group given intramuscular dexamethasone (120 μg/kg/day) and water extract of Piper sarmentosum (125 mg/kg/day) orally. After two months, the femur and serum were taken for ELISA analysis. Results showed that Ps leaf water extract significantly reduced the femur corticosterone concentration (p < 0.05). This suggests that Ps leaf water extract was able to prevent bone loss due to long-term glucocorticoid therapy by acting locally on the bone cells by increasing the dehydrogenase action of 11β-HSD type 1. Thus, Ps may have the potential to be used as an alternative medicine against osteoporosis and osteoporotic fracture in patients on long-term glucocorticoid treatment.