Anti-lipidperoxidative role of exogenous dehydroepiendrosterone (DHEA) administration in normal ageing rat brain

420-424Effects of exogenous dehydroepiendrosterone (DHEA) administration on the levels of lipid proxidation products, malondialdyde (MDA)-a thiobarbuteric acid reactive substance (TBARS) and 4-hydroxy nonenal (4-HNE) in different brain regions viz. cerebral cortex, hippocampus cerebellum, and brain stem of 12 and 22 months old rats were studied. DHEA treatment significantly depressed TBARS and 4-HNE in all the brain regions studied, in both the age group rats. Interestingly, the magnitude of decrease was higher in the 22 months old rats than that in 12 months old rats. The results suggest that older the animal, better will be the response of exogenous DHEA administration against age- related peroxidative products

Exogenous administration of dehydroepiendrosterone attenuates loss of superoxide dismuatse activity in the brain of old rats

57-60The influence of exogenously administered dehyroepiendrosterone (DHEA) on the activity of superoxide dismutase (SOD) was investigated in the mitochondrial and cytosolic fractions from cerebral cortex, cerebellum, hippocampus and medulla regions of the brains of 12- and 22-months old rats. DHEA was administered daily at the dose of 30 mg/kg/body wt, intraperitonially (i.p) in both age groups of rats for 1 month. Results showed that SOD activity was significantly higher in the mitochondrial fraction than in the cytosolic fraction, in DHEA-treated animals in both age groups. This indicated that exogenous DHEA affected mitochondrial SOD more than the cytosolic SOD. In terms of percent increase, 22 months-old animals showed significant increase in the SOD activity in both the fractions of all the four brain regions than in the 12 months old DHEA-treated animals. This showed that exogenous DHEA provided more protection to the SOD in ageing brain of older rats (22 months) than the younger (12 month) ones. The study suggests that exogenous DHEA is more beneficial at old age in terms of neuroprotection against oxidative stress-mediated brain dysfunctions and may protect age-related alterations in cognitive functions like learning and memory

Na⁺ K⁺-ATPase activity in response to exogenous dehydroepiandrosterone administration in aging rat brain

852-854Influence of exogenously administered dehydroepiand-rosterone (DHEA) on the activity of Na+ K+ ATPase was investigated in synaptosomal fraction from cerebral cortex, cerebellum, hippocampus and medulla regions of brain of 12 and 22 months old rats. DHEA was administered daily at the dose of 30 mg/kg/body wt, intraperitonially (ip) in both the age groups of rats for 1 month. Results showed that Na+ K+ ATPase activity, increased in DHEA treated rats in both the age groups. In terms of per cent increase, 22 months old animals showed significant increase in Na+ K+ ATPase activity in the synaptosomal fraction of all the four brain regions than in 12 months old DHEA-treated rats. This showed that exogenous DHEA modulated the activity of Na+ K+ ATPase and also protected the age-related loss of membrane integrity and functions. It was concluded that exogenous DHEA might be beneficial in terms of neuroprotection against age-related loss of Na+ K+ ATPase mediated brain functions like learning and memory

Skin microbiota secretomes modulate cutaneous innate immunity against Borrelia burgdorferi s.s

Abstract In Lyme borreliosis, the skin constitutes a major interface for the host, the bacteria and the tick. Skin immunity is provided by specialized immune cells but also by the resident cells: the keratinocytes and the fibroblasts. Discoveries on the role of the microbiome in the modulation of skin inflammation and immunity have reinforced the potential importance of the skin in vector-borne diseases. In this study, we analyzed in vitro the interaction of human primary keratinocytes and fibroblasts with Borrelia burgdorferi sensu stricto N40 in presence or absence of bacterial commensal supernatants. We aimed to highlight the role of resident skin cells and skin microbiome on the inflammation induced by B. burgdorferi s.s.. The secretomes of Staphylococcus epidermidis, Corynebacterium striatum and Cutibacterium acnes showed an overall increase in the expression of IL-8, CXCL1, MCP-1 and SOD-2 by fibroblasts, and of IL-8, CXCL1, MCP-1 and hBD-2 in the undifferentiated keratinocytes. Commensal bacteria showed a repressive effect on the expression of IL-8, CXCL1 and MCP-1 by differentiated keratinocytes. Besides the inflammatory effect observed in the presence of Borrelia on all cell types, the cutaneous microbiome appears to promote a rapid innate response of resident skin cells during the onset of Borrelia infection