D-Ribose-L-cysteine exhibits adaptogenic-like activity through inhibition of oxido-inflammatory responses and increased neuronal caspase-3 activity in mice exposed to unpredictable chronic mild stress

Adaptogens are substances that act nonspecifically to combat stress by regulating the key elements involved in stress-induced pathologies. D-Ribose-L-cysteine (DRLC), a potent glutathione (GSH) booster, has been recommended for relief of stress. Hence, we investigated its adaptogenic-like effect in mice subjugated to unpredictable chronic mild stress (UCMS). Thirty six male Swiss mice were assigned to 6 groups (n = 6): group 1 received saline (p.o, non-stress control), group 2 (stress-control) also had saline, groups 3 to 5 received DRLC (25, 50 and 100 mg/kg, p.o) whereas group 6 had ginseng (50 mg/kg, p.o). The animals in groups 2-6 were subjugated to UCMS 30 min later, daily for 21 days and afterwards, tested for memory and anxiety. Blood glucose, serum corticosterone concentrations and adrenal weight were determined. The brain tissues were processed for estimation of malondialdehyde (MDA), GSH, superoxide-dismutase (SOD), catalase, tumor necrosis factor-alpha (TNF-α), interleukin-6, acetyl-cholinesterase, and caspase-3 activities. The histomorphologic features and neuronal viability of the hippocampus, amygdala and prefrontal cortex were also determined. DRLC (25-100 mg/kg) reduces anxiety, memory deficit, adrenal gland enlargement, glucose, and corticosterone concentrations in UCMS-mice. The increased brain contents of MDA, TNF-α, interleukin-6, acetyl-cholinesterase and decreased antioxidant (GSH, SOD and catalase) status induced by UCMS were attenuated by DRLC. The DRLC increased caspase-3 activity and reduces histomorphological distortions of neuronal cells of the hippocampus, amygdala and prefrontal cortex of stressed-mice. These findings suggest that DRLC has adaptogenic-like effect which might be related to modulation of corticosterone-mediated oxido-inflammatory processes and altered caspase-3 activity.

Protective effect of Cyperus esculentus (tiger nut) extract against scopolamine-induced memory loss and oxidative stress in mouse brain

Objectives The juice extract of Cyperus esculentus commonly known as tiger nuts (TINUT) is widely used for its numerous health promoting effects including alleviation of symptoms associated with neurological disorders. Herein, we investigated the influence of the aqueous extract of C. esculentus on cognitive disorder and the underlying changes in acetylcholinesterase (AChE) activity and oxidative stress biomarkers in mice exposed to scopolamine. Methods C. esculentus (50-200 mg/kg) or saline (10 mL/kg) was given alone or with scopolamine 30 min after, to male Swiss mice (6/group) daily for seven days. We evaluated the cognitive performance using Y-maze and object recognition on day seven post-treatment. Brains of the animals were afterwards processed for spectrophotometric determination of AChE activity and contents of oxidative stress biomarkers (malondialdehyde [MDA], glutathione [GSH], catalase, superoxide dismutase and nitrite). Results The extract improves cognitive function and also upturned scopolamine amnesia in mice. The extract markedly reduced brain AChE, MDA, and nitrite contents in mice injected with scopolamine (p<0.05). It also attenuated scopolamine-induced deregulated GSH contents and antioxidant enzymes in mouse brain. Conclusions The results of this study suggest that regular consumption of TINUT might offer beneficial effects in memory-related disorders.