Repeated dose of ketamine effect to the rat hippocampus tissue

Prolonged ketamine therapy differentially rescues psychobehavioural deficits via modulation of nitro-oxidative stress and oxytocin receptors in the gut-brain-axis of chronically-stressed mice

Ketamine is an anaesthetic known to have short but rapid-acting anti-depressant effects; however, the neurobehavioural effects of its prolonged use and its role on the oxytocin system in the gut-brain axis are largely undetermined. Female BALB/c mice were either exposed to the chronic unpredictable mild stress (CUMS) paradigm for 21 days and then treated with ketamine in four doses for 14 days or exposed to CUMS and treated simultaneously in four doses of ketamine during the last two weeks of CUMS exposure. After each dose, the forced swim test was conducted to assess depressive-like behaviour. Before sacrifice, all the mice were subjected to behavioural tests to assess anxiety, memory, and social interaction. Prolonged treatment of depression with ketamine did not rescue depressive-like behaviour. It did, however, improve depression-associated anxiety-like behaviours, short-term memory and social interaction deficits when compared to the stressed untreated mice. Furthermore, ketamine treatment enhanced plasma oxytocin levels, expression of oxytocin receptors; as well as abrogated nitro-oxidative stress biomarkers in the intestinal and hippocampal tissues. Taken together, our findings indicate that while short-term use of ketamine has anti-depressant benefits, its prolonged therapeutic use does not seem to adequately resolve depressive-like behaviour in mice.

Nano-hesperetin attenuates ketamine-induced schizophrenia-like symptoms in mice: participation of antioxidant parameters

RATIONALE

Antioxidant natural herb hesperetin (Hst) offers powerful medicinal properties. Despite having noticeable antioxidant properties, it has limited absorption, which is a major pharmacological obstacle.

OBJECTIVES

The goal of the current investigation was to determine if Hst and nano-Hst might protect mice against oxidative stress and schizophrenia (SCZ)-like behaviors brought on by ketamine (KET).

METHODS

Seven treatment groups (n=7) were created for the animals. For 10 days, they received distilled water or KET (10 mg/kg) intraperitoneally (i.p). From the 11th to the 40th day, they received daily oral administration of Hst and nano-Hst (10, 20 mg/kg) or vehicle. With the use of the forced swimming test (FST), open field test (OFT), and novel object recognition test (NORT), SCZ-like behaviors were evaluated. Malondialdehyde (MDA) and glutathione levels and antioxidant enzyme activities were assessed in the cerebral cortex.

RESULTS

Our findings displayed that behavioral disorders induced by KET would be improved by nano-Hst treated. MDA levels were much lower after treatment with nano-Hst, and brain antioxidant levels and activities were noticeably higher. The mice treated with nano-Hst had improved outcomes in the behavioral and biochemical tests when compared to the Hst group.

CONCLUSIONS

Our study's findings showed that nano-Hst had a stronger neuroprotective impact than Hst. In cerebral cortex tissues, nano-Hst treatment dramatically reduced KET-induced (SCZ)-like behavior and oxidative stress indicators. As a result, nano-Hst may have more therapeutic potential and may be effective in treating behavioral impairments and oxidative damage brought on by KET.

N, N-dimethylglycine Protects Behavioral Disturbances and Synaptic Deficits Induced by Repeated Ketamine Exposure in Mice

Ketamine, an N-methyl-d-aspartate receptor (NMDAR) blocker, is gaining ground as a treatment option for depression. The occurrence of persistent psychosis and cognitive impairment after repeated use of ketamine remains a concern. N, N-dimethylglycine (DMG) is a nutrient supplement and acts as an NMDAR glycine site partial agonist. The objective of this study was to assess whether DMG could potentially prevent the behavioral and synaptic deficits in mice after repeated ketamine exposure. Male ICR mice received ketamine (20 mg/kg) from postnatal day (PN) 33-46, twice daily, for 14 days. The locomotor activity, novel location recognition test (NLRT), novel object recognition test (NORT), social interaction test, head twitch response induced by serotonergic hallucinogen, and the basal synaptic transmission and long-term potentiation (LTP) in the hippocampal slices were monitored after repeated ketamine treatment. Furthermore, the protective effects of repeated combined administration of DMG (30 and 100 mg/kg) with ketamine on behavioral abnormalities and synaptic dysfunction were assessed. The results showed that mice exhibited memory impairments, social withdrawal, increased head twitch response, reduced excitatory synaptic transmission, and lower LTP after repeated ketamine exposure. The ketamine-induced behavioral and synaptic deficits were prevented by co-treatment with DMG. In conclusion, these findings may pave a new path forward to developing a combination formula with ketamine and DMG for the treatment of depression and other mood disorders.