Effect of newly synthesized 1,2,4-triazino[5,6-b]indole-3-thione derivatives on olfactory bulbectomy induced depression in rats

Objective:To study the derivatives of 1,2,4-triazino[5,6-b]indole-3-thione for antidepressant activity in olfactory bulbectomized(OBX)rats.Out of various derivatives tested for acute tail suspension test,the two derivatives showiug prominent action were.selected for bilateral olfactory bulbeetomy rsodel of ehronic depression in rats.Methods:The sub aeute effects of 14-day oral pretreatment of two derivatives labeled as 3a(70 mg/kg)and 3r(70 mg/kg),imipramine(20 mg/kg),fluoxetiue(30 mg/kg)and moclobemide(15 mg/kg)were evaluated on bilateral bulbectomy induced rise in body weight,hyperphagia,hyperactivity,and on sexual dysfunction.The serum sodium concentration,body temperature,and heart rate were also recorded.Results:The derivatives3a and 3r showed reversal of drop in body weight,reversed OBX indueed hyperactivity,normalized body temperature,heart rate,and serum sodium concentration.In elevated maze test,moclobemide,3a,3r treatment significantly redueed time spent in open arm as compared to OBX rats.3a and 3r also irsproved sexual behavior parameters.Conclusions:The present study shows promising antidepressant action and provides a proof of concept for the chronic treatrsent of 3a,3r to treat depression.

Factors that modulate olfactory dysfunction

The olfactory system is one of a few areas in the nervous system which is capable of regeneration throughout the life.Olfactory sensory neurons reside in the nasal cavity are continuously replenished with new neurons arising from stem cells.Some factors such as aging,neurodegenerative diseases,head trauma,brain tumor extraction and infection cause olfactory dysfunction which significantly influences physical wellbeing,quality of life,mental health,nutritional status,memory processes,identifying danger and is associated with increased mortality.Therefore,finding a treatment to improve olfactory dysfunction is needed.Recent research efforts in the field have shown some very promising new approaches to treat olfactory dysfunction.This review explores the current studies that have addressed therapeutic approaches to improve olfactory neuron regeneration based on cell transplantation therapy,modulation of physiological olfactory dysfunction and drug treatments.

Intranasal Administration of Conditioned Medium from Cultured Mesenchymal Stem Cells Improves Cognitive Impairment in Olfactory Bulbectomized Mice

Alzheimer’s disease (AD) is the common cause of dementia which shows the neuro-pathologies like an accumulation of amyloid-β (Aβ) and degeneration of cholinergic neuron. Olfactory bulbectomized (OBX) mice show some of AD features, so they have been used to research as AD model. Mesenchymal stem cells (MSCs) can differentiate into many kinds of cells, including neuronal cells. In this study, we intranasally administrated the conditioned medium derived from cultured umbilical cord (UC) MSCs. The intranasal administration of the MSCs medium restored the cognitive impairment observed in OBX mice. In addition, the decreased number of choline acetyltransferase-positive cells in the medial septum was restored by the conditioned medium administration. In conclusion, MSCs-derived conditioned medium may have protective effects of cholinergic neurons in the medial septum, thereby rescuing the cognitive impairment of OBX.

Surface modification of PGP for a neutrophil–nanoparticle co-vehicle to enhance the anti-depressant effect of baicalein

Exploiting cells as vehicles combined with nanoparticles combined with therapy has attracted increasing attention in the world recently. Red blood cells, leukocytes and stem cells have been used for tumor immunotherapy, tissue regeneration and inflammatory disorders, and it is known that neutrophils can accumulate in brain lesions in many brain diseases including depression. N-Acetyl Pro–Gly–Pro(PGP) peptide shows high specific binding affinity to neutrophils through the CXCR2 receptor. In this study, PGP was used to modify baicalein-loaded solid lipid nanoparticles(PGP-SLNs) to facilitate binding to neutrophils in vivo. Brain-targeted delivery to the basolateral amygdala(BLA) was demonstrated by enhanced concentration of baicalein in the BLA. An enhanced anti-depressant effect was observed in vitro and in vivo. The mechanism involved inhibition of apoptosis and a decrease in lactate dehydrogenase release. Behavioral evaluation carried out with rats demonstrated that anti-depression outcomes were achieved. The results indicate that PGP-SLNs decrease immobility time, increase swimming time and climbing time and attenuate locomotion in olfactory-bulbectomized(OB) rats. In conclusion, PGP modification is a strategy for targeting the brain with a cell–nanoparticle delivery system for depression therapy.