Evidences for the involvement of monoaminergic and GABAergic systems in antidepressant-like activity of garlic extract in mice

Objectives:

The present study was undertaken to investigate the effect of the ethanolic extract of Allium sativum L. (Family: Lilliaceae), commonly known as garlic, on depression in mice.

Materials and Methods:

Ethanolic extract of garlic (25, 50 and 100 mg/kg) was administered orally for 14 successive days to young Swiss albino mice of either sex and antidepressant-like activity was evaluated employing tail suspension test (TST) and forced swim test (FST). The efficacy of the extract was compared with standard antidepressant drugs like fluoxetine and imipramine. The mechanism of action of the extract was investigated by co-administration of prazosin (α1-adrenoceptor antagonist), sulpiride (selective D2-receptor antagonist), baclofen (GABA_B agonist) and p-CPA (serotonin antagonist) separately with the extract and by studying the effect of the extract on brain MAO-A and MAO-B levels.

Results:

Garlic extract (25, 50 and 100 mg/kg) significantly decreased immobility time in a dose-dependent manner in both TST and FST, indicating significant antidepressant-like activity. The efficacy of the extract was found to be comparable to fluoxetine (20 mg/kg p.o.) and imipramine (15 mg/kg p.o.) in both TST and FST. The extract did not show any significant effect on the locomotor activity of the mice. Prazosin, sulpiride, baclofen and p-CPA significantly attenuated the extract-induced antidepressant-like effect in TST. Garlic extract (100 mg/kg) administered orally for 14 successive days significantly decreased brain MAO-A and MAO-B levels, as compared to the control group.

Conclusion:

Garlic extract showed significant antidepressant-like activity probably by inhibiting MAO-A and MAO-B levels and through interaction with adrenergic, dopaminergic, serotonergic and GABAergic systems.     

The safety of synthetic colloid in critically ill patients with severe traumatic brain injuries

Purpose

Although 4% albumin is associated with increased mortality in patients with traumatic brain injury (TBI), evidence concerning the safety of synthetic colloids is lacking. We aimed to determine if there is an association between synthetic colloids and mortality in patients with severe TBI.

Materials and Methods

A retrospective cohort study of patients with severe TBI was conducted. Data were collected on all intravenous fluids administered during the first 14 days of admission. Multivariable Cox proportional hazards regression was used to model the association between daily cumulative pentastarch quintiles and mortality.

Results

Patients receiving pentastarch had higher Acute Physiology and Chronic Health II scores (23.9 vs 21.6, P < .01), frequency of craniotomy (42.5% vs 21.6%, P = .02), longer duration of intensive care unit stay (12 vs 4 days, P < .01), and mechanical ventilation (10 vs 3 days, P < .01). On unadjusted Cox regression, patients in the highest quintile of cumulative pentastarch administration had a higher rate of mortality compared with those receiving no colloid (hazard ratio, 3.8; 95% confidence interval, 1.2-12.4; P = .03). However, this relationship did not persist in the final multivariable model (hazard ratio 1.0; 95% confidence interval, 0.25-4.1; P = .98).

Conclusion

There was no association between cumulative exposure to pentastarch and mortality in patients with severe TBI.