Polyherbal formulation (PF) is an Indian herbal medicine containing four herbal drugs - Nyctanthes arbortristis (65 mg/kg), Hippophae salicifolia(50 mg/kg), Ocimum tenuiflorum (45 mg/kg) and Reinwardtia indica (40 mg/kg) . Previous pharmacological studies have shown that four herbs in PH have antagonistic effects on mRNA level of COMT and MAO A & B . Furthermore, oleanceae, elaeagnaceae, lamiaceae and linaceae from the four herbs in PF may provide protective effect in depression. Highly expressed mRNA level of CLOCK& MTHFR gene, leads to decreased level of plasma homocysteine in an individual,thus increasing receptor concentration of neurotransmitter in neurons. However, antidepressant effect has not been reported before and its mechanism has not been fully clarified. The present study aims to investigate the antidepressant potential of ethanol extract of PF and its effect on mRNA level of CLOCK& MTHFR gene. Albino rats models of depression including forced swim test (FST) and tail suspension test (TST) were used to evaluate the effects of the ethanol extract of PF. A possible mechanism was explored in the tests of antagonism of COMT and MAO-A & B in rats in the previous study. The force swim stress-(FSS-) induced depressive rats were applied in exploring the mechanisms of PF treatment as an antidepressant. Daily oral administration of PF for 28 days significantly alleviated the FSS-induced depressive symptoms. In addition, effect of PF on mRNA level of CLOCK& MTHFR gene were determined by using RT-PCR in the frontal, hippocampus and hypothalamus brain region of rats and also investigated the level of hcy by ELISA, the expressions of those molecular bio-markers relating to depression in rat brains were altered by the treatment of PF. These PF-regulated the mRNA levels of Clock and MTHFR and maintained the level of plasma homocysteine (hcy). In previous study, oral administration of the ethanol extract of PF (200, 400, 800mg/kg) or Sertraline (10mg/kg) significantly reduced the duration of immobility in FST and TST. However, the effect was dose-dependent. The results suggested that the anti-depressant- action of PF might be mediated by an increase in level of mRNA of Clock and MTHFR in different areas of rat’s brain and decreases the level of plasma hcy in blood. The rats treated with ethanol extract of PF (200, 400, 800mg/kg) or Sertraline (10mg/kg), which acted agonistic on mRNA level of Clock and MTHFR gene in the frontal cortex, hippocampus and hypothalamus , moreover the maximal up regulation of Clock and MTHFR mRNA levels by PF was obtained at a dose of 200 mg/kg in FSS-exposed rats. Thus, PF could serve as alternative medicine for depressive patients. These results indicate that the ethanol extract of PF produced antidepressant-like effect and the possible mechanism. Being a poly herbal formulation, the observed activity profile may be attributed to one or more bioactive principles present in the components of this formulation. Out of these two preclinical study it is concluded that the PF is effective and safe antidepressant drug
