Orcinol

Orcinol glucoside produces antidepressant effects by blocking the behavioural and neuronal deficits caused by chronic stress.[Pubmed:23838013]

Eur Neuropsychopharmacol. 2014 Jan;24(1):172-80.

This study focused on the antidepressant potential of Orcinol glucoside (OG) and its possible mechanisms of action. We established a depressed rat model using 3 consecutive weeks of chronic unpredictable mild stress (CUMS). The antidepressant-like effect of OG was revealed using the sucrose preference test, the open field test, the forced swimming test (FST), and the tail suspension test (TST). The activity of the hypothalamic-pituitary-adrenal (HPA) axis was evaluated by detecting the serum corticosterone (CORT) concentrations and mRNA expression of corticotrophin-releasing hormone (CRH) in the hypothalamus. The protein expression levels of brain-derived neurotrophic factor (BDNF) and total phosphorylated-ERK1/2 were detected by western blot. The results showed that OG treatment (1.5, 3, or 6mg/kg) alleviated the depression-like behaviour of rats under CUMS, as indicated by the increased sucrose preference and the decreased immobility in both the FST and TST, although the rearing frequency in the open field test increased only in the group that received the lowest dose (1.5mg/kg OG). Rats that received OG treatment exhibited reduced serum CORT levels and CRH mRNA expression in the hypothalamus, suggesting that the hyperactivity of the HPA axis in CUMS rats was reversed by OG treatment. Moreover, OG treatment upregulated the protein levels of BDNF and phosphorylated-ERK1/2 in the hippocampus, even above control levels. Our findings suggest that OG improved depressive behaviour in CUMS rats by downregulating HPA axis hyperactivity and increasing BDNF expression and ERK1/2 phosphorylation in the hippocampus.

Anxiolytic effects of orcinol glucoside and orcinol monohydrate in mice.[Pubmed:25429891]

Pharm Biol. 2015 Jun;53(6):876-81.

CONTEXT: Anxiety is a common psychological disorder, often occurring in combination with depression, but therapeutic drugs with high efficacy and safety are lacking. Orcinol glucoside (OG) was recently found to have an antidepressive action. OBJECTIVE: To study the therapeutic potential of OG and Orcinol monohydrate (OM) as anxiolytic agents. MATERIALS AND METHODS: Anxiolytic effects in mice were measured using the elevated plus-maze, hole-board, and open-field tests. Eight groups of mice were included in each test. Thirty minutes before each test, mice in each group received one oral administration of OG (5, 10, or 20 mg/kg), OM (2.5, 5, or 10 mg/kg), the positive control diazepam (1 or 5 mg/kg), or control vehicle. Each mouse underwent only one test. Uptake of Orcinol (5 mg/kg) in the brain was qualitatively detected using the HPLC-MS method. RESULTS: OG (5, 10, and 20 mg/kg) and OM (2.5 and 5 mg/kg) increased the time spent in open arms and the number of entries into open arms in the elevated plus-maze test. OG (5 and 10 mg/kg) and OM (2.5 and 5 mg/kg) increased the number of head-dips in the hole-board test. At all tested doses, OG and OM did not significantly affect the locomotion of mice in the open-field test. Orcinol could be detected in the mouse brain homogenates 30 min after oral OM administration, having confirmed that OM is centrally active. DISCUSSION AND CONCLUSION: The results demonstrated that OG and OM are anxiolytic agents without sedative effects, indicating their therapeutic potential for anxiety.