Antiandrogenic activities of Glycyrrhiza glabra in male rats.

Abnormal levels of androgens cause many diseases like benign prostatic hyperplasia and hormone dependent cancers. Although the reduction in serum testosterone (T) by Glycyrrhiza glabra has been reported, its effects on seminal vesicle (SV) and prostate tissues have never been reported. This study was carried out to investigate different aspects of antiandrogenic properties of this plant. Immature male rats were divided into five groups (n = 7): castrated rats without any treatment received only vehicle; castrated rats plus T replacement; three castrated groups with T replacement plus various doses of G. glabra extract (75, 150 and 300 mg/kg). All of the injections were carried out once daily in subcutaneous manner for 7 days. On the eighth day, blood samples were collected for total T measurement. Ventral prostate (VP), SV and levator ani muscle were dissected and weighed. Slides prepared from prostate were assessed histologically. The variation in the relative and absolute volume of the prostate tissue compartments was determined. Those receiving the doses of 150 and 300 mg/kg showed a significant reduction (p < 0.05) in prostate weight, total T and VP epithelium/stroma ratio (V/V). These results in SV and levator ani were shown in response to 300 mg/kg of extract. Increasing in T metabolism, down-regulation of androgen receptors or activation of oestrogen receptors could be involved mechanisms. This study showed that alcoholic extract of G. glabra has antiandrogenic properties.

Effects of Urtica dioica extract on lipid profile in hypercholesterolemic rats.

OBJECTIVE: To investigate the effects of extract of Urtica dioica, a perennial herb in Iran, on lipid profile in hypercholesterolemic rats. METHODS: The effects of Urtica dioica extract were tested by using it as a supplement in a high-cholesterol diet. Male rats were fed a high cholesterol diet (10 mL/kg) for 4 weeks with Urtica dioica extract (100 or 300 mg/kg) or 10 mg/kg lovastatin supplementation to study the hypocholesterolemic effects of Urtica dioica on plasma lipid levels, hepatic enzymes activities, and liver histopathological changes. RESULTS: Urtica dioica extract at 100 and 300 mg/kg significantly reduced the levels of total cholesterol (TC), and low-density lipoprotein-cholesterol (LDL-C) and also markedly decreased liver enzymes and weight in animals with a high cholesterol diet. Hematoxylin and eosin staining showed that in the 100 mg/kg extract of Urtica dioica group, the appearance of the liver cells was similar to the control group, and steatosis and inflammation were not found. In the 300 mg/kg extract of Urtica dioica group, mild steatosis was observed but mononuclear inflammatory infiltration was not found. CONCLUSION: The hepatic histopathological results reflect the correlation of Urtica dioica extract with both liver weight and the levels of plasma TC and LDL-C. These results indicate that Urtica dioica extract has hypocholesterolemic effects in the animal model.

Possible role of GABAA-benzodiazepine receptor in anticonvulsant effects of Pasipay in rats.

OBJECTIVE: To investigate the anticonvulsant effects of Pasipay, a commercially available preparation of hydro-alcoholic extract of Passiflora incarnata in rats. METHODS: The anticonvulsant effects of hydro-alcoholic extract of P. incarnata, Pasipay, were observed by intracerebroventricular injection of 0.125, 0.25, 0.55 and 1.5 microg Pasipay. RESULTS: Pasipay could dose-dependently affected minimal clonic seizures and generalized tonic-clonic seizures induced by pentylenetetrazole, through increment in seizure onset significantly. Additionally, pretreatment with 5 nmol/L flumazenil could abolish the anticonvulsant effects of Pasipay on the onset of both seizures. CONCLUSION: The results indicate that Pasipay has anticonvulsant effects in the brain, possibly through positive allosteric modulation of the GABAA receptor complex via interaction at the benzodiazepine site.

Anticonvulsant effects of aerial parts of Passiflora incarnata extract in mice: involvement of benzodiazepine and opioid receptors.

BACKGROUND: Passion flower (Passiflora incarnata) is used in traditional medicine of Europe and South America to treat anxiety, insomnia and seizure. Recently, it has shown antianxiety and sedative effects in human. METHODS: In this study, anticonvulsant effects of hydro- alcoholic extract of Passiflora, Pasipay, were examined by using pentylentetrazole model (PTZ) on mice. Pasipay, diazepam, and normal saline were injected intraperitoneally at the doses 0.4-0.05 mg/kg, 0.5-1 mg/kg and 10 ml/kg respectively 30 minutes before PTZ (90 mg/kg, i.p). The time taken before the onset of clonic convulsions, the duration of colonic convulsions, and the percentage of seizure and mortality protection were recorded. For investigating the mechanism of Pasipay, flumazenil (2 mg/kg, i.p) and naloxone (5 mg/kg, i.p) were also injected 5 minutes before Pasipay. RESULTS: An ED50 value of Pasipay in the PTZ model was 0.23 mg/kg (%95 CL: 0.156, 0.342). Pasipay at the dose of 0.4 mg/kg prolonged the onset time of seizure and decreased the duration of seizures compared to saline group (p < 0.001). At the dose of 0.4 mg/kg, seizure and mortality protection percent were 100%. Flumazenil and naloxone could suppress anticonvulsant effects of Pasipay. CONCLUSION: It seems that Pasipay could be useful for treatment absence seizure and these effects may be related to effect of it on GABAergic and opioid systems. More studies are needed in order to investigate its exact mechanism.