Effects of Crocus sativus petals' extract on rat blood pressure and on responses induced by electrical field stimulation in the rat isolated vas deferens and guinea-pig ileum

We have investigated the effects of Crocus sativus petals' extract on blood pressure in anaesthetised rats and also on responses of the isolated rat vas deferens and guinea-pig ileum induced by electrical field stimulation (EFS). Aqueous and ethanol extracts of C. sativus petals reduced the blood pressure in a dose-dependent manner. For example administration of 50 mg/100 g of aqueous extract changed the blood pressure from 133.5+/-3.9 to 117+/-2.1 (mmHg). EFS of the isolated rat vas deferens and guinea-pig ileum evoked contractions were decreased by aqueous and ethanol extracts of C. sativus petals. The aqueous extract (560 mg/ml) significantly reduced the contractile responses of vas deferens to epinephrine (1 microM) without any change in contraction induced by KCl (300 mM). The present results may suggest that the relaxatory action of C. sativus petals' extract on contraction induced by EFS in the rat isolated vas deferens is a postsynaptic effect.     

Anti-inflammatory and antipyretic effects of Trigonella foenum-graecum leaves extract in the rat

Anti-inflammatory and antipyretic effects of the Trigonella foenum-graecum (TFG) leaves extract, an Iranian medicinal plant, were examined. For anti-inflammatory activity, the formalin-induced edema model was used. Hyperthermia was induced by intraperitoneal injection of 20% (w/v) aqueous suspension of brewer's yeast. Sodium salicylate (SS) was used as a positive control. Both TFG and SS significantly reduced formalin-induced edema in single dose (TFG 1000 and 2000 mg/kg, SS 300 mg/kg) and chronic administration (TFG 1000 mg/kg and SS 300 mg/kg). TFG and SS also significantly reduced hyperthermia induced by brewer's yeast in 1 and 2 h after their administration. The results indicate that the TFG leaves extract possess anti-inflammatory as well as antipyretic properties in both i.p. and p.o. administration. Phytochemical studies indicate that alkaloids, cardiac glycosides, and phenols are the major component in the extract. Although existence of three anti-inflammatory, analgesic and antipyretic effects in this extract suggest a NSAID-like mechanism for it, but the presence of alkaloids, the absence of other effective compounds such as flavonoids, saponins, steroids, etc., and also its analgesic effect on tail-flick test that usually is not produced by NSAIDs, suggest another mechanism for the extract. So the possibility of alkaloids as effective compounds, in this extract, increases.     

Antinociceptive activity of aqueous extract of Pachyptera hymenaea (DC.) in mice

The standardized aqueous extract of leaves of Pachyptera hymenaea (DC.) belonging to family Bignoniaceae was investigated for possible antinociceptive effect in mice. Three different models were used to study the effects of extract on nociception, namely acetic acid-induced writhing test, formalin test (paw licking test) and tail flick test in mice. The extract was administered 1h prior to pain induction in the dose range of 25, 50 and 75mg/kg orally. The extract at the given dose range reduced the acetic acid induced nociception by 44.03, 52.90 and 62.46% respectively. The extract reduced formalin effect in both the phases of experiment by 32.36, 41.94, 54.29% and 35.39, 50.17, 55.86% respectively. In the tail flick study, animals' reaction time were increased by 22.69, 38.24 and 40.26% at the above selected doses respectively at 120min after drug administration. Naloxone (2mg/kg; s.c.) significantly antagonized the effect of extract in formalin and tail flick method, while partially antagonized the effect in writhing test. However caffeine completely reverted the extract effect in both the phases of formalin test. Results of these studies revealed that the extract have significant antinociceptive activity in the used models with a possible involvement of central mechanism and adenosine system.     

Hypericum triquetrifolium Turra. extract exhibits antinociceptive activity in the mouse

The aim of the present study was to investigate the antinociceptive activity of Hypericum triquetrifolium Turra. extract. The lyophilized extract was administered to male Swiss mice. Formalin paw test and tail flick tests were used for the evaluation of the antinociceptive activity. Plant extract (10, 25, 50 and 60 mg kg(-1), i.p.) (n = 16-24 for each group) or vehicle (n = 27) was administered 30 min before the subplantar formalin injection. In the tail flick test, mice were examined for latency to withdraw their tails from a noxious thermal stimulus using a tail flick meter (n = 8 for each group). The effects of the extract on sensorimotor performance was also assessed (n = 16-24 for each group). The extract caused a significant dose-related inhibition of the first phase (50, 60 mg kg(-1), i.p.) and second phase (10, 25, 50 and 60 mg kg(-1), i.p.) of formalin induced hindpaw licking. Additionally, the extract administration (50, 60 mg kg(-1), i.p.) increased the tail flick latencies. No significant change was observed in any of the treatment groups in the sensorimotor performance test. The observed antinociceptive activity of the extract may be due to its noradrenaline and serotonin reuptake blocking activity. Moreover, the probable antiinflammatory activity of the extract may play a role in the dose-related inhibition of the second phase of formalin paw test.     

Andrographis paniculata (Nees) selectively blocks voltage-operated calcium channels in rat vas deferens

The possible blockade of voltage-operated calcium channels (VOCs) by Andrographis paniculata dried extract in vas deferens smooth muscle was investigated in rats. The tissues were incubated in Ca(2+)-free Kreb's solution and stimulated with KCl (40 mM) to produce depolarisation of the membrane. The isometric contractile response to cumulative concentrations of CaCl(2) was effectively blockaded by 0.2 and 0.4 mg/ml A. paniculata. In other experiments, the maximum contractile response induced by norepinephrine was not antagonised by 0.2, 0.4 or 0.8 mg/ml A. paniculata. The possible blockade of Ca(2+) entry by A. paniculata was evaluated with 45Ca(2+) uptake in vas deferens treated with reserpine (5 and 2.5 mg/kg) 48 and 24 h before the experiments. Epididymal segments were incubated with Ca(2+)-free Kreb's solution with KCl, 25 and 50 mM. The influx was completely blockaded with 0.4 mg/ml A. paniculata. These results suggest that A. paniculata selectively blockades VOCs, hence inhibiting the 45Ca(2+) influx.     

Anti-inflammatory and Analgesic Effects of Elephantopus tomentosus Ethanolic Extract

Elephantopus tomentosus is widely used in Asia, especially in Malaysia, for the treatment of pain and inflammation. In the present study, the analgesic and anti-inflammatory effects of a 95% ethanol extract of E. tomentosus were investigated in different experimental models. In the anti-inflammation study, 1000 mg/kg of extract significantly reduced carrageenan-induced hind paw edema (p < 0.05) and inhibited abdominal permeability compared with control (p < 0.01). The analgesic activity was assayed in several experimental models in mice: (1) hot plate, (2) tail flick, (3) writhing test; and rats: carrageenan-induced hyperalgesia pain threshold test. However, at the doses tested, no significant activity was found in the hot plate test and the tail flick test. E. tomentosus ethanol extract at 1000 mg/kg significantly (p < 0.05) increased hyperalgesia pain threshold and inhibited writhing activity. The results suggest that E. tomentosus ethanol extract at 1000 mg/kg dose is effective in anti-inflammatory and non-steroidal anti-inflammatory drug type anti-nociception activities.     

Anti-inflammatory and smooth muscle relaxant activities of the hydroalcoholic extract and chemical constituents from Amburana cearensis A C Smith

Amburana cearensis A. C. Smith, Fagaceae, is a medicinal plant commonly known as 'cumaru' and used in Northeast Brazil for the treatment of respiratory tract diseases. In the present work, we investigated the anti-inflammatory and smooth muscle relaxant activities of the hydroalcoholic extract (HAE), coumarin (Coum) and fl avonoid fraction (FF) isolated from the trunk barks of Amburana cearensis A. C. Smith. It was shown that HAE (200 and 400 mg/kg), Coum (20 and 40 mg/kg) and FF (40 mg/kg), administered orally, significantly inhibited both leukocyte and neutrophil migrations, in the carrageenan or N-formyl-methyl-leucyl-phenylalanine (fMLP)-induced migration in rat peritoneal cavity. The increase in cutaneous vascular permeability induced by serotonin in rats was significantly blocked by HAE (150 mg/kg, i.p.), Coum (5 mg/kg, i.p.) and FF (20 mg/kg, i.p.). However, only HAE blocked the histamine effect on Evans blue extravasation. In the guinea-pig trachea precontracted with carbachol (0.3 microM), histamine (0.1 microM) or KCl (0.1 M), the HAE, Coum and FF evoked a concentration-dependent relaxation in the presence of the three agonists. HAE (100-800 microg/ml) and Coum (4-32 microg/ml) also caused significant relaxation of the rat vas deferens previously contracted with adrenaline, acetylcholine or barium chloride. In addition, HAE, Coum and FF inhibited the histamine and serotonin-induced increase of cutaneous vascular permeability in rats.     

Antiinflammatory activity and effects on isolated smooth muscle of extracts from different Teucrium species

The present study analyses the antiinflammatory effects and the action on in vitro motility of methanol and dichloromethanol extracts and stems of four Teucrium species (T. flavum, T. cartaginenses, T. buxifolium and T. pumillum). The antiinflammatory activity was tested in the carrageenan-induced paw oedema in rats. T. flavum methanol (200 mg/kg, i.p.) and dichloromethanol (138 mg/kg, i.p.) extracts showed a significant anti-inflammatory effect through the 24 h experimental period and reduced the E_max induced by histamine and serotonin in vitro on guinea-pig ileum and rat uterus respectively. These extracts did not modify the contractile effects induced by acetylcholine on rat duodenum and noradrenaline on rat vas deferens. The methanol extracts of T. pumillum (50 mg/kg, i.p.) and T. buxifolium (26 mg/kg, i.p.) exhibited significant antiinflammatory effects only in the acute phase of the oedema (2 h) without affecting the chronic phase (24 h). In guinea-pig ileum, rat uterus and rat vas deferens, the methanol extract of T. pumillum reduced the maximal effect induced by histamine, serotonin and noradrenaline, respectively, whereas the methanol extract of T. buxifolium lacked any effect on the contractile activity induced by various agonists in vitro. When tested for antiinflammatory activity the methanol (200 mg/kg, i.p.) and dichloromethanol (200 mg/kg, i.p.) extracts of T. cartaginenses did not modify the oedematous response induced by carrageenan administration.     

The analgesic effect of the methanolic extract of Acanthus montanus

The analgesic effect of the methanolic leaf extract of Acanthus montanus was studied in rats using the cold water tail flick assay, and in mice using the tail immersion, tail clip, acetic acid induced writhing and formalin pain tests. The results showed dose-dependent and significant (P<0.05) increases in pain threshold, at 60 min post treatment, with doses of 200 and 400 mg/kg of the extract in tail flick, tail immersion and tail clip methods. The effects of the extract were significantly (P<0.05) lower than those produced by morphine (10 mg/kg) in the same tests. The extract (100-400 mg/kg) exhibited a dose-dependent inhibition of writhing and also showed a significant (P<0.001) inhibition of both phases of the formalin pain test, but with a less intense effect on the first than on the second phase. The results indicate that the analgesic effect of Acanthus montanus methanolic extract is both centrally and peripherally mediated.     

Antinociceptive and anti-inflammatory effects of Satureja hortensis L. extracts and essential oil

Satureja hortensis L. (Lamiaceae) is a medicinal plant used in Iranian folk medicine as muscle and bone pain reliever. In the present study, hydroalcoholic extract, polyphenolic fraction and essential oil of the aerial parts of the herb were prepared and evaluated for the analgesic activity using light tail flick, formalin and acetic acid-induced writhing in mice. Also, the anti-inflammatory effects of the above-mentioned preparations were assessed using carrageenan-induced paw edema in rats. Results showed that in the light tail flick test neither the essential oil nor the extracts could exert any significant effect. The hydroalcoholic extract (2000 mg/kg, p.o.) and the essential oil (200 mg/kg, p.o.) inhibited the mice writhing responses caused by acetic acid. In formalin test, hydroalcoholic extract (500-2000 mg/kg, p.o.), polyphenolic fraction (250-1000 mg/kg, p.o.) and the essential oil (50-200 mg/kg, p.o.) showed analgesic activity and pretreatment with naloxone (1 mg/kg, i.p.) or caffeine (20 mg/kg, i.p.) failed to reverse this antinociceptive activity. Polyphenolic fraction (1000 mg/kg, p.o.) and the essential oil (200 mg/kg) reduced edema caused by carrageenan. These results suggest that S. hortensis L. has antinociceptive and anti-inflammatory effects and probably mechanism(s) other than involvement of opioid and adenosine receptors mediate(s) the antinociception.