In vivo and in vitro anti-inflammatory and anti-nociceptive activities of lovastatin in rodents

Statins are among the most prescribed drugs in recent clinical practice. They are also known for their pleiotropic actions, which are independent of their lipid-lowering properties. The effect of lovastatin was investigated against carrageenan-induced paw edema in male Wistar rats (200-250 g) and on leukocyte migration, as measured by carrageenan-induced peritonitis in male Swiss mice (20-25 g), which are models of acute inflammation. Lovastatin (administered 1 h prior to carrageenan), at oral doses of 2, 5, and 10 mg/kg, markedly attenuated paw edema formation in rats at the 4th hour after carrageenan injection (25, 43, and 37 percent inhibition, respectively). Inhibitions of 20, 45 and 80 percent were observed in the leukocyte migration, as evaluated by carrageenan-induced peritonitis in mice with lovastatin doses of 0.5, 1 and 5 mg/kg, as compared to controls. Furthermore, lovastatin (administered 1 h before initiation) reduced the nociceptive effect of the formalin test in mice, at both phases, at doses of 2, 5, and 10 mg/kg: first phase (51, 65, and 70 percent, respectively) and second phase (73, 57, and 66 percent inhibition of licking time, respectively). The anti-nociceptive activity of lovastatin was inhibited by naloxone (3 mg/kg, sc). Lovastatin (0.01, 0.1, and 1 µg/mL) inhibited by 23, 79, and 86 percent, respectively, the release of myeloperoxidase from human neutrophils. Leukocyte (predominantly neutrophils) infiltration was almost completely reduced by lovastatin treatment, as observed in the model of acute paw edema with hematoxylin and eosin staining. In addition, lovastatin decreased the number of cells expressing tumor necrosis factor-α (TNF-α) and the inducible form of nitric oxide synthase (iNOS) activity. Therefore, the alterations in leukocyte activity and cytokine release could contribute to the anti-inflammatory activity of lovastatin.

In vivo and in vitro anti-inflammatory and anti-nociceptive activities of lovastatin in rodents.

Statins are among the most prescribed drugs in recent clinical practice. They are also known for their pleiotropic actions, which are independent of their lipid-lowering properties. The effect of lovastatin was investigated against carrageenan-induced paw edema in male Wistar rats (200-250 g) and on leukocyte migration, as measured by carrageenan-induced peritonitis in male Swiss mice (20-25 g), which are models of acute inflammation. Lovastatin (administered 1 h prior to carrageenan), at oral doses of 2, 5, and 10 mg/kg, markedly attenuated paw edema formation in rats at the 4th hour after carrageenan injection (25, 43, and 37% inhibition, respectively). Inhibitions of 20, 45 and 80% were observed in the leukocyte migration, as evaluated by carrageenan-induced peritonitis in mice with lovastatin doses of 0.5, 1 and 5 mg/kg, as compared to controls. Furthermore, lovastatin (administered 1 h before initiation) reduced the nociceptive effect of the formalin test in mice, at both phases, at doses of 2, 5, and 10 mg/kg: first phase (51, 65, and 70%, respectively) and second phase (73, 57, and 66% inhibition of licking time, respectively). The anti-nociceptive activity of lovastatin was inhibited by naloxone (3 mg/kg, sc). Lovastatin (0.01, 0.1, and 1 µg/mL) inhibited by 23, 79, and 86%, respectively, the release of myeloperoxidase from human neutrophils. Leukocyte (predominantly neutrophils) infiltration was almost completely reduced by lovastatin treatment, as observed in the model of acute paw edema with hematoxylin and eosin staining. In addition, lovastatin decreased the number of cells expressing tumor necrosis factor-α (TNF-α) and the inducible form of nitric oxide synthase (iNOS) activity. Therefore, the alterations in leukocyte activity and cytokine release could contribute to the anti-inflammatory activity of lovastatin.

Anxiolytic-like effects of standardized extract of Justicia pectoralis (SEJP) in mice: Involvement of GABA/benzodiazepine in receptor.

Justicia pectoralis (Acanthaceae) is used as an antiinflammatory, antimicrobial and bronchodilator, and its extract exerts an anxiolytic-like effect profile in animal models. This work presents the behavioral effects of an aqueous standardized extract of Justicia pectoralis (SEJP) in animal models, such as the elevated plus maze (EPM), light/dark, open field, rota rod and pentobarbital sleep time. The extract was administered intragastrically to male mice at single doses of 50, 100 and 200 mg/kg, while diazepam 1 or 2 mg/kg was used as a standard drug and flumazenil 2.5 mg/kg was used to evaluate the participation of benzodiazepinic receptors. The results showed that, similar to diazepam (1 mg/kg), SEJP significantly modified all the observed parameters in the EPM test, without altering the general motor activity in the open field, rota rod and pentobarbital sleep time tests. Flumazenil reversed not only the diazepam effect but also the SEJP effect. In the same way, all doses of SEJP increased the time of permanence in the light box in the light/dark test. The results showed that SEJP presented an anxiolytic-like effect, disproving sedative effects.

A comparative chemical and pharmacological study of standardized extracts and vanillic acid from wild and cultivated Amburana cearensis A.C. Smith.

The objectives of this work were to carry out a comparative chemical study and to evaluate the antinociceptive and anti-inflammatory activities of ethanol extracts (EtOHE) and vanilic acid (VA) from cultivated and wild Amburana cearensis A.C. Smith (Fabaceae), an endangered species used in Northeast Brazil for the treatment of asthma. The HPLC analysis of EtOHE, showed that coumarin (CM) and VA were the major constituents from the cultivated plant, while in the extract from the wild plant the major constituents were amburoside A (AMB) and CM. Pharmacological tests were performed with male Swiss mice or male Wistar rats acutely administered with 100-400mg/kg, p.o. of EtOHEs or 12.5-50mg/kg, p.o. of VA. EtOHEs from A. cearensis with 4, 7 or 9 months of cultivation significantly inhibited, from 32 to 64%, both phases of the formalin test in mice. Similar results were observed with the EtOHE from the wild species. VA significantly reduced both phases of the formalin test. This effect was partially reversed by naloxone. EtOHE from cultivated or wild A. cearensis inhibited the carrageenan (Cg)-induced mice paw edema. Furthermore, VA inhibited the paw edema and the leukocyte migration in rat peritoneal cavity induced by Cg. On the other hand, it did not inhibit the edema and the increase of vascular permeability induced by dextran in the rat paw. All together, these results indicate that the EtOHE from cultivated A. cearensis exhibit similar chemical and pharmacological profiles, as related to the wild plant. VA is, at least partially, responsible for these pharmacological effects. Its antinociceptive effect occurs by a mechanism partly dependent upon the opioid system, while the anti-inflammatory action was manifested in inflammatory processes dependent on polymorphonuclear cells and are probably related to the VA inhibition of cytokines as observed by others.

Studies on the anti-oedematogenic properties of a fraction rich in lonchocarpin and derricin isolated from Lonchocarpus sericeus.

The acute anti-inflammatory properties of a fraction rich in the chalcones lonchocarpin and derricin, from the roots of Lonchocarpus sericeus (HFLS), were studied for the first time, using a paw oedema model induced in rats by various stimuli. Results showed that HFLS (100 and 200 mg kg(-1), i.p.) was ineffective in inhibiting dextran-induced paw oedema. The HFLS (200 mg kg(-1), p.o. or i.p.) also failed to inhibit the bradykinin-induced oedema. In the yeast-elicited oedema, the HFLS (200 mg kg(-1), i.p.) caused inhibitions ranging from 42 to 59% in the first to fourth hours. Orally administered HFLS (200 mg kg(-1)) was active only in the second (27%) and fourth (32%) hours after yeast injection. It was observed that HFLS (50, 100 and 200 mg kg(-1), i.p.) showed inhibitions of 34, 57 and 74%, respectively, in the third hour for the carrageenan-induced oedema. The inhibition was smaller when the HFLS (100 and 200 mg kg(-1)) was administered orally. The effect of the HFLS (20 mg kg(-1), i.p.) in the carrageenan-induced oedema was not modified by the L-NAME, but the association of pentoxifylline and HFLS increased its effect, suggesting an involvement of the PDE enzyme.

Bisabolol-induced gastroprotection against acute gastric lesions: role of prostaglandins, nitric oxide, and KATP+ channels.

The effects of Matricaria recutita and alpha-bisabolol, a bioactive component from Chamomile species, were investigated against gastric damage induced by absolute ethanol (96%, 1 mL per animal) in rats. The effects of M. recutita extract and alpha-bisabolol on gastric mucosal damage were assessed by determination of changes in mean gastric lesion area. Mechanistic studies were carried out at with 100 mg=kg alpha-bisabolol. We further examined the possible participation of prostaglandins, nitric oxide, and KATP+ channels in its mechanism. M. recutita reduced gastric damage in all doses tested. Alpha-bisabolol at oral doses of 50 and 100 mg=kg markedly attenuated the gastric lesions induced by ethanol to the extent of 87% and 96%, respectively. Pretreatments with the nitric oxide antagonist N-nitro-l-arginine methyl ester (10 mg=kg, i.p.) or with indomethacin, an inhibitor of cyclooxygenase, failed to block effectively the gastroprotective effect of alpha-bisabolol. Furthermore, the alpha-bisabolol effect was significantly reduced in rats pretreated with glibenclamide, an inhibitor of KATP+ channel activation. Thus we provide evidence that alpha-bisabolol reduces the gastric damage induced by ethanol, at least in part, by the mechanism of activation of KATP+ channels.

Acute effects of guarana (Paullinia cupana Mart.) on mouse behaviour in forced swimming and open field tests.

Guarana, a herbal extract from the seeds of Paullinia cupana Mart. has been evaluated in comparison with caffeine on mouse behaviour in forced swimming and open field tests. Guarana (25 and 50 mg/kg, p.o.) and caffeine (10 and 20 mg/kg, p.o.) each significantly reduced the duration of immobility in the forced swimming test suggesting an antidepressant-like effect in mice. At these doses, neither substance affected ambulation in the open field test. However, a high dose of guarana (100 mg/kg) and caffeine (30 mg/kg) significantly enhanced the locomotor activity in the open field test. Caffeine, but not guarana, could effectively block an adenosine agonist, cyclopentyl adenosine (CPA)-induced increase in swimming immobility suggesting that mechanism(s) other than the adenosinergic mechanism are involved in the antidepressant-like activity of guarana.

Amburoside A, a glucoside from Amburanacearensis, protects mesencephalic cells against 6-hydroxydopamine-induced neurotoxicity.

This study evaluates the potential neuroprotective properties of amburoside A, a glucoside isolated from Amburana cearensis, on rat mesencephalic cell cultures exposure to the neurotoxin 6-hydroxydopamine (6-OHDA). The parameters determined were cell viability by the 3[4,5-dimethylthiazole-2-il]-2,5-diphenyltetrazolium bromide (MTT) method, nitric oxide (NO) and free radical formation by the measurement of nitrite concentration and thiobarbituric acid reacting substance (TBARS) formation as an indication of cellular lipid peroxidation. The results showed that AMB was less effective as a curative agent in the MTT assay, since its addition after 6-OHDA did not reverse the neurotoxin's effect, except at the highest concentration (AMB, 100 microg/ml). Similarly, the higher nitrite levels observed after exposure of the cells to 6-OHDA were only partially reversed by AMB, at this highest concentration. However, when AMB (0.5, 1, 10 and 100 microg/ml) was added before the toxin, it appeared to protect neuronal cells against 6-OHDA toxicity in a concentration-dependent manner, as shown by MTT assay. AMB also prevented free radical formation indicated by the increased nitrite concentration induced by 6-OHDA. Cells exposed to 6-OHDA showed a 3.4 times increase in TBARS concentration as compared to controls, and this effect was inhibited from 24% up to 64% by AMB (0.1-100 microg/ml), indicative of a neuroprotective effect. In conclusion, we show that AMB, acting as an antioxidant compound, presents a significant neuroprotective effect, suggesting that this compound could provide benefits as a therapeutic agent in neurodegenerative disease such as Parkinson's.

Sedative and anticonvulsant effects of hydroalcoholic extract of Equisetum arvense.

The hydroalcoholic extract of Equisetum arvense (HAE) tested at the doses of 200 and 400 mg/kg showed a significant activity on the open-field, enhanced the number of falls in the rota-rod reducing the time of permanence in the bar and increased the sleeping time (46% and 74%) in the barbiturate-induced sleeping time. In the pentylenetetrazole-seizure, it increased the first convulsion latency, diminished the severity of convulsions, reduced the percentage of animals which developed convulsion (50% and 25%) and protected animals from death. On the contrary, in the elevated plus maze, the doses 50, 100 and 150 mg/kg did not affect the evaluated parameters. Thus, HAE presented anticonvulsant and sedative effects. Phytochemical analysis detected the presence of tannins, saponins, sterols and flavonoids.

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.

Análise de timol por CLAE na tintura de Lippia sidoides Cham. (alecrim-pimenta) produzida em diferentes estágios de desenvolvimento da planta

O teor de timol, princípio ativo usado como marcador nas tinturas das folhas de Lippia sidoides Cham. (Verbenaceae) preparadas com material coletado antes, durante e após a floração e designadas como T1, T2 e T3, foi determinado por CLAE, utilizando-se cromatógrafo Shimadzu CLASS-VP, coluna RP-18 (Supelco), com fase móvel isocrática acetonitrila:água (78:22) e fluxo 0,8 ml/min com detecção em 254 nm. As amostras foram injetadas num volume de 20 μl e analisadas em triplicata. Os teores de timol encontrados foram 1,97 ± 0,07 em T1; 2,00 ± 0,03 em T2 e 2,34 ± 0,06 mg/ml em T3. Os resultados mostram discretas diferenças nas concentrações de timol nas tinturas das folhas de alecrim-pimenta preparadas em diferentes momentos de seu desenvolvimento. Contudo, observou-se que o melhor momento para a coleta da planta parece ser após a sua floração (T3), que mostrou o maior teor de timol.

Lippia sidoides Cham. (Verbenaceae) is popularly known in Northeast Brazil as "alecrim-pimenta". The goal of the present work is to perform a quantitative analysis of timol, used as a marker in phytomedicine prepared from the leaves of L. sidoides, collected before, during and after the flower. At least three samples of tincture of L. sidoides were analyzed by HPLC. Among the samples analyzed, the tincture produced from the leaves after the flower showed slightly high concentration of timol (2,34 ± 0,06 mg/ml) when compared with before (1,97 ± 0,07 mg/ml) or during the flower (2,00 ± 0,03 mg/ml). The best period to collect leaves of L. sidoides seems to be after the flower.

Antinociceptive, anti-inflammatory and bronchodilator activities of Brazilian medicinal plants containing coumarin: a comparative study.

This work studied the antinociceptive, antiinflammatory and bronchodilator activities of hydroalcoholic extracts (HAEs) from Torresea cearensis, Justicia pectoralis, Eclipta alba, Pterodon polygaliflorus and Hybanthus ipecacuanha. These plants are largely used in north-eastern Brazil for respiratory tract diseases, and have in common coumarin, one of their active principles. The antinociceptive effects of all HAEs in mice were similar, and the inhibition of the acetic acid-induced writhing was 35-55% with 200 mg/kg, p.o. At this dose, the effect ranged from 41-77% with the formalin test in mice, and all the HAEs inhibited preferentially the 2nd phase of the response. In one case (P. polygaliflorus), the effect was partially reversed by naloxone. Except for the HAE from T. cearensis (200 mg/kg, p.o.) which inhibited carrageenan-induced edema by 47%, the others presented no effect orally but showed a significant activity intraperitoneally. On the other hand, T. cearensis was not active in the dextran model, while inhibitions with the other ones were lower than 30%. The bronchodilator activities of J. pectoralis and P. polygaliflorus HAEs as determined in isolated guinea-pig trachea were the most active.

Antinociceptive and antiedematogenic effects of the hydroalcoholic extract and coumarin from Torresea cearensis Fr. All.

This work studied the antinociceptive and antiedematogenic effects of the hydroalcoholic extract (HAE) and coumarin (Coum) from T. cearensis in experimental models of nociception in mice, and carrageenan- and dextran-induced paw edema in rats. HAE (100 and 200 mg/kg, p.o.) and Coum (5-20 mg/kg, p.o.) reduced in a dose - dependent manner the nociception produced by acetic acid and formalin. In the hot plate test, HAE (100-400 mg/kg, p.o.) and Coum (5 and 10 mg/kg, p.o.) increased the latency time to the thermal stimulus 90 min after administration. While naloxone partially reversed the antinociceptive effect of the HAE but not that of Coum, L-arginine reversed the antinociceptive effect of Coum in the formalin test. HAE (200 mg/kg, p.o.) and Coum (10 and 20 mg/kg, p.o.) significantly inhibited the carrageenan-induced edemas in rats but not the dextran-induced edema. This antiedematogenic effect on the carrageenan model was supported by histological studies performed in sections of the rat paw. In conclusion, the antinociceptive effects of HAE and Coum occur by a mechanism at least in part dependent on the opioid system. The nitric oxide system possibly has also a role in the Coum nociception. In addition, the antiedematogenic activity is manifested in inflammatory processes dependent on polimorphonuclear cells.