Terminalia fagifolia Mart. & Zucc. elicits vasorelaxation of rat thoracic aorta through nitric oxide and K+ channels dependent mechanism.

Terminalia fagifolia Mart. & Zucc. (Combretaceae) is a plant commonly found in the regions of the Brazilian cerrado, popularly used for the treatment of gastrointestinal disorders. There are no reports in the literature on the use of T. fagifolia for the treatment of the cardiovascular system conditions. Nevertheless, plants of the same genus, such as Terminalia arjuna (Roxb.) Wight & Arn and Terminalia superba Engler & Diels, present cardioprotective, hypotensive and vasodilatating effects. In light of this, the aim of the study was to investigate the effect of the ethanolic extract (Tf-EE) and of its aqueous (Tf-AQF), hexanic (Tf-HEXF) and hydroethanolic (Tf-HAF) partition fractions obtained from the stem bark of T. fagifolia Mart. & Zucc. The effects of the extract and partition fractions of T. fagifolia were evaluated on isometric tensions in the thoracic aorta rings of Wistar rats (250-300 g). Tf-EE, Tf-HEXF and Tf-HAF presented a concentration-dependent vasorelaxant effect, and Tf-AQF presented a vasorelaxant effect that was more potent in the presence of endothelium. The relaxation curves of the aorta promoted by the fraction investigated were attenuated in the presence of the following pharmacological tools: L-NAME, ODQ or PTIO. The vasorelaxant effect of the aorta promoted by Tf-AQF was attenuated in the presence of TEA and 4-AP. Tf-EE induced a concentration-dependent and endothelium-independent vasorelaxation. Tf-HAF and Tf-HEXF presented concentration-dependent and vascular-endothelium-independent vasorelaxation, but did not obtain 100% of relaxation. On the other hand, Tf-AQF presented concentration-dependent vasorelaxation that was more potent in aorta rings with vascular endothelium. The relaxant mechanism induced by the Tf-AQF involves the NO/sGC/cGMP pathway and channels Kv.

Anti-inflammatory effect of the monoterpene myrtenol is dependent on the direct modulation of neutrophil migration and oxidative stress.

Myrtenol is a bicyclic monoterpene with anti-inflammatory properties. However, the mechanisms involved are partially unknown. Here, we investigated the effect of myrtenol during experimental chronic arthritis and the possible modulating activity of oxidative stress and neutrophil migration. Complete Freund's Adjuvant (CFA)-sensitized rats were treated with vehicle (1 mL/kg, po), myrtenol (12.5, 25 or 50 mg/kg, po), indomethacin (10 mg/kg, po) or dexamethasone (0.4 mg/kg) followed by intra-articular injection of CFA (0.5 mg/mL, 50 µL per joint). Then, paw edema and articular incapacitation (paw elevation time) were evaluated for 14 days. On the last day, a blood concentration superoxide dismutase (SOD) and nitrite was determined. In another experimental setting, human neutrophils were incubated with vehicle (sterile saline, 1 mL) or myrtenol (10-100 ng/mL) and the in vitro chemotaxis to N-formylmethionine-leucyl-phenylalanine (fMLP) (10-7 M/well) was evaluated. In addition, antiinflammatory effect of myrtenol was investigated in carrageenan-induced peritonitis. We found that CFA induced a prominent paw swelling and incapacitation of the joint, which were significantly prevented by myrtenol (P < 0.05). In addition, blood accumulation nitrite was attenuated by myrtenol when compared with vehicle-treated CFA group (P < 0.05). Furthermore, plasma levels of SOD were significantly increased by myrtenol versus vehicle-treated CFA group (P < 0.05). Moreover, fMLP-triggered neutrophil chemotaxis and carrageenan-induced peritonitis were markedly prevented by myrtenol (P < 0.05). Therefore, myrtenol showed anti-inflammatory and antinociceptive effects on experimental chronic arthritis, which seems to be related to the direct modulation of neutrophil migration and antioxidant activity.

Enhancement of orofacial antinociceptive effect of carvacrol, a monoterpene present in oregano and thyme oils, by ß-cyclodextrin inclusion complex in mice.

Orofacial pain is associated with diagnosis of chronic pain of head, face, mouth, neck and all the intraoral structures. Carvacrol, a naturally occurring isoprenoid with diverse class of biological activities including anti-inflammatory, analgesic, antitumor and antioxidant properties. Now, the antinociceptive effect was studied in mice pretreatment with carvacrol (CARV) and ß-cyclodextrin complex containing carvacrol (CARV-ßCD) in formalin-, capsaicin-, and glutamate- induced orofacial nociception. Mice were pretreated with vehicle (0.9% Nacl, p.o.), CARV (10 and 20mg/kg, p.o.), CARV-ßCD (10 and 20mg/kg, p.o.) or MOR (10mg/kg, i.p.) before the nociceptive behavior induced by subcutaneous injections (s.c.) of formalin (20µl, 2%), capsaicin (20µl, 2.5µg) or glutamate (20µl, 25µM) into the upper lip respectively. The interference on motor coordination was determined using rotarod and grip strength meter apparatus. CARV-ßCD reduced the nociceptive during the two phases of the formalin test, whereas CARV did not produced the reduction in face-rubbing behavior in the initial phase. CARV-ßCD (20mg/kg, p.o.) produced 49.3% behavior pain while CARV alone at 20mg/kg, p.o, produced 28.7% of analgesic inhibition in the second phase of formalin test. CARV, CARV-ßCD and Morphine (MOR) showed a significant reduction against nociception caused by capsaicin or glutamate injection. Thus the encapsulation of carvacrol in ß-cyclodextrin can acts as a considerable therapeutic agent with pharmacological interest for the orofacial pain management.

Antioxidant activity and mechanisms of action of natural compounds isolated from lichens: a systematic review.

Chronic diseases such as cancer, diabetes, neurodegenerative and cardiovascular diseases are characterized by an enhanced state of oxidative stress, which may result from the overproduction of reactive species and/or a decrease in antioxidant defenses. The search for new chemical entities with antioxidant profile is still thus an emerging field on ongoing interest. Due to the lack of reviews concerning the antioxidant activity of lichen-derived natural compounds, we performed a review of the antioxidant potential and mechanisms of action of natural compounds isolated from lichens. The search terms "lichens", "antioxidants" and "antioxidant response elements" were used to retrieve articles in LILACS, PubMed and Web of Science published until February 2014. From a total of 319 articles surveyed, 32 met the established inclusion and exclusion criteria. It was observed that the most common isolated compound studied was usnic acid, cited in 14 out of the 32 articles. The most often described antioxidant assays for the study of in vitro antioxidant activity were mainly DPPH, LPO and SOD. The most suggested mechanisms of action were scavenging of reactive species, enzymatic activation and inhibition of iNOS. Thus, compounds isolated from lichens are possible candidates for the management of oxidative stress, and may be useful in the treatment of chronic diseases.

Anti-inflammatory and antinociceptive effects of Sterculia striata A. St.-Hil. & Naudin (Malvaceae) in rodents.

The present work reports the anti-inflammatory and antinociceptive activities of the ethanol extract obtained from the stem bark of Sterculia striata A. St.-Hil. & Naudin (Ss-EtOH) in the experimental models of edema induced by carrageenan, dextran, or histamin and nociception induced by chemical stimuli, such as acetic acid, formalin, capsaicin, or glutamate. The Ss-EtOH (50 mg/kg) promoted a marked inhibition on the hind paw edema induced by carrageenan or dextran (30% and 73%, respectively). Besides, Ss-EtOH (25 mg/kg) exhibited a slight activity (30%) on the hind paw edema induced by histamin. The Ss-EtOH (12.5 and 25 mg/kg) showed the antinociceptive activity on chemical stimuli induced by acetic acid (65.59% and 38.37%, respectively), formalin, in the initial (35.08% and 31.5%, respectively) and late phases (44.09% and 83.57%, respectively), capsaicin (43.77% and 51.31%, respectively), or glutamate (36.6% and 52.12%, respectively). Regarding the possible mechanism involved in the antinociceptive effect, Ss-EtOH (12.5 mg/kg) showed a decrease in the antinociceptive effect (65.8%) in the acetic acid model after pretreatment with naloxone. Thus, opioid mechanisms might be underlying this response.

Cyclodextrin-complexed Ocimum basilicum leaves essential oil increases Fos protein expression in the central nervous system and produce an antihyperalgesic effect in animal models for fibromyalgia.

O. basilicum leaves produce essential oils (LEO) rich in monoterpenes. The short half-life and water insolubility are limitations for LEO medical uses. ß-Cyclodextrin (ß-CD) has been employed to improve the pharmacological properties of LEO. We assessed the antihyperalgesic profile of LEO, isolated or complexed in ß-CD (LEO/ß-CD), on an animal model for fibromyalgia. Behavioral tests: mice were treated every day with either LEO/ß-CD (25, 50 or 100 mg/kg, p.o.), LEO (25 mg/kg, p.o.), tramadol (TRM 4 mg/kg, i.p.) or vehicle (saline), and 60 min after treatment behavioral parameters were assessed. Therefore, mice were evaluated for mechanical hyperalgesia (von Frey), motor coordination (Rota-rod) and muscle strength (Grip Strength Metter) in a mice fibromyalgia model. After 27 days, we evaluated the central nervous system (CNS) pathways involved in the effect induced by experimental drugs through immunofluorescence protocol to Fos protein. The differential scanning analysis (DSC), thermogravimetry/derivate thermogravimetry (TG/DTG) and infrared absorption spectroscopy (FTIR) curves indicated that the products prepared were able to incorporate the LEO efficiently. Oral treatment with LEO or LEO-ßCD, at all doses tested, produced a significant reduction of mechanical hyperalgesia and we were able to significantly increase Fos protein expression. Together, our results provide evidence that LEO, isolated or complexed with ß-CD, produces analgesic effects on chronic non-inflammatory pain as fibromyalgia.

Gastroprotective effect of an ethanolic extract from Neoglaziovia variegata (Arruda) Mez (Bromeliaceae) in rats and mice.

This study investigates the gastroprotective effect of a crude ethanolic extract of Neoglaziovia variegata (Arruda) Mez (Bromeliaceae), designated Nv-EtOH, in experimental models of gastric ulcer. In the ethanol-induced gastric ulcer model, Nv-EtOH showed gastroprotection at doses of 200 and 400 mg/kg body weight (BW) (57.0% and 79.7%, respectively). Nv-EtOH also significantly reduced the formation of gastric lesions induced by ethanol/HCl (31.6% and 63.5%), ibuprofen (70.0% and 74.3%), or ischemia/reperfusion in rats (65.0% and 87.0%) at 200 and 400 mg/kg BW when compared with the vehicle group. In the antioxidant activity assessment, Nv-EtOH (400 mg/kg BW) increased the catalase activity and sulfhydryl groups (SH) levels, respectively. Moreover, gastroprotection against ethanol damage was decreased after ibuprofen pretreatment. Nv-EtOH (400 mg/kg BW) promoted a significant increase in the content of gastric wall mucus. The Nv-EtOH effect was significantly reduced in mice pretreated with N(G)-nitro-L-arginine (L-NOARG) or glibenclamide, inhibitors of nitric oxide synthase and K(ATP) channel activation, respectively, suggesting the involvement of these mechanisms in the Nv-EtOH-induced gastroprotective effect. Nv-EtOH decreased the total acidity, but did not modify other gastric juice parameters. Nv-EtOH was also effective in promoting the healing process in chronic gastric ulcer induced by acetic acid in rats.

ß-Cyclodextrin-complexed (-)-linalool produces antinociceptive effect superior to that of (-)-linalool in experimental pain protocols.

Many plants produce (-)-linalool, a plant-derived monoterpene alcohol, including members of the Lamiaceae (mints) and Lauraceae family (laurels, cinnamon, rosewood). The anti-inflammatory and analgesic effects of (-)-linalool have been widely suggested for various studies. Poor chemical stability and short half-life restrain the clinical applications of some essential oil and monoterpenes, including (-)-linalool. However, ß-cyclodextrin (ß-CD) has been used to increase solubility and stability of lipophilic compounds and also to improve the pharmacological effects. In this study, the antinociceptive effect of (-)-linalool and (-)-linalool/ß-CD was examined using the acetic acid writhing reflex, formalin and hotplate tests in rodents. (-)-Linalool and (-)-linalool/ß-CD demonstrated strong antinociceptive activity in all the chemical- and heat-induced mice models (p < 0.01 or p < 0.001). These findings imply the involvement of both peripheral and central antinociceptive mechanisms. In peritonitis induced by carrageenan, isolated monoterpene or ß-CD complex also reduced total leucocyte migration and TNF-α levels in peritoneal fluid. The inclusion complexes, (-)-linalool/ß-CD, revealed that the antinociceptive effect was significantly (p < 0.01) improved when compared with (-)-linalool alone. Such results were unlikely to be provoked by any motor abnormality. Together, our results suggest that ß-CD might represent an important tool for improvement of analgesic and anti-inflammatory profiles of (-)-linalool and other water-insoluble compounds, such as lipophilic monoterpenes or essential oils.

The pressor effect of angiotensin-(1-7) in the rat rostral ventrolateral medulla involves multiple peripheral mechanisms.

OBJECTIVE: In the present study, the peripheral mechanism that mediates the pressor effect of angiotensin-(1-7) in the rostral ventrolateral medulla was investigated. METHOD: Angiotensin-(1-7) (25 pmol) was bilaterally microinjected in the rostral ventrolateral medulla near the ventral surface in urethane-anesthetized male Wistar rats that were untreated or treated (intravenously) with effective doses of selective autonomic receptor antagonists (atenolol, prazosin, methyl-atropine, and hexamethonium) or a vasopressin V1 receptor antagonist [d(CH2)5 -Tyr(Me)-AVP] given alone or in combination. RESULTS: Unexpectedly, the pressor response produced by angiotensin-(1-7) (16 ± 2 mmHg, n = 12), which was not associated with significant changes in heart rate, was not significantly altered by peripheral treatment with prazosin, the vasopressin V1 receptor antagonist, hexamethonium or methyl-atropine. Similar results were obtained in experiments that tested the association of prazosin and atenolol; methyl-atropine and the vasopressin V1 antagonist or methyl-atropine and prazosin. Peripheral treatment with the combination of prazosin, atenolol and the vasopressin V1 antagonist abolished the pressor effect of glutamate; however, this treatment produced only a small decrease in the pressor effect of angiotensin-(1-7) at the rostral ventrolateral medulla. The combination of hexamethonium with the vasopressin V1 receptor antagonist or the combination of prazosin, atenolol, the vasopressin V1 receptor antagonist and methyl-atropine was effective in blocking the effect of angiotensin-(1-7) at the rostral ventrolateral medulla. CONCLUSION: These results indicate that angiotensin-(1-7) triggers a complex pressor response at the rostral ventrolateral medulla that involves an increase in sympathetic tonus, release of vasopressin and possibly the inhibition of a vasodilatory mechanism.

The pressor effect of angiotensin-(1-7) in the rat rostral ventrolateral medulla involves multiple peripheral mechanisms

OBJECTIVE: In the present study, the peripheral mechanism that mediates the pressor effect of angiotensin-(1-7) in the rostral ventrolateral medulla was investigated. METHOD: Angiotensin-(1-7) (25 pmol) was bilaterally microinjected in the rostral ventrolateral medulla near the ventral surface in urethane-anesthetized male Wistar rats that were untreated or treated (intravenously) with effective doses of selective autonomic receptor antagonists (atenolol, prazosin, methyl-atropine, and hexamethonium) or a vasopressin V1 receptor antagonist [d(CH2)5 -Tyr(Me)-AVP] given alone or in combination. RESULTS: Unexpectedly, the pressor response produced by angiotensin-(1-7) (16 ± 2 mmHg, n = 12), which was not associated with significant changes in heart rate, was not significantly altered by peripheral treatment with prazosin, the vasopressin V1 receptor antagonist, hexamethonium or methyl-atropine. Similar results were obtained in experiments that tested the association of prazosin and atenolol; methyl-atropine and the vasopressin V1 antagonist or methyl-atropine and prazosin. Peripheral treatment with the combination of prazosin, atenolol and the vasopressin V1 antagonist abolished the pressor effect of glutamate; however, this treatment produced only a small decrease in the pressor effect of angiotensin-(1-7) at the rostral ventrolateral medulla. The combination of hexamethonium with the vasopressin V1 receptor antagonist or the combination of prazosin, atenolol, the vasopressin V1 receptor antagonist and methyl-atropine was effective in blocking the effect of angiotensin-(1-7) at the rostral ventrolateral medulla. CONCLUSION: These results indicate that angiotensin-(1-7) triggers a complex pressor response at the rostral ventrolateral medulla that involves an increase in sympathetic tonus, release of vasopressin and possibly the inhibition of a vasodilatory mechanism.

Orofacial analgesic-like activity of carvacrol in rodents.

Carvacrol (CARV) is a phenolic monoterpene present in the essential oil of several aromatic spices. The purpose of the present study was to evaluate the antinociceptive effect of CARV on formalin-, capsaicin-, and glutamate-induced orofacial nociception in mice. Male mice were pretreated with CARV [25, 50, and 100 mg/kg body weight (BW), intraperitoneal (i.p.)], morphine (5 mg/kg BW, i.p.), or vehicle (distilled water + one drop of 0.3% cremophor in distilled water), before formalin (20 microl, 2%), capsaicin (20 microl, 2.5 microg), or glutamate (40 microl, 25 microM) was injected into the right upper lip. Our results revealed that i.p. pretreatment with CARV was effective in reducing the nociceptive face-rubbing behaviour in both phases of the formalin test and also produced a significant antinociceptive effect at all doses in the capsaicin and glutamate tests. Further, we showed that the action of CARV on the central nervous system (CNS) did not affect these results, since this compound did not exert a significant CNS-depressant effect, as shown by the pentobarbital-induced hypnosis. Our results suggest that CARV might represent an important tool for the treatment of orofacial pain.

Anti-inflammatory and anti-ulcer activities of carvacrol, a monoterpene present in the essential oil of oregano.

This study reports a pharmacological evaluation of anti-inflammatory and anti-ulcer activities of carvacrol, a phenolic monoterpene constituent of essential oils produced by oregano and other several aromatic plants and spices, in experimental models of edema induced by different phlogistic agents and gastric lesions induced by acetic acid. In models of paw edema induced by dextran or histamine, carvacrol was effective at 50 mg/kg (46% and 35%, respectively); in these models, cyproheptadine reduced edema formation (61% and 43%, respectively). In edema induced by substance P, carvacrol (100 mg/kg) and ruthenium red (3 mg/kg) also decreased the edema formation (46% and 40%, respectively). Carvacrol significantly reduced the ear edema induced by 12-O-tetradecanoylphorbol acetate and arachidonic acid at 0.1 mg per ear (43% and 33%, respectively), similar to indomethacin at 0.5 mg per ear or 2.0 mg per ear (55% and 57%, respectively). Carvacrol (at doses of 25, 50, and 100 mg/kg) showed a healing capacity on gastric lesions induced by acid acetic (60%, 91%, and 81%, respectively) after 14 days of treatment. These results suggest that carvacrol acts on different pharmacological targets, probably interfering in release and/or synthesis of inflammatory mediators, such as the prostanoids, and thus favoring the healing process for gastric ulcers.

Gastroprotective activity of Sterculia striata A. St. Hil. & Naudin (Malvaceae) in rodents.

The Sterculia striata ethanolic extract (Ss-EtOH) inhibited gastric lesions induced by ethanol, HCl/ethanol, and ischemia/reperfusion, but not those induced by indomethacin, and did not alter the gastric secretion. Ss-EtOH restored the catalase activity and content of nonprotein sulfhydryl groups in the stomach of mice treated with ethanol. The gastroprotection induced by Ss-EtOH in the ethanol-induced gastric lesion model was abolished by N(G)-nitroL-arginine methyl ester (L-NAME) pretreatment, suggesting the involvement of nitric oxide and antioxidant compounds, but not prostaglandins, in this activity. Lupeol obtained from Ss-EtOH promoted gastroprotection as well as the extract at the same dose, and it must therefore contribute to the observed effects.

Carvacrol attenuates mechanical hypernociception and inflammatory response.

Carvacrol is a phenolic monoterpene present in the essential oil of the family Lamiaceae, as in the genera Origanum and Thymus. We previously reported that carvacrol is effective as an analgesic compound in various nociceptive models, probably by inhibition of peripheral mediators that could be related with its strong antioxidant effect observed in vitro. In this study, the anti-hypernociceptive activity of carvacrol was tested in mice through models of mechanical hypernociception induced by carrageenan, and the involvement of important mediators of its signaling cascade, as tumor necrosis factor-alpha (TNF-α), prostaglandin E(2) (PGE(2)), and dopamine, were assessed. We also investigated the anti-inflammatory effect of carvacrol on the model of carrageenan-induced pleurisy and mouse paw edema, and the lipopolysaccharide (LPS)-induced nitrite production in murine macrophages was observed. Systemic pretreatment with carvacrol (50 or 100 mg/kg; i.p.) inhibited the development of mechanical hypernociception and edema induced by carrageenan and TNF-α; however, no effect was observed on hypernociception induced by PGE(2) and dopamine. Besides this, carvacrol significantly decreased TNF-α levels in pleural lavage and suppressed the recruitment of leukocytes without altering the morphological profile of these cells. Carvacrol (1, 10, and 100 µg/mL) also significantly reduced (p < 0.001) the LPS-induced nitrite production in vitro and did not produce citotoxicity in the murine peritoneal macrophages in vitro. The spontaneous locomotor activity of mice was not affected by carvacrol. This study adds information about the beneficial effects of carvacrol on mechanical hypernociception and inflammation. It also indicates that this monoterpene might be potentially interesting in the development of novel tools for management and/or treatment of painful conditions, including those related to inflammatory and prooxidant states.

Antiulcer activity of ethanolic extract of Encholirium spectabile Mart. ex Schult & Schult f. (Bromeliaceae) in rodents.

This study evaluated the antiulcer activity of an ethanolic extract of Encholirium spectabile (ES-EtOH) by using different standard experimental models of induced acute gastric ulceration. ES-EtOH (100 mg/kg p.o) protected the gastric mucosa against ulceration that was induced by absolute ethanol (53%), ethanol/HCl (75%), ibuprofen (52 %) and ischemia/reperfusion (43 %). It also restored catalase activity and non-protein sulfhydryl group concentration in the gastric wall of mice that had been treated with ethanol. The pre-treatment of mice with N-nitro-L-arginine (70 mg/kg i.p.) abolished the protective activity of ES-EtOH, which indicates that prostaglandins, antioxidant compounds and nitric oxide synthase activity are involved in the gastroprotective activity of the extract.

Gastroprotective effect of the ethanolic extract of Parkia platycephala Benth. leaves against acute gastric lesion models in rodents.

Parkia platycephala Benth. (Leguminosae--Mimosoideae), popularly known as "visgueira", fava bean tree or "fava-de-bolota", is widely found in the Northern and Northeastern regions of Brazil. Its pods are used as cattle food supplement in the drought period. Compounds with a gastroprotective activity were obtained from the genus Parkia. Therefore, this study aimed at investigating the gastroprotective effect of the ethanolic extract of Parkia platycephala Benth. leaves (Pp-EtOH), as well as evaluating its possible mechanisms of action in experimental ulcer induction models. Lesions were induced by absolute ethanol, ethanol-HCl, ischemia-reperfusion and indomethacin in rodents. Pp-EtOH showed a protective effect in the lesion models (66, 48 and 52%, respectively), but it was not able to protect gastric mucosa against indomethacin-induced lesions. Results show a possible participation of the NO-synthase pathway in the gastroprotection and an antioxidant activity, by the increase of the catalase activity. The participation of prostaglandins and potassium channels sensitive to ATP in the gastroprotective effect of Pp-EtOH seems less likely to occur. More comprehensive studies, therefore, should be carried out to elucidate the antiulcerative effects of this promising natural product against this gastrointestinal disorder.

Gastroprotective effect of the ethanolic extract of Parkia platycephala Benth. leaves against acute gastric lesion models in rodents

Parkia platycephala Benth. (Leguminosae - Mimosoideae), popularly known as "visgueira", fava bean tree or "fava-de-bolota", is widely found in the Northern and Northeastern regions of Brazil. Its pods are used as cattle food supplement in the drought period. Compounds with a gastroprotective activity were obtained from the genus Parkia. Therefore, this study aimed at investigating the gastroprotective effect of the ethanolic extract of Parkia platycephala Benth. leaves (Pp-EtOH), as well as evaluating its possible mechanisms of action in experimental ulcer induction models. Lesions were induced by absolute ethanol, ethanol-HCl, ischemia-reperfusion and indomethacin in rodents. Pp-EtOH showed a protective effect in the lesion models (66, 48 and 52 percent, respectively), but it was not able to protect gastric mucosa against indomethacin-induced lesions. Results show a possible participation of the NO-synthase pathway in the gastroprotection and an antioxidant activity, by the increase of the catalase activity. The participation of prostaglandins and potassium channels sensitive to ATP in the gastroprotective effect of Pp-EtOH seems less likely to occur. More comprehensive studies, therefore, should be carried out to elucidate the antiulcerative effects of this promising natural product against this gastrointestinal disorder.

Antiulcer activity of ethanolic extract of Encholirium spectabile Mart. ex Schult & Schult f. (Bromeliaceae) in rodents

This study evaluated the antiulcer activity of an ethanolic extract of Encholirium spectabile (ES-EtOH) by using different standard experimental models of induced acute gastric ulceration. ES-EtOH (100 mg/kg p.o) protected the gastric mucosa against ulceration that was induced by absolute ethanol (53 percent), ethanol/HCl (75 percent), ibuprofen (52 percent) and ischemia/reperfusion (43 percent). It also restored catalase activity and non-protein sulfhydryl group concentration in the gastric wall of mice that had been treated with ethanol. The pre-treatment of mice with N-nitro-L-arginine (70 mg/kg i.p.) abolished the protective activity of ES-EtOH, which indicates that prostaglandins, antioxidant compounds and nitric oxide synthase activity are involved in the gastroprotective activity of the extract.

Avaliação da toxicidade aguda, efeitos citotóxico e espasmolítico de Pomacea lineata (Spix, 1827) (Mollusca, Caenogastropoda) / Evaluation of the acute toxicity, cytotoxic and spasmolytic effects of Pomacea lineata (Spix, 1827) (Mollusca, Caenogastropoda)

Pomacea sp. e sua desova têm uso popular para tratar diarréia e doenças respiratórias. Este trabalho objetivou avaliar a toxicidade aguda e os efeitos citotóxico e espasmolítico dos liófilos de Pomacea lineata e de sua desova. Os liófilos não apresentaram toxicidade aguda (até 2 g/kg v.o.) ou efeito citotóxico (até 1 mg/mL). P. lineata relaxou a traquéia pré-contraída com CCh na presença (Emax = 48,8 ± 6,4 por cento) e na ausência (Emax = 47,3 ± 9,1 por cento) de epitélio, já a desova relaxou apenas na presença (Emax = 36,3 ± 2,5 por cento) de epitélio. Os liófilos foram ineficazes sobre o tônus espontâneo da traquéia. P. lineata foi mais potente em inibir as contrações do íleo induzidas por ACh (logCI50 = 2,5 ± 0,04 µg/mL) que por hist. (logCI50 = 2,7 ± 0,04 µg/mL). A desova inibiu igualmente as contrações induzidas por ACh (logCI50 = 2,5 ± 0,02 µg/mL) e hist. (logCI50 = 2,5 ± 0,06 µg/mL). P. lineata foi mais potente em relaxar o íleo pré-contraído com ACh (logCE50 = 1,7 ± 0,12 µg/mL) do que com KCl (logCE50 = 2,4 ± 0,06 µg/mL) ou hist. (logCE50 = 2,2 ± 0,18 µg/mL). A desova relaxou equipotentemente o íleo pré-contraído com KCl (logCE50 = 2,3 ± 0,15 µg/mL), ACh (logCE50 = 1,9 ± 0,14 µg/mL) ou hist. (logCE50 = 2,2 ± 0,16 µg/mL), sugerindo um bloqueio dos CaV. P. lineata e sua desova apresentam efeito espasmolítico justificando a sua utilização no tratamento de diarréia e de doenças respiratórias.

Pomacea sp. and its eggs are used against diarrhea and respiratory diseases in folk medicine. The aim of this study was to investigate acute toxicity, cytotoxic and spasmolytic activity of lyophilized Pomacea lineata and its eggs. P. lineata and its eggs present no acute toxicity (until 2 g/kg p.o.) or cytotoxic effect (until 1 mg/mL). P. lineata and its eggs have no effect on guinea-pig trachea spontaneous tonus. P. lineata relaxed trachea pre-contracted with CCh in the presence (Emax = 48.8 ± 6,4 percent) and absence (Emax = 47.3 ± 9,1 percent) of epithelium, the eggs relaxed only in the presence (Emax = 36.3 ± 2.5 percent) P. lineata was more potent to inhibit contractions induced by ACh (logIC50 = 2.5 ± 0.04 µg/mL) than histamine (logIC50 = 2.7 ± 0.04 µg/mL). The eggs inhibited contractions induced by ACh (logIC50 = 2.5 ± 0.02 µg/mL) and histamine (logIC50 = 2.5 ± 0.06 µg/mL) in a non-selective manner. P. lineata was more potent in relax ileum pre-contracted with ACh (logEC50 = 1.7 ± 0.12 µg/mL) than KCl (logEC50 = 2.4 ± 0.06 µg/mL) or histamine (logEC50 = 2.2 ± 0.18 µg/mL). The eggs were equipotent in relax ileum pre-contracted with of KCl (logEC50 = 2.3 ± 0.15 µg/mL), ACh (logEC50 = 1.9 ± 0.14 µg/mL) or histamine (logEC50 = 2.2 ± 0.16 µg/mL), that is suggestive of the blockade of the voltage-operated calcium channels. Collectively, the results validate folk use of P. lineata and its eggs to treat diarrhea and respiratory diseases.