Absence of maternal-fetal adverse effects of Alternanthera littoralis P. Beauv. following treatment during pregnancy in mice.

Alternanthera littoralis P. Beauv is a plant native to Brazil that exhibits various beneficial activities including antioxidant, antibacterial, antifungal, antiprotozoal, anti-hyperalgesic, and anti-inflammatory properties. The aim of this study was to assess the impact of the ethanol extract of Alternanthera littoralis (EEAl) on reproductive outcomes, embryofetal development, and DNA integrity of pregnant female mice. Pregnant Swiss female mice were randomly assigned to three experimental groups (n = 10): controls were administered either 1% Tween 80 (vehicle), EEAl 100 mg/kg or EEAl 1000 mg/kg. Treatment was administered through gavage during the gestational period until day 18. On gestational days 16, 17, and 18, a peripheral blood sample from the tail vein was obtained for DNA integrity analysis (micronucleus test). After the last collection, animals were euthanized by cervical dislocation. Maternal organs and fetuses were collected, weighed, and subsequently analyzed. Reproductive outcome parameters were assessed by measurement of number of implants, live fetuses, and resorptions. Embryonic development was determined by adequacy of weight for gestational age as well as determination of external, visceral, and skeletal malformations. Data demonstrated that EEAl did not produce maternal toxicity at either dose associated with no marked alterations in any of the reproductive outcome parameters including implantation sites, live/dead fetuses ratio, fetal viability, post-implantation losses, resorptions, and resorption rate. However, EEAl 1000 group reduced embryofetal development by lowering placental weight. In addition, there was an increase in the frequency of external and skeletal malformations in the EEAl 1000 group, which could not be attributed to extract exposure as these values were within control levels. Based upon our findings, evidence indicates that the EEAl at the concentrations employed in our study may be considered safe for use during pregnancy and extracts of this plant show potential for development of phytomedicines to be used in pregnancy.

Chemical composition and effects of ethanolic extract and gel of Cochlospermum regium (Schrank) Pilg. Leaves on inflammation, pain, and wounds.

ETHNOPHARMACOLOGICAL RELEVANCE: Cochlospermum regium is well-known as "Algodãozinho do cerrado" in folk Brazilian medicine, and is used to fight infections, inflammation and skin disorders. AIM OF THE STUDY: To identify the phytochemical constituents and the effects of the ethanolic extract of C. regium leaves (EECR) on inflammation and pain, and the effects of C. regium gel (GEECR) on wound healing. MATERIALS AND METHODS: Animals were treated with EECR (30-300 mg/kg) or GEECR (1.25 and 2.5%) and studies were conducted using carrageenan-induced pleurisy and paw edema tests, formalin-induced pain model, and excision wound model. RESULTS: In total, 25 compounds, including quercitrin, methyl gallate, and 1,2,3,4,6-pentagalloylhexose, with highest detectability were identified. The treatments reduced leukocyte migration, nitric oxide production, protein extravasation, edema, mechanical hyperalgesia, pain in both phases (neurogenic and inflammatory), cold hypersensitivity, and improved wound closure and tissue regeneration. CONCLUSIONS: The present findings established the anti-inflammatory, anti-nociceptive, and wound healing potential of the leaves of C. regium, confirming the potential therapeutic effect of this plant.

Potential anti-arthritic and analgesic properties of essential oil and viridiflorol obtained from Allophylus edulis leaves in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Viridiflorol was identified and isolated from the essential oil of Allophylus edulis leaves (EOAE). A. edulis was used as "tereré", which is a drink made by the infusion of herbs in cold water, to treat pain (toothache and headache). All anti-nociceptive (analgesic) and anti-arthritic properties of EOAE and viridiflorol have not been completely scientifically clarified. AIM OF THE STUDY: The aim of the present study was to investigate the analgesic (anti-hyperalgesic and anti-nociceptive) and anti-arthritic properties of EOAE and viridiflorol using in vivo models. MATERIALS AND METHODS: The oral administration (p.o.) of EOAE (30, 100 and 300 mg/kg), viridiflorol (30, 100 and 200 mg/kg), morphine (1 mg/kg, subcutaneous route (s.c.)) and the intraplantar (local) administration (i.pl.) of viridiflorol (100 µg/paw) were tested using formalin model in Swiss mice. EOAE (100 mg/kg, p.o.), viridiflorol (200 mg/kg, p.o.), and dexamethasone (1 mg/kg, s.c.) were tested by zymosan-articular inflammation and in open-field models. Viridiflorol (0.3, 20 and 200 µg/paw) was also tested in carrageenan model, and viridiflorol (200 µg/paw) was also tested in tumor necrosis factor-α (TNF-α), and dopamine (DOPA) models. RESULTS: The oral administration of EOAE (100 and 300 mg/kg, p.o.), viridiflorol (200 mg/kg, p.o.), morphine (1 mg/kg, s.c.) (MOR) and local administration of viridiflorol (100 µg/paw) significantly inhibited edema and nociception in formalin model. Oral treatments with EOAE and viridiflorol (200 mg/kg) did not cause motor impairment in the open field test since they did not reduce locomotor activity. EOAE, viridiflorol and dexamethasone significantly reduced mechanical hyperalgesia, edema, total leukocytes, polymorphonuclear cells, nitric oxide and protein exudation in the zymosan-induced articular inflammation model. The local administration of viridiflorol (200 µg/paw, i.pl.) significantly inhibited mechanical hyperalgesia and edema induced by carrageenan, TNF-α and DOPA. CONCLUSIONS: This study confirms the potential anti-arthritic, anti-nocicepttive and anti-hyperalgesic properties of EOAE and viridiflorol. These properties could explain, at least in part, the folk use of A. edulis against including pain (toothache and headache). Viridiflorol could be partially responsible for the EOAE anti-hyperalgesic, anti-nociceptive and anti-arthritic properties and its mechanism of action could involve the inhibition of TNF-α and DOPA pathways.

Palicourea tomentosa (Aubl.) Borhidi: Microscopy, chemical composition and the analgesic, anti-inflammatory and anti-acetylcholinesterase potential.

ETHNOPHARMACOLOGICAL RELEVANCE: Palicourea tomentosa (Aubl.) Borhidi (synonym Psychotria poeppigiana Müll. Arg.) leaves are used in the popular treatments of inflammation and pain; however, there are no scientific studies demonstrating their activity as the methanolic extract of P. tomentosa. AIM OF STUDY: This study was undertaken to investigate the potential antioxidant, anti-acetylcholinesterase, anti-hyperalgesic, anti-nociceptive and anti-inflammatory properties, as well as the chemical composition and concentrations of constituents of the methanolic extract of P. tomentosa leaves (MEPT). The study also analyzes the micromorphology and histochemistry of leaves of P. tomentosa. MATERIALS AND METHODS: The MEPT was analysed by ultra-high-pressure liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS/MS). The concentrations of total phenols, flavonoids, flavonols and condensed tannin were determined. The micromorphology and histochemistry of leaves were performed using standard reagents, light and field emission scanning electron microscopy, beyond energy-dispersive X-ray spectroscopy. The antioxidant activity was evaluated for DPPH, ß-carotene and MDA. The anti-inflammatory activity of MEPT (30, 100, and 300 mg/kg) was assayed in carrageenan-induced models of paw oedema, mechanical hyperalgesia (Von Frey), cold allodynia (acetone) and pleurisy in mice. The anti-nociceptive potential of MEPT (30, 100, and 300 mg/kg) was evaluated by the formalin method in mice. The anti-acetylcholinesterase properties were evaluated in vivo in four rat brain structures. RESULTS: The total ion chromatogram of MEPT demonstrated two alkaloids, one coumarin, one iridoid and two terpene derivatives. The highest phenol, flavonoid, flavonol and condensed tannin concentrations were found in the extract. A comprehensive explanation of the leaf micromorphology and histochemistry was presented. MEPT was significantly inhibited by the DPPH, ß-carotene and MDA models. MEPT (30, 100 and 300 mg/kg) reduced the inflammation and hyperalgesic parameters in a carrageenan model and reduced formalin-induced nociception in both phases, which were cold sensitivity and oedema formation. The oral administration of 30 and 100 mg/kg MEPT significantly inhibited AChE activity in the frontal cortex. CONCLUSION: This is the first chemical and biological study performed with a P. tomentosa methanolic extract and anatomical and histochemical analysis. The present study showed that MEPT inhibited pain and inflammatory parameters contributing, at least in part, to explain the popular use of this plant as analgesic natural agent. Also, anatomical and histochemistry of leaves described in the present study provide microscopical information, which aids species identification.

Can maternal exposure to tamoxifen compromise sperm and behavioural parameters of male rat offspring?

Tamoxifen, a selective non-steroidal estrogen receptor modulator, is the standard adjuvant endocrine treatment for breast cancer. Since information on the risk of using tamoxifen during pregnancy is still scarce, this study evaluated whether the in utero and lactational treatment with this drug could compromise reproductive and behavioural parameters in male offspring. Pregnant Wistar rats were exposed to three doses of tamoxifen (0.12; 0.6; 3 µg/kg), by gavage, from gestational day 15 to lactational day 20. Tamoxifen exposure did not alter the anogenital distance in the male offspring; however, there was a significant increase in the body weight in the 0.12 µg/kg dose and a decrease in the 0.6 µg/kg dose. The male offspring treated with the highest dose exhibited a delay in the onset of puberty, evidenced by an increase in the age of preputial separation. Regarding sperm parameters, there was an increase in the sperm count in the cauda epididymis in the intermediate and highest dose groups, in addition to an increase in the number of static sperm and a decrease in the progressive sperm in the same groups. Moreover, an increase in the number of hyperplasia of the epithelial clear cells was observed in the epididymis. In conclusion, the present study demonstrated that maternal exposure to tamoxifen compromised the installation of puberty of the male offspring and the maturation of the epididymis, affecting sperm storage and motility in the adult life.

Chemical analysis and antioxidant, anti-inflammatory and toxicological evaluations of the hydromethanolic extract of Psidium guineense Swartz leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Psidium guineense, popularly known as "araçá-do-campo", is used in popular medicine for the treatment of inflammatory diseases. Our research group studied an essential oil obtained from its leaves and reported anti-inflammatory and analgesic properties. However, to date, the anti-inflammatory actions of the leaf extract have not been evaluated although the traditional folk use of this plant has these indications. AIM OF STUDY: The current study was designed to evaluate the antioxidant and anti-inflammatory effects and toxicity of the hydromethanolic extract of the leaves from P. guineense (HME-PG), as well as to investigate the chemical composition. MATERIALS AND METHODS: HME-PG was chemically investigated by Ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The antioxidant activity was evaluated with 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and malondialdehyde (MDA). Swiss mice were orally (p.o.) pretreated with HME-PG (30, 100 and 300 mg/kg), and after 1 h received carrageenan via paw injection (edema, cold sensitivity and mechanical hyperalgesia were analyzed) or pleural injection (leukocyte migration was analyzed after 4 h) and for nociception using the formalin model. Acute (14 days) and subacute (28 days) toxicity was assessed with female Wistar rats orally treated with 500 and 2000 mg/kg HME-PG. RESULTS: HME-PG showed high levels of phenolic and flavonoid compounds. Six compounds were identified based on UHPLC-MS/MS analysis, including gallic acid, quercetin, 3'-formyl-2',4',6'-trihydroxy-5'-methyldihydrochalcone, vanillic acid, ursolic acid and corilagin. HME-PG exhibited an IC50 of 48.14 µg/mL in the MDA assay and an IC50 of 45.15 µg/mL in the DPPH test. The treatment with HME-PG (100 and 300 mg/kg) significantly inhibited edema at all time points evaluated, mechanical hyperalgesia after 4 h and the response to cold 3 and 4 h after carrageenan injection and anti-nociceptive effects in both phases of formalin nociception. All oral HME-PG treatments significantly inhibited leukocyte migration and plasma extravasation in the pleurisy model. Toxicity tests did not cause signs of toxicity in the treated animals. CONCLUSIONS: The present study showed that HME-PG has antioxidant and anti-inflammatory properties, and no toxicity was detected after acute or subacute treatment with HME-PG, showing the possibility for the safe traditional use of P. guineense.

Anti-inflammatory properties of ethanolic extract from Vatairea macrocarpa leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: In Brazilian traditional folk medicine, the leaves and heartwood from Vatairea macrocarpa (Benth) Ducke (Angelim-of-Cerrado) (Fabaceae family) are used as remedy after cold maceration for the treatment of the condition popularly known as rheumatism, as well as for the general inflammatory aspects such as pains, injury and swelling. The rheumatological and rheumatic diseases affect 0.3-1.0% of the world population and all long-term treatment with conventional medications lead to adverse effects. AIM OF THE STUDY: To investigate the chemical composition and the anti-inflammatory properties and of the ethanolic extract from V. macrocarpa leaves (EEVM) in experimental models. MATERIAL AND METHODS: EEVM was chemically analyzed by spectrophotometry and the compounds characterization was performed by nuclear magnetic resonance and mass spectrometry. EEVM was evaluated in methylthiazolyldiphenyl-tetrazolium bromide (MTT) (3, 10, 30, and 90 µg/ml) and neutrophils phagocytic activity (1, 3, and 10 µg/ml) tests. For in vivo models, the EEVM (10, 30, 100, and 300 mg/kg) was orally administered (p.o.) for inflammatory evaluation in carrageenan-induced pleurisy in Swiss mice. The EEVM (30 and 100 mg/kg, p.o.) was tested against the Complete Freund Adjuvant (CFA)-induced paw persistent inflammation and Mycobacterium bovis (bacillus Calmette-Guerin - BCG)-induced pleurisy in C57bL6 mice. RESULTS: The chemical composition of EEVM showed 157.06 mg (GAE)/g in relation to phenolic compounds, 82.13 mg (RUE)/g in relation to flavonoids and 48.99 mg (TAE)/g in relation to tannins. The flavonoid compounds identified were catechin, epicatechin and kaempferol-3-O-a-l-rhamnopyranoside. EEVM did not present cytotoxicity in MTT assay, however EEVM reduced phagocytic neutrophils activity at all tested concentration. EEVM significantly inhibited leukocytes migration/proteins exudation in carrageenan-induced pleurisy model. The daily administration of EEVM inhibited the inflammatory parameters in BCG and CFA models. CONCLUSIONS: The present study showed anti-inflammatory features of EEVM (V. macrocarpa) as a natural agent against inflammatory diseases.

Analgesic and anti-inflammatory articular effects of essential oil and camphor isolated from Ocimum kilimandscharicum Gürke leaves.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaves from Ocimum kilimandscharicum Gürke (Lamiaceae) are popularly used against articular pain. AIM OF STUDY: The aim of this study was to test the anti-inflammatory and anti-hyperalgesic (analgesic) properties of the essential oil and camphor isolated from O. Kilimandscharicum leaves (EOOK) in 4 models including zymosan induced-articular inflammation model in mice. MATERIAL AND METHODS: For in vivo models, EOOK was tested in carrageenan-induced paw edema model with oral doses of 30, 100, and 300 mg/kg (oral administration = p.o.) and in zymosan-induced articular inflammation (including knee edema, leukocyte infiltration, mechanical hyperalgesia and nitric oxide), EOOK (100 mg/kg, p. o.) and camphor (30 mg/kg, p. o.) were tested. EOOK (100 mg/kg, p. o.) was tested in the rolling and also in the adhesion of leukocytes to the mesenteric microcirculation in situ model of carrageenan induced inflammation and EOOK (1, 3, 10, 30, and 60 µg/mL) was tested in vitro against neutrophils chemotaxis induced by N-formyl methionyl leucyl phenylalanine (fMLP). RESULTS: The treatment with EOOK significantly inhibited the carrageenan-induced edema, mechanical and cold hyperalgesia. Both, EOOK and camphor inhibited all articular parameters induced by zymosan. In situ intravitral microscopy analysis, EOOK significantly inhibited carrageenan-induced leukocyte rolling and adhesion. In vitro neutrophils chemotaxis, EOOK inhibited the leukocyte chemotaxis induced by fMLP. CONCLUSIONS: The present study showed that EOOK inhibited pain and inflammatory parameters contributing, at least in part, to explain the popular use of this plant as analgesic natural agent. This study also demonstrates that camphor and some known anti-inflammatory compounds present in EOOK could contribute for analgesic and anti-inflammatory articular properties.

Anti-inflammatory and anti-arthritic activity in extract from the leaves of Eriobotrya japonica.

ETHNOPHARMACOLOGICAL RELEVANCE: The Eriobotrya japonica (EJ) is a Chinese medicinal plant that is currently grown in Brazil. E. japonica leaves infusion is traditionally used in the treatment of inflammation; however, there are few scientific studies showing the effects of these properties on joint articular and persistent experimental inflammation. AIM OF THE STUDY: The present research had objective investigation of the effect of infusion obtained from leaves of E. japonica (EJLE) on acute and persistent experimental articular inflammation. MATERIALS AND METHODS: The Swiss mice were treated orally with EJLE and analyzed for acute pleural inflammation (30, 100, and 300 mg/kg), paw edema induced by carrageenan (100 mg/kg), acute knee inflammation induced by zymosan (100 mg/kg), and persistent inflammation induced by Complete Freund's Adjuvant (CFA) (30 and 100 mg/kg). Mechanical hyperalgesia, cold and edema were analyzed. RESULTS: The chromatographic analysis of EJLE revealed the presence of corosolic acid, oleanolic acid, and ursolic acid. EJLE presented anti-inflammatory activity in the pleurisy model, inhibiting leukocyte migration, protein extravasation and nitric oxide production. In the articular inflammation model, EJLE reduced the number of leukocytes in the joint cavity, paw edema and hyperalgesia (4 h after induction). In the persistent inflammation model induced by CFA, the extract reduced paw edema after 11 days of mechanical and cold hyperalgesia on day 6. CONCLUSIONS: The EJLE has anti-inflammatory and antihyperalgesic potential in models of acute and persistent experimental articular inflammation, making this infusion a new possibility for complementary treating acute or chronic articular inflammatory diseases.

Antioxidant, anti-rheumatic and anti-inflammatory investigation of extract and dicentrinone from Duguetia furfuracea (A. St.-Hil.) Benth. & Hook. f.

ETHNOPHARMACOLOGICAL RELEVANCE: The preparations of teas and syrups using Duguetia furfuracea have been used in folk medicine to treat rheumatism and back pain. Several rheumatic diseases are anti-inflammatory and are treated with several anti-inflammatories. AIM OF THE STUDY: The objective of this work were to evaluate the chemical investigation of methanolic extract obtained from leaves of D. furfuracea (MEDF) and test the MEDF, such as chloroform (CF), ethyl acetate (EAF) and hydromethanol (HMF) fractions and the alkaloid dicentrinone (DF-1) in vitro antioxidant effects and in vivo models of inflammation. MATERIAL AND METHODS: MEDF and CF were analyzed by LC-PDA and the results revealed the presence of alkaloid aporphine and oxoaporphine. The concentrations of total phenols, flavonoids and flavonols were determined. Additionally, MEDF, fractions and dicentrinone were evaluated free radical scavenging activity 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and peroxidation ß-carotene/linoleic acid and malondialdehyde (MDA) assays. The anti-inflammatory effects of MEDF, fractions and dicentrinone were studied in carrageenan-induced paw edema. The anti-rheumatic potential was studied in air pouch model and zymosan-induced arthritis. RESULTS: CF fractionation resulted in the isolation of the oxaporphine alkaloid dicentrinone (DF-1). The highest phenols (624.37mg GAE/g extract), flavonoids (580.51mg QE/g extract) and flavonols (254.44mg QE/g extract), concentration was found in extract. In antioxidant tests, MEDF exhibited the highest scavenging activity and lipoperoxidation. The extract (30-300mg/kg) and all tested fractions inhibited the edema induced by carrageenan. The oral administration of DF-1 inhibited both edema associated with carrageenan-induced inflammation in mice. In air pouch model of inflammation, MEDF (30-300mg/kg) and DF-1 (100mg/kg) inhibited leukocyte migration and plasmatic leakage induced by carrageenan in mice. Finally, MEDF (100mg/kg) did not alter zymozan-induced arthritis in mice. CONCLUSION: The results showed that D. furfuracea exhibits antioxidant, anti-rheumatic potential and anti-inflammatory activity. The presence of the alkaloid dicentrinone in extract and CF fraction could be responsible, at least in part, for the observed effects.

Anti-nociceptive, anti-hyperalgesic and anti-arthritic activity of amides and extract obtained from Piper amalago in rodents.

ETHNOPHARMACOLOGICAL RELEVANCE: Piper amalago (Piperaceae) has been used in folk medicine as an analgesic. This study aimed to evaluate the pharmacological effects of extract and pure amides obtained from P. amalago on pain to provide a pharmacological basis for their use in traditional medicine. AIM OF THE STUDY: This study evaluated the anti-nociceptive, anti-hyperalgesic, anti-arthritic and anti-depressive activities of the ethanolic extract of P. amalago (EEPA) and the amides N-[7-(3',4'-methylenedioxyphenyl)-2(Z),4(Z)-heptadienoyl] pyrrolidine (1) and N-[7-(3',4'-methylenedioxyphenyl)-2(E),4(E)-heptadienoyl] pyrrolidine (2) obtained from P. amalago in animal models. MATERIALS AND METHODS: Mice treated daily with EEPA (100mg/kg, p.o.) were assayed for 20 days for knee edema (micrometer measurement), mechanical hyperalgesia (analgesiometer analysis), heat sensitivity and immobility (forced swim test) in the Complete Freund's Adjuvant (CFA) model. Cold (acetone test) and mechanical hyperalgesia (electronic von Frey analysis) responses were evaluated for 15 days in rats treated with oral EEPA (100mg/kg) in the spared nerve injury (SNI) model. Meanwhile, mice were evaluated for carrageenan-induced edema and mechanical hyperalgesia and for nociception using the formalin model after a single administration of EEPA (100mg/kg) or amides 1 and 2 (1mg/kg). RESULTS: Amides (1) and (2) were detected and isolated from the EEPA. The EEPA inhibited mechanical hyperalgesia, knee edema, and heat hyperalgesia, but not depressive-like behavior, induced by the intraplantar injection of CFA. When evaluated in the SNI model, the EEPA inhibited mechanical and cold hyperalgesia. The EEPA, 1 and 2 prevented the mechanical hyperalgesia induced by carrageenan and the anti-nociceptive effects in both phases of formalin nociception. The EEPA did not induce alterations in the open field test. CONCLUSION: The EEPA was effective for inhibition of pain and arthritic parameters but was not effective against depressive-like behavior; additionally, it did not alter locomotor activity. The amides obtained seemed to be the active component(s) present in the EEPA because they proved to be anti-nociceptive and anti-hyperalgesic in models of acute pain. Considering that few drugs are currently available for the treatment of chronic pain, especially neuropathic pain, the present results may have clinical relevance and open new possibilities for the development of new anti-hyperalgesic and anti-arthritic agents from P. amalago.

Antiulcerogenic effect of Croton urucurana Baillon bark.

ETHNOPHARMACOLOGICAL RELEVANCE: Croton urucurana (Euphorbiaceae) bark is used to treat gastric ulcers. However, to our knowledge, no study has been conducted to confirm this therapeutic property. AIM OF THE STUDY: To evaluate the antiulcerogenic effect and any possible toxic effects of Croton urucurana bark in an induced gastric ulcer model in rats. MATERIALS AND METHODS: The preventive and healing properties of Croton urucurana bark methanol extract (CUE) were evaluated in experimental models of acute (ethanol and indomethacin) and chronic (acetic acid) gastric ulcers. The gastric juice and mucous were evaluated using the pylorus ligation model, while the gastroprotective action of sulphydryl compounds and nitric oxide were analysed using the ethanol model. The toxicity was evaluated with acute and subacute toxicity tests. RESULTS: No signs of toxicity were observed in the parameters analysed. All of the CUE doses tested (50, 100 and 250mg/kg) significantly reduced the gastric lesions by 70.25, 95.40 and 98.71%, respectively. Treatment with 30mg/kg lansoprazole (positive control) inhibited 82.58% of the gastric lesions. In the indomethacin model, the 50, 100 and 250mg/kg doses of CUE significantly reduced gastric damage by 67.85, 82.50 and 71.01%, respectively, and the positive control, cimetidine (200mg/kg), reduced gastric damage by 91.02%. The CUE (100mg/kg) and cimetidine (200mg/kg) treatments significantly reduced the ulcerative pathology induced by acetic acid, promoting 81.55 and 72.62% healing, respectively. Nitric oxide did not change the cytoprotection generated by CUE. However, the antiulcerogenic activity of CUE appears to involve sulphydryl compounds because CUE activity was inhibited in animals receiving a sulphydryl compound blocker. In addition, CUE exhibited systemic effects, increasing mucous production and decreasing gastric acidity. CONCLUSIONS: The present study shows that Croton urucurana bark exerts gastroprotective activity in rats without causing toxicity. This effect appears to involve sulphydryl compounds, increasing mucus production and reducing gastric acidity.