Gastroprotective activity of ferruginol in mice and rats: effects on gastric secretion, endogenous prostaglandins and non-protein sulfhydryls.

The gastroprotective mechanism of the natural diterpene ferruginol was assessed in mice and rats. The involvement of gastric prostaglandins (PGE(2)), reduced glutathione, nitric oxide or capsaicin receptors was evaluated in mice either treated or untreated with indometacin, N-ethylmaleimide (NEM), N-nitro-L-arginine methyl ester (L-NAME) or ruthenium red, respectively, and then orally treated with ferruginol or vehicle. Gastric lesions were induced by oral administration of ethanol. The effects of ferruginol on the parameters of gastric secretion were assessed in pylorus-ligated rats. Gastric PGE(2) content was determined in rats treated with ferruginol and/or indometacin. The reduction of gastric glutathione (GSH) content was determined in rats treated with ethanol after oral administration of ferruginol, lansoprazole or vehicle. Finally, the acute oral toxicity was assessed in mice. Indometacin reversed the gastroprotective effect of ferruginol (25 mg kg(-1)) but not NEM, ruthenium red or L-NAME. The diterpene (25 mg kg(-1)) increased the gastric juice volume and its pH value, and reduced the titrable acidity but was devoid of effect on the gastric mucus content. Ferruginol (25, 50 mg kg(-1)) increased gastric PGE(2) content in a dose-dependent manner and prevented the reduction in GSH observed due to ethanol-induced gastric lesions in rats. Single oral doses up to 3 g kg(-1) ferruginol did not elicit mortality or acute toxic effects in mice. Our results showed that ferruginol acted as a gastroprotective agent stimulating the gastric PGE(2) synthesis, reducing the gastric acid output and improving the antioxidant capacity of the gastric mucosa by maintaining the GSH levels.

Vernonia polyanthes as a new source of antiulcer drugs.

Methanolic (VPME) and chloroformic (VPCL) extracts, obtained from the aerial parts of Vernonia polyanthes, were investigated for its antiulcerogenic properties. Administration of VPME (250 mg/kg) and VPCL (50 mg/kg) significantly inhibited the gastric mucosa damage (64% and 90%, respectively) caused by absolute ethanol (p.o.). Otherwise, in NSAID-induced gastric damage, their gastroprotective effects have decreased. Since the VPCL extract resulted to be more effective than the VPME we focused our efforts over VPCL action mechanism of action.

Antiulcerogenic effect and cytotoxic activity of semi-synthetic crotonin obtained from Croton cajucara Benth.

Trans-dehydrocrotonin, the major diterpene isolated from the bark of Croton cajucara, has good antiulcerogenic activity which, however, is accompanied by toxic effects. On the basis of these results, a semi-synthetic crotonin, named 4SRC, was prepared to determine whether this substance has similar antiulcerogenic activity with lower or no toxicity. The natural crotonin was also isolated from the bark of C. cajucara but was not used due to the small amount obtained. The cytotoxic effect of semi-synthetic crotonin, expressed as cell viability, was assessed in (a) lung fibroblast cell line (V79) derived from Chinese hamsters, a system commonly used for cytotoxicity studies, and (b) rat hepatocytes isolated from male Wistar rats. After treatment, cell viability was determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide reduction (MTT reduction), total acid content and neutral red uptake assays. To evaluate V79 cell viability, different concentrations of semi-synthetic crotonin were incubated with the cells. To evaluate the antiulcerogenic effects of semi-synthetic crotonin (50, 100 and 200 mg/kg), we used the models of gastric ulcer induced by ethanol/HCl, stress, indomethacin/bethanechol, and ethanol in male Swiss mice and male Wistar rats. The substance had an IC(50)=500 microM in the neutral red uptake and MTT reduction tests and an IC(50)=200 microM in the nucleic acid content test. With regard to hepatocyte viability after treatment with semi-synthetic crotonin at different concentrations, semi-synthetic crotonin had an IC(50)=10-500 microM in the nucleic acid content and MTT reduction tests and an IC(50)=120 microM in the neutral red uptake test. In another experiment, V79 cells were incubated with the metabolites produced by hepatocytes treated with different concentrations of semi-synthetic crotonin. After a 4-h incubation, semi-synthetic crotonin had an IC(50)=500 microM in the MTT reduction and neutral red uptake tests and an IC(50)=370 microM in nucleic acid content test. The substance had significant antiulcerogenic activity in all models studied, suggesting the presence of a possible antisecretory effect combined with a cytoprotective effect. For this reason, the effect of semi-synthetic crotonin was also evaluated on biochemical parameters of gastric juice and gastric wall mucus, both obtained from pylorus-ligated mice. No significant differences were observed in these parameters between semi-synthetic crotonin-treated and control animals. The results obtained with semi-synthetic crotonin are promising, with a significant preventive effect against gastric ulcer induced by different agents. Our data also show that semi-synthetic crotonin was less toxic than dehydrocrotonin and that the cytotoxic effects decreases with the time that isolated hepatocytes were in culture.

Application of preparative high-speed counter-current chromatography for the separation of flavonoids from the leaves of Byrsonima crassa Niedenzu (IK).

The methanolic extract of the leaves of the medicinal plant Byrsonima crassa (Malpighiaceae) contain flavonoids with antioxidant activity. They were separated in a preparative scale using high-speed counter-current chromatography. The optimum solvent system used was composed of a mixture of ethyl acetate-n-propanol-water (140:8:80 (v/v/v)) and led to a successful separation between monoglucosilated flavonoids (quercetin-3-O-alpha-L-arabinoside, quercetin-3-O-beta-D-galactoside) and the biflavonoid amentoflavone in only 3.5 h. The purities of quercetin-3-O-alpha-L-arabinoside (95 mg), quercetin-3-O-beta-D-galactoside (16 mg) and the biflavonoid amentoflavone (114 mg) were all isolated at purity over 95%. Identification was performed by 1H NMR, 13C NMR and UV analyses.

Antiulcer activity and subacute toxicity of trans-dehydrocrotonin from Croton cajucara.

The antiulcerogenic activity of trans-dehydrocrotonin (DHC), a nor-clerodane diterpene isolated from Croton cajucara Benth. (Euphorbiaceae), and its subacute (35 days) toxicity were studied in mice and rats, respectively. For the antiulcerogenic tests, models of gastric ulcers induced in mice by ethanol/HCl or stress were used. In both models, an oral dose of DHC (100 mg/kg) significantly reduced (P < 0.01) the formation of gastric lesions. DHC was also tested for its ability to scavenge free radicals, but no such action was observed in rat liver mitochondria. To assess the subacute toxicity, rats were treated orally with DHC (25, 50 and 100 mg/kg) for 5 weeks. A significant increase in liver weight was observed in male and female rats at highest doses, whereas a significant reduction in plasma alkaline phosphatase and cholesterol levels and an increase in gamma glutamyl transpeptidase were observed only at the highest dose (100 mg/kg) in female rats. DHC caused histopathological alterations in the liver that included a turbid tumefaction, microvacuolar degeneration and nuclear alterations. Despite the beneficial antiulcerogenic activity of DHC, our results suggest that the long-term use of this compound may induce liver damage.

The effect of a minor constituent of essential oil from Citrus aurantium: the role of ß-myrcene in preventing peptic ulcer disease.

The monoterpene ß-myrcene has been widely used in cosmetics, food and beverages, and it is normally found in essential oil from citrus fruit. The aim of this study was to investigate the anti-ulcer effects of ß-myrcene on experimental models of ulcers that are induced by ethanol, NSAIDs (non-steroidal anti-inflammatory drugs), stress, Helicobacter pylori, ischaemia-reperfusion injury (I/R) and cysteamine in order to compare with the essential oil of Citrus aurantium and its major compound limonene. The results indicate that the oral administration of ß-myrcene at a dose of 7.50mg/kg has important anti-ulcer activity with significantly decreased gastric and duodenal lesions as well as increased gastric mucus production. The results showed treatment with ß-myrcene caused a significant increase in mucosal malondialdehyde level (MDA), an important index of oxidative tissue damage. The ß-myrcene was also endowed with marked enhancement of antioxidant enzyme activity from GR system as evidenced by the decreased activity of superoxide dismutase (SOD) and increased levels of glutathione peroxidase (GPx), glutathione reductase (GR), and total glutathione in gastric tissue. Our results also shown that treatment with ß-myrcene is not involved with thioredoxin reductase (TrxR) activity. Our results reveal, for the first time, the importance of ß-myrcene as an inhibitor of gastric and duodenal ulcers and demonstrate that an increase in the levels of gastric mucosa defence factors is involved in the anti-ulcer activity of ß-myrcene.

Anti-ulcerogenic mechanisms of the sesquiterpene lactone onopordopicrin-enriched fraction from Arctium lappa L. (Asteraceae): role of somatostatin, gastrin, and endogenous sulfhydryls and nitric oxide.

Arctium lappa L. has been used in folk medicine as a diuretic, depurative, and digestive stimulant and in dermatological conditions. The mechanisms involved in the anti-ulcerogenic activity of the sesquiterpene onopordopicrin (ONP)-enriched fraction (termed the ONP fraction), obtained from A. lappa leaves, were studied. The gastroprotective mechanism of the ONP fraction was evaluated in experimental in vivo models in rodents, mimicking this disease in humans. ONP fraction (50 mg/kg, p.o.) significantly inhibited the mucosal injury induced by ethanol/HCl solution (75%), indomethacin/bethanecol (68.9%), and stress (58.3%). When the ONP fraction was investigated in pylorus ligature, it did not induce alteration in the gastric volume but did modify the pH and total acid concentration of gastric juice. ONP fraction significantly increased serum somatostatin levels (82.1±4.1 vs. control group 12.7±4 pmol/L) and decreased serum gastrin levels (62.6±6.04 vs. control group 361.5±8.2 µU/mL). Mucus production was not significantly altered by the ONP fraction. Gastroprotection by the ONP fraction was completely inhibited by N-ethylmaleimide treatment and did not modify the effect in the animals pretreated with l-N(G)-nitroarginine methyl ester. These results suggest an antisecretory mechanism involved with the antiulcerogenic effect of the ONP fraction. However, only endogenous sulfhydryls play an important role in gastroprotection of the ONP fraction.

Liquid chromatography/electrospray ionization tandem mass spectrometry profiling of compounds from the infusion of Byrsonima fagifolia Niedenzu.

A rapid analytical approach suitable to achieve a comprehensive characterization of the compounds present in the infusion prepared from the leaves of Byrsonima fagifolia Niedenzu (Malpighiaceae), a Brazilian plant used as an infusion to treat gastric disorders, was developed. The method was based on high-performance liquid chromatography coupled to electrospray negative ionisation multistage ion trap mass spectrometry (HPLC/ESI-ITMSn). The main ions in the ESI-ITMS spectra were attributed to a quinic acid core containing from one to five galloyl units. Quercetin derivatives containing one and two sugar moieties as well as galloyl esterification were also detected. These results indicated that HPLC/ESI-ITMSn is easily applicable to infusions of this plant and allows the rapid and direct identification of these compounds in crude plant extracts.

Gastroprotective effects of essential oil from Protium heptaphyllum on experimental gastric ulcer models in rats

Peptic ulcers are a common disorder of the entire gastrointestinal tract, its etiology has not been completely elucidated. The basic physiopathological of peptic ulcers result from an imbalance between some endogenous aggressive factor and cytoprotective factors. The treatment of this disease is usually done with antacids or proton pump, but are currently being used plants derivated compounds. We evaluated the gastroprotective properties and its possible mechanisms of action of the essential oil from Protium heptaphyllum (Aubl.) Marchand, Burseraceae (BB). The formation of ulcers, were evaluated in three experimental models, through the induction of gastric lesions by ethanol, nonsteroidal anti-inflammatory drugs and acetic acid. The mechanisms of action were evaluated through the pylorus ligature experiment, western blot, GSH, GR, SOD, GPx, MDA and MPO activities. BB significantly inhibited the formation of ulcers induced by the three different models, increased the GSH and GR levels and maintained the same levels of SOD and GPx of the sham group, inhibited MPO and MDA, did not produce significant modification in gastric juice content and showed increased COX-2 and EGF. BB exerts its gastroprotective activity, possibly, by increasing COX-2 and EGF expression and due to its possible antioxidant property.

Anti-inflammatory and analgesic potential of hydrolyzed extract of Agave sisalana Perrine ex Engelm., Asparagaceae / Potencial anti-inflamatório e analgésico do extrato hidrolisado de Agave sisalana Perrine ex Engelm, Asparagaceae

The hemolytic, anti-inflammatory and antinociceptive properties from hydrolyzed extract Agave sisalana Perrine ex Engelm., Asparagaceae (HEAS) was evaluated on classic inflammation models. Male Swiss mice and male Wistars rats received HEAS (500 mg/kg) in two administration p.o. and i.p. in saline solution 0.9 percent. The acid hydrolysis inhibited the hemolytic action of saponins due to the retreat of side chain sugar. The treatment of the ear induced oedema by xylene with HEAS significantly reduced in two routes 13±1.5 and 10±0.63 mg, respectively, p.o. and i.p., in comparison with controls 27±1.5 saline and 13.5±1.2 AAS. The HEAS also diminished edema induced by carrageenin 43±1.58 mg (p.o.) and 17±1.26 mg (i.p.), when compared with control groups 52±1.58 mg (saline) and 10.05±1.58 (indomethacin). HEAS showed analgesic effects in abdominal constrictions 30.7 percent (p.o.), 88.7 percent (i.p.) comparable to that produced by (AAS) 70.6 percent. However in granuloma cotton pellet a chronic model of inflammation just the i.p. pathway decreased granulomatous tissue (20.4±1.32 mg) compared with controls 30.5±2.53 mg (saline) and 20.2±2.18 mg (dexamethasone). These data suggest that HEAS has anti-inflammatory and analgesic activity on acute and chronic processes.

As propriedades hemolítica, anti-inflamatória e antinociceptiva do extrato hidrolisado de Agave sisalana Perrine ex Engelm, Aparagaceae (HEAS) foram avaliadas em modelos clássicos de inflamação. Camundongos Swiss e ratos Wistars machos receberam HEAS (500 mg/kg) em duas vias de administração p.o e i.p em solução salina 0.9 por cento. A hidrólise ácida inibiu a ação hemolítica das saponinas através da retirada das cadeias laterais de açúcar. O tratamento com HEAS reduziu significativamente o edema de orelha induzido por xilol em duas vias 13±1.5 e 10±0.63 mg respectivamente, p.o e i.p, em comparação com os controles 27±1.5 salina e 13.5±1.2 AAS. O HEAS também diminuiu o edema induzido por carragenina 43±1.58 mg (p.o) e 17±1.26 mg (i.p), quando comparado com os grupos controle 52±1.58 (salina) e 10.05±1.58 (indometacina). HEAS apresentou efeito analgésico em modelo de contorções abdominais 30.7 por cento (p.o), 88.7 por cento (i.p) comparado com aquele produzido pelo (AAS) 70.6 por cento. Contudo, no modelo crônico de inflamação granuloma cotton pellet apenas a via i.p diminuiu o tecido granulomatoso (20.4±1.32 mg) comparado com os controles 30.5±2.53 (salina) e 20.2±2.18 mg (dexametasona). Esses dados sugerem que o HEAS possui atividades anti-inflamatória e analgésica em processos agudos e crônicos.

Chronic treatment with bark infusion from Croton cajucara lowers plasma triglyceride levels in genetic hyperlipidemic mice.

Aqueous infusion and preparations containing dehydrocrotonin (DHC) and essential oil from Croton cajucara bark were tested for plasma lipid-lowering effects in genetically modified hyperlipidemic mice. Two mouse models were tested: 1) primary hypercholesterolemia resulting from the LDL-receptor gene knockout, and 2) combined hyperlipidemia resulting from crosses of LDL-receptor knockout mice with transgenic mice overexpressing apolipo protein (apo) CIII and cholesteryl ester-transfer protein. Mice treated with bark infusion, DHC, essential oil, or placebos for 25 days showed no signals of toxicity as judged by biochemical tests for liver and kidney functions. The bark infusion reduced triglyceride plasma levels by 40%, while essential oil and DHC had no significant effects on plasma lipid levels. The bark infusion treatment promoted a redistribution of cholesterol among the lipoprotein fractions in combined hyperlipidemic mice. There was a marked reduction in the VLDL fraction and an increase in the HDL fraction, in such a way that the (VLDL + LDL)/HDL ratio was reduced by half. The bark infusion treatment did not modify cholesterol distribution in hypercholesterolemic mice. In conclusion, C. cajucara bark infusion reduced plasma triglycerides levels and promoted a redistribution of cholesterol among lipoproteins in genetically combined hyperlipidemic mice. These changes modify risk factors for the development of atherosclerotic diseases.

Antimicrobial activity of Byrsonima species (Malpighiaceae) / Atividade antimicrobiana de espécies de Byrsonima (Malpighiaceae)

Byrsonima species, family Malpighiaceae, is popularly known as "murici". There are several properties attributed to the leaves of Byrsonima species including febrifuge, to treat gastrointestinal dysfunctions and skin diseases. In this work, the antimicrobial activity of Byrsonima fagifolia, B. basiloba and B. intermedia extracts obtained from the leaves were evaluated by using the disc-diffusion method. The results obtained showed that the methanol extracts of leaves had presented antimicrobial activity against all the microorganisms tested.

Espécies de Byrsonima, família Malpighiaceae, são popularmente conhecidas como "murici". Existem várias propriedades atribuídas às folhas de espécies de Byrsonima incluindo febrífuga, no tratamento de disfunções gastrintestinais e doenças de pele. Neste trabalho avaliamos a atividade antimicrobiana dos extratos das folhas de Byrsonima fagifolia, B. basiloba e B. intermedia usando o método de difusão em disco. Os resultados obtidos mostraram que os extratos metanólicos das folhas apresentaram atividade antimicrobiana contra todos os microrganismos testados.