Bárbara Mayer

Gastroprotective constituents of Salvia officinalis L.

The gastrointestinal activity of hydroalcoholic extract (HE) of Salvia officinalis was evaluated in a model of ethanol-induced gastric lesion. HE showed excellent activity, with ID(50) 84.0 (54.8-128.9) mg/kg. The acetic acid-induced ulcer and the total acidity of the gastric secretion were also reduced by HE, and, in vitro experiments, the H(+),K(+)-ATPase activity was inhibited. Carnosol was identified as a possible active constituent for the gastroprotective effect of HE.

Gastroprotective activity of the chloroform extract of the roots from Arctium lappa L.

Arctium lappa L. is used in folk medicine as a diuretic, depurative and digestive stimulant and in dermatological conditions. The objective of this study was to evaluate the effect and the possible mechanisms involved in the gastroprotective effects of a chloroform extract (CE) of the roots from A. lappa and its fractions. Oral pretreatment with CE (10, 30 and 100 mgkg−1) significantly reduced gastric lesions induced by ethanol by 61%, 70% and 76%, respectively. Oral administration of CE (100 mgkg−1 per day for 7 days) reduced the chronic gastric ulceration induced by acetic acid by 52%. Intraduodenal CE (100, 300 and 600 mgkg−1) reduced the total acidity of gastric secretion by 22%, 22% and 33%, respectively, while i.p. administration (10, 30 and 100 mgkg−1) inhibited total acidity by 50%, 60% and 67%, respectively. In‐vitro, CE inhibited H+, K+‐ATPase activity with an EC50 of 53 μgmL−1 and fraction A (30 and 100 μgmL−1) reduced this by 48% and 89%, respectively. CE had no effect on gastrointestinal motility. CE (250 μgmL−1) and fraction B (100 and 250 μgmL−1) had free‐radical scavenging ability, inhibiting 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical activity by 50%, 20% and 55%, respectively. Collectively, the results show that the CE protects animals from gastric lesions by reducing gastric acid secretion via inhibition of gastric H+, K+‐ATPase.

Antiulcerogenic activity of bark extract of Tabebuia avellanedae, Lorentz ex Griseb

Tabebuia avellanedae is commonly used for the treatment of peptic ulcers. We carried out this study with the ethanolic extract of bark from Tabebuia avellanedae (EET) (30-1000 mg/kg) to determine its gastroprotective activity and to clarify the pathways involved in this effect. Acute gastric ulceration in rats was produced by oral administration of ethanol and ibuprofen. After ethanol administration, the gastric wall mucus was examined. Chronic gastric ulceration was produced by injection of acetic acid in rat gastric subserosa. Anti-secretory studies were undertaken using Shay rat pylorus ligature technique and measurement of enzymatic activity of H+, K+-ATPase in vitro. Administration of EET p.o. or i.p. significantly inhibited gastric mucosa damage induced by ethanol and ibuprofen. The anti-ulcer effect was further confirmed by enhanced gastric mucus production. In pylorus ligature rats, EET significantly reduced the basal gastric acid secretion and total acidity; moreover, it inhibited the increase in total acidity induced by histamine. In addition, EET reduced the activity of H+, K+, ATPase. The results obtained in the present pharmacological assay indicate that this plant has a protective action against gastric lesions, involving the maintenance of protective factors, such as mucus and prostaglandin, besides the reduction of gastric total acidity.

Muscarinic-dependent inhibition of gastric emptying and intestinal motility by fractions of Maytenus ilicifolia Mart ex. Reissek

ETHNOPHARMACOLOGICAL RELEVANCE Maytenus ilicifolia Mart. ex. Reissek (Celastraceae) is widely used in Brazilian folk medicine to treat gastric disturbances. AIM OF THE STUDY This work intended to characterize the effects of Maytenus ilicifolia on gastrointestinal motility. MATERIALS AND METHODS Gastric emptying and intestinal transit were measured in the same animal. Mice received a semisolid marked with phenol red, half an hour after treatment with extracts. The amount of marker in the stomach and the distance reached in the intestine after 15 min were measured as index of gastrointestinal emptying and intestinal transit, respectively. RESULTS Intraperitoneal administration of a flavonoid-rich extract potently reduced the gastric emptying (ED(50)=89 mg/kg) and the intestinal transit (ED(50)=31 mg/kg) of mice. Bio-guided purification of the flavonoid-rich extract by chemical partition with solvents of decreasing polarity yielded fraction insF with about 12-14 times higher activity than the initial flavonoid extract in both the gastric emptying and the intestinal transit. The inhibitory effects of the insF (9.7 mg/kg, i.p.) on gastric emptying and intestinal transit were reversed by co-administration of bethanechol (10 mg/kg, s.c.) but not by co-administration of metoclopramide (30 mg/kg, p.o.) indicating muscarinic but not dopaminergic interaction of the compounds of Maytenus. Chemical investigation of the insF fraction by HPLC-MS allowed the identification of 4 free flavonoids (catechin, epicatechin, quercetin and kaempferol), 29 flavonol glycosides and 8 tannins. The flavonol glycosides ranged from 1 to 4 monosaccharide units, having mainly quercetin and kaempferol as aglycone moieties, and the tannins were composed by catechin/epicatechin and/or afzelechin/epiafzelechin. CONCLUSIONS Overall, the results indicate that the components of Maytenus ilicifolia have a potential use in the treatment of gastrointestinal motility disturbances such as diarrhea.

Antinociceptive properties of the hydroalcoholic extract, fractions and compounds obtained from the aerial parts of Baccharis illinita DC in mice.

The present study assessed the possible antinociceptive action of the hydroalcoholic extract, fractions and pure compounds obtained from the aerial parts of Baccharis illinita DC (Asteraceae) in behavioural models of chemical nociception in mice. The hydroalcoholic extract and fractions (hexane and aqueous but not EtOAc fraction) obtained from B. illinita (30-1000 mg/kg orally) produced a dose-related inhibition of the acetic acid-induced nociceptive response. However, the hexane fraction was more potent than the hydroalcoholic extract and the aqueous fraction. The hexane fraction derivatives baurenol, alpha-spinasterol and oleanolic acid (0.00001-10 mg/kg intraperitoneally) also caused potent inhibition of acetic acid-induced pain. The hexane fraction (300-1000 mg/kg orally) produced inhibition of both phases of formalin-induced pain. Moreover, the hexane fraction (30-600 mg/kg orally) also caused a dose-dependent inhibition of glutamate-induced pain. Nevertheless, the hexane fraction only at the dose of 300 mg/kg orally, produced partial inhibition of the paw oedema caused by carrageenan. Furthermore, the hexane fraction (300 mg/kg orally) caused inhibition of the nociceptive response induced by intrathecal injection of N-methyl-d-aspartic acid, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, tumour necrosis factor-alpha and interleukin-1beta. In contrast, the hexane fraction did not affect the biting response induced by the metabotropic or ionotropic glutamatergic receptor agonist (+/-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid and kainate, respectively. In addition, the antinociception caused by the hexane fraction (300 mg/kg orally) in the acetic acid test was not affected by intraperitoneal treatment of mice with naloxone (a non-selective opioid receptor antagonist). The precise mechanism responsible for the antinociceptive effect of the hexane fraction remains unclear, but appears to be partly associated with an inhibition of glutamatergic transmission and an inhibition of pathways dependent on pro-inflammatory cytokines. Finally, baurenol, alpha-spinasterol and oleanolic acid have an important role in the antinociceptive effects of the hexane fraction. Moreover, the antinociceptive action demonstrated in the present study supports the ethnomedical uses of this plant.

GC/FID-based authentication of Baccharis trimera: a quality control study of products commercialized in Curitiba and metropolitan region (Brazil)

Baccharis trimera (carqueja) is a medicinal plant used for stomach pain, bad digestion, heart bum, kidney problems and constipation. The objective of the present work was a quality study of carqueja commercialized in Curitiba and metropolitan region (Parana-Brazil) using gas chromatography techniques (GC/FID) for analyses of the essential oil, which was extracted through hydrodistillation using a Clevenger system. Macro and microscopic analyses were also done. Some samples were contaminated by other species of plants, fungi and small insects, some of them could be identified. Among all samples, 21 showed similar chromatographic profile to the standard oil, and 7 had different profile in relation to the standard. The chromatogram analyses showed that most of the analyzed samples had the similar profile as the standard oil of Baccharis trimera. GC/FID-based authentication of Baccharis trimera may be useful as a rapid tool to ensure quality control and safety monitoring of this kind of herbal pharmaceuticals.

Gastroprotective effect of hydroalcoholic extract from barks of Persea major Kopp (Lauraceae) in rats

Persea major Kopp (Lauraceae) is used in folk medicine to treat skin wounds and gastric disorders. This study evaluates the potential of crude hydroalcoholic extract (EHA) as gastroprotective and its acute toxicity. Swiss mice were treated with EHA by oral (p.o.) and intraperitoneal (i.p.) routes with doses of 0.125 to 10 g/kg and were observed until 14 days after the administration of the extract. The calculated LD50 of EHA after i.p. administration was 480 mg/kg in mice and the LD50 values of EHA by the oral route were calculated to be up to 10 g/kg in mice. Wistar rats were orally pretreated with EHA (30, 100, 300 and 1000 mg/kg) before induction of gastric lesions by 70% ethanol (0.5 mL/animal, p.o.), indomethacin (20 mg/kg, s.c.) and hypothermic restraint stress (during 3 h at 4 oC). The EHA protected the gastric mucosa against lesions induced by ethanol, but did not reduce the stress- and indomethacin-induced gastric lesions. When the EHA was injected into the duodenal lumen (i.d.), the volume, pH and total acidity of the gastric secretion of rats with pylorus ligature was not altered with different doses of the extract. Results therefore suggest that the cytoprotective effect of this extract against the direct necrosing action of ethanol and its effect were not related with reduction of gastric acid secretion.

Modulation of antioxidant systems by subchronic exposure to the aqueous extract of leaves from Achillea millefolium L. in rats

We determined the effects of subchronic exposure to aqueous extract of leaves from Achillea millefolium (AE) on enzyme- and non-enzyme-dependent antioxidant systems in rats. Seven days treatment with AE (1 g/kg/twice a day, p.o.) altered the reduced glutathione (GSH) levels and antioxidant enzyme activities in several organs of the animals. Amount of GSH in uterus was increased (73%) while in kidneys it was decreased (23%). Besides, NAD(P)H quinone oxidoreductase 1 (NQO1) activity was increased in forestomach (26%) and in liver (64%), while glutathione S-transferase activity was decreased in the forestomach (32%) and increased in the liver (41%), kidney (35%) and uterus (37%). In preliminary experiments targeting the interaction of AE with acetaminophen (600 mg/kg, p.o.), we observed augmentation of acetaminophen-induced increase of the plasmatic alanine aminotransaminase, aspartate aminotransaminase and lactate dehydrogenase. Overall, the results indicate a potential toxic interaction of AE compounds with xenobiotics that use the glutathione pathway.