Hillaire & Moquin (Polygalaceae)

Gastroprotective activity of hydroalcoholic extract obtained from the leaves of Brassica oleracea var. acephala DC in different animal models

ETHNOPHARMACOLOGICAL RELEVANCE

Brassica oleracea var. acephala DC has been extensively used in Brazilian traditional medicine to treat gastric ulcer.

AIM OF THE STUDY

This study was conducted to evaluate the antiulcerogenic property of hydroalcoholic extract obtained from the leaves of Brassica oleracea.

MATERIALS AND METHODS

Antiulcer assays were performed using the protocol of ulcer induced by ethanol/HCl, and non-steroidal anti-inflammatory drugs (NSAIDs). Parameters of gastric secretion (volume, pH and [H(+)]) were determined by the pylorus ligation model and mucus in gastric contents.

RESULTS

In the ethanol-induced ulcer model, we observed a significant reduction in all the parameters analyzed, obtaining curative ratios of 58.8 ± 11.5, 86.2 ± 12.2 and 42.8 ± 6.6% for the groups treated with 50 and 100mg/kg of extract and omeprazole (30 mg/kg), respectively. The dose of 25mg/kg of hydroalcoholic extract of Brassica oleracea showed no significant results. In the indomethacin-induced ulcer, the percentages of ulcer inhibition were 64.3 ± 9.9, 66.4 ± 12.3 and 81.2 ± 7.5% for the groups treated with 50 and 100mg/kg extract and positive control (cimetidine, 100mg/kg), respectively. The results showed a significant increase in pH and mucus production in the groups treated with Brassica oleracea when compared with the control group. No sign of toxicity was observed in the acute toxicity study.

CONCLUSIONS

The results of the present study show that hydroalcoholic extract of Brassica oleracea displays antiulcer activity, as demonstrated by the significant inhibition of ulcer formation induced using different models. The data suggest that the effectiveness of the extract is based on its ability to stimulate the synthesis of mucus, increase pH and decrease H(+) ions in the stomach. This work corroborates the ethnopharmacology use of Brassica oleracea preparations, contributing to its pharmacological validation by suggesting that preparations obtained from Brassica oleracea could be used for the development of new phytopharmaceuticals for the treatment of gastric ulcer.

Antiulcerogenic effects and possible mechanism of action of Quassia amara (L. Simaroubaceae) extract and its bioactive principles in rats

The effects of Quassia amara extract (Q. amara) and its bioactive principles-quassin and 2-methoxycanthin-6-one on gastric ulceration were studied in albino rats. Q. amara (200-800 mg/kg p.o.; 5-20 mg/kg i.p) and 2-methoxycanthin-6-one (12.5, 25.0 and 50.0 mg/kg p.o; 1, 2 and 4 mg/kg i.p) but not quassin (12.5, 25.0 and 50 mg/kg p.o; 1, 2 and 4 mg/kg i.p) significantly inhibited gastric ulceration induced by indomethacin (40mg/kg). Administration of Q. amara (800 mg/kg p.o and 20 mg/kg i.p) and 2-methoxycanthin-6-one (12.5 mg/kg p.o; 4 mg/kg i.p) caused between 77%-85% cytoprotection against indomethacin (40 mg/kg, i.p) - induced gastric ulceration. Quassin did not cause any significant change in indomethacin-induced gastric ulceration. The inhibition of gastric ulceration produced by Q. amara and 2-methoxycanthin-6 one was accompanied by significant dose-dependent decreases (P< 0.01) in total gastric acidity. To investigate the probable mechanism of action, the individual effects of the extract and its principles alone and in combination with histamine (1 mg/kg) or cimetidine (0.12 mg/kg) on gastric acid secretion in situ were studied. Q. amara (20 mg/kg) and 2-methoxycanthin-6-one (4 mg/kg) but not quassin significantly (P< 0.01) inhibited the basal and histamine-induced gastric acid secretion. Inhibition of gastric acid secretion by Q. amara and 2-methoxycanthin-6-one was accentuated by cimetidine. The results suggest that Q. amara and its bioactive principle, 2-methoxycanthin-6-one possess antiulcer activity probably acting via histamine H2 receptor. This could be a potential source of potent and effective antiulcer agents.

A glycosidic spinasterol from Koreana stewartia promotes procollagen production and inhibits matrix metalloproteinase-1 expression in UVB-irradiated human dermal fibroblasts

Methanol extract of Koreana stewartia leaves (SKE) stimulated collagen production in ultraviolet-B (UVB)-irradiated human fibroblast cells. An active compound was isolated from SKE by successive partitioning and chromatography, and the chemical structure was determined to be 3-O-β-D-glucopyranosylspinasterol (spinasterol-Glc) by spectroscopic characterization. Spinasterol-Glc increased collagen production in the supernatant of UVB-irradiated dermal fibroblast cell cultures in a dose-dependent manner. The effects of spinasteol-Glc on expression of procollagen and matrix metalloproteinase-1 (MMP-1) were further evaluated. We found that the compound stimulated collagen production in UVB-treated fibroblasts than in vehicle-treated control cells by about 3-fold. In addition, we also demonstrate that the compound increased the mRNA and protein levels of procollagen in UVB-treated fibroblast cells, while it inhibited expression of MMP-1. These results indicate that spinasterol-Glc protects fibroblast cells from the adverse effects of UV radiation via stimulation of procollagen synthesis as well as inhibition of MMP-1 expression. Spinasterol-Glc may be useful in the future development of therapeutic and cosmetic applications.

Gastroprotective activity of methanol extract and marrubiin obtained from leaves of Marrubium vulgare L. (Lamiaceae)

Objectives

The purpose of this study was to assess the gastroprotective properties of the methanol extract and the diterpene marrubiin obtained from the leaves of M. vulgare.

Methods

Assays were performed using different protocols in mice. Studies focusing on mechanisms of gastroprotection were also undertaken.

Key findings

In the model of ethanol-induced ulcers, we observed a significant reduction in all the parameters analysed; the curative ratios obtained were 49.31 ± 0.57, 74.31 ± 0.91 and 79.86 ± 0.59 for the groups treated with 50 and 100 mg/kg of extract of M. vulgare and omeprazole (30 mg/kg), respectively. For indomethacin-induced ulcers, the percentages of ulcer inhibition were 50.32 ± 5.60, 66.24 ± 4.30, 82.17 ± 04.09 and 67.52 ± 4.38, for the groups treated with 25, 50 and 100 mg/kg M. vulgare and positive control (cimetidine), respectively. In both models, the marrubiin (25 mg/kg) produced a significant reduction in all the parameters when compared with the control group (P &lt; 0.01). There was also a significant increase in pH and mucus production in the groups treated with M. vulgare extract and marubiin. The results also demonstrated that the gastroprotection induced by the extract and marubiin is related to the activity of nitric oxide and endogenous sulfhydryls, which are important gastroprotective factors.

Conclusions

The results of this study show that the extract of M. vulgare and marrubiin displays antiulcer activity and that this effect can be partly attributed to the isolated diterpene.

Pharmacological mechanisms underlying the anti-ulcer activity of methanol extract and canthin-6-one of Simaba ferruginea A. St-Hil. in animal models

RELEVANCE

Simaba ferruginea A. St-Hil. (Simaroubaceae) is a subshrub typical of the Brazilian Cerrado, whose rhizomes are popularly used as infusion or decoction for the treatment of gastric ulcers, diarrhea and fever.

AIM OF THE STUDY

To evaluate the pharmacological mechanism(s) of action of the antiulcer effects of the methanol extract of Simaba ferruginea and its alkaloid canthin-6-one.

MATERIALS AND METHODS

Rhizome of Simaba ferruginea was macerated with methanol to obtain the methanol extract (MESf) from which was obtained, the chloroform fraction. Canthin-6-one alkaloid (Cant) was purified and then isolated from the chloroform fraction (CFSf). The isolated Cant was identified by HPLC. Anti-ulcer assays were determined using ethanol and indomethacin-induced ulcer models in mice and rats respectively. In order to determine the probable mechanisms of actions of MESf and Cant animals were pretreated with l-NAME prior to anti-ulcer agent treatments and ulcer induction and nitric oxide (NO) level determined in order to assess NO involvement in the gastroprotective effects. Assays of malondialdehyde (MDA), myeloperoxidase (MPO), pro-inflammatory cytokines: interleukin 8 (IL-8) and tumor necrosis factor-alpha (TNF-α) and prostaglandin E(2) (PGE(2)) were also carried out according to previously described methods.

RESULTS

The results indicate that the antiulcerogenic effects of MESf and Cant in ethanol-induced ulcer is mediated in part through increase in the production of protective endogenous NO as the antiulcerogenic activity of MESf and Cant was reduced in animals pre-treated with l-NAME. In indomethacin-induced ulcer pre-treatment with MESf and Cant showed reduction in the levels of MPO and MDA in the gastric tissue, thus indicating the participation of the antioxidant mechanisms on the gastroprotective effects. The plasma levels of IL-8 in ulcerated rats with indomethacin were also reduced by Cant, but not by MESf, indicating that inhibition of this cytokine contributes to the gastroprotective effect of Cant. However MESf and Cant had no effect on the mucosal membrane levels of PGE(2), indicating that the gastroprotective effects of these agents is independent of PGE(2) modulation.

CONCLUSION

The results obtained in this study with MESf and Cant added insights into the pharmacological mechanisms involved in their mode of antiulcer action. The results indicate that Cant is one of the compounds responsible for these effects. Such findings are of extreme importance in the strive for future development of potent, safer and effective antiulcer agent. The efficacy of MESf and Cant in gastroprotection shows that Simaba ferruginea might be a promising antiulcer herbal medicine, in addition to confirming the popular use of this plant against gastric ulcer models utilised in this study.

Antiulcer effects of Achyrocline satureoides (Lam.) DC (Asteraceae) (Marcela), a folk medicine plant, in different experimental models

ETHNOPHARMACOLOGICAL RELEVANCE

Achyrocline satureoides is a medium-sized South American indigenous herb, commonly known as "Marcela" or "Macela". The infusion obtained from inflorescences of this plant is widely used in Brazilian folk medicine as an antispasmodic, anti-inflammatory, hypoglycemic, and hypocholesterolemic, mainly to treat gastrointestinal disorders such as gastric ulcers and dyspepsia. However, the antiulcer properties of this species have not yet been fully studied.

AIM OF THE STUDY

This study was conducted to evaluate and contribute to validating the antiulcer activity of hydroalcoholic extract of inflorescences of Achyrocline satureoides.

MATERIALS AND METHODS

The antiulcer assays were performed using the ethanol-induced ulcer, and nonsteroidal anti-inflammatory drug (NSAID)-induced ulcer protocols. Gastric secretion parameters were also evaluated (volume, pH and total acidity) by the pylorus ligated model, and the mucus in the gastric content was determined.

RESULTS

In the ethanol-induced ulcer model, it was observed that the treatment with Achyrocline satureoides extract significantly reduced the lesion index by 75.1+/-8.6, 85.0+/-9.2, 86.6+/-7.4 and 75.5+/-5.3 for the groups treated with 100, 250 and 500 mg/kg of extract of inflorescences of Achyrocline satureoides and the positive control (omeprazole 30 mg/kg), respectively. Significant inhibition was also observed in the lesion index in the indomethacin-induced ulcer model, with decreases of 62.5+/-7.1, 62.5+/-6.1, 63.6+/-5.5 and 96.2+/-3.6 for the groups treated with 100, 250 and 500 mg/kg of extract and the positive control (cimetidine 100 mg/kg), respectively. The parameters of gastric secretion (pH, volume, [H(+)]) showed no alteration in the different doses of the treatment. On the other hand the treatment with the hydroalcoholic extract of Achyrocline satureoides (100, 250 and 500 mg/kg), significantly increased mucus production (p<0.01), when compared with the groups treated with indomethacin (100 mg/kg), cimetidine (100 mg/kg) and negative control (vehicle). No signs of toxicity was observed in the acute toxicity study.

CONCLUSIONS

The results of the present study show that hydroalcoholic extract of Achyrocline satureoides displays antiulcer activity, as demonstrated by the significant inhibition of the formation of ulcers induced using different models. However, this activity appears not be related to the antisecretor mechanisms. Moreover, this work suggests that preparations obtained from Achyrocline satureoides could be used for the development of new phytotherapic drugs for the treatment of gastric ulcer.