Inhibition of gastric acid secretion by a standardized aqueous extract of Cecropia glaziovii Sneth and underlying mechanism

Evaluation of the gastroprotective and ulcer healing properties by Fridericia chica (Bonpl.) L.G. Lohmann hydroethanolic extract of leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Fridericia chica (Bonpl.) L.G. Lohmann (Bignoniaceae), is a climber native to Brazil, found in all Brazilian biomes. It is mostly known in Brazil as "carajiru," and home medicines made from the leaves have been used to cure disorders including stomach ulcers and other gastrointestinal disorders.

AIM OF THE STUDY

The objective of the study was to investigate the F. chica hydroethanolic extract of leaves (HEFc) preventative and curative antiulcer gastrointestinal efficacy as well as the mechanisms of action using in vivo rodent models.

MATERIALS AND METHODS

F. chica was collected in the municipality of Juína, Mato Grosso, and its leaves were used to prepare the extract by maceration technique (70% hydroethanol in the 1:10 ratio, w/v) to obtain the HEFc. The chromatographic analysis of HEFc was carried out by High Performance Liquid Chromatography-Photo Diode Array-Electrospray Ionization-Mass Spectrometry (HPLC-PDA-ESI-MS)- LCQ Fleet™ system. To determine the potential antiulcer potential of HEFc (1, 5 and 20 mg/kg, p.o.), the gastroprotective activity was assessed in various animal models of stomach ulcers caused by acidified ethanol, water constraint stress, indomethacin, (acute), and acid acetic (chronic). Additionally, the prokinetic properties of the HEFC were assessed in mice. The gastroprotective underlying mechanisms were evaluated by the histopathological analysis and determination of gastric secretion (volume, free and total acidity), gastric barrier mucus, activation of PGs, NO, K ⁺_ATP channels, α₂-adrenoceptor, antioxidant activity (GSH, MPO and MDA), NO and mucosal cytokines (TNF-α, IL-1β, and IL-10) levels.

RESULTS

The chemical composition of HEFc was analyzed and apigenin, scutellarin, and carajurone were identified. HEFc (1, 5 and 20 mg/kg) showed effect against acute ulcers induced by HCl/EtOH with a reduction in the ulcerated area of 64.41% (p < 0.001), 54.23% (p < 0.01), 38.71% (p < 0.01), respectively. In the indomethacin experiment, there was no change in the doses tested, whereas in the water immersion restraint stress ulcer there was a reduction of lesions at doses of 1, 5, and 20 mg/kg by 80.34% (p < 0.001), 68.46% (p < 0.01) and 52.04% (p < 0.01). HEFc increased the mucus production at doses of 1 and 20 mg/kg in 28.14% (p < 0.05) and 38.36% (p < 0.01), respectively. In the pyloric ligation-induced model of gastric ulceration, the HEFc decreased the total acidity in all doses by 54.23%, 65.08%, and 44.40% (p < 0.05) and gastric secretory volume in 38.47% at dose of 1 mg/kg (p < 0,05) and increased the free acidity at the dose of 5 mg/kg by 11.86% (p < 0.05). The administration of EHFc (1 mg/kg) showed a gastroprotective effect possibly by stimulating the release of prostaglandins and activating K⁺_ATP channels and α_2-adrenoreceptors. Also, the gastroprotective effect of HEFc involved an increase in CAT and GSH activities, and a reduction in MPO activity and MDA levels. In the chronic gastric ulcer model, the HEFc (1, 5 and 20 mg/kg) decreased the ulcerated area significantly (p < 0.001) at all doses by 71.37%, 91.00%, and 93.46%, respectively. In the histological analysis, HEFc promoted the healing of gastric lesions by stimulating the formation of granulation tissue and consequently epithelialization. On the other hand, regarding the effect of HEFc on gastric emptying and intestinal transit, it was observed that the extract did not alter gastric emptying, but there was an increase in intestinal transit at the dose of 1 mg/kg (p < 0.01).

CONCLUSION

These outcomes confirmed the advantages of Fridericia chica leaves for the treatment of stomach ulcers, which are well-known. HEFc was discovered to have antiulcer characteristics through multitarget pathways, which might be related to an increase in stomach defense mechanisms and a decrease in defensive factor. HEFc can be regarded as a potential new antiulcer herbal remedy because of its antiulcer properties, which may be attributed to the mixture of flavonoids, apigenin, scutellarin and carajurone.

Procyanidin C1 Location, Interaction, and Aggregation in Two Complex Biomembranes

Procyanidins are known for their many benefits to human health and show a plethora of biological effects. One of the most important procyanidin is the procyanidin trimer C1 (PC1). Due to its relatively high lipid–water partition coefficient, the properties of PC1 could be attributed to its capability to interact with the biomembrane, to modulate its structure and dynamics, and to interact with lipids and proteins, however, its biological mechanism is not known. We have used all-atom molecular dynamics in order to determine the position of PC1 in complex membranes and the presence of its specific interactions with membrane lipids, having simulated a membrane mimicking the plasma membrane and another mimicking the mitochondrial membrane. PC1 has a tendency to be located at the membrane interphase, with part of the molecule exposed to the water solvent and part of it reaching the first carbons of the hydrocarbon chains. It has no preferred orientation, and it completely excludes the CHOL molecule. Remarkably, PC1 has a tendency to spontaneously aggregate, forming high-order oligomers. These data suggest that its bioactive properties could be attributed to its membranotropic effects, which therefore supports the development of these molecules as therapeutic molecules, which would open new opportunities for future medical advances.

Procyanidin C1 from Viola odorata L. inhibits Na+,K+-ATPase

Members of the Viola genus play important roles in traditional Asian herbal medicine. This study investigates the ability of Viola odorata L. extracts to inhibit Na⁺,K⁺-ATPase, an essential animal enzyme responsible for membrane potential maintenance. The root extract of V. odorata strongly inhibited Na⁺,K⁺-ATPase, while leaf and seeds extracts were basically inactive. A UHPLC-QTOF-MS/MS metabolomic approach was used to identify the chemical principle of the root extract’s activity, resulting in the detection of 35,292 features. Candidate active compounds were selected by correlating feature area with inhibitory activity in 14 isolated fractions. This yielded a set of 15 candidate compounds, of which 14 were preliminarily identified as procyanidins. Commercially available procyanidins (B1, B2, B3 and C1) were therefore purchased and their ability to inhibit Na⁺,K⁺-ATPase was investigated. Dimeric procyanidins B1, B2 and B3 were found to be inactive, but the trimeric procyanidin C1 strongly inhibited Na⁺,K⁺-ATPase with an IC₅₀ of 4.5 µM. This newly discovered inhibitor was docked into crystal structures mimicking the Na₃E₁∼P·ADP and K₂E₂·P_i states to identify potential interaction sites within Na⁺,K⁺-ATPase. Possible binding mechanisms and the principle responsible for the observed root extract activity are discussed.

Dietary proanthocyanidins on gastrointestinal health and the interactions with gut microbiota

Many epidemiological and experimental studies have consistently reported the beneficial effects of dietary proanthocyanidins (PAC) on improving gastrointestinal physiological functions. This review aims to present a comprehensive perspective by focusing on structural properties, interactions and gastrointestinal protection of PAC. In brief, the main findings of this review are summarized as follows: (1) Structural features are critical factors in determining the bioavailability and subsequent pharmacology of PAC; (2) PAC and/or their bacterial metabolites can play a direct role in the gastrointestinal tract through their antioxidant, antibacterial, anti-inflammatory, and anti-proliferative properties; (3) PAC can reduce the digestion, absorption, and bioavailability of carbohydrates, proteins, and lipids by interacting with them or their according enzymes and transporters in the gastrointestinal tract; (4). PAC showed a prebiotic-like effect by interacting with the microflora in the intestinal tract, and the enhancement of PAC on a variety of probiotics, such as Bifidobacterium spp. and Lactobacillus spp. could be associated with potential benefits to human health. In conclusion, the potential effects of PAC in prevention and alleviation of gastrointestinal diseases are remarkable but clinical evidence is urgently needed.

Pharmacognostic Evaluation of Ten Species of Medicinal Importance of Cecropia: Current Knowledge and Therapeutic Perspectives

This work covers a systematic review of literature about the genus Cecropia from 1978 to 2020, emphasizing the analysis of 10 of the most relevant species and their associated biological activities. Cecropia is a neotropical genus, which comprises about 61 native species in the American continent where it is known to be part of the traditional medicine of numerous countries. Secondary metabolites described for this genus showed an elevated structural and functional diversity, where polyphenols have been the most abundant. Based on this diversity, Cecropia phytochemicals represent an important source of potential therapeutic agents yet to be exploited. This review also highlights the effectiveness of combining chemometrics and ultra-performance liquid chromatography-tandem mass spectrometry as a novel approach to successfully single out Cecropia species phytochemicals. While the medicinal use of Cecropia species is officially recognized in National Pharmacopoeias and Formularies of several Latin American countries, it is important to recognize that these phytomedicines are complex mixtures requiring a thorough understanding of their chemical composition and their correlation with biological activities to guarantee their quality, safety, and efficacy.

Potential Antiulcer Agents From Plants: A Comprehensive Review

Background:

Peptic ulcer is a deep gastrointestinal erosion disorder that involves the entire mucosal thickness and can even penetrate the muscular mucosa. Nowadays, several plants and compounds derived from it have been screened for their antiulcer activity. In the last few years, there has been an exponential growth in the field of herbal medicine. This field has gained popularity in both developing and developed countries because of their natural origin and less side effects.

Objective:

This review aims to provide a comprehensive summary of currently available knowledge of medicinal plants and phytoconstituents reported for their anti-ulcer properties.

Methods:

The worldwide accepted database like SCOPUS, PUBMED, SCIELO, NISCAIR, ScienceDirect, Springerlink, Web of Science, Wiley, SciFinder and Google Scholar were used to retrieve available published literature.

Results:

A comprehensive review of the present paper is an attempt to list the plants with antiulcer activity. The review narrates the dire need to explore potential chemical moieties that exert an antiulcer effect, from unexploited traditional plants. Furthermore, the present study reveals the intense requirement to exploit the exact mechanism through which either the plant extracts or their active constituents exhibit their antiulcer properties.

Conclusion:

This article is the compilation of the plants and its constituents reported for the treatment of peptic ulcers. The Comprehensive data will surely attract the number of investigators to initiate further research that might lead to the drugs for the treatment of ulcers. As sufficient scientific data is not available on plants, most of the herbals cannot be recommended for the treatment of diseases. This can be achieved by research on pure chemical structures derived from plants or to prepare new lead compounds with proven beneficial preclinical in vitro and in vivo effects. However, a lot remains to be done in further investigations for the better status of medicinal plants.

Development of Caco-2 cells-based gene reporter assays and evaluation of herb-drug interactions involving CYP3A4 and CYP2D6 gene expression

The indiscriminate use of medicinal plants and herbal medicinal products concomitantly with conventional drugs may result in herb-drug interactions that may lead to fluctuations in drug bioavailability, therapeutic failure, and/or toxic effects. CYP450 enzymes play an important role in drug biotransformation and herb-drug interactions. Thus, the aim of this study was to develop and apply Caco-2 cells-based gene reporter assays to study in vitro the potential occurrence of CYP3A4 and CYP2D6 gene expression modulation by standardized extracts of selected medicinal plants. Reporter cell lines developed showed a significant increase in CYP3A4 and CYP2D6 reporter fluorescent emission, 4 and 16-fold respectively, when compared to the controls. The standardized extracts of Cecropia glaziovii, Bauhinia forficata and Echinacea sp. significantly increased CYP3A4 reporter fluorescence, and those of Ilex paraguariensis, Bauhinia forficata and Echinacea sp. significantly decreased CYP2D6 reporter fluorescence in Caco-2 cells-based gene reporter assays. The data obtained suggest that CYP3A4 and CYP2D6 gene expression seem to be modulated by the extracts tested. In addition, the reporter cell lines developed are functional assays that could be used to study drug-drug and herb-drug interactions during the research and development of new drugs.

Phytochemical characterization and comparative studies of four Cecropia species collected in Panama using multivariate data analysis

Plant species of the genus Cecropia (Urticaceae) are used as traditional medicine in Latin-America, and are commercially available as food supplements. The aim of this study was to characterize and compare the phytochemical constituents of four Cecropia species collected in Panama. The structures of 11 compounds isolated from leaves of C. obtusifolia were elucidated based on high resolution mass spectrometry (HRMS) and nuclear magnetic resonance (NMR) spectroscopic analysis; the polyphenolic constituents of leaves of all four Cecropia species and commercial products were characterized using high performance liquid chromatography-diode array detection-quadrupole time of flight-tandem high resolution mass spectrometry (HPLC-DAD-QTOF). Forty-seven compounds were fully identified or tentatively characterized. Thirty-nine of these have not been previously reported for the species under investigation. Multivariate analysis revelead that C. obtusifolia and C. insignis are the most related species, while C. hispidissima is the most segregated one. Considering the importance of the description of novel chemical entities and the increasing interest and use of natural products, this study may be of great help for chemotaxonomic purposes, the interpretation of medicinal properties and for quality assessment of herbal supplements containing Cecropia leaves.

Antiulcer Agents: From Plant Extracts to Phytochemicals in Healing Promotion

In this narrative review, we have comprehensively reviewed the plant sources used as antiulcer agents. From traditional uses as herbal remedies, we have moved on to preclinical evidence, critically discussing the in vitro and in vivo studies focusing on plant extracts and even isolated phytochemicals with antiulcerogenic potential. A particular emphasis was also paid to Helicobacter pylori activity, with emphasis on involved mechanisms of action. Lastly, the issue of safety profile of these plant products has also been addressed.

Selection of chemical markers for the quality control of medicinal plants of the genus Cecropia

CONTEXT

Several Cecropia (Cecropiaceae) species are traditionally used in Latin America for the treatment of a variety of diseases including diabetes, arterial hypertension, asthma, bronchitis, anxiety, and inflammation. At present, a number of commercial products based on these plants have been introduced into the market with very little information on methods for guaranteeing their quality and safety.

OBJECTIVE

This work proposes potential chemical markers for the quality control of the raw materials of Cecropia obtusifolia Bertol., Cecropia peltata L., Cecropia glaziovii Snethl., Cecropia pachystachya Trécul, and Cecropia hololeuca Miq.

METHODS

The Herbal Chemical Marker Ranking System (Herb MaRS) developed by the National Institute of Complementary Medicine (NICM) at the University of Western Sydney was used for selecting chemical markers for the quality control of selected medicinal species of Cecropia. This review covers the period from 1982 to 2016.

RESULTS

Chlorogenic acid, flavonoidal glycosides (orientin, isoorientin, vitexin, isovitexin, and rutin), catechin, epicatechin, procyanidins (B2, B5, and C1), steroids (β-sitosterol), and triterpenoids (α-amyrin, pomolic, tormentic and ursolic acids) were selected as chemical markers for the quality control of the leaves.

CONCLUSION

It is necessary to establish comprehensive standards for guaranteeing quality, safety and efficacy of herbal drugs. The selection of adequate chemical markers for quality control purposes requires a good knowledge about the chemical composition of medicinal plants and their associated biological properties. To the best of our knowledge this review article is the first to address the identification and quantitative determination of the chemical markers for the genus Cecropia.

In vitro antiherpes effect of C-glycosyl flavonoid enriched fraction of Cecropia glaziovii encapsulated in PLGA nanoparticles

In this work is reported a novel and promising approach for the preparation of C-glycosylflavonoid enriched fraction of Cecropia glaziovii (EFF-Cg) loaded PLGA nanoparticles (NP) with antiherpes properties. The purpose of this study was to evaluate and to compare the effect of two nonionic surfactants (poloxamer 188 (PLU) and polyvinyl alcohol (PVA)), and also an emulsion stabilized by solid particles of cellulose nanocrystal (CNC) in place of surfactants. The characterization of these nanoparticles was in terms of size, polydispersity index, zeta potential, morphology, thermogravimetric analysis (TGA), loading capacity and percent yield. Since TGA analysis revealed thermo stability especially for NP-PLU, this formulation was selected for the evaluation of drug release profile, cytotoxicity and antiherpes activity. The drug delivery profile demonstrated a sustained release through the polymer structure and a significant reduction of the polymer molecular weight at 21-day period. The cytotoxicity of these nanoparticles was determined on Vero cells, and the selected formulation did not exhibit cytotoxicity even at the highest tested concentration. The results demonstrated a potential antiherpetic effect of the EFF-Cg loaded NP at 48h of testing. In summary, EFF-Cg loaded NP exhibited a promising system for the effective drug delivery in the treatment of herpes infections.

The Gastrointestinal Tract as a Key Target Organ for the Health-Promoting Effects of Dietary Proanthocyanidins

Proanthocyanidins (PACs) are polymers of flavan-3-ols abundant in many vegetable foods and beverages widely consumed in the human diet. There is increasing evidence supporting the beneficial impact of dietary PACs in the prevention and nutritional management of non-communicable chronic diseases. It is considered that PACs with a degree of polymerization >3 remain unabsorbed in the gastrointestinal (GI) tract and accumulate in the colonic lumen. Accordingly, the GI tract may be considered as a key organ for the healthy-promoting effects of dietary PACs. PACs form non-specific complexes with salivary proteins in mouth, originating the sensation of astringency, and with dietary proteins, pancreatic enzymes, and nutrient transporters in the intestinal lumen, decreasing the digestion and absorption of carbohydrates, proteins, and lipids. They also exert antimicrobial activities, interfering with cariogenic or ulcerogenic pathogens in the mouth (Streptococcus mutans) and stomach (Helicobacter pylori), respectively. Through their antioxidant and antiinflammatory properties, PACs decrease inflammatory processes in animal model of gastric and colonic inflammation. Interestingly, they exert prebiotic activities, stimulating the growth of Lactobacillus spp. and Bifidobacterium spp. as well as some butyrate-producing bacteria in the colon. Finally, PACs are also metabolized by the gut microbiota, producing metabolites, mainly aromatic acids and valerolactones, which accumulate in the colon and/or are absorbed into the bloodstream. Accordingly, these compounds could display biological activities on the colonic epithelium or in extra-intestinal tissues and, therefore, contribute to part of the beneficial effects of dietary PACs.

Anti-inflammatory and antioxidant activities of aqueous extract of Cecropia glaziovii leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Cecropia glaziovii Sneth leaves extract is widely used as a traditional folk medicine in Brazil, especially for the treatment of diabetes, and as an antihypertensive and antiinflammatory agent.

AIM OF THE STUDY

To investigate the anti-inflammatory and antioxidant properties of crude aqueous extract (CAE) of C. glaziovii leaves.

MATERIALS AND METHODS

The in vivo anti-inflammatory and antioxidant effect of the CAE (10-300mg/kg, intragastrically) was investigated in the animal model of pleurisy. The cell migration, proinflammatory cytokines (TNF-α, IL-1β and IL-6), nitrite/nitrate concentration, myeloperoxidase (MPO) activity, oxidative damage in lipids and proteins, lactate dehydrogenase (LDH) activity and total protein content were also analyzed. Furthermore, the in vitro antioxidant activity of CAE was evaluated by the inhibition of formation of thiobarbituric acid reactive substances (TBARS), induced by free radical generators (H2O2, FeSO4 and AAPH) on a lipid-rich substrate. Hence, the chemical characterizarion of CAE by HPLC was therefore performed. The results showed that the inflammatory process caused by the administration of carragenin (Cg) into the pleural cavity resulted in a substantial increase in inflammatory parameters and oxidative damage. These levels seems to be reversed after CAE treatment in animals with similar results to Dexamethasone (Dex) treatment. Further, the CAE was effective in reducing proinflammatory cytokines, cell infiltrate, MPO activity, nitrite/nitrate concentration, LDH activity, and total protein levels with concomitant attenuation of all parameters associated with oxidative damage induced by Cg. Finally, the CAE presented in vitro antioxidant activity induced by free radical generators at all the concentrations investigated. HPLC analysis confirmed the presence of chlorogenic acid and C-glycosylflavonoids (isoorientin and isovitexin) as the major compounds of the CAE.

CONCLUSION

CAE of C. glaziovii exerts significant antiinflammatory and antioxidant activities and this effect can be attributed, at least in part, to the presence of chlorogenic acid and the C-glycosylflavonoids.

Gastroprotective activity of ethanolic root extract of Potentilla fulgens Wall. ex Hook

ETHNOPHARMACOLOGICAL RELEVANCE

Potentilla fulgens (Wall.) ex Hook. (Rosaceae) is a potent medicinal plant of the Western Himalayas, known under the name "Himalayan Cinquefoil or Bajradanti", and has been used traditionally to treat ailments including peptic ulcers, mouth ulcers, diarrhea, diabetes and cancer.

OBJECTIVE

The aim of the present study was to scientifically evaluate the gastric-ulcer protective effect of P. fulgens ethanolic root extract (EPF) on experimental rats.

MATERIAL AND METHODS

The gastroprotective activity of EPF was evaluated on four gastric-ulcer models such as pyloric ligation (PL), ethanol (EtOH), cold restrain stress (CRS) and aspirin (ASP)-induced gastric ulcers. The gastric acid obtained from 4h PL-induced gastric ulcer rats was determined for total volume content, pH and total acid-pepsin output. Total carbohydrates and protein ratio, expressed as index of mucin activity, and DNA content were estimated in the gastric juice and gastric mucosal tissue. The microvascular permeability, H(+)K(+)-ATPase activity, gastric mucus and histamine content were also determined. The levels of antioxidant enzymes (superoxide dismutase, catalase, and glutathione) and malondialdehyde in the stomach tissue (mucosal scrapings) were quantified. A histopathological study of the stomach was evaluated using eosin-haematoxylin stain.

RESULTS

EPF (200-400mg/kg, p.o.) showed significant protection against acute gastric-ulcer induced by EtOH, PL and CRS (400mg/kg, p.o.), but was found to be ineffective against ASP-induced ulcerogens. The effect of EPF on gastric juice studies in 4h PL rats significantly produced an increased level in gastric pH, whereas the effect on gastric volume and acid-pepsin output was observed to decrease significantly. However, EPF was found to have no significant effect on the defensive factors, thus revealing its antisecretory property by inhibiting the aggressive factors. EPF, significantly decreased the histamine level, inhibited the H(+)K(+)-ATPase activity and prevented the microvascular injury caused by ethanol in the rat stomach. Moreover, it was also observed to have antioxidant effects by producing a significant increase in the levels of SOD, CAT, and GSH and decreased the LPO activity. Histopathological studies showed that EPF significantly prevented gastric lesions caused by ethanol.

CONCLUSIONS

The present study showed that EPF has potent gastroprotective and antisecretory effects, thus justifying the traditional usage of this herb to treat gastric ulcers.

Hepatoprotective effects and HSV-1 activity of the hydroethanolic extract of Cecropia glaziovii (embaúba-vermelha) against acyclovir-resistant strain

CONTEXT

Cecropia glaziovii Snethl. (Cecropiaceae), commonly known as "embaúba-vermelha", is widely distributed throughout Latin America and has been reported in Brazilian folk medicine to treat cough, asthma, high blood pressure and inflammation.

OBJECTIVE

Investigate the hepatoprotective properties of crude hydroethanolic extract of C. glaziovii as well as its in vitro antioxidant and antiviral (HSV-1 acyclovir resistant strain) activities.

MATERIALS AND METHODS

The hepatoprotective effect, the antioxidant properties and antiviral activity of crude hydroethanol extract (RCE40) from C. glaziovii leaves were evaluated by carbon-tetrachloride (CCl(4))-induced hepatotoxicity, by TBARS (thiobarbituric acid reactive species) and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assays, respectively.

RESULTS

The RCE40 extract (20 mg/kg) inhibited lipid peroxidation on liver in post injury treatment and decreased serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). In addition, in this protocol the RCE40 (20 mg/kg) enhanced the activity of hepatic enzymes (SOD/CAT) which are involved in combating reactive oxygen species (ROS), suggesting that it possesses the capacity to attenuate the CCl(4)-induced liver damage. Moreover the RCE40 (20 mg/kg) inhibited TBARS formation induced by several different inductors of oxidative stress showing significant antioxidant activity, including physiologically relevant concentration, as low as 2 µg/mL. Concerning antiviral activity, the RCE40 was effective against herpes simplex virus type 1 replication (29R acyclovir resistant strain) with EC(50) = 40 µg/mL and selective index (SI) = 50.

DISCUSSION AND CONCLUSION

These results indicate that C. glaziovii could be a good source of antioxidant and anti-HSV-1 lead compounds.

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.

Antisecretory actions of Baccharis trimera (Less.) DC aqueous extract and isolated compounds: analysis of underlying mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Baccharis trimera (Less.) DC. (Asteraceae) is a species native to South America used in Brazilian folk medicine to treat gastrointestinal and liver diseases, kidney disorders and diabetes. Previous studies from this laboratory confirmed the antacid and antiulcer activities of the plant aqueous extract (AE) in rat and mouse models.

AIM OF THE STUDY

To investigate the mechanisms involved in the antacid action of AE and isolated compounds from Baccharis trimera.

MATERIALS AND METHODS

AE was assayed in vivo in cold-restraint stress gastric ulcers and in pylorus-ligated mice. Nine fractions (F2-F10) previously isolated from AE were assayed in vitro on acid secretion measured as [(14)C]-aminopyrine ([(14)C]-AP) accumulation in rabbit gastric glands, and on gastric microsomal H(+), K(+)-ATPase preparations. Chlorogenic acids (F2, F3, F6, F7), flavonoids (F9), an ent-clerodane diterpene (F8) and a dilactonic neo-clerodane diterpene (F10) have been identified in these fractions.

RESULTS

Intraduodenal injection of AE (1.0 and 2.0 g/kg) in 4h pylorus-ligated mice decreased the volume (20 and 50%) and total acidity (34 and 50%) of acid secretion compared to control values. Administered orally at the same doses AE protected against gastric mucosal lesions induced in mice by restraint at 4°C. Exposure of isolated rabbit gastric glands to fractions F8 (10-100 μM) and F9 (10-300 μg/ml) decreased the basal [(14)C]-AP uptake by 50 and 60% of control (Ratio=6.2±1.1), whereas the remaining fractions were inactive. In the presence of the secretagogues F2 and F4 (30-300 μg/ml) decreased the [(14)C]-AP uptake induced by histamine (His) with a 100-fold lower potency than that of ranitidine. F5 and F6 reduced the [(14)C]-AP uptake stimulated by carbachol (CCh), but they were 10 to 20-fold less potent than atropine. F8 (diterpene 2) and F9 (flavonoids) decreased both the His- and CCh-induced [(14)C]-AP uptake, whereas F10 (diterpene 1) was inactive against the [(14)C]-AP uptake stimulated by secretagogues. Diterpene 2 was the most active of all tested compounds being 7-fold less potent than ranitidine and equipotent to atropine in reducing acid secretion in vitro. This compound also reduced the gastric H(+), K(+)-ATPase activity by 20% of control, while the remaining fractions were inactive on the proton pump in vitro.

CONCLUSIONS

The results indicate that Baccharis trimera presents constituents that inhibit gastric acid secretion by acting mainly on the cholinergic regulatory pathway. The plant extract also contains compounds that exert moderate inhibition of the histaminergic regulatory pathway of acid secretion and the gastric proton pump. Altogether these active constituents appear to provide effective inhibition of acid secretion in vivo, which may explain the reputed antiulcer activity of the plant extract.

Chemical and Pharmacological Aspects of the Genus Cecropia

The Cecropia genus consists of about 60 species distributed throughout Latin America, mostly in Brazil. These species are widely used in traditional medicine to treat cough, asthma, bronchitis, high blood pressure, inflammation, heart disease, and as a diuretic. In recent years, there has been an increase in research on Cecropia species, with several phytochemical and pharmacological reports. Concerning its chemical composition, C-glycosylflavonoids and proanthocyanidins have been described as the main constituents of C. glaziovii, C. hololeuca and C. pachystachya, while terpenoids and steroids have been reported in several species, including C. adenopus and C. pachystachya. Among the pharmacological properties described for the genus, the most frequently reported are hypoglycemic activity for C. obtusifolia and C. peltata, and hypotensive and central nervous system activity for C. glaziovii. The present review compiles the information available on this genus because of its ethnopharmacological relevance and the potential therapeutic uses of these species.

Experimental design as a tool to evaluate chlorogenic and caffeic acids extracted from Cecropia glaziovii Sneth

The effects of different parameters, including ethanol concentration, time of drug:solvent contact, temperature and the presence of a preservative, on chlorogenic acid (CGA) and caffeic acid (CFA) yields in Cecropia glaziovii Sneth extracts were investigated using an experimental design. In order to quantify the phenolic acids in these extracts a high-performance liquid chromatography-diode array detection (HPLC-DAD) method was developed and validated. Extracts with 80% ethanol presented a higher CGA content, but low amounts of CFA. Extracts with 20% ethanol showed a higher CFA concentration, but a sharp reduction in CGA extraction yield. The presence of a preservative, under the same extraction conditions, resulted in a slight difference or no difference in the CGA and CFA extraction yields. When the temperature was controlled at refrigerator or room temperature, a slight alteration in the concentrations of the phenolics studied was observed. The present approach can be applied in order to determine the optimum conditions for the preparation of C. glaziovii Sneth extracts based on CGA or CFA extraction yield as a chemical marker.

Spices, herbal xenobiotics and the stomach: Friends or foes?

Spices and herbal remedies have been used since ancient times to treat a variety of disorders. It has been experimentally demonstrated that spices, herbs, and their extracts possess antimicrobial, anti-inflammatory, antirheumatic, lipid-lowering, hepatoprotective, nephroprotective, antimutagenic and anticancer activities, besides their gastroprotective and anti-ulcer activities. Despite a number of reports on the toxicity of herbs and spices, they are generally accepted as safer alternatives to conventional therapy against gastric ulcers. To this end, it is also believed, that excessive consumption of spices may favor the pathogenesis of gastric and duodenal ulcer and some studies have substantiated this common perception. Based on various in vivo experiments and clinical studies, on the effects of spices and herbs on gastric ulcers, it has indeed been shown that certain spices do possess remarkable anti-ulcer properties mediated by antisecretory, cytoprotective, antioxidant, and anti-Helicobacter pylori effects and mechanisms regulated by nitric oxide, prostaglandins, non-protein sulfhydryl molecules and epidermal growth factor expression. Accordingly, their consumption may attenuate and help prevent peptic ulcer disease. In the present review, the beneficial effects of spices and herbal nutritive components on the gastric mucosa are discussed against the paradigm of their deleterious potential.

Anti-secretory, anti-inflammatory and anti-Helicobacter pylori activities of several fractions isolated from Piper carpunya Ruiz & Pav

ETHNOPHARMACOLOGICAL RELEVANCE

The leaves of Piper carpunya Ruiz & Pav. (syn Piper lenticellosum C.D.C.) (Piperaceae), are widely used in folk medicine in tropical and subtropical countries of South America as an anti-inflammatory, anti-ulcer, anti-diarrheal and anti-parasitical remedy as well as an ailment for skin irritations.

AIMS OF THE STUDY

To study the anti-inflammatory, anti-secretory and anti-Helicobacter pylori activities of different fractions isolated from an ethanolic extract of the leaves of Piper carpunya, in order to provide evidence for the use of this plant as an anti-ulcer remedy. Moreover, to isolate the main compounds of the extract and relate their biological activity to the experimental results obtained with the fractions.

MATERIALS AND METHODS

Sixteen fractions were obtained from the ethanolic extract (F I-XVI) and 16 pure compounds were isolated and identified from these fractions. We studied the effects of the fractions (0.1-400microg/mL) on the release of myeloperoxidase (MPO) enzyme from rat peritoneal leukocytes, on rabbit gastric microsomal H(+), K(+)-ATPase activity and anti-Helicobacter pylori anti-microbial activity using the microdilution method (MM). The main compounds contained in the fractions were isolated and identified by (1)H- and (13)C NMR spectra analysis and comparison with the literature data.

RESULTS

Eight fractions showed inhibition of MPO enzyme (F I-IV, X, XII, XIV and XV). The highest inhibition was observed with F XIV (50microg/mL, 60.9%, p<0.001). F X and XII were the most active ones, inhibiting the gastric H(+), K(+)-ATPase activity with IC(50) values equal to 22.3microg/mL and 28.1microg/mL, respectively. All fractions, except F XV, presented detectable anti-Helicobacter pylori activity, with a diameter of inhibition zones ranging from 11mm up to 50mm. The best anti-Helicobacter pylori activity was obtained with F III and V. Both fractions killed Helicobacter pylori with lowest concentration values, about 6.25mug/mL. Sixteen pure compounds were isolated, five of them are flavonoids that possess strong anti-oxidant and free radical scavenging activity, e.g. vitexin, isovitexin, and rhamnopyranosylvitexin. Terpenoids like sitosterol, stigmasterol and phytol, which have shown gastroprotective activity, and dihydrochalcones, like asebogenin, with anti-bacterial activity, were also isolated. Furthermore, the rare neolignan 1, that is a DNA polymerase beta lyase inhibitor, and (6S, 9S)-roseoside, that shows strong anti-bacterial activity, were isolated, for the first time, from the genus Piper.

CONCLUSIONS

We suggest that the flavonoids isolated from F I and II (vitexin, isovitexin, rhamnopyranosylvitexin and isoembigenin) contribute to the anti-MPO activity, as well as to their anti-Helicobacter pylori activity. These flavonoids may also be responsible for the important inhibition of H(+), K(+)-ATPase activity. Also the phytosterols and phytol obtained from F XIV and XV could be involved in these gastroprotective activities. These results encourage us to continue phytochemical studies on these fractions in order to obtain full scientific validation for this species.

Effect of a gastrin-releasing peptide receptor antagonist and a proton pump inhibitor association in an animal model of gastritis

It has been proposed that reactive oxygen species play a causative role of gastric mucosal damage induced by increased gastric secretion. Gastrin-releasing peptide is a typical neuropeptide that stimulates acid secretion by release of gastrin. In the present work we have investigated the mechanism of indomethacin (IDM)-induced gastric ulcer caused by ROS and determined the effects of a selective gastrin-releasing peptide receptor antagonist, RC-3095, alone and in association with omeprazole (OM) and compared it with an established antioxidant compound N-acetyl cysteine (NAC). Adult male Wistar rats were pre-treated for 7 days with OM, RC-3095, NAC, both drugs and water (control). The animals were then submitted to fasting for 24h; IDM was administered. Rats were killed 6h after that and the stomachs were used for evaluation of macroscopic damage and oxidative stress parameters. Our results showed that IDM increased mitochondrial superoxide production; OM and RC-3095 alone did not prevent such effect, but the combination of these drugs was effective. TBARS assay revealed that IDM-induced lipid peroxidation in gastric tissue and that OM and RC-3095, alone or in combination, prevented this effect with superior action that NAC. Finally, we verified that IDM increased protein carbonyl content and that this effect was prevented RC-3095, alone or in combination with OM, being similar to standard antioxidant. The present results support the view that, besides the inhibition of acid secretion, the protective effects exerted by OM and RC-3095 against IDM-induced gastric damage can be ascribed to a reduction of gastric oxidative injury.