Anti-ulcer activity of Cyrtocarpa procera analogous to that of Amphipterygium adstringens, both assayed on the experimental gastric injury in rats

Ethnopharmacological relevance

The bark of Amphipterygium adstringens (Aa) is commonly mixed or adulterated with the bark of Cyrtocarpa procera (Cp) and sold in Mexican markets. Aa is a well known species in Mexico used as decoction to relieve ulcers. Scientific reports reinforcing the anti-ulcer activity of Aa have been previously described, but those describing the anti-ulcer properties of Cp as a substitute for Aa in folk medicine are scarce.

Aim of the study

To investigate anatomical and phytochemical differences between these species, as well as to assess the anti-ulcer effect of Cp extracts in comparison to the Aa extracts.

Material and methods

Anatomical micro-technique and physical and spectroscopic data were used to analyze differences between Cp and Aa. Regard to the pharmacological activity, it was assessed by using the ethanol-induced gastric damage model in rats.

Results

Whereas the bark anatomy of Aa was characterized by vertical canals in the periderm and the rare occurrence of fibers in its phloem, a periderm without vertical canals and abundant fibers in the phloem were distinctive features of Cp. Phytochemical analysis allowed the identification of tirucallane, masticadienonic and 3α-hydroxymasticadienonic acids as major components in Aa, while β-amyrin and β-sitosterol were obtained from Cp. Gastric lesions observed in the control group decreased in the presence of 100 mg/kg of hexane, ethyl acetate and methanol extracts from the normal or regenerated bark of Cp, thus resembling the anti-ulcer effect of Aa. Nevertheless, major anti-ulcer potency was observed with the most active methanol extract from Cp obtained from normal [the effective dose fifty ED₅₀ = 45.54 mg/kg] or regenerated (ED₅₀ = 36.68 mg/kg) bark in comparison to Aa (ED₅₀ = 115.64 mg/kg).

Conclusion

Chemical and anatomical differences were found between these species, but since the anti-ulcer activity of Cp is similar to that shown by Aa our results reinforce the use of both species for the relief of gastric ulcer in folk medicine.     

Mechanisms of action underlying the gastric antiulcer activity of the Rhizophora mangle L

Ethnopharmacological relevance

Rhizophora mangle, the red mangrove, has long been known as a traditional antiulcer medicine. The present work evaluated the mechanisms of action involved in the anti-ulcer properties of the Rhizophora mangle bark extracts.

Materials and methods

Gastroprotection of Rhizophora mangle was evaluated in rodent experimental models (ethanol). To elucidate the mechanisms of action the antisecretory action and involvement of NO, SH, mucus and PGE₂ were evaluated. The acetic acid-induced gastric ulcer model, Western blotting assay (COX-1, COX-2 and EGF) and immunohistochemical localization of HSP-70, PCNA and COX-2 were also used to evaluate the Rhizophora mangle healing properties.

Results

Results showed that Rhizophora mangle bark crude extract (CE), as well as ethyl acetate (EtOAc) and butanolic fractions (BuOH) provided significant gastroprotection at all the tested doses. Thereby, the following protocols were performed using the lowest dose capable of producing the most effective gastroprotection, which was the BuOH 0.5 mg/kg (P < 0.001). Several mechanisms are involved in the antiulcer activity of Rhizophora mangle, such as, participation of NO, SH and mucus. The enhancement of PGE₂ levels and the upregulation of COX-2 and EGF seem to be directly linked to the antisecretory, cytoprotective and healing effects of BuOH. HSP-70 and PCNA are also involved in this cicatrisation process. No sign of toxicity was observed in this study, considering the analyzed parameters.

Conclusion

Our study reinforces its traditional medicinal use. Considering that the current therapies are based on the use of antisecretory or cytoprotective drugs, the Rhizophora mangle arises as a promising alternative antiulcer therapy.     

Protective effects of methanolic extract of Hedyotis puberula (G. Don) R. Br. ex Arn. against experimentally induced gastric ulcers in rat

Aim of the study

This study was aimed to evaluate the antiulcer activity of the whole plants of Hedyotis puberula (G. Don) R. Br. ex Arn.

Materials and methods

Gastroprotective potential of the Hedyotis puberula methanol extract (200 and 400 mg/kg body weight) was studied on indomethacin (IND), ethanol and pyloric ligation (PL)-induced gastric ulcer models in rats.

Results

The treatment with Hedyotis puberula extract at 400 mg/kg p.o. protected the rats against the ulceration which was comparable to the reference drug omeprazole. Pretreatment with extract protected rats from gastric lesion development by way of increased pH and decreased volume, acidity and pepsin content of gastric secretion. Furthermore, total carbohydrate: protein ratio of the gastric juice were noticeably increased in pretreated rats.

Conclusion

Results of our study showed that Hedyotis puberula possess significant gastroprotective activity and validate the folklore claim.     

In vivo antiulcer activity of the aqueous extract of Bauhinia purpurea leaf

Ethnopharmacological relevance

Bauhinia purpurea (Fabaceae) is a medicinal plant traditionally used to treat various ailments, including ulcers. In order to establish pharmacological properties of the leaf of Bauhinia purpurea, studies were performed on antiulcer activity of the plant's aqueous extract.

Materials and methods

The Bauhinia purpurea aqueous extract (BPAE) was prepared in the doses of 100, 500 and 1000 mg/kg. Antiulcer activity of BPAE was evaluated by absolute ethanol- and indomethacin-induced gastric ulcer, and pyloric ligation models. Acute toxicity was also carried out.

Results

BPAE, at the dose of 5000 mg/kg, did not cause any signs of toxicity to rats when given orally. Oral administration of BPAE exhibited antiulcer activity (p < 0.05) in all models used. However, the dose-dependent activity was observed only in the absolute ethanol-induced gastric ulcer model. Histological studies supported the observed antiulcer activity of BPAE. In pyloric ligation assay, BPAE increased the gastric wall mucus secretion.

Conclusions

The BPAE exhibits antiulcer activity, which could be due to the presence of saponins or sugar-free polyphenols, and, thus, confirmed the traditional uses of Bauhinia purpurea in the treatment of ulcers.     

Gastric antisecretory and antiulcer activities of Cedrus deodara (Roxb.) Loud. in Wistar rats

Ethnopharmacological relevance: Cedrus deodara (Roxb.) Loud. is used in Ayurvedic medicine to treat peptic ulcer.

Aim of the study

To evaluate the gastric antisecretory and antiulcer activity of Cedrus deodara.

Materials and methods

The volatile oil extracted by steam distillation of Cedrus deodara wood was examined for its gastric antisecretory and antiulcer effect in the pylorus-ligated rat model and ethanol induced gastric lesions in rats.

Results

The volatile oil showed significant antisecretory activity as evidenced by decreased gastric fluid volume, total acidity, free acidity and increase in the pH of the gastric fluid in pylorus-ligated rats. Our studies also revealed that pretreatment with Cedrus deodara significantly reduced the number of ulcer, ulcer score and ulcer index in pylorus-ligated and ethanol treated rats. The antiulcer activity of Cedrus deodara is further supported by histopathological study which showed protection of mucosal layer from ulceration and inflammation.

Conclusion

The present findings conclude that volatile oil of Cedrus deodara wood has potent antisecretory and antiulcer effects and justify the traditional usage of this herb to treat peptic ulcers.     

Abarema cochliacarpos: Gastroprotective and ulcer-healing activities

Ethnopharmacological relevance

Abarema cochliacarpos (Gomes) Barneby & Grimes (Mimosaceae) is a species - in folk medicine of Lagarto city, Sergipe state, northeastern Brazil - reputed to heal gastric ulcer and gastritis.

Aim of the study

Chloroform (CE) and methanolic (ME) extracts as well as ethyl acetate fraction (AF), butanolic fraction (AC) and aqueous fraction (AQF) of the methanolic extract of Abarema cochliacarpos bark were evaluated against acute gastric ulcer. The AC fraction was selected to assess its activity in ulcer healing and its gastroprotective effects via mucus and gastric secretion.

Material and methods

The gastroprotective action of CE and ME extracts and the fractions of the latter were evaluated in a rodent experimental model. The action mechanisms, involvements of the antisecretory action and mucus production, toxicological and healing activity of the AC (150 mg/kg, p.o.) were evaluated. We also used histological analysis (HE and PAS) and immunohistochemical (PCNA, COX-2, VEGF and HSP-70) assays to evaluate the effects of Abarema cochliacarpos.

Results

CE (200 and 400 mg/kg, p.o.) and ME (100, 200 and 400 mg/kg, p.o.) extracts were able to protect gastric mucosa against absolute ethanol. Respective inhibitions produced were: 65.31% and 83.80% by the first; 91.69%, 96.75% and 99.80% by the second; and 74.24% by the AC fraction. Antisecretory and mucus production effects were exhibited by the AC fraction, which also accelerated the healing of ulcerated gastric mucosa by stimulating proliferation factors (PCNA) and induced healing factors including COX-2, VEGF and HSP-70.

Conclusion

All these results suggest that Abarema cochliacarpos (Gomes) Barneby & Grimes presents gastroprotective effects and wound-healing properties.     

Anti-inflammatory effect of Ajuga bracteosa Wall Ex Benth. mediated through cyclooxygenase (COX) inhibition

Ethnopharmacological relevance

Ajuga bracteosa Wall Ex Benth. (Labiateae) is described in Ayurveda for the treatment of rheumatism, gout, palsy and amenorrhea.

Aim of the study

The aim of present investigation is to study anti-inflammatory activity of Ajuga bracteosa, to understand possible mechanism of action and to identify the constituents responsible for its activity.

Materials and methods

The anti-inflammatory activity of 70% ethanolic extract was evaluated in TPA-induced mouse ear edema assay and in vitro cyclooxygenase (COX)-1 and COX-2 inhibitory activity was determined using EIA kits employing appropriate reference standards. Aajugarin I, lupulin A, withaferin A, reptoside and 6-deoxyharpagide were isolated from the 70% ethanolic extract by silica gel column chromatography.

Results

The 70% ethanol extract of whole plants of Ajuga bracteosa showed a significant (p < 0.05) and dose-dependent anti-inflammatory activity in an acute inflammation model at the dose of 0.5 and 1.0 mg/ear. The extract also exhibited a strong in vitro COX-1 and COX-2 inhibitory activity at 25 and 50 μg/mL concentration. Among the isolated compounds 6-deoxyharpagide exhibited highest COX-2 inhibition while rest of the compounds exhibited weak to moderate COX-1 and COX-2 inhibition at 30 μM concentration.

Conclusions

The results suggest that the 70% ethanol extract of Ajuga bracteosa possesses promising anti-inflammatory activity, which is possibly mediated through inhibition of COX-1 and COX-2 enzymes. The isolated constituents could be responsible in part for its anti-inflammatory and COX inhibitory activity. The study supports traditional use of Ajuga bracteosa for inflammatory diseases.     

Neuroprotective effect of Alpinia galanga (L.) fractions on Aβ(25-35) induced amnesia in mice

Ethnopharmacological relevance

The rhizomes of Alpinia galanga (L.) Willd (Zingiberaceae), a ginger substitute for flavouring food was traditionally used as nervine tonic and stimulant.

Aim of the study

This investigation is designed to screen cognitive improvement of Alpinia galanga (AG) fractions in Alzheimer's type of amnesia in mice induced by Aβ_(25-35).

Materials and methods

Alzheimer's disease induced mice treated with fractions (n-hexane, chloroform and ethyl acetate) of AG in 200 and 400 mg/kg. Neurotoxicity was induced by intracerebroventricular injection of Aβ_(25-35) on the 14th day of 21 days drug treatment. Open field and water maze were carried to determine habituation memory and hippocampal memory. Na⁺/K⁺-ATPase, acetylcholinesterase (AChE) and antioxidant enzymes (SOD, GPx, catalase and vitamin C) were determined in brain tissue homogenate to estimate the brain biochemical changes and its anti-amnesic potential with intensity of oxidative stress signaling. Further bioactive (chloroform) fraction was eluted through column chromatography to identify the lead molecules.

Results

Increased habituation memory and decreased escape latency in behavioral parameter are the indicative of the cognitive enhancement after treatment with Alpinia galanga fractions. Increment in Na⁺/K⁺-ATPase and antioxidant activity depicts brain membrane integrity improvement and free radical scavenging property. AChE level was decreased to improve the cognition by enhancing cholinergic transmission.

Conclusion

Anti-amnesic effect was exerted by various fractions of Alpinia galanga. Among all fractions, preeminent neuroprotection was exerted by chloroform fraction, which has compound, 1′δ-1′-acetoxyeugenol acetate and it may be a potential therapeutic agent for Alzheimer's type of amnesia. These results further motivate us to explore the activity of lead compound's anti-amnesic effect on transgenic mice model of AD.     

Indigofera suffruticosa Mill as new source of healing agent: involvement of prostaglandin and mucus and heat shock proteins

Ethnopharmacological relevance

Indigofera suffruticosa is specie typical of the “Cerrado” or Brazilian savannah; it is a member of the Fabaceae family - in folkmedicine is used for gastric disorders, infection and inflammation.

Aim of the study

Ethyl acetate fraction (AcF) and aqueous fraction (AqF) of the methanolic extract of I. suffruticosa leaves were evaluated against acute gastric ulcer. The AcF fraction was selected to assess its activity in ulcer healing and its gastroprotective effects via mucus and gastric secretion.

Materials and methods

The gastroprotective action of AcF and AqF fractions were evaluated in a rodent experimental model. The action mechanisms, involvements of the antisecretory action, mucus and prostaglandin production, toxicological and healing activity of the AcF (100 mg/kg, p.o.) were evaluated. We also used histological analysis (HE and PAS) and immunohistochemical (PCNA and HSP-70) assays to evaluate the effects of I. suffruticosa.

Results

AcF significantly inhibited the gastric mucosal damage caused by ethanol. This effect was statistically significant in 100 mg/kg group compared vehicle. AcF did not interfered with gastric secretion, significantly increased the PGE₂ and mucus production (validated in PAS technique). The gastroprotection was attenuated by pretreatment with N-ethylmaleimide, but not L-NAME. In acid-acetic-induced ulcer model AcF accelerated ulcer healing. Immunohistochemistry analysis showed induction of proliferating cell (PCNA) and heat shock protein (HSP 70).

Conclusions

These results showed that AcF acted as gastroprotective agent stimulating prostaglandin, mucus and HSP70.     

Inhibition of the toxic effects of Bothrops asper venom by pinostrobin,a flavanone isolated from Renealmia alpinia (Rottb.) MAAS

Ethnopharmacological relevance

Renealmia alpinia has been traditionally used to treat snakebites by indigenous Embera-Katíos tribes belonging to the regions of Antioquia and Chocó, Colombia, and it has been shown to inhibit the enzymatic and biological activities of Bothrops venoms and their purified phospholipase A₂ (PLA₂) toxins. In addition to its common local usage against snakebites, Renealmia alpinia is commonly used to treat pain. To evaluate the inhibitory ability of pinostrobin, the main compound in the dichloromethane extract of Renealmia alpinia, on the toxic effects of Bothrops asper venom through in vitro and in vivo models and to evaluate its activity against pain and edema.

Materials and methods

Pinostrobin was isolated from the dichloromethane extract of Renealmia alpinia leaves. The protective properties of the extract and of pinostrobin against the indirect hemolytic, coagulant and proteolytic effects of Bothrops asper venom were evaluated in vitro, and the anti-hemorrhagic and anti-inflammatory activity were evaluated in vivo.

Results

Renealmia alpinia extract significantly inhibited the proteolytic activity and indirect hemolytic activity of Bothrops asper venom at a venom:extract ratio of 1:20. Moreover, the present data demonstrate that pinostrobin may mitigate some venom-induced local tissue damage due to hemorrhagic effects, and the compound is also responsible for the analgesic and anti-inflammatory activity of the extract from Renealmia alpinia. This is the first report to describe pinostrobin in the species Renealmia alpinia and its properties in vitro against Bothrops asper venom.

Conclusion

Our studies of the activity of Renealmia alpinia against the venom of Bothrops asper have confirmed that this species possesses inhibitory effects against Bothrops asper venom in both in vitro and in vivo models and that these effects may be due to pinostrobin, supporting the traditional usage of the plant. Additionally, pinostrobin may be responsible for the anti-hemorrhagic and analgesic activity (peripheral analgesic activity) of Renealmia alpinia.     

Gastroprotective and safety effects of WIN-34B, a novel treatment for osteoarthritis, compared to NSAIDs

Ethnopharmacological relevance

The dried flowers of Lonicera japonica, also known as Japanese honeysuckle, and the dried root of Anemarrhena asphodeloides, the component herbs of WIN-34B, are traditionally used in Eastern medicine to treat various inflammatory conditions including arthritis.

Objective

To study the acute and chronic toxicities of WIN-34B and to compare its effects on gastric mucosa with those of diclofenac, a widely used NSAID, and celecoxib, a selective COX-2 inhibitor.

Materials and methods

To investigate acute toxicity, we orally administered a single dose of 5000 mg/kg WIN-34B to rats. To investigate chronic toxicity, we orally administered 500, 1000 or 2000 mg/kg WIN-34B to rats daily for 13 weeks. To assess its effects on gastric mucosa, rats received either a single dose or repeated doses of WIN-34B (400, 1000, or 2000 mg/kg), diclofenac (10, 40, or 80 mg/kg), celecoxib (100 or 1000 mg/kg), or vehicle, after which samples of gastric mucosa were assessed grossly and histologically. We also measured tissue activity of myeloperoxidase and synthesis of eicosanoids, including prostaglandin E₂ (PGE₂) and leukotriene B₄ (LTB₄). To further assess its effects, we administered WIN-34B to rats either intraperitoneally or orally, measured gastric injury scores using a rat model of diclofenac-induced gastric injury, and measured eicosanoid synthesis.

Results

WIN-34B showed no signs of acute or chronic toxicity in terms of general behavior, gross appearance of the internal organs, blood chemistry, or mortality. WIN-34B did not cause significant gastric mucosal damage after single or repeated doses. In contrast, diclofenac and celecoxib both caused gastric damage. In terms of eicosanoid synthesis, WIN-34B significantly suppressed LTB₄ synthesis while both diclofenac and celecoxib increased LTB₄ synthesis. WIN-34B slightly reduced PGE₂ production, while both diclofenac and celecoxib significantly reduced PGE₂ production. In a rat model of diclofenac-induced gastric injury, WIN-34B significantly suppressed LTB₄ synthesis and restored PGE₂ release.

Conclusions

These results demonstrate that WIN-34B did not cause acute or chronic toxicity in male or female rats. In addition, WIN-34B did not cause significant gastric mucosal damage, instead appearing to protect the mucosa from diclofenac-induced gastric damage through the regulation of PGE₂ and LTB₄.     

Antiulcerogenic activity of Lantana camara leaves on gastric and duodenal ulcers in experimental rats

Ethnopharmacological relevance

Lantana camara L. (Verbenaceae), a widely growing shrub has been used in the traditional medicine for treating many ailments. The objective of the present study was to evaluate the effects of methanolic extract of Lantana camara leaves on gastric and duodenal ulcers.

Materials and methods

The antiulcerogenic effect of methanolic extract of Lantana camara was evaluated in aspirin induced gastric ulcerogenesis in pyloric ligated rats, ethanol induced gastric ulcer, and cysteamine induced duodenal ulcer models. The extract was administered orally at two different doses of 250 mg/kg and 500 mg/kg. The lipid peroxidation, reduced glutathione levels of ethanol induced gastric ulcer model and inhibition zone in diameter against Helicobacter pylori also determined.

Results

The L. camara extract significantly (P < 0.01) reduced ulcer index, total acidity and significantly (P < 0.01) increased the gastric pH of aspirin + pylorus-ligation induced ulcerogenesis and ethanol induced gastric ulcer models. The extract also significantly (P < 0.01) reduced the ulcer index of cysteamine induced duodenal ulcer. The L. camara showed significant (P < 0.01) reduction in lipid peroxidation and increase in reduced glutathione levels. The inhibition zone in diameter of extract against H. pylori was 20 mm.

Conclusion

The methanolic extract of Lantana camara leaves shown healing of gastric ulcers and also prevents development of duodenal ulcers in rats.     

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 100 mg/kg of extract and omeprazole (30 mg/kg), respectively. The dose of 25 mg/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 100 mg/kg extract and positive control (cimetidine, 100 mg/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.     

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 [¹⁴C]-aminopyrine ([¹⁴C]-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 4 h 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 [¹⁴C]-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 [¹⁴C]-AP uptake induced by histamine (His) with a 100-fold lower potency than that of ranitidine. F5 and F6 reduced the [¹⁴C]-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 [¹⁴C]-AP uptake, whereas F10 (diterpene 1) was inactive against the [¹⁴C]-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.     

Evaluation of antiulcer activity of chromanone fraction from Calophyllum brasiliesnse Camb

Ethnopharmacological relevance

Calophyllum brasiliense Camb. (Clusiaceae), popularly known as ‘guanandi’, is found in the tropical areas and swampy lands. The latex exuding from its bark is used in the treatment of gastric ulcer in folk medicine. Several active compounds have been isolated from its stem bark among them, are the chromanone acids. Therefore, this study aimed to evaluate antiulcer activity and probable mechanism(s) of action of a fraction containing a mixture of chromanone acids (BI), derived by column chromatography fractionation of the hexane extract of the stem bark of Calophyllum brasiliense (HECb), using experimental in vitro and in vivo models.

Materials and methods

Ulcer was induced by oral administration of ethanol (75%, v/v) and indomethacin (50 mg/kg). Malondialdehyde, reduced glutathione and catalase activity was measured in stomach tissue after ethanol induced ulcer. In order to evaluate the effect of BI on nitric oxide, ulcer was induced by ethanol in l-NAME pretreated animals. Anti-Helicobacter pylori activity was verified in disk diffusion and broth microdilution in vitro assays, using cagA+ and vacA+ Helicobacter pylori strains.

Results

BI prevented the gastric ulceration caused by ethanol and indomethacin treatments. Its gastroprotective mechanism in ethanol-induced ulcer was partly due to reduction of MDA and CAT levels in the gastric tissue. BI did not affect the GSH levels and its gastroprotective effect was not reversed by pretreatment with l-NAME. BI showed anti-Helicobacter pylori in the both assays.

Conclusion

The results indicate that BI is partly responsible for the HECb antiulcer and anti-Helicobacter pylori effects.     

Microencapsulation enhances the anti-ulcerogenic properties of Entada africana leaf extract

Ethnopharmacological relevance

The antiulcer potentials of most plants still remain largely unexplored, despite their prospects evidenced by their use as ethnomedicine. Entada africana (Mimosaceae) has been widely used in Africa for the treatment of skin infections, wounds, tonic for stomach troubles and against diphtheria-like throat complaints. The aim of the present study was to evaluate the anti-ulcer properties of Entada africana (EA) ethanol leaf extract and to obtain a novel multiparticulate pharmaceutical formulation (ACE) with it.

Materials and methods

Ethanol or Indomethacin was administered to rats after oral administration of EA (200, 400 and 800 mg extract/kg b.w), ACE (400 and 800 mg/kg bw), cimetidine (100 mg/kg bw), misoprostol (40 μg/kg bw) or distilled water/saline (vehicle). Anti ulcer property was evaluated by examining and scoring stomach lesions.

Results

The extract exhibited significant (P < 0.01) cytoprotective effect against ethanol and indomethacin induced gastro ulceration. The microcapsules showed enhanced cytoprotective effect against ethanol and indomethacin induced gastro ulceration. Histopathologically, the effects of EA and ACE on mucus epithelia were mild with reduced neutrophil, eosinophil and lymphocytic infiltration in stomach tissues of rats ulcerated with ethanol.

Conclusions

Our current findings show that EA and its multiparticulate formulation may be a useful preparation in peptic ulcer disease.     

Centaurium erythrea (Gentianaceae) leaf extract alleviates streptozotocin-induced oxidative stress and β-cell damage in rat pancreas

Aims of the study

The present study was carried out to evaluate the effect of dried mature unripe Morinda citrifolia L. (Rubiaceae) fruit, commonly known as “Noni”, in an aqueous extract preparation (AFE) as used in Thai traditional medicine and its biomarker scopoletin on gastro-esophageal inflammatory models that are related to the claimed pharmacological properties of AFE and/or resembled the human esophagitis or gastric ulcer.

Materials and methods

The powder of dried mature unripe Noni fruit was boiled in water until it became a sticky paste and was then dried into a powder by lyophilization. The pharmacological activity of AFE and pure scopoletin at the same equivalent dose present in AFE was investigated in rat on gastro-esophageal inflammatory models (acid reflux esophagitis, acute gastritis induced by ethanol and serotonin, and chronic gastric ulcer induced by acetic acid); gastric biochemical parameters and gastrointestinal motility.

Results

AFE (0.63-2.50 g/kg) significantly prevented the formation of acid reflux esophagitis, reduced the formation of ethanol-induced acute gastric lesions, suppressed the development of gastric lesions in response to serotonin, and accelerated the healing of acetic acid-induced chronic gastric ulcer in rats with equal potency to those obtained by standard antisecretory agents (ranitidine and lansoprazole). AFE also significantly inhibited gastric acid secretion and pepsin activity in pylorus ligated rats. Additionally, AFE strongly increased the gastrointestinal transit of charcoal meal with a higher potency than cisapride. Pure scopoletin, when compared at the same equivalent dose containing in AFE, possessed similar antiulcer and antisecretory properties to that of AFE although it exerted a less prokinetic activity than AFE.

Conclusion

The findings indicated that AFE as well as its biomarker: scopoletin may be beneficial as a potential preventive and therapeutic agent for gastro-esophageal inflammatory diseases, mainly through its antisecretory and prokinetic activities including an inhibitory activity on serotonin, free radicals, and cytokine-mediated inflammation. Additionally, scopoletin might be one of the biomarker constituents to use for the quality assessment of Noni fruit products used for treating gastro-esophageal inflammatory diseases.     

Gastroprotective mechanism of Bauhinia thonningii Schum

Ethnopharmacological relevance

Bauhinia thonningii Schum. (Cesalpiniaceae) is locally known as Tambarib and used to treat various diseases including gastric ulcer.

Aim of the study

The current study aims to evaluate the gastroprotecive mechanism(s) of methanolic (MEBT) and chloroform (CEBT) extracts of Bauhinia thonningii leaves on ethanol-induced gastric ulceration.

Materials and methods

Gastric acidity, quantification and histochemistry of mucus, gross and microscopic examination, nitric oxide, lipid peroxidation, 2D gel electrophoresis, mass spectroscopy and biochemical tests were utilized to assess the mechanism(s) underlying the gastroprotective effects of MEBT and CEBT. Effect of these extracts into lipopolysaccharide/interferon-γ stimulated rodent cells were done in vitro. In vitro and in vivo toxicity studies were also conducted. Antioxidant activities of MEBT and CEBT were examined using DPPH, FRAP and ORAC assays. Phytochemical analyses of MEBT and CEBT were conducted using chemical and spectroscopic methods.

Results

Gross and histological features confirmed the anti-ulcerogenic properties of Bauhinia thonningii. Gastroprotective mechanism of MEBT was observed to be mediated through the modulation of PAS-reactive substances, MDA and proteomics biomarkers (creatine kinase, malate dehydrogenase, ATP synthase, actin and thioredoxin). MEBT and CEBT showed no significant in vitro and in vivo effects on nitric oxide. Methanolic extract (MEBT) showed superior gastroprotective effects, polyphenolic content and antioxidant activities compared to CEBT. The plant extracts showed no in vitro or in vivo toxicity.

Conclusion

It could be concluded that MEBT possesses anti-ulcer activity, which could be attributed to the inhibition of ethanol-induced oxidative damage and the intervention in proteomic pathways but not the nitric oxide pathway.     

Evaluation of the anti-neuraminidase activity of the traditional Chinese medicines and determination of the anti-influenza A virus effects of the neuraminidase inhibitory TCMs in vitro and in vivo

Etnopharmacological relevance

Neuraminidase (NA) inhibitors are currently the most effective drugs to treat influenza A viruses infection. Many traditional Chinese medicines (TCMs) have been used in the clinics to treat influenza. The anti-viral mechanisms of these TCMs and their inhibitory effects towards NA need to be systematically tested.

Aim of the study

To evaluate the anti-NA activity of the TCMs and the anti-influenza A virus effects of the NA inhibitory TCMs in vitro and in vivo.

Material and methods

We tested the inhibitory activity of water extracts from 439 TCMs towards NA. The in vitro anti-influenza virus activities of the 5 TCMs were evaluated using the strain A/California/7/2009 (H1N1) NYMC X-179A of influenza A virus. A randomly selected TCM with NA inhibitory activity, Melia toosendan extract, was further evaluated using a mouse model infected with influenza A virus.

Results

Five TCMs, Duchesnea indica (Andr.) Focke [Fragaria indica Andr.], Liquidambar formosana Hance., Lithospermum erythrorhizon Sieb. et Zucc., Melia toosendan Sieb. et Zucc., and Prunella vulgaris L., exerted potent inhibitory activity towards NA. These TCMs in the range of 25-250 μg/mL had the ability to reduce virus-induced cytopathic effect (CPE) and the virus yield in MDCK cells. Melia toosendan significantly reduced death rate and prolonged mean day to death (MDD) of the viral infected mice.

Conclusions

This study describes five TCMs exerted strong inhibitory activities towards NA, and exhibited antiviral effect against influenza A virus by reducing viral reproduction and reduced CPE of the viral infected cells. Melia toosendan, significantly reduced death rate and prolonged survival of the H1N1 viral infected mice.