Protective effect of ethyl acetate fraction of Acacia ferruginea DC. against ethanol-induced gastric ulcer in rats

Integrated network pharmacology and metabolomics to investigate the effects and possible mechanisms of Dehydroevodiamine against ethanol-induced gastric ulcers

ETHNOPHARMACOLOGICAL RELEVANCE

Tetradium ruticarpum (A.Juss.) T.G.Hartley, a traditional Chinese medicine with thousands of years of medicinal history, has been employed to address issues such as indigestion, abdominal pain, and vomiting. Dehydroevodiamine (DHE) is a quinazoline alkaloid extracted from traditional Chinese medicine Tetradium ruticarpum (A.Juss.) T.G.Hartley. Previous studies have shown that DHE has anti-inflammatory, analgesic, and antioxidant activities. However, it is still unclear whether DHE has an effect on ethanol-induced gastric ulcers.

AIM OF THE STUDY

The objective of this study is to investigate the therapeutic efficacy and underlying mechanisms of action of DHE on ethanol-induced gastric ulcers using network pharmacology and metabolomics strategies.

METHODS

In this study, we used ethanol-induced rats as a model to assess the efficacy of DHE by biochemical indicator assays and pathological tissue detection. The integration of network pharmacology and metabolomics was used to explore possible mechanisms and was validated by western blot experiments. Finally, molecular docking was used to analyze the binding energy between DHE and the targets of PIK3CG and PLA2G2A.

RESULTS

DHE was able to reverse ethanol-induced abnormalities in biochemical indicators and improve pathological tissue. Network pharmacology results indicated that DHE may be involved in the regulation of gastric ulcers by modulating 79 targets, and metabolomics results showed that a total of 13 metabolites were changed before and after DHE administration. Integrating network pharmacology and metabolomics, PIK3CG and PLA2G2A were identified as possible targets to exert therapeutic effects. In addition, the MAPKs pathway may also be involved in the regulation of ethanol-induced gastric ulcers. Finally, molecular docking results showed that DHE had low binding energies with both PIK3CG and PLA2G2A.

CONCLUSIONS

These findings suggest that DHE was able to exert a protective effect against ethanol-induced gastric ulcers by modulating multiple metabolites with multiple targets. This study provides a valuable reference for the development of antiulcer drugs.

Phenolic acids-rich fraction from Ficus drupacea leaves for the prevention and treatment of ethanol-induced gastric mucosal injury in rats

Bioactivity-guided fractionation of F. drupacea Thunb. extract revealed that the water fraction (FDWF) increased pH of the artificial gastric juice from 1.2 to 5.67 ± 0.015. The gastroprotective effect of FDWF against ulcer induced by ethanol was evaluated in rats. In ulcerogenic rats, increase in the gastric juice volume and ulcer lesions, and decrease in the gastric pH were evident. However, pretreatment with FDWF (100 mg/kg b.wt., p.o.) significantly inhibited lesion index, reduced gastric juice volume by 56.09% and increased gastric pH value. When given after ethanol, the same dose of FDWF led to significant healing of the gastric ulcer, with 75.60% reduction of gastric juice volume, and increase in pH value. In both prophylactic and therapeutic-treated groups, the level of superoxide dismutase and reduced glutathione in gastric homogenate were increased, while that of malondialdehyde was decreased. Also, the levels of succinate dehydrogenase and lactate dehydrogenase were increased, while that of acid phosphatase was decreased. In addition, the inflammatory markers; IL-10 and PGE2 were significantly increased. The histopathological results confirmed the above findings and indicated that the antiulcer effect of FDWF is mediated, at least in part, through antioxidant and anti-inflammatory mechanisms. Twenty-three compounds were tentatively identified in FDWF using UPLC-PDA-ESI-MS/MS and most of them were found to be phenolic acid derivatives. FDWF was standardized to contain 23.66 ± 2.62 mg/g and 8.86 ± 0.29 mg/g of quinic acid and chlorogenic acid, respectively. Accordingly, FDWF is a potential natural product that could increase the healing of gastric mucosal injury and prevents the development of ethanol-induced gastric mucosal injury in rats.

Antiulcerogenic and antioxidant activities of Plantago ovata ethanolic extract in rats

This study aimed to determine the antiulcerogenic and antioxidant activities of Psyllium (Plantago ovata Forssk) seed ethanolic extract in rats. We assessed the antioxidant potential using free radical scavenging on DPPH, β-carotene bleaching activity, ferric reducing power, and hydroxyl radical scavenging activity. In the antiulcerogenic study, pre-treatment with Plantago ovata seeds ethanolic extract (POE) (400 mg/kg b.wt) significantly protected against ethanol-induced gastric ulcer in rats by decreasing the ulcer index value and preserving the integrity of the gastric mucosa. The oxidative stress status in the stomach tissues showed a significant increase in the antioxidant enzyme levels of superoxide dismutase, catalase, and glutathione peroxidase with a significant decrease in lipid peroxidation during pre-treatment with POE. In conclusion, the POE protects against gastric ulcer due to its antioxidant potential and presence of bioactive molecules.

Gastric acid-response chitosan/alginate/tilapia collagen peptide composite hydrogel: Protection effects on alcohol-induced gastric mucosal injury

Long-term excessive alcohol intake can easily lead to gastritis, gastric ulcer, and gastric bleeding. In this paper, the gastric acid-responsive hydrogel of CS-NAC/alginate/tilapia collagen peptide (CS-NAC/ALG/TCP) was developed. Its structure and properties were determined. The alcohol-induced gastric mucosal injury models in mice were established to evaluate the protective effects of CS-NAC/ALG/TCP. The results showed that CS-NAC/ALG/TCP was successfully fabricated, and it showed a sustained release of TCP, strong mucoadhesion, and excellent biodegradability in vitro. In the animal experiments, CS-NAC/ALG/TCP improved the oxidative stress status of the gastric mucosa by increasing the levels of SOD, GSH, and CAT in tissues. It also down-regulated the expression of MPO, TNF-α, IL-1β, and IL-6, and increased the production of gastric protective factors such as PGE2 and NO in mouse stomach, thereby reducing the alcohol-induced inflammation and protecting the gastric mucosal injury. Besides, CS-NAC/ALG/TCP can also increase the activities of alcohol metabolism enzymes to improve alcohol metabolism, thereby reducing alcoholic damage. In conclusion, CS-NAC/ALG/TCP is a promising candidate for the treatment of alcohol-induced gastric injury.

Exploring the phyto- and physicochemical evaluation, fluorescence characteristics, and antioxidant activities of Acacia ferruginea Dc: an endangered medicinal plant

Background

Herbal plants are potent in curing various ailments of ancient times as they have comparatively lesser side effects. The demands for natural drugs, mostly from plant sources, are increasing over the past few decades. Because of their potent antioxidant activity, Acacia species are used to treat a variety of diseases. One of the species Acacia ferruginea, an endangered medicinal plant, is widely used in the traditional medicine system, and it is considered that standardization would be beneficial. The present study investigates the physicochemical parameters, preliminary phytochemical screening, trace metals by SEM–EDS, and fluorescence properties of various extracts (non-polar to polar) of leaf and bark parts. Standard spectrophotometric methods (UV–Vis, FT-IR, fluorescence spectroscopy) are employed to analyze the functional groups, and the DPPH and total antioxidant methods are used to assess antioxidant potential.

Results

The ethyl acetate extract of leaves and ethanol extract of the bark are found to be the highest in yield, 16.32% and 2.54%. Results reveal that the total ash percentage and moisture content are of bark and the water-soluble ash of leaves is higher (10.3 ± 0.85, 7.6 ± 0.34, 3.22 ± 0.24%). The bark polar extract contained more macro-elements such as Na, K, Mg, Ca, S, and Cl. Phytochemical analysis reveals the polar extracts of leaves and bark show saponins, flavonoids, steroids, phenolic compounds, and non-polar extracts show mild positive. The total alkaloids, phenolics, and terpenoids (1.58 ± 0.08%; 0.56 ± 0.11; 0.75 ± 0.15) are found to be higher in A. ferruginea leaves. The FT-IR result shows the presence of alkanes, alkenes, aromatic compounds, aldehydes, phenolics and does not contain any toxic substances since there is no peak observed in the region between 2220 and 2260 cm−1. The in vitro antioxidant activity of the species demonstrated that both the leaf and bark parts have prominent antioxidant properties.

Conclusions

The results obtained from the preliminary standardization of A. ferruginea are very helpful in the determination of the quality and purity of the crude drug. The refurbished findings of A. ferruginea are promising, and further research is important to identify the bioactive compounds, thereby developing nutritional supplements and medications through therapeutic compound isolation.

Graphical Abstract

Medicinal Plants in the Treatment of Peptic Ulcer Disease: A Review

Peptic Ulcer Disease (PUD) is the most common disorder of the stomach and duodenum, which is associated with Helicobacter pylori infection. PUD occurs due to an imbalance between offensive and defensive factors and Proton Pump Inhibitors (PPI), Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) and antibiotics are frequently used for the treatment. Recently, medicinal plants have emerged as efficacious, safe and widely available alternative therapies for PUD. The aim of this review was to study the medicinal plants and phytochemicals, which have been used for PUD treatment to evaluate the potential role of natural compounds to develop herbal remedies for PUD. Information was obtained using a literature search of electronic databases, such as Web of Science, Google Scholar, PubMed, Sci Finder, Reaxys and Cochrane. Common and scientific names of the plants and keywords such as 'peptic ulcer', 'gastric ulcer', 'stomach ulcer' and 'duodenal ulcer' were used for search. Eventually, 279 plants from 89 families were identified and information on the plant families, part of the plant used, chemical constituents, extracts, ulcer model used and dosage were abstracted. The results indicated that most of the anti-PUD plants were from Asteraceae (7.1%) and Fabaceae (6.8%) families while flavonoids (49%), tannins (13%), saponins (10%) and alkaloids (9%) were the most common natural compounds in plants with anti-PUD activity.

Tetramethylpyrazine ameliorates indomethacin-induced gastric ulcer in rats: Impact on oxidative, inflammatory, and angiogenic machineries

Available antiulcer medications reveal partial efficacy and numerous adverse reactions. Tetramethylpyrazine (TMP) was known for its potential antioxidant, anti-inflammatory and angiogenic properties. The aim of current study was to investigate the potential gastroprotective effect of TMP against indomethacin-induced gastric ulcer in rats with possible underlying mechanisms. TMP was tested at 3 doses (15, 30 & 60 mg/kg/d po) three days before indomethacin challenge (25 mg/kg ip). Gastric tissue was evaluated morphologically and histopathologically. Oxidative statuses were assessed via glutathione content (GSH), malondialdhyde (MDA) and catalase (CAT) activity, while TNFα and IL-6 were measured as inflammatory mediators. Gastric PGE2 was investigated in addition to vascular endothelial growth factor (VEGF). TMP was effective (at 30 and 60 mg/kg/d) in promoting mucus secretion and preventing histopathologic changes induced by indomethacin. Mechanistically, TMP significantly enhanced GSH content and CAT activity while reducing lipid peroxidation as expressed by MDA concentration. Moreover, TMP effectively reduced TNFα, IL-6 and intracellular adhesion molecule (ICAM-1) concentrations. On the other hand, TMP enhanced both COX-1 and PGE2 and encouraged angiogenesis via increasing VEGF expression. In conclusion, TMP possesses a protective effect against indomethacin-induced gastric ulcer. This could be explained - at least partly - by its antioxidant, anti-inflammatory and angiogenic effects.

Evaluation of Gastro-protective Activity of Myristica fragrans on Ethanol-induced Ulcer in Albino Rats

Myristica fragrans seeds are traditionally used to treat dyspepsia, vomiting and abdominal pain. The purpose of this study was to investigate the protective effect of Myristica fragrans in ethanol induced gastric ulcer. Study was carried out on rats, divided into four groups; negative control, positive control, standard drug control, and Myristica fragrans extract treated rats. The pH, ulcer index, acidity values and histopathological examination of stomach were evaluated. Myristica fragrans significantly (P<0.05) reduced gastric lesions by 41.68% in ethanol induced ulcer model at 200 mg/kg when compared to sucralfate (60.41%). However, histopathological findings appeared similar in Myristica fragrans extract treated and standard drug control groups, where stomachs were found with mild erosion of superficial epithelium and few infiltrated inflammatory cells. pH of gastric contents of rats from extract treated was increased (4.25 ± 0.25) as compared to positive control group (2.25 ± 0.25). Ulcer index of extract treated rats was improved (41.74%). Moreover, total acidity of extract treated group (60.0 ± 0.47) was decreased as compared to control group (74.50 ± 1.04). It is concluded that Myristica fragrans showed significant protecting activity in ethanol induced ulcer. Isolation and purification of phytochemicals responsible for gastroprotective activity becomes necessary.

Modulatory effects of Viola odorata flower and leaf extracts upon oxidative stress-related damage in an experimental model of ethanol-induced hepatotoxicity

Ethanol is the most widely abused drug in the world and its long-term use induces oxidative stress in the liver tissue. The aim of this study was to evaluate protective effect of Viola odorata against ethanol-induced hepatotoxicity in Wistar rat. Animals were divided into 9 groups as follows: control (normal saline), ethanol (10 mg/kg, intraperitoneally), ethanol with 3 doses (125, 250, and 500 mg/kg) of ethyl acetate flower and leaf extracts, and positive control (vitamin E 80 mg/kg). Animals were gavaged 30 min before ethanol injection for 28 days. Then, animals were killed and the livers were separated. Oxidative stress parameters, including reactive oxygen species, lipid peroxidation, and protein carbonyl as well as glutathione content, were evaluated. Also, histopathological examination was performed and assessment of blood alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and total antioxidant capacity were evaluated. Ethanol significantly increased oxidative stress markers in liver. Interestingly, administration of both extracts significantly decreased oxidative stress markers in liver tissue and biochemical parameters in the plasma. In addition, abnormal pathological features were improved after treatment with flower and leaf extracts. These results suggested that V. odorata can be considered a candidate for improving conditions due to ethanol-induced tissue oxidative damage because of its antioxidant activity.

Phytochemical evaluation and anti-hemorrhoidal activity of bark of Acacia ferruginea DC

The present study has been carried out to evaluate antihemorrhoidal activity of bark of Acacia ferruginea DC. The total phenolic, total flavonoid and saponins were determined. Anti-hemorrhoidal potential of bark extract was determined by levels of inflammatory cytokines such as TNF-α, IL-6, PGE2 and recto-anal coefficient (RAC). The histopathological examination was done to evaluate the severity score in the treated and untreated groups. The results of phytochemical screening of the hydroalcoholic extract of A. ferruginea revealed the presence of alkaloids, flavonoids, triterpenoid, saponins, tannins and phenolic compounds The total phenolic, flavonoid and saponin contents were found to be 438.8mg/g GAE, 66.6mg/gRE and 34%w/w respectively. Hydroalcoholic extract of bark of A. ferruginea significantly reduced the inflammatory cytokines {TNF-α(8.40±0.188), IL-6(3.95±0.181), PGE2(53.27±2.956) and RAC(0.998±0.094)}as compared to positive control group{TNF-α(13.36±0.141), IL-6(7.25±0.161), PGE2(82.34±3.395) and RAC(1.131 ± 0.008)}. Noticeably the results were comparable to that of standard pilex granules {TNF-α (7.12±0.166), IL-6(3.01±0.156), PGE2(42.51±2.157) and RAC (0.968±0.084)}. Molecular docking and structure based pharmacophore mapping further confirmed the anti-inflammatory mediated antihemorrhoidal activity of the hydroalcoholic extract. The antihemorrhoidal activity of hydroalcoholic extract of A. ferruginea may attribute to the flavonoids.

In vitro investigation of cytotoxic and antioxidative activities of Ardisia crispa against breast cancer cell lines, MCF-7 and MDA-MB-231

Background

Ardisia crispa Thunb. D.C is used mostly in some parts of the Asian region by traditional practitioners to treat certain diseases associated with oxidative stress and inflammation including cancer and rheumatism. In Malaysia, it is popularly known as ‘Mata Ayam’ and local traditional practitioners believed that the root of the plant is therapeutically beneficial.

Methods

The cytotoxic effect of hydromethanolic extract of A. crispa and its solvents partitions (ethyl acetate and aqueous extracts) against breast cancer cells were evaluated by using MTT assay. The cells were treated with concentration of extracts ranging from 15.63 μg/mL- 1000 μg/mL for 72 h. The quantification of phenolic and flavonoid contents of the extracts were carried out to determine the relationship between of phytochemical compounds responsible for cytotoxic and antioxidative activities. The antioxidant capacity was measured by DPPH and ABTS free radical scavenging assay and expressed as milligram (mg) Trolox equivalent antioxidant capacity per 1 g (g) of tested extract.

Results

The hydromethanolic and ethyl acetate extracts showed moderate cytotoxic effect against MCF-7 with IC₅₀ values of 57.35 ± 19.33 μg/mL, and 54.98 ± 14.10 μg/mL, respectively but aqueous extract was inactive against MCF-7. For MDA-MB-231, hydromethanolic, ethyl acetate and aqueous extracts exhibited weak cytotoxic effects against MDA-MB-231 with IC₅₀ values more than 100 μg/mL. The plant revealed high total phenolic content, total flavonoid and antioxidant capacity.

Conclusion

The response of different type of breast cancer cell lines towards A. crispa extract and its partitions varied. Accordingly, hydromethanolic and ethyl acetate extracts appear to be more cytotoxic to oestrogen receptor (ER) positive breast cancer than oestrogen receptor (ER) negative breast cancer. However, aqueous extract appears to have poor activity to both types of breast cancer. Besides that, hydromethanolic and ethyl acetate extracts exhibit higher TPC, TFC and antioxidant capacity compared to aqueous extract. Synergistic effect of anticancer and antioxidant bioactives compounds of A. crispa plausibly contributed to the cytotoxic effects of the extract.

In vivo cellular and molecular gastroprotective mechanisms of chrysin; Emphasis on oxidative stress, inflammation and angiogenesis

Gastric ulcer is one of the major gastrointestinal disorders affecting people worldwide. Despite medical advances, management of gastric ulcer and its complications remains a challenge facing medicine nowadays. In addition, currently available medicines exhibit limited efficacy and several side effects. In the current study, the potential protective effects of chrysin -naturally occurring flavonoid - were tested against indomethacin-induced gastric ulcer model in rats. It was found that chrysin in both doses; 50 and 100mg/kg were effective in promoting mucus secretion and preventing the rise in ulcer and lesion indices, acid production and histologic changes induced by indomethacin. During investigation of the possible underlying mechanisms, chrysin significantly attenuated indomethacin-induced oxidative injury and inflammatory response. Also, chrysin activated peroxisome proliferator activated receptor-ɣ (PPAR-ɣ) leading to a phenotypic switch from pro-inflammatory M1 macrophages to the anti-inflammatory M2 macrophages that evidenced by the upregulated mRNA expression levels of PPAR-ɣ and M2 marker genes (Arg-1 and CD206) and down regulation of M1 marker genes (IL-6 and CCL3). Furthermore, chrysin promoted angiogenesis via increasing expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and cluster of differentiation-31 (CD31). Collectively, these findings indicate that chrysin possesses a potential protective effect against indomethacin-induced gastric ulcer.

The gastroprotective effect of ethyl acetate fraction of hot water extract of Trichosanthes cucumerina Linn and its underlying mechanisms

BACKGROUND

Antacids, anticholinergic drugs, histamine H2- receptor antagonists and irreversible proton pump inhibitors have been used for the treatment of gastric ulcers. However, prolonged use of these drugs may lead to series of adverse effects such as diarrhea, headache, rash, hypertension, muscular and joint pain. Therefore, there is an urgent need of more effective and safer treatments with fewer side effects. The aim of the present study was to scientifically evaluate the gastroprotective activity of fractions of the hot water extract of Trichosanthes cucumerina Linn (Family: Cucurbitaceae) aerial parts with a view to identifying the fraction with the best gastroprotective activity and the possible mechanism/s by which this fraction exert gastroprotection.

METHODS

Gastroprotective activity of hexane fraction (HF), ethyl acetate fraction (EF), butanol fraction (BF) and aqueous fraction (AF) were evaluated by the assessment of ability to reduce the ulcer index in ethanol-induced rat model and the mode of action by which the most active fraction mediating gastroprotection.

RESULTS

EF showed the maximum gastroprotection effect followed by BF and AF. EF (75 mg/kg) exhibited significantly higher gastroprotection compared to the reference drugs. Further investigations with two lower doses of EF confirmed that EF can mediated a significant and dose dependent gastroprotection. The rats treated with the EF showed significant reduction in free acidity (45%), total acidity (by 48%) in the gastric juice, increased the amount of mucus produced by the rat gastro mucosa and potent antihistamine activity (by 25.6%). EF was also rich in phenolic compounds and flavonoids.

CONCLUSION

Gastroprotective mechanism of EF is possibly involves inhibition of acidity, elevation in mucus content, inhibition of histamine and antioxidant mechanisms.

The antiulcer effect of Cibotium barometz leaves in rats with experimentally induced acute gastric ulcer

Cibotium barometz is a pharmaceutical plant customarily used in traditional medicine in Malaysia for the treatment of different diseases, such as gastric ulcer. The gastroprotective effect of C. barometz leaves against ethanol-induced gastric hemorrhagic abrasions in Sprague Dawley rats has been evaluated in terms of medicinal properties. Seven groups of rats (normal control and ulcerated control groups, omeprazole 20 mg/kg, 62.5, 125, 250, and 500 mg/kg of C. barometz correspondingly) were used in antiulcer experiment and pretreated with 10% Tween 20. After 1 hour, the normal group was orally administered 10% Tween 20, whereas absolute alcohol was fed orally to ulcerated control, omeprazole, and experimental groups. Gastric's homogenate were assessed for endogenous enzymes activities. Stomachs were examined macroscopically and histologically. Grossly, the data demonstrated a significant decrease in the ulcer area of rats pretreated with plant extract in a dose-dependent manner with respect to the ulcerated group. Homogenates of the gastric tissue exhibited significantly increased endogenous enzymes activities in rats pretreated with C. barometz extract associated with the ulcerated control group. Histology of rats pretreated with C. barometz extract group using hematoxylin and eosin staining exhibited a moderate-to-mild disruption of the surface epithelium with reduction in submucosal edema and leucocyte infiltration in a dose-dependent manner. In addition, it showed heat shock protein70 protein up-expression and BCL2-associated X protein downexpression. These outcomes might be attributed to the gastroprotective and antioxidative effects of the plant.

The gastro protective effects of Cibotium barometz hair on ethanol-induced gastric ulcer in Sprague-Dawley rats

BACKGROUND

Cibotium barometz is a medical herb used traditionally in the Malaysian peninsula for several ailments, including gastric ulcer. The aim of this study was assessment the anti-ulcer effects of C. barometz hair on ethanol-induced stomach hemorrhagic abrasions in animals. Seven groups of Sprague Dawley (SD) rats were administered 10% Tween 20 in the normal control and ulcer control groups, and omeprazole 20 mg/kg and 62.5, 125, 250, and 500 mg/kg of C. barometz hair extract in the experimental groups. After 60 min, the normal control group of rats was orally administered 10% Tween 20, while absolute ethanol was orally administered to the groups of ulcer control, omeprazole and experimental groups. Stomachs of the rats were examined macroscopically and histologically. Homogenates of stomachs were used to evaluate endogenous antioxidant enzyme activities.

RESULTS

Rats pre-fed with plant extract presented a significant decrease in the sore area, increased pH of gastric contents and preserved stomach wall mucus compared to the ulcer group. Histologically, rats pre-fed with C. barometz hair extract showed mild to moderate disruptions of the surface epithelium while animals pre-fed with absolute ethanol showed severe disruptions of the stomach epithelium with edema and leucocyte penetration of the submucosal layer. A Periodic acid Schiff (PAS) staining revealed that each rat pre-treated with the plant extract displayed an intense uptake of stomach epithelial glycoprotein magenta color compared to the ulcer control group. Immunohistochemical analysis revealed that rats pre-fed with the plant extract showed an up-regulation of the heat shock protein 70 (HSP70) and down-regulation of Bax proteins compared to ulcer control rats. Homogenates of the stomach tissue demonstrated significant increases in the endogenous antioxidant enzymatic activity and decreased lipid peroxidation (MDA) in rats pre-treated with C. barometz hair extract compared with the ulcer control rats. In acute toxicity, the liver and kidney revealed no hepatotoxic or nephrotoxic effects histologically.

CONCLUSIONS

The gastric cytoprotective action of C. barometz hair extract might be attributed to antioxidants, an increase in gastric pH, stomach mucus preservation, increased endogenous antioxidant enzymes, decreased lipid peroxidation, up-regulation of HSP70 and down-regulation of Bax proteins.

Rahman S, Hamid SSA, Ching SM, Teh LK, Salleh MZ, Deny S, Taher M. Antinociception of petroleum ether fraction derived from crude methanol extract of Melastoma malabathricum leaves and its possible mechanisms of action in animal models

Background

Melastoma malabathricum L. (family Melastomaceae) has been traditionally used as remedies against various ailments including those related to pain. The methanol extract of M. malabathricum leaves has been proven to show antinociceptive activity. Thus, the present study aimed to determine the most effective fraction among the petroleum ether- (PEMM), ethyl acetate- (EAMM) and aqueous- (AQMM) fractions obtained through successive fractionation of crude, dried methanol extract of M. malabathricum (MEMM) and to elucidate the possible mechanisms of antinociception involved.

Methods

The effectiveness of fractions (100, 250 and 500 mg/kg; orally) were determine using the acetic acid-induced abdominal constriction test and the most effective extract was further subjected to the hot plate- or formalin-induced paw licking-test to establish its antinociceptive profile. Further elucidation of the role of opioid and vanilloid receptors, glutamatergic system, and nitric oxide/cyclic guanosine phosphate (NO/cGMP) pathway was also performed using the appropriate nociceptive models while the phytoconstituents analyses were performed using the phytochemical screening test and, HPLC-ESI and GCMS analyses.

Results

PEMM, EAMM and AQMM significantly (p < 0.05) attenuated acetic acid-induced nociception with the recorded EC₅₀ of 119.5, 125.9 and 352.6 mg/kg. Based on the EC₅₀ value, PEMM was further studied and also exerted significant (p < 0.05) antinociception against the hot plate- and formalin-induced paw licking-test. With regards to the mechanisms of antinociception,: i) PEMM significantly (p < 0.05) attenuated the nociceptive action in capsaicin- and glutamate-induced paw licking test.; ii) naloxone (5 mg/kg), a non-selective opioid antagonist, failed to significantly (p < 0.05) inhibit PEMM’s antinociception iii) L-arginine (a nitric oxide precursor), but not N^G-nitro-L-arginine methyl esters (L-NAME; an inhibitor of NO synthase), methylene blue (MB; an inhibitor of cGMP), or their respective combination, significantly (p < 0.05) reversed the antinociception of PEMM. Phytochemical analyses revealed the presence of several antinociceptive-bearing bioactive compounds, such as triterpenes and volatile compounds like oleoamide and palmitic acid. The presence of low flavonoids, such as gallocatechin and epigallocatechin, saponins and tannins in PEMM might synergistically contribute to enhance the major compounds antinociceptive effect.

Conclusion

PEMM exerted a non-opioid-mediated antinociceptive activity at the central and peripheral levels via the inhibition of vanilloid receptors and glutamatergic system, and the activation of NO-mediated/cGMP-independent pathway. Triterpenes, as well as volatile oleoamide and palmitic acid, might be responsible for the observed antinociceptive activity of PEMM.

Novokinin inhibits gastric acid secretion and protects against alcohol-induced gastric injury in rats

Novokinin (Arg-Pro-Leu-Lys-Pro-Trp), a potent vasorelaxing and hypotensive peptide modified from ovokinin, exhibits highly selective affinity for the AT₂ receptor. However, its role in gastrointestinal functions is still not fully understood. In this study, we found that novokinin inhibited basal gastric acid secretion and protected gastric mucosa from alcohol-induced injury in a dose-related manner in rats after intracerebroventricular (i.c.v.) administration. Novokinin significantly decreased basal gastric acid output at the dose of 50 and 100 nmol/rat. The effect of novokinin on gastric acid secretion was reversed by central injection of PD 123319 (10 nmol/rat), an AT₂ receptor antagonist, and peripheral injection of indomethacin (10 mg/kg), an inhibitor of prostaglandin synthesis. Meanwhile, pre-treatment with novokinin at doses of 10, 50, and 100 nmol/rat significantly reduced the alcohol-induced gastric mucosal injury compared to the ulcer-control group, which was inhibited by indomethacin (10 mg/kg). The result showed a remarkable increase in the level of prostaglandin E2 (PGE₂), glutathione (GSH), and a decrease in malondialdehyde (MDA) after i.c.v. administration of novokinin. These findings suggest that the inhibitory effect of novokinin on gastric acid secretion is probably mediated via an AT₂ receptor-prostaglandins (PGs) pathway. The gastroprotective effect of novokinin might be attributed to the inhibition of acid secretion, the cytoprotection of PGs, and the antioxidant property.

Protective effects of alginate-chitosan microspheres loaded with alkaloids from Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. (Zuojin Pill) against ethanol-induced acute gastric mucosal injury in rats

Zuojin Pill (ZJP), a traditional Chinese medicine formula, consists of Coptis chinensis Franch. and Evodia rutaecarpa (Juss.) Benth. in a ratio of 6:1 (w/w) and was first recorded in “Danxi’s experiential therapy” for treating gastrointestinal disorders in the 15th century. However, the poor solubility of alkaloids from ZJP restricted the protective effect in treating gastritis and gastric ulcer. The aim of the study was to investigate the protective mechanism of mucoadhesive microspheres loaded with alkaloids from C. chinensis Franch. and E. rutaecarpa (Juss.) Benth. on ethanol-induced acute gastric mucosal injury in rats. Surface morphology, particle size, drug loading, encapsulation efficiency, in vitro drug release, mucoadhesiveness, and fluorescent imaging of the microspheres in gastrointestinal tract were studied. The results showed that the mucoadhesive microspheres loaded with alkaloids could sustain the release of drugs beyond 12 hours and had gastric mucoadhesive property with 82.63% retention rate in vitro. The fluorescence tracer indicated high retention of mucoadhesive microspheres within 12 hours in vivo. The mucoadhesive microspheres loaded with alkaloids could reduce the gastric injury by decreasing the mucosal lesion index, increasing the percentage of inhibition and increasing the amount of mucus in the gastric mucosa in an ethanol-induced gastric mucosal injury rat model. Moreover, the mucoadhesive microspheres loaded with alkaloids reduce the inflammatory response by decreasing the levels of tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), downregulating the mRNA expression of inducible nitric oxide synthase, TNF-α, and IL-1β in gastric mucosa. All the results indicate that mucoadhesive microspheres loaded with alkaloids could not only increase the residence time of alkaloids in rat stomach, but also exert gastroprotective effects through reducing the inflammatory response on ethanol-induced gastric mucosal damage. Thus, these microspheres could be developed as a potential controlled release drug for treatment of gastric ulcer.

Synergy Effects of Three Plant Extracts on Protection of Gastric Mucosa

The gastric mucosa protection effect of three natural plant extracts, Hericium erinaceus (HE), Centella asiatica (CA) and Amomum villosum (AV), were evaluated using the indomethacin damage model. Compared with a single extract, a combination of HE/CA/AV, especially with the ratios of 80:10:10, 45:45:10 and 45:10:45, showed significant synergistic effects for protection of the gastric mucosa with gastric ulcer inhibition rates of 97.8 ± 0.7%, 86.5 ± 2.8% and 86.1 ± 3.6%, respectively. Microscopic appearances of the gastric mucosa were carried out to help confirm the results.

Effect of acetone extract from stem bark of Acacia species (A. dealbata, A. ferruginea and A. leucophloea) on antioxidant enzymes status in hydrogen peroxide-induced HepG2 cells

Acacia species are multipurpose trees, widely used in the traditional systems of medicine to treat various ailments. The major objective of the present study was to determine the gene expression of enzymatic antioxidants by acetone extract from the stem bark of three Acacia species (Acacia dealbata, Acacia ferruginea and Acacia leucophloea) in hydrogen peroxide (H2O2)-induced human hepatoma (HepG2) cells. The expression of antioxidant enzymes such as superoxide dismutase containing copper-zinc (CuZnSOD)/manganese (MnSOD), catalase (CAT) and glutathione peroxidase (GPx) in HepG2 cells was evaluated by real-time PCR. The results of antioxidant enzyme expression in real-time PCR study revealed that the H2O2 (200 μM) challenged HepG2 cells reduced the expression of enzymes such as SOD, GPx and CAT. However, the cells pre-treated with acetone extracts of all the three Acacia species significantly (P > 0.05) up-regulated the expression of antioxidant enzymes in a concentration dependent manner (25, 50 and 75 μg/mL). In conclusion, the findings of our study demonstrated that the acetone extract of Acacia species effectively inhibited H2O2 mediated oxidative stress and may be useful as a therapeutic agent in preventing oxidative stress mediated diseases.

Antiulcerogenic activity of Scutia buxifolia on gastric ulcers induced by ethanol in rats

Gastric ulcers affect many people around the world and their development is a result of the imbalance between aggressive and protective factors in the gastric mucosa. Scutia buxifolia, commonly known as coronilha, has attracted the interest of the scientific community due to its pharmacological properties and its potential therapeutic applications. In this study, the preventive effects of the crude extract of Scutia buxifolia (ceSb) against gastric ulcer induced by 70% ethanol were evaluated in male Wistar rats. In addition, the composition of ceSb was clarified by high-performance liquid chromatography (HPLC). S. buxifolia extract (100, 200 and 400 mg/kg body weight) attenuated oxidative and histopathological features induced by ethanol. Moreover, all evaluated doses of ceSb caused significant (P<0.001 and P<0.0001) and dose-dependent increase in sulfhydryl groups (NPSH) levels, catalase (CAT) and superoxide dismutase (SOD) activities. Furthermore, the administration of ceSb reversed the increase in lipid peroxidation produced by ethanol. The protective effect of the extract could be attributed to antioxidant compounds present in the ceSb, such as flavonoids and phenolic acids, which were quantified by HPLC. Thus, an antioxidant effect of the extract leads to a protection on gastric tissue. These results indicate that S. buxifolia could have a beneficial role against ethanol toxicity by preventing oxidative stress and gastric tissue injury.