Protective effect of Polyalthia longifolia var. pendula leaves on ethanol and ethanol/HCl induced ulcer in rats and its antimicrobial potency

Development of oral pH-sensitive redox nanotherapeutics for gastric ulcer therapy

Gastric ulcer is a common gastrointestinal disorder worldwide. Although its pathogenesis is unclear, the overproduction of reactive oxygen species (ROS), which results in an oxidative imbalance, has been reported as a central driving mechanism. Within the scope of this investigation, we developed two different self-assembling redox nanoparticles (RNPs) with ROS-scavenging features for the oral treatment of gastric ulcers. One of them, referred to as RNPN, disintegrates in response to acidic pH, whereas the other, denoted as RNPO, remains intact regardless of pH variations. Both types of RNPs showed different free radical scavenging activities in vitro. Protonation of the amino linkages in the side chains of RNPN caused the micelle structure to collapse and the nitroxide radicals encapsulated in the core were exposed to the outside, resulting in a significant increase in antioxidant capacity as the pH decreases. In contrast, RNPO maintained its spherical structure and consistent antioxidant reactivity irrespective of pH changes. The in vivo gastric retention of orally administered RNPN was significantly improved compared to that of RNPO which might be explained by the increased exposure of cationic protonating segments in RNPN on the negatively charged gastric mucosal surface. Owing to its improved gastric retention and enhanced ROS scavenging capacity under acidic pH conditions, RNPN exhibited superior protective effects against oxidative stress induced by aspirin in a gastric ulcer mouse model compared to RNPO. In addition, neither RNPN nor RNPO resulted in severe lethal effects or significant changes in the morphology of zebrafish embryos, indicating their biosafety. Our results suggest that the oral administration of RNPs has a high therapeutic potential for gastric ulcer treatment.

Phytochemical profiling and nephroprotective potential of ethanolic leaf extract of Polyalthia longifolia against cisplatin-induced oxidative stress in rat model

ETHNOPHARMACOLOGICAL RELEVANCE

Kidney problems are becoming more common globally and are considered a major health issue in the modern world with high mortality rate. Polyalthia longifolia (Sonn.) Thwaites is a tropical ethnomedicinal plant used to treat various diseases like diabetes, hypertension and urinary disorders and possess antioxidant and anti-inflammatory properties.

AIM OF THE STUDY

This study aimed to investigate the phytochemical composition of 70% ethanolic leaf extract of Polyalthia longifolia (Sonn.) Thwaites (PL) and evaluates its nephroprotective effects against cisplatin-induced nephrotoxicity in Wistar rats.

MATERIALS AND METHODS

The leaves of PL were extracted with 70% ethanol and performed the phytochemical profiling using Liquid Chromatography-Mass Spectrometry (LC-MS). The nephroprotective effect of PL leaf extract was evaluated at three doses (150, 300 and 600 mg/kg, p.o.) for 14 days against cisplatin toxicity (16 mg/kg, i.p., once) in male Wistar rats. Body and kidney weight indices, kidney function markers and lipid profile markers in serum, and oxidative stress markers in kidney tissue were performed along with the histopathological analysis of kidney.

RESULTS

The LC-MS chromatograph confirmed the presence of various phytocompounds include N-Methylhernagine (aporphine alkaloid), 4-Acetamidobutanoic acid (gamma amino acid) and choline, etc. in the PL leaf extract. Exposure of cisplatin (16 mg/kg, i.p., once only) to the animals significantly elevated the levels of kidney functional markers (i.e. serum urea, uric acid, creatinine) and the lipid markers (triglyceride and total cholesterol) in blood circulation with depletion of serum albumin which were reversed by the therapy of PL leaf extract (150, 300 and 600 mg/kg) in dose-dependent manner. The altered level of body and kidney weight in cisplatin treated group was also restored by the therapy. PL leaf extract effectively improved the antioxidant defense system of kidney at all doses by restoring the levels of tissue glutathione, superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase with the dose-dependent reduction of lipid peroxidation against cisplatin-induced renal oxidative stress. The histopathological observations also showed the significant recovery in cellular morphology after PL treatment when compared to the cisplatin toxicity group. The highest dose 600 mg/kg of PL leaf extract showed more pronounced renal recovery (p < 0.001) followed by other two doses, which was similar to the silymarin treatment group (a reference drug) against nephrotoxicity.

CONCLUSION

The results of this study revealed the nephroprotective effects of PL leaves against cisplatin-induced nephrotoxicity by reversing the level of biochemical markers and mitigating oxidative stress as well as improving the architecture of renal tissues. This renal protection by PL might be due to the synergistic effect of its phytoconstituents and antioxidant efficacy.

Metabolomic profiling and bactericidal effect of Polyalthia longifolia (Sonn.) Twaites. stem bark against methicillin-resistant Staphylococcus aureus

Objective. The present study was carried out to establish the chemical profile of the methanolic extract of Polyalthia longifolia stem bark and investigate its antibacterial property against some human pathogenic bacteria. Methods. The extract was analysed using liquid and gas chromatography coupled to mass spectrometry. Antibacterial activity of P. longifolia extract against some human pathogenic bacteria was screened using the AlamarBlue method, and MIC and MBC were determined. Results and Conclusion. Liquid chromatography-mass spectrometry (LC-MS) revealed the presence of 21 compounds among which 12 were identified. Gas chromatography-mass spectrometry (GC-MS) allowed identification of 26 compounds, the three major ones being the following: cis vaccenic acid (17.79 %), 3-ethyl-3-hydroxyandrostan-17-one (13.80 %) and copaiferic acid B (12.82 %). P. longifolia extract was active against Gram-positive bacteria with MIC ranging from 1 to 2 mg ml^-1 and MBC from 2 to 6 mg ml^-1. This study demonstrated the bactericidal effect of the methanolic extract of Polyalthia longifolia stem bark against some human pathogenic bacteria, including methicillin-resistant S. aureus . This effect could be related to the presence in the extract of a broad diversity of well-known compounds with established pharmacological properties. These results support the ethnomedicinal use of P. longifolia stem bark in Cameroon for the management of methicillin-resistant S. aureus (MRSA)-related infections.

Nephroprotective potential of Polyalthia longifolia roots against vancomycin-induced renal toxicity in experimental animals

This study was done to investigate the possible nephroprotective effect of an ethanolic root extract of Polyalthia Longifolia (PL) on vancomycin-induced nephrotoxicity using curative and protective models. Vancomycin (150 mg/kg, intravenous) was given to healthy Wistar albino rats in the curative model before the start of treatment, whereas the protective group received vancomycin at the conclusion of the 10-day treatment procedure. Animals were divided into six groups for both models; group I served as the normal control, while groups II, III, IV, V, and VI were kept as toxic control, standard (selenium, 6 mg/kg), LDPL (low dose of PL 200 mg/kg), HDPL (high dose of PL 400 mg/kg), and HDPL + selenium (interactive) groups, respectively. Renal biomarkers [(uric acid, creatinine, blood urea nitrogen (BUN), serum proteins], and blood electrolyte levels were measured for all tested groups. When compared to the vancomycin group, the HDPL significantly (p < 0.01) showed greater effectiveness in lowering the BUN, potassium, and calcium levels. Additionally, in the curative model, there was a significant (p < 0.05) decrease in the blood levels of uric acid, creatinine, BUN, potassium, and calcium in the animals who received the combination of selenium and HDPL. Both LDPL and HDPL did not provide any distinguishable effect in the protective model, but groups that received HDPL with selenium did provide detectable protection by significantly lowering their levels of uric acid, BUN, serum potassium, and total serum protein in comparison to the vancomycin control group. These findings indicate that, whether administered before or after renal damage is induced, the Polyalthia longifolia root extract provided only modest protection to nephrons, which require selenium support to prevent vancomycin-induced kidney damage.

Anti-Helicobacter pylori, anti-Inflammatory, and Antioxidant Activities of Trunk Bark of Alstonia boonei (Apocynaceae)

An ulcer is an erosion of the gastric mucosa that occurs following an imbalance between the aggression and protective factors and/or an infection with Helicobacter pylori (H. pylori). About 90-100% of duodenal ulcers and 70-80% of gastric ulcers are caused by H. pylori. The objective of this work was to evaluate in vitro the anti-H. pylori activity and then the anti-inflammatory and antioxidant properties of aqueous and methanol extracts of Alstonia boonei. The anti-H. pylori tests (CMI and antiureasic activity) were determined using the agar well diffusion method, the microbroth dilution method, and the measurement of ammonia production by the indophenol method; the anti-inflammatory properties were evaluated by inhibition of proteinases, denaturation of albumin, production of NO by macrophages, cell viability, and hemolysis of red blood cells by heat; then, the antioxidant properties were evaluated by the FRAP method (ferric reducing antioxidant power) and the DPPH (1,1-diphenyl-2-picrylhydrazyl) test. The results show that the best trapping of the DPPH radical was obtained with the methanol extract (EC₅₀ = 8.91 μg/mL) compared to the aqueous extract (EC₅₀ = 19.86 μg/mL). The methanol extract also showed greater iron-reducing activity than the aqueous extract and vitamin C. Furthermore, at the concentration of 200 μg/mL, the methanol extract showed a percentage (96.34%) strains of H. pylori higher than that of the aqueous extract (88.52%). The MIC₉₀ of the methanol extract was lower than that of the aqueous extract. The methanol extract showed a higher percentage inhibition (85%) of urease than the aqueous extract (73%). The methanol extract at a concentration of 1000 μg/mL showed the greatest ability to inhibit proteinase activity, albumin denaturation, and red blood cell hemolysis; on the other hand, maximum cell viability and greater production of nitrite oxide by macrophages were obtained with the aqueous extract. Aqueous and methanol extracts of Alstonia boonei possess anti-H. pylori which would probably be linked to their antioxidant and anti-inflammatory properties.

Protective Effect and Potential Mechanism of the Traditional Chinese Medicine Shaoyao-Gancao Decoction on Ethanol-Induced Gastric Ulcers in Rats

Background

Shaoyao-Gancao decoction (SGD) is a classic prescription in traditional Chinese medicine. SGD is effective in the treatment of gastric and duodenal ulcers. However, the biological activity and possible mechanisms of SGD in the treatment of gastric ulcers have not been fully elucidated. The purpose of this study was to scientifically evaluate the protective effect and potential mechanism of SGD against ethanol-induced gastric ulcers in rats.

Methods

A single gavage of 10 mL/kg of 75% ethanol was used to establish a rat gastric ulcer model. A histopathological examination of the gastric tissue was performed. The levels of TNF-α, EGF, PGE₂, SOD, and TBARS in gastric tissue were measured by ELISA. Cellular apoptosis in gastric tissues was assessed by TUNEL assay. The expression levels of caspase-3 and Bcl-2 were determined by immunohistochemistry. The potential mechanism of SGD in treating gastric ulcers was further studied using a network pharmacology research method.

Results

The gastric tissue of rats with ethanol-induced gastric ulcers had obvious injury throughout the mucosal layer, which was significantly weakened in rats treated with SGD. Furthermore, treatment with SGD significantly increased the levels of EGF, PGE₂, SOD, and Bcl-2 and decreased the levels of TNF-α, TBARS, and caspase-3 in the gastric tissue of rats with ethanol-induced gastric ulcers. SGD reduced ethanol-induced cell apoptosis in gastric tissue from rats with gastric ulcers. A traditional Chinese medicine-based network pharmacology study revealed that SGD exerts its anti-gastric ulcer effect by acting on multiple pathways.

Conclusions

The above results indicate that SGD can improve gastric ulcers induced by ethanol. Moreover, this study demonstrated multicomponent, multitarget, and multipathway characteristics of SGD in the treatment of gastric ulcers and provided a foundation for further drug development research.

The ameliorative impacts of wheat germ oil against ethanol-induced gastric ulcers: involvement of anti-inflammatory, antiapoptotic, and antioxidant activities

This study examined if wheat germ oil (WGO) has gastroprotective impacts against ethanol-induced gastric ulcer in rats. Rats were assigned into control, WGO, ethanol, omeprazole + ethanol, and WGO + ethanol. WGO prevented gastric ulceration and damage induced by ethanol, the same effect induced by omeprazole, a widely known medication used for gastric ulcer treatment. WGO reduced gastric ulcer index, nitric oxide, and malondialdehyde levels in the stomach. WGO boosted the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), Bcl2, and the antioxidants. WGO showed inflammatory and anti-inflammatory impacts through the control of interleukin (IL)-1β, Tumor necrosis factor alpha (TNF-α), and IL-10 that were altered in ethanol-administered rats. Ethanol up-regulated caspase-3 and nuclear factor-kappa B (NF-kB) expression and showed histopathological changes such as necrosis and mucosal degeneration that were mitigated by pre-administration of WGO. Moreover, WGO decreased gastric immunoreactivity of NF-kB and increased transforming growth factor beta-1 (TGF-β1) that were associated with upregulation of Nrf2, heme oxygenase-1 (HO-1), and antioxidant expression and production. In conclusion, WGO reduced ethanol-induced stomach toxicity by regulating genes involved in oxidative stress, inflammation, and apoptotic/antiapoptotic pathways.

Effects of the probiotic, Lactobacillus rhamnosus GG, on ulcer pathogenesis, HSP70 stress protein and nitric oxide levels in stress induced ulcer

Peptic ulcer is a gastric or duodenal mucosal injury; psychological stress may participate in development of the lesions. Heat shock protein-70 (HSP70) is a molecular chaperone that is responsible for cellular healing; it is an early biomarker of cellular damage. Nitric oxide (NO) is an intra- and intercellular messenger in the gastrointestinal system that protects mucosal integrity. Lactobacillus rhamnosus is among the microflora of the intestinal tract; it is resistant to gastric acidity. We investigated the efficacy of L. rhamnosus administration on ulcer pathogenesis, stress protein HSP70 and NO levels in experimental stress induced ulcer. The proton pump inhibitor, pantoprazole, was used for comparison with the gastroprotective effect of the probiotic. We administered 10 mg/kg pantoprazole and L. rhamnosus at doses of 3 × 10⁸ cfu/ml (M1), 15 × 10⁸ cfu/ml (M5), 30 × 10⁸ cfu/ml (M10) to rats according to McFarland-1, McFarland-5, McFarland-10 standards, respectively. Rats were stressed by immobilization at 4 °C, then sacrificed. The pH, amounts of gastric mucus, NO and HSP70 levels were measured and the histological structure of stomach was assessed. We found increased NO levels in the M5 group and increased HSP70 expression in the pantoprazole group. Significant epithelial damage was observed in the stressed groups and minimal epithelial damage was observed in M5 group compared to controls. The probiotic, L. rhamnosus, may be useful for preventing stress induced ulcers.

Gastroprotective Effect of Microencapsulated Myrtus communis Essential Oil against Ethanol/HCl-Induced Acute Gastric Lesions

Myrtus communis L. essential oil (EO), mainly composed of myrtenyl acetate (30.6%), linalool (14.9%), α-pinene (11.10%) and 1,8-cineole or eucalyptol (9.9%), was microencapsulated with maltodextrin by emulsification and spray-drying, reaching a yield and efficiency of 43.7 and 48.7%, respectively. The microencapsulated myrtle EO (MMEO) was then evaluated regarding its gastroprotective activity in a model of ethanol/HCl-induced acute gastric ulcer in Wistar rats. Pretreatment with MMEO induced a remarkable inhibition of gastric lesions and acidity, correlated to high healing and protection percentages. Moreover, it exerted a potent anti-inflammatory effect on the gastric mucosa, counteracting EtOH-induced gastric lipoperoxidation and preventing the depletion of the antioxidant enzyme activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Taken together, the gastroprotective action of encapsulated MMEO may be multi-factorial, and ascribable, at least in parts, to its anti-inflammatory and antioxidant properties.

Antiviral Potential of Selected Medicinal Herbs and Their Isolated Natural Products

Viruses are responsible for a variety of human pathogenesis. Owing to the enhancement of the world population, global travel, and rapid urbanization, and infectious outbreaks, a critical threat has been generated to public health, as preventive vaccines and antiviral therapy are not available. Herbal medicines and refined natural products have resources for the development of novel antiviral drugs. These natural agents have shed light on preventive vaccine development and antiviral therapies. This review intends to discuss the antiviral activities of plant extracts and some isolated plant natural products based on mainly preclinical (in vitro and in vivo) studies. Twenty medicinal herbs were selected for the discussion, and those are commonly recognized antiviral medicinal plants in Ayurveda (Zingiber officinale, Caesalpinia bonducella, Allium sativum, Glycyrrhiza glabra, Ferula assafoetida, Gymnema sylvestre, Gossypium herbaceum, Phyllanthus niruri, Trachyspermum ammi, Withania somnifera, Andrographis paniculata, Centella asiatica, Curcuma longa, Woodfordia fruticose, Phyllanthus emblica, Terminalia chebula, Tamarindus indica, Terminalia arjuna, Azadirachta indica, and Ficus religiosa). However, many viruses remain without successful immunization and only a few antiviral drugs have been approved for clinical use. Hence, the development of novel antiviral drugs is much significant and natural products are excellent sources for such drug developments. In this review, we summarize the antiviral actions of selected plant extracts and some isolated natural products of the medicinal herbs.

Phytochemicals from Polyalthia Species: Potential and Implication on Anti-Oxidant, Anti-Inflammatory, Anti-Cancer, and Chemoprevention Activities

Polyalthia belong to the Annonaceae family and are a type of evergreen tree distributed across many tropical and subtropical regions. Polyalthia species have been used long term as indigenous medicine to treat certain diseases, including fever, diabetes, infection, digestive disease, etc. Recent studies have demonstrated that not only crude extracts but also the isolated pure compounds exhibit various pharmacological activities, such as anti-oxidant, anti-microbial, anti-tumor, anti-cancer, etc. It is known that the initiation of cancer usually takes several years and is related to unhealthy lifestyle, as well as dietary and environmental factors, such as stress, toxins and smoking. In fact, natural or synthetic substances have been used as cancer chemoprevention to delay, impede, or even stop cancer growing. This review is an attempt to collect current available phytochemicals from Polyalthia species, which exhibit anti-cancer potentials for chemoprevention purposes, providing directions for further research on the interesting agents and possible clinical applications.

Royal jelly attenuates gastric mucosal injury in a rat ethanol-induced gastric injury model

The aim of the study was to investigate traditionally used Royal Jelly (RJ) for treating an ethanol-induced gastric ulcer model in rats. A total of 32 Wistar albino male rats were divided into 4 groups of 8: group I = Control, group II = Ethanol, group III = RJ + Ethanol, and group IV = Lansoprazole + Ethanol. In groups II, III, and IV, animals were administered 1 ml of absolute ethanol orally after a 24-h fast to induce ulcer formation. The histopathological changes in the gastric mucosa were determined using hematoxylin-eosin (H&E) staining. Immunohistochemically, inducible nitric oxide (iNOS) and nuclear factor kappa beta (Nf-κβ) markings were evaluated in gastric tissue. Cell death in the gastric mucosa was determined by the TUNEL method. Oxidative status markers, superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT), and myeloperoxidase (MPO) levels were determined spectrophotometrically. Expression of the interleukin - 1 beta (IL-1β) and tumor necrosis factor-α (TNF-α) genes in gastric tissues was determined by real-time PCR; and TNF-α, IL-10, and IL-1β levels were determined. RJ was found to inhibit iNOS and Nf-κβ activity in the gastric mucosa and prevent epithelial cell apoptosis. In particular, pro-inflammatory cytokines TNF-α and IL-1β levels were significantly decreased in the RJ + Ethanol group compared to the Ethanol group. In addition, a decrease in the MPO level indicated that RJ prevented tissue damage, especially by preventing inflammatory cell infiltration. The study demonstrated a possible gastroprotective effect of RJ in a rat ethanol-induced gastric ulcer model.

Effectiveness of Opuntia ficus indica L. inermis Seed Oil in the Protection and the Healing of Experimentally Induced Gastric Mucosa Ulcer

Gastric ulcer is a painful lesion of the gastric mucosa which can be disabling, or even more very serious in the case of a perforation of the stomach and internal hemorrhage. Traditional pharmacopeias have shown the efficacy of various plant extracts in the treatment of this pathology. Some extracts from Opuntia ficus indica (OFI) have been proven to have medicinal therapeutic benefits. The aim of this study was to investigate the preventive and curative effects of OFI seed oil extracted by cold pressing on an ethanol-induced gastric ulcer model in rats. Gastroprotective activities of the oil were assessed as pretreatments prior to ethanol gavage of Wistar rats compared to reference drugs. Two oil dose effects were tested. Ulcer and gastric parameters were measured (ulcerated areas (mm²), % of ulcer inhibition, gastric juice volume and pH, and mucus weight). Macroscopical and microscopical assessments of the stomachs as well as gastric biopsy histological studies were carried out. OFI oil exhibited a high efficiency in the protection of the cytoarchitecture and function of the gastric mucosa against the severe damages provoked by ethanol intake. Ulcerated areas were very significantly reduced and the % of ulcer inhibition was the highest under OFI oil pretreatment. Mucus production was stimulated, gastric juice volume was reduced, and its pH was increased. Histopathological examination of H&E-stained biopsies collected from gastric mucosae from the different experimental groups confirmed the gastroprotective efficacy of OFI oil against ethanol-induced symptoms such as inflammation and damages like bleeding, erosions, lesions, necrosis, and ulcers. Furthermore, OFI oil treatment speeded-up the reduction of the surface of ethanol-induced ulcerated areas in a dose-dependent manner, leading to a time gain in the healing process. The healing rate reached 91% on day 2 and 99% on day 3, and a complete heal was attained at the fourth day under OFI oil treatment, while ulcer areas were still partially unhealed in all the other groups. The therapeutic effects of OFI oil against gastric ulcer could be mediated by its varied bioactive compounds that we have demonstrated in the analytical study. They could act synergistically or in a delayed manner to optimize the healing process through protective antioxidant properties, as well as an antagonism against histamine H₂-receptors, a stimulation of the signaling pathways necessary for mucus and bicarbonate production, and reduction of inflammatory processes in the gastric mucosa. Additionally, OFI oil fatty acids (especially unsaturated) and triacylglycerols contribute to the reconstruction and the repair of the cell membrane lipid bilayer during the gastric ulcer healing process.

Influence of the Novel Histamine H3 Receptor Antagonist/Inverse Agonist M39 on Gastroprotection and PGE2 Production Induced by (R)-Alpha-Methylhistamine in C57BL/6 Mice

The role of histamine H3 receptors (H3Rs) in the regulation of gastroprotection and production of prostaglandin E2 (PGE2) as well as somatostatin remains contradictory. Therefore, the effects of the H3R antagonist/inverse agonist M39 on in vivo acidified ethanol-induced gastric ulcers and gastric acid secretion in the C57BL/6 mice were assessed. Results showed that acute systemic administration of H3R agonist (R)-α-methylhistamine (RAMH, 100 mg/kg, i.g.) significantly reduced the severity of ulcer index, increased gastric acid output, and increased mucosal PGE2 production without any alteration of somatostatin concentration in gastric juice. However, only acute systemic administration of the H2R agonist dimaprit (DIM, 10 mg/kg, p.o.) significantly decreased the level of somatostatin measured in gastric juice. Moreover, acute systemic administration of M39 (0.3 mg/kg, i.g.) abrogated the RAMH-induced increase of acid output as well as PGE2 production, but not the DIM (10 mg/kg, i.g.)-stimulated acid secretion, indicating that RAMH as well as M39 modulate the gastroprotective effects through interactions with histamine H3Rs. The present findings indicate that agonistic interaction with H3Rs is profoundly involved in the maintenance of gastric mucosal integrity by modulating PGE2 as well as gastric acid secretion, with no apparent role in the regulation of the inhibitory influence of somatostatin.

Peptic Ulcer Disease: A Brief Review of Conventional Therapy and Herbal Treatment Options

Peptic ulcer is a chronic disease affecting up to 10% of the world's population. The formation of peptic ulcers depends on the presence of gastric juice pH and the decrease in mucosal defenses. Non-steroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori (H. pylori) infection are the two major factors disrupting the mucosal resistance to injury. Conventional treatments of peptic ulcers, such as proton pump inhibitors (PPIs) and histamine-2 (H2) receptor antagonists, have demonstrated adverse effects, relapses, and various drug interactions. On the other hand, medicinal plants and their chemical compounds are useful in the prevention and treatment of numerous diseases. Hence, this review presents common medicinal plants that may be used for the treatment or prevention of peptic ulcers.

Gastro-protective, therapeutic and anti-inflammatory activities of Pistacia lentiscus L. fatty oil against ethanol-induced gastric ulcers in rats

Pistacia lentiscus L. (Anacardiaceae) (PL) is a flowering plant that grows in the Mediterranean area. It is traditionally used in the treatment of various skin, respiratory and gastrointestinal disorders AIM OF THE STUDY: In the present study, we investigated the anti-ulcerogenic activity of Pistacia lentiscus fatty oil (PLFO) on ethanol-induced gastric ulcers in Wistar rats MATERIAL AND METHODS: PLFO was orally administered to two experimental groups of rats before or after ethanol induction of gastric ulcer. The lesions of the gastric mucosa were evaluated by macroscopic and histopathological examination. In addition, the amount of nitric oxide (NO) and pro-inflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)] in the supernatant from cultures of gastric mucosa explants were assessed. Finally, the mucus production and iNOS (inducible NO synthase) expression were determined by histochemical and immunohistochemical analysis, respectively RESULT: Our results indicated that the PLFO pretreatment or PLFO treatment significantly reduced ulcerated and hemorrhagic areas. Additionally, pretreatment or treatment with PLFO after ethanol-induced ulceration significantly reduced the plasma concentration of NO. Furthermore, a significant decrease of NO, IL-6 and TNF-α levels was observed in explant culture supernatants. iNOS expression was also reduced in the gastric mucosa. In contrast, mucus production by goblet cells was enhanced. Interestingly, histological analysis of the gastric mucosa has indicated that PLFO- pretreated and treated groups displayed normal histology CONCLUSION: Our results demonstrate that PLFO display significant prophylactic and therapeutic effects against gastric ulcers. Importantly, the mechanism underlying PLFO activities might implicate inhibition of inflammatory responses during gastric ulcer.

Gastroprotective and Antiulcer Effects of Celastrus paniculatus Seed Oil Against Several Gastric Ulcer Models in Rats

Peptic ulcer is a recurrent chronic illness and has become almost a hallmark of the so-called civilized life. In folk medicine, the Celastrus paniculatus plant has been used for the prevention and treatment of various diseases and gastrointestinal disturbances, including dyspepsia and stomach ulcers. The aim of this study is to evaluate the gastroprotective and antiulcer effects of Celastrus paniculatus seed oil (CPO) against several gastric ulcer models in rats. The gastroprotective and antiulcer effects of CPO were evaluated using pylorus-ligated ulcer ethanol- and indomethacin-induced ulcers using rantidine (40 mg/kg per os [PO]) as standard. Gastrointestinal motility was determined by gastric emptying time and gastrointestinal transit ratio. The results of the pharmacological studies of CPO (200 mg/kg, 400 mg/kg) demonstrated effective gastroprotection against ethanol- and indomethacin-induced ulcer models. In pylorus-ligated rats, the seed oil showed gastroprotective activity by decreasing total gastric juice volume and gastric acidity while increasing the gastric pH. The gastroprotection against ethanol and indomethacin is partially attributed to effective inhibition of proinflammatory cytokines, TNF-α and IL-6, and increase in the levels of IL-10. Treatment with CPO in ethanol-induced ulcer rats significantly (p < .05) decreased MDA (malondialdehyde) levels, which were accompanied by an increase in the activities of SOD (superoxide dismutase) and catalase. CPO reduced the rate of gastric emptying but had no effect on gastrointestinal transit. The present findings indicate that CPO has potent gastroprotective effects and support the folkloric usage of the seed oil to treat various gastrointestinal disturbances.

Clerodane diterpenes from Polyalthia longifolia (Sonn) Thw. var. pendula: Potential antimalarial agents for drug resistant Plasmodium falciparum infection

BACKGROUND

Plasmodium falciparum drug resistance is a major public health challenge in sub-Sahara Africa. Many people are now resorting to the use of herbs in managing malaria due to the increasing treatment failures with the conventional drugs. In this study the ethanolic extract of Polyalthia longifolia (Sonn) Thw. var. pendula, a variety fondly used in folklore medicine in Ghana was investigated for potential antimalarial drug development.

METHOD

The ethanolic extract of P. longifolia (Sonn) Thw. var. pendula stem bark was screened against the multidrug resistant, K1 strain of P. falciparum by the parasite lactate dehydrogenase (pLDH) assay and a good antiplasmodial activity (IC50 22.04± 4.23µg/ml) was observed which led to further chromatographic analysis in search for actives.

RESULTS

Bioassay guided fractionation of the extract yielded; three clerodane diterpenes [16-hydroxycleroda-3,13-dien-16,15-olide (1), 16-oxocleroda-3,13E-dien-15-oic acid (2) and 3,16-dihydroxycleroda-4(18),13(14)Z-dien-15,16-olide (3)], a steroid [beta-stigmasterol (4)] and two alkaloids [darienine (5) and stepholidine (6)]. While compounds 4, 5 and 6 exhibited weak antiplasmodial activity (IC50 22-105µg/ml), the clerodane diterpenes exhibited significantly potent (p<0.005) blood schizonticidal activity (IC50: 3-6µg/ml). This is the first report of the antiplasmodial activity of compounds 2 and 3. In combination assay with chloroquine, compounds 1, 2, 3 and 5 antagonized the antiplasmodial activity of chloroquine while 4 and 6 demonstrated a synergistic action.

CONCLUSION

The potent antiplasmodial activity of the extract of P. longifolia (Sonn) Thw. var. pendula and compounds therein strongly suggests its usefulness as an antimalarial agent and supports its inclusion or exploitation in formulations of herbal remedies for malaria in Ghana.

Anticancer effect of the extracts from Polyalthia evecta against human hepatoma cell line (HepG2)

OBJECTIVE

To investigate the anticancer activity of Polyalthia evecta (P. evecta) (Pierre) Finet & Gagnep against human hepatoma cell line (HepG2).

METHODS

The anticancer activity was based on (a) the cytotoxicity against human hepatoma cells (HepG2) assessed using a neutral red assay and (b) apoptosis induction determined by evaluation of nuclei morphological changes after DAPI staining. Preliminary phytochemical analysis of the crude extract was assessed by HPLC analysis.

RESULTS

The 50% ethanol-water crude leaf extract of P. evecta (EW-L) showed greater potential anticancer activity with high cytotoxicity [IC50 = (62.8 ± 7.3)µg/mL] and higher selectivity in HepG2 cells than normal Vero cells [selective index (SI) = 7.9]. The SI of EW-L was higher than the positive control, melphalan (SI = 1.6) and the apoptotic cells (46.4 ± 2.6) % induced by EW-L was higher than the melphalan (41.6 ± 2.1)% (P<0.05). The HPLC chromatogram of the EW-L revealed the presence of various kinds of polyphenolics and flavonoids in it.

CONCLUSIONS

P. evecta is a potential plant with anticancer activity. The isolation of pure compounds and determination of the bioactivity of individual compounds will be further performed.

Gastroprotective activity of Annona muricata leaves against ethanol-induced gastric injury in rats via Hsp70/Bax involvement

The popular fruit tree of Annona muricata L. (Annonaceae), known as soursop and graviola, is a widely distributed plant in Central and South America and tropical countries. Leaves of A. muricata have been reported to possess antioxidant and anti-inflammatory activities. In this study, the gastroprotective effects of ethyl acetate extract of A. muricata leaves (EEAM) were investigated against ethanol-induced gastric injury models in rats. The acute toxicity test of EEAM in rats, carried out in two doses of 1 g/kg and 2 g/kg, showed the safety of this plant, even at the highest dose of 2 g/kg. The antiulcer study in rats (five groups, n=6) was performed with two doses of EEAM (200 mg/kg and 400 mg/kg) and with omeprazole (20 mg/kg), as a standard antiulcer drug. Gross and histological features showed the antiulcerogenic characterizations of EEAM. There was significant suppression on the ulcer lesion index of rats pretreated with EEAM, which was comparable to the omeprazole effect in the omeprazole control group. Oral administration of EEAM to rats caused a significant increase in the level of nitric oxide and antioxidant activities, including catalase, glutathione, and superoxide dismutase associated with attenuation in gastric acidity, and compensatory effect on the loss of gastric wall mucus. In addition, pretreatment of rats with EEAM caused significant reduction in the level of malondialdehyde, as a marker for oxidative stress, associated with an increase in prostaglandin E2 activity. Immunohistochemical staining also demonstrated that EEAM induced the downregulation of Bax and upregulation of Hsp70 proteins after pretreatment. Collectively, the present results suggest that EEAM has a promising antiulcer potential, which could be attributed to its suppressive effect against oxidative damage and preservative effect toward gastric wall mucus.

Gastroprotective and anti-Helicobacter pylori potential of herbal formula HZJW: safety and efficacy assessment

Background

A traditional Chinese Medicine (TCM) formula, HZJW, has been applied in clinics in China for gastrointestinal disorders. However, the therapeutic mechanism underlying its efficacy and safety remained to be defined. The present investigation was undertaken to evaluate the formula HZJW for its gastroprotective potential, possible effect on Helicobacter pylori along with safety to justify its anti-ulcer action and safe clinical application.

Methods

The gastroduodenal cytoprotective potential was evaluated in rodent experimental models (HCl/Ethanol and NSAID-induced ulcer protocols). The anti-H. pylori property was assessed by agar dilution assay in vitro and analysis in vivo including rapid urease test, immunogold test and histopathology. For toxicity assessment, acute toxicity study was performed according to fixed dose procedure with a single oral administration of HZJW to mice. In the oral chronic toxicity, rats (80 males, 80 females) were administrated HZJW orally in 0, 1000, 2500, or 5000 mg/kg/day doses for 26 weeks (n = 40/group of each sex). Clinical signs, mortality, body weights, feed consumption, ophthalmology, hematology, serum biochemistry, gross findings, organ weights and histopathology were examined at the end of the 13- and 26-week dosing period, as well as after the 4-week recovery period.

Results

In the HCl/Ethanol-induced ulcer model, it was observed that oral administration with HZJW (260, 520 and 1040 mg/kg) and ranitidine (250 mg/kg) significantly reduced the ulcerative lesion index (116.70 ± 36.4, 102.20 ± 18.20, 84.10 ± 12.1 and 73.70 ± 16.70) in a dose-dependent manner, respectively, with respect to control group (134.10 ± 31.69). Significant inhibition was also observed in ulcerative index from aspirin-induced ulcer model, with decreases of 35.40 ± 5.93, 31.30 ± 8.08, 26.80 ± 8.27and 20.40 ± 6.93 for the groups treated with HZJW and ranitidine, in parallel to controls (41.60 ± 10.80). On the other hand, treatment with HZJW efficaciously eradicated H. pylori in infected mice in rapid urease test (RUT) and immunogold antibody assay, as further confirmed by reduction of H. pylori presence in histopathological analysis. In the in vitro assay, MICs for HZJW and amoxicillin (positive control) were 125 and 0.12 μg/mL respectively. The LD₅₀ of HZJW was over 18.0 g/kg for mice. No drug-induced abnormalities were found as clinical signs, body weight, food consumption, hematology, blood biochemistry, ophthalmology and histopathology results across three doses. No target organ was identified. The No Observed Adverse Effect Level (NOAEL) of HZJW was determined to be 5,000 mg/kg/day for both sexes, a dose that was equivalent to 50 times of human dose.

Conclusions

These results suggested the efficacy and safety of HZJW in healing peptic ulcer and combating H. pylori, which corroborated their conventional indications and contributed to their antiulcer pharmacological validation, lending more credence to its clinical application for the traditional treatment of stomach complaints symptomatic of peptic ulcer disease (PUD). HZJW might have the potential for further development as a safe and effective alternative/complementary to conventional medication in treating gastrointestinal (GI) disorders.