Effect of fucoidan on aspirin-induced stomach ulceration in rats. Chem Biol Interact. 2010;183:249-254. [PMID: 19788892 DOI: 10.1016/j.cbi.2009.09.015]

Antisecretory, gastroprotective, antioxidant and anti-Helicobcter pylori activity of zerumbone from Zingiber zerumbet (L.) Smith

BACKGROUND

Zingiber zerumbet Smith is a perennial herb, broadly distributed in many tropical areas. In Malaysia, it's locally known among the Malay people as "lempoyang" and its rhizomes, particularly, is widely used in traditional medicine for the treatment of peptic ulcer disease beyond other gastric disorders.

AIM OF THE STUDY

The aim of the current study is to evaluate the gastroprotective effect of zerumbone, the main bioactive compound of Zingiber zerumbet rhizome, against ethanol-induced gastric ulcer model in rats.

MATERIALS AND METHODS

Rats were pre-treated with zerumbone and subsequently exposed to acute gastric ulcer induced by absolute ethanol administration. Following treatment, gastric juice acidity, ulcer index, mucus content, histological analysis (HE and PAS), immunohistochemical localization for HSP-70, prostaglandin E2 synthesis (PGE2), non-protein sulfhydryl gastric content (NP-SH), reduced glutathione level (GSH), and malondialdehyde level (MDA) were evaluated in ethanol-induced ulcer in vivo. Ferric reducing antioxidant power assay (FRAP) and anti-H. pylori activity were investigated in vitro.

RESULTS

The results showed that the intragastric administration of zerumbone protected the gastric mucosa from the aggressive effect of ethanol-induced gastric ulcer, coincided with reduced submucosal edema and leukocyte infiltration. This observed gastroprotective effect of zerumbone was accompanied with a significant (p <0.05) effect of the compound to restore the lowered NP-SH and GSH levels, and to reduce the elevated MDA level into the gastric homogenate. Moreover, the compound induced HSP-70 up-regulation into the gastric tissue. Furthermore, zerumbone significantly (p <0.05) enhanced mucus production, showed intense PAS stain and maintained PG content near to the normal level. The compound exhibited antisecretory activity and an interesting minimum inhibitory concentration (MIC) against H. pylori strain.

CONCLUSION

The results of the present study revealed that zerumbone promotes ulcer protection, which might be attributed to the maintenance of mucus integrity, antioxidant activity, and HSP-70 induction. Zerumbone also exhibited antibacterial action against H. pylori.

Activity of alkaloids on peptic ulcer: what's new?

Peptic ulcer is a common disease characterized by lesions that affect the mucosa of the esophagus, stomach and/or duodenum, and may extend into the muscular layer of the mucosa. Natural products have played an important role in the process of development and discovery of new drugs, due to their wide structural diversity and present, mostly specific and selective biological activities. Among natural products the alkaloids, biologically active secondary metabolites, that can be found in plants, animals or microorganisms stand out. The alkaloids are compounds consisting of a basic nitrogen atom that may or may not be part of a heterocyclic ring. This review will describe 15 alkaloids with antiulcer activity in animal models and in vitro studies.

Sulfated glycans in inflammation

Sulfated glycans such as glycosaminoglycans on proteoglycans are key players in both molecular and cellular events of inflammation. They participate in leukocyte rolling along the endothelial surface of inflamed sites; chemokine regulation and its consequential functions in leukocyte guidance, migration and activation; leukocyte transendothelial migration; and structural assembly of the subendothelial basement membrane responsible to control tissue entry of cells. Due to these and other functions, exogenous sulfated glycans of various structures and origins can be used to interventionally down-regulate inflammation processes. In this review article, discussion is given primarily on the anti-inflammatory functions of mammalian heparins, heparan sulfate, chondroitin sulfate, dermatan sulfate and related compounds as well as the holothurian fucosylated chondroitin sulfate and the brown algal fucoidans. Understanding the underlying mechanisms of action of these sulfated glycans in inflammation, helps research programs involved in developing new carbohydrate-based drugs aimed to combat acute and chronic inflammatory disorders.

Fucoidan supplementation improves exercise performance and exhibits anti-fatigue action in mice

Fucoidan (FCD) is a well-known bioactive constituent of seaweed extract that possess a wide spectrum of activities in biological systems, including anti-cancer, anti-inflammation and modulation of immune systems. However, evidence on the effects of FCD on exercise performance and physical fatigue is limited. Therefore, we investigated the potential beneficial effects of FCD on ergogenic and anti-fatigue functions following physiological challenge. Male ICR mice from three groups (n = 8 per group) were orally administered FCD for 21 days at 0, 310 and 620 mg/kg/day, which were, respectively, designated the vehicle, FCD-1X and FCD-2X groups. The results indicated that the FCD supplementations increased the grip strength (p = 0.0002) and endurance swimming time (p = 0.0195) in a dose-depend manner. FCD treatments also produced dose-dependent decreases in serum levels of lactate (p < 0.0001) and ammonia (p = 0.0025), and also an increase in glucose level (p < 0.0001) after the 15-min swimming test. In addition, FCD supplementation had few subchronic toxic effects. Therefore, we suggest that long-term supplementation with FCD can have a wide spectrum of bioactivities on health promotion, performance improvement and anti-fatigue.

Gastroprotective effect of nymphayol isolated from Nymphaea stellata (Willd.) flowers: contribution of antioxidant, anti-inflammatory and anti-apoptotic activities

Gastric ulcer is an illness that affects a great number of people worldwide. The goal of the present research was to assess the anti-ulcerogenic activity of nymphayol (NYM), isolated from Nymphaea stellata, against an ethanol-induced ulcer model in rats. Administration of ethanol elevates the levels of the ulcer index (UI) along with causing tremendous increases in lipid peroxidation and myeloperoxidase (MPO) and significant decreases in gastric mucus, catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), and prostaglandin E2 (PGE2). However, the NYM- (45 mg/kg) pretreated animals showed considerable increases in antioxidants, gastric mucus, and PGE2 level and significant decreases in UI, lipid peroxidation, and MPO level. Pro-inflammatory cytokines such as interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) were increased and the level of interleukin-10 (IL-10), an anti-inflammatory cytokine, was decreased in ethanol-induced ulcerated animals, and these inequalities were amended by NYM pretreatment. Pro-apoptotic markers including caspase-8, caspase-9, and caspase-3 were decreased and Bcl-2, an anti-apoptotic marker, was increased through NYM pretreatment, as compared with the ethanol-induced ulcer group. Pretreatment with indomethacin, SC560, rofecoxib, and Nω-Nitro-L-arginine methyl ester (L-NAME) considerably prevented the ulcer protective activity of NYM (45 mg/kg), indicating the involvement of cyclooxygenase (COX) and nitric oxide synthase (NOS) in NYM-mediated gastroprotection against ethanol-induced ulcer. These outcomes suggest that the gastroprotective effect of NYM might be mediated by adjustment of inflammatory mediators and apoptotic markers and increasing antioxidants.

Apple polyphenol extracts protect against aspirin-induced gastric mucosal damage in rats

The protective role of two apple polyphenol extracts, Douglas-FB (FB) and Douglas-EF (EF), on gastric mucosal damage following aspirin ingestion was investigated in healthy rats. Polyphenol content of the apple extracts varied, with the EF extract having 20% w/w polyphenols and a high proportion of flavanols as epicatechin and procyanidin, whereas the FB extract comprised 12% w/w polyphenols, which were mostly flavonols as quercetin glycosides. Male Sprague-Dawley rats were allocated to control, FB and EF groups and fed the experimental diet during the 10-day trial. Control treatment rats received 1 mL of deionised water, whereas apple polyphenol treatment group rats, FB and EF received a concentration of 10(-2)  m polyphenols in 1 mL deionised water daily via oral gavage. At the end of 10-day feeding period, rats were fasted overnight, and the following morning, aspirin (200 mg/kg) was given by oral gavage. Four hours after aspirin administration, the animals were euthanised, and samples taken for analysis. Both apple polyphenol extracts significantly reduced the ulcer area, ulcer lesion index and gastric injury score. The glutathione in gastric mucosa was increased significantly in rats given FB apple extract. Despite their different polyphenol compositions, FB and EF apple extracts assisted in protecting the gastric mucosa following acute aspirin administration in rats.

Effect of diallyl disulfide on acute gastric mucosal damage induced by alcohol in rats

This study investigated the gastroprotective effects of diallyl disulfide (DADS), a secondary organosulfur compound derived from garlic (Allium sativum L.) on experimental model of ethanol (EtOH)-induced gastric ulcer in rats. The antiulcerogenic activity of DADS was evaluated by gross/histopathological inspection, pro-inflammatory cytokines, and lipid peroxidation with antioxidant enzyme activities in the stomach. DADS (100 mg/kg) was administered by oral gavage 2 h prior to EtOH treatment (5 ml/kg). The animals were killed 1 h after receiving EtOH treatment. Pretreatment with DADS attenuated EtOH-induced gastric mucosal injury, as evidenced by decreased severity of hemorrhagic lesions and gastric ulcer index upon visual inspection. DADS also prevented histopathological alterations and gastric apoptotic changes caused by EtOH. An increase in tumor necrosis factor-α (TNF-α) and inducible nitric oxide synthase was observed in the gastric tissues of EtOH-treated rats that coincided with increased serum TNF-α and interleukin 6 levels. In contrast, DADS effectively suppressed production of pro-inflammatory mediators induced by EtOH. Furthermore, DADS prevented the formation of gastric malondialdehyde and the depletion of reduced glutathione content and restored antioxidant enzyme activities, such as catalase, glutathione peroxidase, and glutathione reductase in the gastric tissues of EtOH-treated rats. These results indicate that DADS prevents gastric mucosal damage induced by acute EtOH administration in rats and that the protective effects of DADS may be due to its potent antioxidant and anti-inflammatory activities.

Effects of β-glucan pretreatment on acetylsalicylic acid-induced gastric damage: An experimental study in rats

BACKGROUND

NSAIDs have been found to induce gastrointestinal tract damage. Recently, it has been suggested that this might be mediated by lipid peroxidation.

OBJECTIVE

The aim of this study was to assess the potential protective effects of β-glucan against acetylsalicylic acid (ASA-induced gastric damage by means of its antioxidant capacity in an experimental rat model.

METHODS

Thirty-two male Wistar albino rats (200-250 g) were randomized into 4 groups consisting of 8 rats each. The β-glucan group received 50 mg/kg β-glucan once a day for 10 days and 30 minutes before anesthesia. The ASA group received saline once a day for 10 days and 300 mg/kg (20 mg/mL) ASA as a single dose, 4 hours before anesthesia. The ASA+β-glucan group was administered 50 mg/kg β-glucan once a day for 10 days and 30 minutes before anesthesia. Additionally, 300 mg/kg (20 mg/mL) ASA was administered as a single dose, 4 hours before anesthesia. The control group received saline once a day for 10 days and 30 minutes before anesthesia. All medications were administered by intragastric gavage. The stomach from each rat was dissected and divided into 2 parts for histologic and biochemical analysis. Gastric tissue malondialdehyde (MDA), nitric oxide (NO) levels, catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities were determined for oxidative parameter analysis.

RESULTS

The gastroprotective and antioxidant effects of β-glucan appeared to attenuate the ASA-induced gastric tissue damage. Compared with the control group, MDA and NO levels and CAT and GSH-Px activities were significantly increased in the stomachs of ASA-treated rats (MDA, 4.12 [0.44] to 13.41 [1.05] μmol/L; NO, 8.04 [7.25-9.10] vs 30.35 [22.34-37.95] μmol/g protein; CAT, 0.050 [0.004] to 0.083 [0.003] k/g protein; GSH-Px, 0.57 [0.42-0.66] to 1.55 [1.19-1.76] U/L; all, P < 0.001), whereas SOD activity was significantly decreased in the same group (291 [29] to 124 [6] U/mL; P < 0.001). In the ASA+β-glucan group, MDA and NO levels and CAT and GSH-Px activities were found to be significantly lower, while SOD activity was found to be significantly higher, in comparison with the ASA-treated group (all, P < 0.001).

CONCLUSION

β-Glucan appeared to attenuate the gastric damage caused by ASA in these rats.

In vivo anti-ulcer, anti-stress, anti-allergic, and functional properties of gymnemic acid isolated from Gymnema sylvestre R Br

BACKGROUND

Gymnema sylvestre is a highly valued ethno pharmacologically important medicinal plant used currently in many poly-herbal formulations due to its potential antidiabetic activity and other health benefits. The present study was carried out to analyze the anti-stress, anti-allergic, and antiulcer activity of the bioactive compounds present in Gymnema sylvestre leaves.

METHODS

The preliminary phytochemical screening for bioactive compounds from aqueous extracts revealed the presence of alkaloids, triterpenes, flavonoids, steroids, and saponins. The antioxidant activities were investigated using DPPH radical scavenging method. The characterization of the extract was carried out using standard compound by High Performance Thin Layer Chromatography (HPTLC) and phytochemical analysis in terms of total phenol, total flavonoids, reducing power and antioxidant potentials, etc. The in vivo studies on albino mice proved the purified fraction has anti-stress/anti-allergic activity against milk induced leucocytosis/eosinophilia and able to inhibit the aspirin induced gastric ulcers.

RESULTS

The quantitative estimation for aqueous extract exhibited total antioxidant (9.13 ± 0.04 μg/g), flavonoids (125.62 ± 26.84 μg/g), tannin (111.53 ± 15.13 μg/g), total phenol content (285.23 ± 1.11 μg/g) and free radical scavenging (52.14 ± 0.32%). Further the aqueous extract was consecutively purified by TLC and silica column chromatography. The purified fractions were characterized by HPTLC and GC-MS and the component was identified as gymnemic acid. The potency of the antimicrobial activity of the extract was studied with bacteria. Pharmacological experiments clearly demonstrated that the extracts of all plants given orally showed significant gastric protection against the asprin-induced gastric ulcer model in mice. Furthermore, healing effects were also confirmed through histopathological examination.

CONCLUSIONS

The aqueous extracts of the leaves of Gymnema sylvestre possess anti ulcerogenic, Anti allergic, Anti stress, properties that may be due to cytoprotective mechanism. These results support the ethno medical uses of the plant in the treatment of gastric ulcer.

Protective role of hydrogen-rich water on aspirin-induced gastric mucosal damage in rats

AIM: To investigate the role of the hydrogen-rich water (HRW) in the prevention of aspirin-induced gastric mucosal injury in rats.

METHODS: Forty male rats were allocated into four groups: normal control group, HRW group, aspirin group, and HRW plus aspirin group. The protective efficacy was tested by determining the gastric mucosal damage score. Malondialdehyde (MDA), superoxide dismutase (SOD), myeloperoxidase (MPO), interleukin (IL)-06 and tumor necrosis factor (TNF)-α in gastric tissues were evaluated. The serum levels of IL-1β and TNF-α were also detected. Histopathology of gastric tissues and localization of Cyclooxygenase 2 (COX-2) were detected using hematoxylin and eosin staining and immunohistochemistry, respectively.

RESULTS: Pretreatment with HRW obviously reduced aspirin-induced gastric damage scores (4.04 ± 0.492 vs 2.10 ± 0.437, P < 0.05). The oxidative stress levels of MDA and MPO in the gastric tissues increased significantly in the aspirin-treated group compared with the HRW group (2.43 ± 0.145 vs 1.79 ± 0.116 nmol/mg prot, P < 0.05 and 2.53 ± 0.238 vs 1.40 ± 0.208 U/g tissue, P < 0.05, respectively). HRW could obviously elevated the SOD levels in the gastric tissues (37.94 ± 8.44 vs 59.55 ± 9.02 nmol/mg prot, P < 0.05). Pretreatment with HRW significantly reduced IL-06 and TNF-α in the gastric tissues (46.65 ± 5.50 vs 32.15 ± 4.83 pg/mg, P < 0.05 and 1305.08 ± 101.23 vs 855.96 ± 93.22 pg/mg, P < 0.05), and IL-1β and TNF-α in the serum (505.38 ± 32.97 vs 343.37 ± 25.09 pg/mL, P < 0.05 and 264.53 ± 28.63 vs 114.96 ± 21.79 pg/mL, P < 0.05) compared to treatment with aspirin alone. HRW could significantly decrease the COX-2 expression in the gastric tissues (staining score: 8.4 ± 2.1 vs 2.9 ± 1.5, P < 0.05).

CONCLUSION: HRW pretreatment alleviated the aspirin-induced gastric lesions by inhibiting the oxidative stress, inflammatory reaction and reducing the COX-2 in the gastric tissues.

Fucoidan as a marine anticancer agent in preclinical development

Fucoidan is a fucose-containing sulfated polysaccharide derived from brown seaweeds, crude extracts of which are commercially available as nutritional supplements. Recent studies have demonstrated antiproliferative, antiangiogenic, and anticancer properties of fucoidan in vitro. Accordingly, the anticancer effects of fucoidan have been shown to vary depending on its structure, while it can target multiple receptors or signaling molecules in various cell types, including tumor cells and immune cells. Low toxicity and the in vitro effects of fucoidan mentioned above make it a suitable agent for cancer prevention or treatment. However, preclinical development of natural marine products requires in vivo examination of purified compounds in animal tumor models. This review discusses the effects of systemic and local administration of fucoidan on tumor growth, angiogenesis, and immune reaction and whether in vivo and in vitro results are likely applicable to the development of fucoidan as a marine anticancer drug.

Protective effect of chelerythrine against ethanol-induced gastric ulcer in mice

The quaternary benzo[c]phenanthridine alkaloid, chelerythrine (CHE), is of great practical and research interest because of its pronounced, widespread physiological effects, primarily antimicrobial and anti-inflammatory, arising from its ability to interact with proteins and DNA. Although CHE was originally shown to possess anti-inflammatory properties, its effects on acute gastric ulcer have not been previously explored. The aim of the present study is to evaluate the protective effect of CHE on ethanol induced gastric ulcer in mice. Administration of CHE at doses of 1, 5 and 10mg/kg bodyweight prior to ethanol ingestion dose-dependently inhibited gastric ulcer. The gastric mucosal lesion was assessed by ulcer area, gastric juice acidity, myeloperoxidase (MPO) activities, macroscopic and histopathological examinations. CHE significantly reduced the gastric ulcer index, myeloperoxidase activities, macroscopic and histological score in a dose-dependent manner. In addition, CHE also significantly inhibited nitric oxide (NO) concentration, pro-inflammatory interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) level in serum and gastric mucosal in the mice exposed to ethanol induced ulceration in a dose-dependent manner. In addition, immunohistochemical analysis revealed that CHE markedly attenuated the overexpression of nuclear factor-κB in gastric mucosa of mice. It was concluded that CHE represents a potential therapeutic option to reduce the risk of gastric ulceration. In addition, acute toxicity study revealed no abnormal sign to the mice treated with CHE (15mg/kg). These findings suggest that the gastroprotective activity of CHE might contribute in adjusting the inflammatory cytokine by regulating the NF-κB signalling pathway.

Fucoidan enhances intestinal barrier function by upregulating the expression of claudin-1

AIM: To evaluate the protective effects of fucoidan on oxidative stress-induced barrier disruption in human intestinal epithelial cells.

METHODS: In Caco-2 cell monolayer models, the disruption of barrier function by oxidative stress is mediated by H₂O_2. The integrity of polarized Caco-2 cell monolayers was determined by measuring the transepithelial resistance (TER) and permeability was estimated by measuring the paracellular transport of FITC-labeled 4-kDa dextran (FD4). The protective effects of fucoidan on epithelial barrier functions on polarized Caco-2 cell monolayers were evaluated by TER and FD4 flux. The expression of tight junction (TJ) proteins was assessed using reverse-transcription polymerase chain reaction (RT-PCR) and immunofluorescence staining.

RESULTS: Without H₂O₂ treatment, fucoidan significantly increased the TER compared to control (P < 0.05), indicating a direct enhancement of intestinal epithelial barrier function. Next, H₂O₂ disrupted the epithelial barrier function in a time-dependent manner. Fucoidan prevented the H₂O₂-induced destruction in a dose-dependent manner. Fucoidan significantly decreased H₂O₂-induced FD4 flux (P < 0.01), indicating the prevention of disruption in paracellular permeability. RT-PCR showed that Caco-2 cells endogenously expressed claudin-1 and -2, and occludin and that H₂O₂ reduced the mRNA expression of these TJ proteins. Treatment with fucoidan attenuated the reduction in the expressions of claudin-1 and claudin-2 but not occludin. Immunofluorescence staining revealed that the expression of claudin-1 was intact and high on the cell surface. H₂O₂ disrupted the integrity of claudin-1. Treatment with fucoidan dramatically attenuated the expression of claudin-1.

CONCLUSION: Fucoidan enhanced intestinal epithelial barrier function by upregulating the expression of claudin-1. Thus, fucoidan may be an appropriate therapy for the treatment of inflammatory bowel diseases.

Fucoidan from seaweed Fucus vesiculosus inhibits migration and invasion of human lung cancer cell via PI3K-Akt-mTOR pathways

BACKGROUND

Recently there has been an increased interest in the pharmacologically active natural products associated with remedies of various kinds of diseases, including cancer. Fucoidan is a polysaccharide derived from brown seaweeds and has long been used as an ingredient in some dietary supplement products. Although fucoidan has been known to have anti-cancer activity, the anti-metastatic effects and its detailed mechanism of actions have been poorly understood. Therefore, the aims of this study were to demonstrate the anti-metastatic functions of fucoidan and its mechanism of action using A549, a highly metastatic human lung cancer cell line.

METHODS AND PRINCIPAL FINDINGS

Fucoidan inhibits the growth of A549 cells at the concentration of 400 µg/ml. Fucoidan treatment of non-toxic dose (0-200 µg/ml) exhibits a concentration-dependent inhibitory effect on the invasion and migration of the cancer cell via decreasing its MMP-2 activity. To know the mechanism of these inhibitory effects, Western blotting was performed. Fucoidan treatment down-regulates extracellular signal-related kinase 1 and 2 (ERK1/2) and phosphoinositide 3-kinase (PI3K)-Akt-mammalian target of rapamycin (PI3K-Akt-mTOR) pathways. Furthermore, fucoidan decreases the cytosolic and nuclear levels of Nuclear Factor-kappa B (p65).

CONCLUSIONS/SIGNIFICANCE

The present study suggests that fucoidan exhibits anti-metastatic effect on A549 lung cancer cells via the down-regulation of ERK1/2 and Akt-mTOR as well as NF-kB signaling pathways. Hence, fucoidan can be considered as a potential therapeutic reagent against the metastasis of invasive human lung cancer cells.

Protective effects of Ankaferd blood stopper on aspirin-induced oxidative mucosal damage in a rat model of gastric injury

The exposure of gastric mucosa to damaging factors, such as ethanol and some therapeutic drugs, produces pathological changes: inflammatory process, hemorrhagic erosions and even acute ulcers. Ankaferd blood stopper (ABS) comprises a standardized mixture of five different plant extracts. The purpose of our present investigations is to explain the participation of reactive oxygen species in acute gastric mucosal damage by acetylsalicylic acid (ASA) and the effects of new hemostatic agent ABS. Experiments were carried out on 23 male Wistar rats. To assess gastric mucosal damage, biochemical and histopathological data were used. The colorimetric assays were used to determine the malondialdehyde (MDA) and superoxide dismutase (SOD) activity. The level of myeloperoxidase (MPO) activity, the level of nitric oxide (NO) and the proinflammatory cytokine tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay technique. We demonstrated that the biological effects of ROS were estimated by measuring the tissue and plasma levels of MDA, the products of lipid peroxidation, as well as the activity of SOD and the scavenger of ROS produced by ASA in the experiment group. Moreover, it was found that MPO activity as well as NO and TNF-α levels also demonstrated significant improvement by ABS treatment. The pathogenesis of experimental ASA-induced mucosal damage in rat stomach includes the generation of ROS that seems to play an important role, due to the generation of lipid peroxides, accompanied by the impairment of antioxidative enzyme activity of cells. ABS appeared to attenuate the oxidative and inflammatory changes caused by ASA-induced gastric mucosal damage in rats.

Evaluation of antiulcer activity of indole-3-carbinol and/or omeprazole on aspirin-induced gastric ulcer in rats

The present work is an attempt to elucidate the antiulcer activity of indole-3-carbinol (I3C), which is one of the anticarcinogenic phytochemicals found in the vegetables of Cruciferae family such as broccoli and cauliflower, alone or in combination with omeprazole (OMP), a proton pump inhibitor, to diminish the effects of induced acute gastric ulcer by aspirin (ASA) in male albino rats. A total of 48 adult male albino rats were used in the present study. Animals were divided into eight experimental groups (six animals each group). They were given different experimental inductions of ASA at a dose of 500 mg/kg/body weight, OMP at a dose of 20 mg/kg/body weight and I3C at a dose of 20 mg/kg/body weight either alone or in combination with each other orally for a duration of 7 days. Inner stomach features, ulcer index, pH activity, body weight, stomach weight, hematological investigations, serum total protein albumin and reduced glutathione activity  were investigated in addition to the histological, histochemical and immunohistochemical stain of cyclooxygenase-2 to the stomach tissue of normal control, ulcerated and treated ulcerated rats. The results of this study revealed that oral administration of ASA to rats produced the expected characteristic mucosal lesions. OMP accelerated ulcer healing but the administration of I3C either alone or in combination with OMP to ASA-ulcerated rats produced a profound protection to the gastric mucosa from injury induced by ASA. Our results suggested that administration of antiulcer natural substances such as I3C in combination with the perused treatment such as OMP is a very important initiative in the development of new strategies in ulcer healing.

Gastroprotective activities of Turnera diffusa Willd. ex Schult. revisited: Role of arbutin

ETHNOPHARMACOLOGICAL RELEVANCE

Turnera diffusa Willd. ex Schult. has been used for the treatment of several human disorders including peptic ulcer.

OBJECTIVES OF THE STUDY

The current study is an attempt to evaluate the anti-ulcerogenic activities of arbutin, a major constituent of Turnera diffusa on two ulcer models. The possible involvement of lipid peroxidation, nitric oxide, IL-6, IL-10, TNF-α and mucus barrier mechanism has been investigated.

MATERIALS AND METHODS

Effects of arbutin on ulcer index, gastric juice acidity, mucus content and histochemistry, gross and histological gastric lesions, nitric oxide, cytokines levels (IL-6, IL-10 and TNF-α), and thiobarbituric acid reactive substances (TBARS), were evaluated in aspirin or ethanol-induced ulcer in vivo. Acute toxicity of arbutin was also examined in rodent model. MTT assay was used to assess the cytotoxicity of the compound on normal liver cells (WRL-68).

RESULTS

Pre-treatment with arbutin or omeprazole protected the gastric mucosa as seen by reduction in ulcer area and mucosal content, reduced or absence of edema, inflammation and leucocytes infiltration on both models. Arbutin significantly (P<0.05) lowered the elevated TBARS level into gasteric homogenate. Arbutin did not produce significant inhibition of NO. This natural compound has modulated the levels of interleukin-6, interleukin-10 and TNF-α. No in vitro or in vivo toxicities for arbutin were observed.

CONCLUSION

Thus it can be concluded that Turnera diffusa possesses anti-ulcer activity, which could be attributed to lipid peroxidation inhibitory, immuno modulatory and anti-oxidant mechanisms of arbutin but not to the intervention with nitric oxide inflammation pathway.

Gastroprotective activity and mechanism of novel dichlorido-zinc(II)-4-(2-(5-methoxybenzylideneamino)ethyl)piperazin-1-iumphenolate complex on ethanol-induced gastric ulceration

Zinc complexes were reported to have anti-ulcer activity and used as drug for the treatment of gastrointestinal disorders. A novel compound dichlorido-zinc(II)-4-(2-(5-methoxybenzylidene amino)ethyl)piperazin-1-iumphenolate (ZnHMS) was synthesized, characterized and evaluated for its gastroprotective activity against ethanol-induced ulcer in rats. Gross and microscopic lesions, histochemical staining of glycogen storage, biochemical and immunological parameters were taken into consideration. Oral administration of ZnHMS (30 and 60 mg/kg; 14 days) dose-dependently inhibited gastric lesions. It significantly increased the mucus content and total acidity compared to the control group (P<0.01). Serum levels of aspartate (AST), alanine (ALT) transaminases, pro-inflammatory interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and anti-inflammatory interleukin-10 (IL-10) in the rats exposed to ethanol induced ulceration have been altered. ZnHMS considerably enhances (P<0.05) the protection of gastric epithelia by modulating the acute alterations of AST, ALT, IL-6, IL-10, TNF-α and stomach glycogen. Interestingly, ZnHMS did interfere with the natural release of nitric oxide. In addition, acute toxicity study revealed no abnormal sign to the rats treated with ZnHMS (2000 mg/kg). These findings suggest that the gastroprotective activity of ZnHMS might contribute in adjusting the inflammatory cytokine-mediated oxidative damage to the gastric mucosa.

Therapies from fucoidan; multifunctional marine polymers

Published research on fucoidans increased three fold between 2000 and 2010. These algal derived marine carbohydrate polymers present numerous valuable bioactivities. This review discusses the role for fucoidan in the control of acute and chronic inflammation via selectin blockade, enzyme inhibition and inhibiting the complement cascade. The recent data on toxicology and uptake of fucoidan is detailed together with a discussion on the comparative activities of fractions of fucoidan from different sources. Recent in vivo, in vitro and clinical research related to diverse clinical needs is discussed. Targets include osteoarthritis, kidney and liver disease, neglected infectious diseases, hemopoietic stem cell modulation, protection from radiation damage and treatments for snake envenomation. In recent years, the production of well characterized reproducible fucoidan fractions on a commercial scale has become possible making therapies from fucoidan a realizable goal.

Heterofucan from Sargassum filipendula induces apoptosis in HeLa cells

Fucan is a term used to denominate a family of sulfated polysaccharides rich in sulfated l-fucose. Heterofucan SF-1.5v was extracted from the brown seaweed Sargassum filipendula by proteolytic digestion followed by sequential acetone precipitation. This fucan showed antiproliferative activity on Hela cells and induced apoptosis. However, SF-1.5v was not able to activate caspases. Moreover, SF-1.5v induced glycogen synthase kinase (GSK) activation, but this protein is not involved in the heterofucan SF-1.5v induced apoptosis mechanism. In addition, ERK, p38, p53, pAKT and NFκB were not affected by the presence of SF-1.5v. We determined that SF-1.5v induces apoptosis in HeLa mainly by mitochondrial release of apoptosis-inducing factor (AIF) into cytosol. In addition, SF-1.5v decreases the expression of anti-apoptotic protein Bcl-2 and increased expression of apoptogenic protein Bax. These results are significant in that they provide a mechanistic framework for further exploring the use of SF-1.5v as a novel chemotherapeutics against human cervical cancer.

Fucoidan reduces the toxicities of chemotherapy for patients with unresectable advanced or recurrent colorectal cancer

Combination chemotherapy with oxaliplatin plus 5-fluorouracil/leucovorin (FOLFOX) or irinotecan plus 5-fluorouracil/leucovorin (FOLFIRI) has become a standard regimen for advanced or recurrent colorectal cancer. Numerous studies have reported that long-term use of FOLFOX or FOLFIRI leads to better survival for these patients. Thus, control of the toxicity of these drugs may be crucial to prolonging survival. Fucoidan is one of the major sulfated polysaccharides of brown seaweeds and exhibits a wide range of biological activities. In the present study, we analyzed the effect of fucoidan on suppressing the toxicity of anti-cancer drugs. A total of 20 patients with unresectable advanced or recurrent colorectal cancer scheduled to undergo treatment with FOLFOX or FOLFIRI were randomly allocated into a fucoidan treatment group (n=10) and a control group without fucoidan treatment (n=10). Results showed that fucoidan regulated the occurrence of fatigue during chemotherapy. Chemotherapy with fucoidan was continued for a longer period than chemotherapy without fucoidan. Additionally, the survival of patients with fucoidan treatment was longer than that of patients without fucoidan, although the difference was not significant. Thus, fucoidan may enable the continuous administration of chemotherapeutic drugs for patients with unresectable advanced or recurrent colorectal cancer, and as a result, the prognosis of such patients is prolonged.

Immunomodulatory activity of fucoidan against aspirin-induced gastric mucosal damage in rats

Gastric ulcers and related complications associated with the use of non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin, represent a major global health problem. In the present study, we investigate the immunological activity of fucoidan against aspirin-induced gastric mucosal damage in rats. Thirty-six rats were randomly divided into the following, normal (Carboxy methyl cellulose 0.05 %), aspirin (Asp-400mg/kg) treated, fucoidan alone (Fu-0.02 g/kg, daily for 14 days) and Fu+Asp. Cytokines, total nitrite and nitrate (NOx) analysis and tissue localization of Cyclooxygenase 1, 2 and epidermal growth factor receptor (EGFR) were done using Elisa and immunohistochemistry respectively. Histopathology of gastric tissue, collagen deposition was performed using Hematoxylin and Eosin and Masson's trichrome were performed. Treatment of rats with a single dose of aspirin (400mg/kg, orally) led to significant alterations in the levels of total nitrite and nitrate (NOx), interleukins (IL-4, 6, 10, 12), tumor necrosis factor (TNF-α), and interferon gamma (IFN-γ). Notably, collagen deposition in glandular tissue and localization of cyclooxygenase 1, 2, and epidermal growth factor were considerably affected in aspirin-treated rats. These severities were prevented to a significant extent in rats pretreated with fucoidan (0.02 g/kg/day for two weeks orally). Our findings collectively indicate that the gastro-protective effect of fucoidan against aspirin-induced ulceration in rats is mediated through its immunomodulatory properties.