MATERIALS AND METHODS: Five groups of rats (n=6) were administered orally once daily for 7 days with 8% Tween 80 (negative control), 100 mg/kg ranitidine (positive control), or MEMC (100, 250 or 500 mg/kg), followed by the ulcer induction via ligation of the pyloric part of the rat's stomach. This was followed by the macroscopic analysis of the stomach, evaluation of gastric content parameters, and quantification of mucus content. The antioxidant (measured using the superoxide anion and 2,2-diphenyl-1-picrylhydrazyl (DPPH)-radical scavenging, oxygen radical absorbance capacity (ORAC) and total phenolic content (TPC) assays), anti-inflammatory (evaluated using the in vitro lipoxygenase and xanthine oxidase assays), phytoconstituents and HPLC analysis of MEMC were also carried out.
RESULTS: The MEMC significantly (p<0.05) reduced gastric lesion in this model. Furthermore, the extract also significantly (p<0.01) reduced the volume of gastric content whereas the total acidity was significantly (p<0.05) reduced in the doses of 100 and 500 mg/kg MEMC. Moreover, the mucus content increased significantly (p<0.01) in MEMC-treated rats. The extract also showed high antioxidant and anti-inflammatory activities in all assays tested, and demonstrated the presence of high tannins and saponins followed by flavonoids.
CONCLUSION: The MEMC exerted gastroprotective effect via several mechanisms including the anti-secretory, antioxidant and anti-inflammatory activities. These activities could be attributed to the presence of tannins, saponins and flavonoids (e.g. rutin, quercitrin, fisetin and dihydroquercetin).
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.
METHODS: Core flow rate, chitosan coating, and flaxseed mucilage concentration were optimised for the microencapsulation of L. rhamnosus. The microbeads were characterised and evaluated on microencapsulation efficiency and cell released after 6 h of sequential digestion.
RESULTS: The optimised parameters for the L. rhamnosus microencapsulation were 1.0 mL/min core flow rate, 0.4% (w/v) chitosan coating, and 0.4% (w/v) flaxseed mucilage. The L. rhamnosus microbeads with flaxseed mucilage in core and wall materials had a smooth surface with 781.3 µm diameter, the highest microencapsulation efficiency (98.8% w/w), lowest swelling (5196.7% w/w) and erosion ratio (515.5% w/w), and least cell release (<40% w/w) with 9.31 log10 CFU mL-1 after sequential digestion.
CONCLUSIONS: This study showed the protective capacity of flaxseed mucilage towards the L. rhamnosus GG during microencapsulation and gastrointestinal environment.
METHODS: This study describes the formulation design, optimisation, characterisation and evaluation of insulin concentration via oral delivery in rats. A reversed-phase high-performance liquid chromatography (HPLC) method was developed and validated to quantify insulin concentration in rat plasma. The proposed method produced a linear response over the concentration range of 0.39 to 50 µg/ml.
RESULTS: In vitro release study showed that dissolution of insulin in simulated gastric juice of pH 1.2 was prevented by alginate core and chitosan coating but rapidly released in simulated intestinal fluid (pH 6.8). Additionally, Formulation 3 (F3) has a particle size of 340.40 ± 2.39 nm with narrow uniformity exhibiting encapsulation efficiency (EE) of 72.78 ± 1.25 % produced highest absorption profile of insulin with a bioavailability of 40.23 ±1.29% and reduced blood glucose after its oral administration in rats.
CONCLUSION: In conclusion, insulin oral delivery system containing alginate and chitosan as a coating material has the ability to protect the insulin from enzymatic degradation thus enhance its absorption in the intestine. However, more work should be done for instance to involve human study to materialise this delivery system for human use.
OBJECTIVE: The present study was aimed to circumvent the pharmaceutical issues related to DsiRNA delivery to colon for the treatment of colorectal cancer.
METHOD: In this study, we have prepared water-soluble chitosan (WSC)-DsiRNA complex nanoparticles (NPs) by a simple complexation method and subsequently coated with pectin to protect DsiRNA from gastric milieu.
RESULTS: The mean particle size and zeta potential of the prepared WSC-DsiRNA complexes were varied from 145 ± 4 nm to 867 ± 81 nm and +38 ± 4 to -6.2 ± 2.7 mV respectively, when the concentrations of WSC (0.1%, 0.2% and 0.3% w/v) and pectin (0.1%, 0.2% and 0.25% w/v) were varied. The electron microscopic analysis revealed that morphology of WSC-DsiRNA complexes was varied from smooth spherical to irregular spherical. Cytotoxicity analysis demonstrated that viability of colorectal adenocarcinoma cell was decreased when the dose of WSC-DsiRNA was increased over the incubation from 24 to 48 h. A significantly low cumulative release of DsiRNA in simulated gastric (<15%) and intestinal fluids (<30%) and a marked increase in its release (>90%) in simulated colonic fluid (SCF) evidenced the feasibility and suitability of WSC-DsiRNA complexes for the colonic delivery.
CONCLUSION: These findings clearly indicated promising potential of WSC-DsiRNA complexes as a carrier to delivery DsiRNA to colon for the treatment of colorectal cancer.
METHODS: Rats were pre-treated orally with 2% Tween 80 (vehicle), 100 mg/kg ranitidine (reference drug) or MMMC (ratios of 1:1, 1:3 and 3:1 (v/v); doses of 15, 150 or 300 mg/kg) and then subjected to the ethanol-induced gastric ulcer or pyloric ligation assays. Stomach of rats from the former assay was collected and subjected to the macroscopic and microscopic observations, and enzymatic and non-enzymatic antioxidant studies while the gastric juice content and tissue from the latter assay were subjected to the antisecretory activity study. The UHPLC analysis of MMMC was also performed.
RESULT: MMMC, in the ratio 1:1, demonstrated the most effective (P gastric content but increased the gastric wall mucus content in the pyloric-ligation test. MMMC also demonstrated remarkable antioxidant activity indicated by the highest total phenolic content (TPC) value and oxygen radical absorbance capacity (ORAC) activity with the recorded IC50 value of approximately 53 μg/mL for the 2,2- diphenyl-1-picrylhydrazyl (DPPH) scavenging activity. MMMC also improved the catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), prostaglandin E2 (PGE2) and malondialdehyde (MDA) activities of the gastric tissue intoxicated by ethanol. UHPLC analysis of MMMC confirmed the presence several flavonoid-based bioactive compounds.
CONCLUSION: MMMC, at the ratio of 1:1 (v/v), exerts gastroprotective activity partly by activating its antisecretory and antioxidant activities, and via modulation of the gastric tissue endogenous antioxidant system.