A DNA-inspired injectable adhesive hydrogel with dual nitric oxide donors to promote angiogenesis for enhanced wound healing.

Chronic diabetic wounds are a severe complication of diabetes, often leading to high treatment costs and high amputation rates. Numerous studies have revealed that nitric oxide (NO) therapy is a promising option because it favours wound revascularization. Here, base-paired injectable adhesive hydrogels (CAT) were prepared using adenine- and thymine-modified chitosan (CSA and CST). By further introducing S-nitrosoglutathione (GSNO) and binary l-arginine (bArg), we obtained a NO sustained-release hydrogel (CAT/bArg/GSON) that was more suitable for the treatment of chronic wounds. The results showed that the expression of HIF-1α and VEGF was upregulated in the CAT/bArg/GSON group, and improved blood vessel regeneration was observed, indicating an important role of NO. In addition, the research findings revealed that following treatment with the CAT/bArg/GSON hydrogel, the viability of Staphylococcus aureus and Escherichia coli decreased to 14 ± 2 % and 6 ± 1 %, respectively. Moreover, the wound microenvironment was improved, as evidenced by a 60 ± 1 % clearance of DPPH. In particular, histological examination and immunohistochemical staining results showed that wounds treated with CAT/bArg/GSNO exhibited denser neovascularization, faster epithelial tissue regeneration, and thicker collagen deposition. Overall, this study proposes an effective strategy to prepare injectable hydrogel dressings with dual NO donors. The functionality of CAT/bArg/GSON has been thoroughly demonstrated in research on chronic wound vascular regeneration, indicating that CAT/bArg/GSON could be a potential option for promoting chronic wound healing. STATEMENT OF SIGNIFICANCE: This article prepares a chitosan hydrogel utilizing the principle of complementary base pairing, which offers several advantages, including good adhesion, biocompatibility, and flow properties, making it a good material for wound dressings. Loaded GSNO and bArg can steadily release NO and l-arginine through the degradation of the gel. Then, the released l-arginine not only possesses antioxidant properties but can also continue to generate a small amount of NO under the action of NOS. This design achieves a sustained and stable supply of NO at the wound site, maximizing the angiogenesis-promoting and antibacterial effects of NO. More neovascularization and abundant collagen were observed in the regenerated tissues. This study provides an effective repair hydrogel material for diabetic wound.

Cranberry and Sumac Extracts Exhibit Antibacterial and Anti-Adhesive Effects Against Streptococcus pyogenes.

Group A Streptococci (GAS) or Streptococcus pyogenes is responsible for acute bacterial pharyngitis in children as well as adults. Streptococcal pharyngitis is initiated by successful attachment and colonization of the bacteria, followed by the establishment of the biofilm in various environments. In this study, we examined the antibacterial activities of in-house prepared aqueous and ethanolic extracts of 10 Atlantic Canada fruits in the context of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), time-kill kinetics, and adhesion inhibition properties against S. pyogenes. Per our findings, MIC and MBC for all the tested extracts ranged from 0.25 to 8 mg/mL and from 4 to 64 mg/mL, respectively. Accordingly, at 1/2 × MBC, cranberry and sumac extracts also lowered the attachment of GAS to the uncoated and fibronectin-coated substratum. Particularly, cranberry and sumac aqueous extracts were more effective against the adhesion of S. pyogenes ATCC 19615 to the fibronectin-coated surface than a clinical strain. In conclusion, ethanolic and aqueous extracts of cranberry and sumac could potentially be incorporated into natural health products designed for the amelioration of strep throat, yet a detailed understanding of its mode of action (e.g., biofilm inhibition and eradication) could pave its path to the field of antibacterial natural health product discovery, design, and development.

Taxifolin and gastro-adhesive microparticles containing taxifolin promotes gastric healing in vivo, inhibits Helicobacter pylori in vitro and proton pump reversibly in silico.

Taxifolin (3,5,7,3,4-pentahydroxy flavanone or dihydroquercetin, Tax) was identified as a gastroprotective compound and a gastroadhesive formulation was recently developed to prolong its residence time and release in the stomach. So, the gastric healing effectiveness of Tax and gastro-mucoadhesive microparticles containing Tax (MPTax) against the acetic acid induced-gastric ulcer in rats was investigated in this study. Moreover, the interactions between Tax and H+/K+-ATPase were investigated in silico, and its anti- H. pylori activity was determined in vitro. The oral treatment with MPTax (81.37 mg/kg, containing 12.29% of Tax) twice a day for seven days reduced the ulcer area by 63%, compared to vehicle-treated group (Veh: 91.9 ± 10.3 mm2). Tax (10 mg/kg, p.o) reduced the ulcer by 40% but with a p = 0.07 versus Veh group. Histological analysis confirmed these effects. Tax and MPTax increased the gastric mucin amount, reduced the myeloperoxidase activity, and increased the glutathione reduced content at ulcer site. However, only MPTax decreased the lipoperoxide accumulation at ulcer site. Besides, Tax and MPTax normalize the catalase and glutathione S-transferase activity. Tax showed reversible interaction with H+/K+-ATPase in silico and its anti-H. pylori effects was confirmed (MIC = 625 µg/mL). These results suggest that the antiulcer property of Tax involves the strengthening of the gastric protective factors in parallel to its inhibitory interaction with H+/K+-ATPase and H. pylori. Considering that ulcer healing action displayed by Tax was favored by gastroadhesive microparticles, this approach seems to be promising for its oral delivery to treat acid-peptic diseases.

Technological Application of Tannin-Based Extracts.

Tannins are polyphenolic compounds naturally found in vegetables. Their presence in nature has prompted their historical use in many different ways. The revision of their traditional utilization has allowed their further modification aiming for an industrial application. Sometimes these modifications have implied the addition of harmful substances such as formaldehyde, classified as a carcinogen of category B1. In other cases, these natural tannins have been replaced by synthetic compounds that threaten human and animal health and damage the environment. Therefore, currently, both academy and industry are searching for the substitution of these unsafe complexes by the increasing inclusion of tannins, natural molecules that can be obtained from several and diverse renewable resources, modified using harmless additives. To achieve promising results, cost-efficient and eco-friendly extraction methods have been designed. Once these green alternatives have been isolated, they have been successfully applied to many fields with very assorted aims of utilization such as coagulants, adhesives, floatation agents, tannings, dyes, additives, or biomolecules. Therefore, this review offers a global vision of the full process that involves the tannin's technological application including an overview of the most relevant tannin sources, effective extraction methods, and their utilization in very diverse fields.

Effect of surface flattening and phototherapy on shear bond strength immediately after bleaching with different modes of universal adhesive.

OBJECTIVE: The aim of this study was to compare to effect of phototherapy and surface flattening after immediately bleaching on the shear bond strength to bleached enamel. METHODS: Ninety-six human upper incisors were divided into 4 groups (n = 24). Group NB: no bleached, group P: phototherapy with YSGG laser, group F: 0.5 mm surface flattening, group PF: 0.5 mm surface flattening and phototherapy with Er;Cr:YSGG laser. Then, each group was assigned to 2 subgroups according to adhesive mode (n = 12) as; subgroup S (self-etching mode), subgroup T (total-etching mode) which are universal adhesives. All surface conditionings and restorations were performed with composite resin materials immediately after bleaching. Shear bond strength test was performed by using universal testing machine. The surfaces were also evaluated with SEM. The data were statistically analyzed with one-way ANOVA post-hoc Tukey tests. RESULTS: The lowest SBS values were achieved in FS (13.72 ± 2.29) while the highest ones in PT (28.01 ± 6.81). However, the differences were not significant (P > 0.05). All surface conditioning methods provided SBS values similar to the control (P > 0.05). All subgroups of self-etching mode were significantly lower than their total-etching counterparts (P < 0.05). CONCLUSIONS: The present study showed that surface removal and phototherapy have a potential clinical application for eliminate to undesirable effect of bleaching treatment. Surface conditioning with either flattening and/or phototherapy may provide clinicians to restore bleached teeth at the same visit with bleaching and reduce chair-time.

Large-Scale and Rapid Preparation of Nanofibrous Meshes and Their Application for Drug-Loaded Multilayer Mucoadhesive Patch Fabrication for Mouth Ulcer Treatment.

Electrospinning provides a simple and convenient method to fabricate nanofibrous meshes. However, the nanofiber productivity is often limited to the laboratory scale, which cannot satisfy the requirements of practical application. In this study, we developed a novel needleless electrospinning spinneret based on a double-ring slit to fabricate drug-loaded nanofibrous meshes. In contrast to the conventional single-needle electrospinning spinneret, our needless spinneret can significantly improve nanofiber productivity due to the simultaneous formation of multiple jets during electrospinning. Curcumin-loaded poly(l-lactic acid) (PLLA) nanofiber meshes with various concentrations and on the large scale were manufactured by employing our developed needleless spinneret-based electrospinning device. We systematically investigated the drug release behaviors, antioxidant properties, anti-inflammatory attributes, and cytotoxicity of the curcumin-loaded PLLA nanofibrous meshes. Furthermore, a bilayer nanofibrous composite mesh was successfully generated by electrospinning curcumin-loaded PLLA solution and diclofenac sodium loaded poly(ethylene oxide) solution in a predetermined time sequence, which revealed potent antibacterial properties. Subsequently, novel mucoadhesive patches were assembled by combining the bilayer composite nanofibrous meshes with (hydroxypropyl)methyl cellulose based mucoadhesive film. The multilayered mucoadhesive patch has excellent adhesion properties on the porcine buccal mucosa. Overall, our double-ring slit spinneret can provide a novel method to rapidly produce large-scale drug-loaded nanofibrous meshes to fabricate mucoadhesive patches. The multiple-layered mucoadhesive patches enable the incorporation of multiple drugs with different targets of action, such as analgesic, anti-inflammatory, and antimicrobial compounds, for mouth ulcer or other oral disease treatments.

Effect of mucoadhesive agent HEC on herbal extracts retention and VSC producing bacteria reduction in an experimental oral biofilm.

Mucoadhesive tablets containing herbal formulation have been previously shown to reduce oral malodour. The aim of the present in vitro study was to test the effect of the mucoadhesive agent hydroxyethylcellulose (HEC) added to a liquid phase herbal extract formulation on the mucoadhesive retention of the active ingredients and their effect against malodour production. Experimental oral biofilms were grown on mucin coated glass slides treated with liquid phase solutions of herbal extract with or without HEC as well as saline and 0.2% chlorhexidine as controls. Biofilms were quantified for volatile sulfide compounds (VSC) producing bacteria using CLSM and sampled for a salivary incubation assay to test for malodour production (odour judge), VSC production (Halimeter) and salivary protein degradation (SDS-PAGE). Results showed that the addition of HEC to the herbal extracts solution has significantly increased its mucin retained activity against malodour producing bacteria and their resulting malodour and VSC production and proteolytic activities. Taken together, results of the present study suggest that the addition of HEC to a liquid phase herbal extract solution may increase its bioavailability time and efficacy. However, due to the limitations of this in vitro study additional clinical investigations are needed.

Randomized clinical trial of a mucoadhesive formulation containing curcuminoids (Zingiberaceae) and Bidens pilosa Linn (Asteraceae) extract (FITOPROT) for prevention and treatment of oral mucositis - phase I study.

Preclinical repeated-dose toxicity and efficiency studies developed by our group suggest the potential of FITOPROT in treating mucositis. This serious limiting side effect is observed at a rate of 40-100% in patients under antineoplastic therapy and despite different palliative measures and therapeutic agents have been investigated, still no therapy was completely successful. Therefore, this study aimed to establish the safety and recommended phase II dose of FITOPROT for the prevention and treatment of chemoradiotherapy-induced oral mucositis (OM) in patients with head and neck cancer. Twenty healthy adult participants were randomized into two groups that received pre-established concentrations of the collutory: group 1 (FITOPROT A - mucoadhesive formulation containing 10 mg/mL of curcuminoids extract plus 20% v/v of Bidens pilosa L. extract) and group 2 (FITOPROT B - mucoadhesive formulation containing 20 mg/mL of curcuminoids extract, plus 40% v/v of Bidens pilosa L. extract). Participants rinsed their mouths with FITOPROT, three times daily, for ten consecutive days. No participant experienced toxicity or unacceptable discomfort and/or adverse reactions (CTCAE v5.0), with laboratory and clinical parameters under normal conditions. Side effects observed were low intensity and temporary mucosa/dental surface pigmentation (n = 7) and tooth sensitivity (n = 4), which disappeared after formulation use ceased. No significant cellular genotoxic effects were observed (p > 0.05), and micronuclei frequencies were not changed (p > 0.05). Biochemical assays reveled no altered levels of myeloperoxidase (p = 0.2268), malondialdehyde (p = 0.1188) nor nitric oxide (p = 0.5709) concentration, and no significant difference were found in the levels of pro-inflammatory cytokines (p > 0.05). Thus, FITOPROT demonstrated to be safe and tolerable in both tested doses and is suitable for evaluation in a phase II trial as treatment against OM.

Mucoadhesive Properties of Thiolated Pectin-Based Pellets Prepared by Extrusion-Spheronization Technique.

The aim of this study was to develop mucoadhesive pellets on a thiolated pectin base using the extrusion-spheronization technique. Thiolation of pectin was performed by esterification with thioglycolic acid. The molecular weight and thiol group content of the pectins were determined. Pellets containing pectin, microcrystalline cellulose, and ketoprofen were prepared and their mucoadhesive properties were evaluated through a wash-off test using porcine intestinal mucosa. The in vitro ketoprofen release was also evaluated. Thiolated pectin presented a thiol group content of 0.69 mmol/g. Thiolation caused a 13% increase in polymer molecular weight. Pellets containing thiolated pectin were still adhering to the intestinal mucosa after 480 min and showed a more gradual release of ketoprofen. Conversely, pellets prepared with nonthiolated pectin showed rapid disintegration and detached after only 15 min. It can be concluded that thiolated pectin-based pellets can be considered a potential platform for the development of mucoadhesive drug delivery systems for the oral route.

[Guilu Erxian Glue Induced Osteogenic Differentiation of BMMSCs and Its Effects on Wnt Signal Pathway].

Objective To observe the effects of Guilu Erxian Glue (GEG) containing serum on osteogenin differentiation of bone marrow mesenchymal stem cells (BMMSCs) and Wnt signal pathway related factors. Methods Totally 100 three months old female SD rats had their bilateral ovaries excised peritoneally They were divided into the low, middle, high GEG groups, and the blank control group by random digit table, 25 in each group. The dose of GEG was calculated according to body surface area, and GEG containing serum was administered by gastrogavage for 7 successive days. Blood was collect- ed by abdominal aorta to prepare drug containing serum. F3 passage BMMSCs of 1-month SD rats were i- solated by whole bone marrow adherent method, and cultured in vitro for 3 passages. The cell surface markers (CD45 and CD90) of F3 passage were detected by flow cytometry (FCM). BMMSCs were trea- ted with different concentrations GEG containing serum for 72 h. Then the cell cycle was determined by FCM, and the proliferation index calculated. The optimal intervention concentration was determined. Then F3 passage BMMSCs were divided into four groups, i.e., the fetal bovine serum (FBS) group, the blank control group, the GEG group, the classical induction group. After they were treated with corresponding medium for 21 days, BMMSCs were dyed with alizarin red staining (ARS) to observe their osteogenin dif- ferentiation. mRNA expressions of alkaline phosphatase (ALP) and osteocalcin (OC) of BMMSCs were detected by RT-PCR. mRNA and protein expressions of Wnt5a, ß-catenin, and lymphoid enhancer factor- 1 (Lef-1) were detected by RT-PCR and Western blot. Results The ratio of CD45 positive expression was 1. 46% ?0. 23%, and the ratio of CD90 positive expression was 96. 97% ±3. 21%. Middle EGE contai- ning serum (10%) could significantly stimulate the proliferation of BMMSCs. In ARS citrus red calcium nodules could be seen in the GEG group and the classical induction group. Compared with the FBS group and the blank control group, mRNA expressions of OC and ALP were up-regulated, mRNA and protein expressions of Wnt5a and p-catenin were up-regulated in the GEG group and the classical induction group (P<0. 05). Compared with the FBS group, the blank control group, and the classical induction group, mRNA and protein expressions of Lef-1 were up-regulated in the EGE group (P <0. 05). Compared with the FBS group and the blank control group, protein expressions of Lef-1 increased in the classical induc- tion group (P <0. 05). Conclusions GEG containing serum had the functions of stimulating the prolifera- tion of BMMSCs, and inducing the osteogenic differentiation of BMMSCs. Its mechanism might be possi- bly related with regulating Wnt signal pathway related factors.

Hydrogen peroxide generation and biocompatibility of hydrogel-bound mussel adhesive moiety.

To decouple the extracellular oxidative toxicity of catechol adhesive moiety from its intracellular non-oxidative toxicity, dopamine was chemically bound to a non-degradable polyacrylamide hydrogel through photo-initiated polymerization of dopamine methacrylamide (DMA) with acrylamide monomers. Network-bound dopamine released cytotoxic levels of H2O2 when its catechol side chain oxidized to quinone. Introduction of catalase at a concentration as low as 7.5 U/mL counteracted the cytotoxic effect of H2O2 and enhanced the viability and proliferation rate of fibroblasts. These results indicated that H2O2 generation is one of the main contributors to the cytotoxicity of dopamine in culture. Additionally, catalase is a potentially useful supplement to suppress the elevated oxidative stress found in typical culture conditions and can more accurately evaluate the biocompatibility of mussel-mimetic biomaterials. The release of H2O2 also induced a higher foreign body reaction to catechol-modified hydrogel when it was implanted subcutaneously in rat. Given that H2O2 has a multitude of biological effects, both beneficiary and deleterious, regulation of H2O2 production from catechol-containing biomaterials is necessary to optimize the performance of these materials for a desired application.

Development of pectinate-ispagula mucilage mucoadhesive beads of metformin HCl by central composite design.

Ionotropically-gelled mucoadhesive beads of metformin HCl composed of low methoxy (LM) pectin-ispaghula husk mucilage (IHM) polymer-blend was developed and optimized using central composite design (spherical type, single center point, and α=1.414). Effects of LM pectin and IHM amounts on drug encapsulation efficiency (DEE) and cumulative drug release at 10h (R10h) were analysed using response surface methodology. The optimized beads containing metformin HCl (F-O) showed DEE of 86.98 ± 3.26% and R10h of 47.20 ± 1.28%. All these beads exhibited suitable controlled in vitro sustained drug release pattern with super case-II transport mechanism over 10h. These beads were also characterized by SEM and FTIR. The optimized beads also exhibited pH-dependent swelling, good mucoadhesivity with goat intestinal mucosa and significant hypoglycemic effect in alloxan-induced diabetic rats over prolonged period after oral administration, which could possibly be lucrative in terms of prolonged systemic absorption of metformin HCl maintaining tight blood glucose level and advanced patient compliance.

[Effects of bionic glue on experimental population dynamics of Paratrioza sinica and its natural enemies].

OBJECTIVE: To find out whether and how the newly invented technique-bionic glue affects the main pest of wolf berry-Paratrioza sinica and its natural enemies Tamarixia lyciumi and Chrysopa septempunctata. METHOD: Spraying bionic glue in field when wolf berry just geminated, investigated the adults and nymphs of P. sinica and it's natural enemies: adults of T. lyciumi and eggs of C. septempunctata. RESULT AND CONCLUSION: Bionic glue can significantly reduce the population number of P. sinica, but with little impacts on its natural enemies of T. lyciumi and C. septempunctata, and more experiments are need for further research.

In vitro biocompatibility of thermally gelling liquid mucoadhesive loaded curcuminoids in colorectal cancer chemoprevention.

PURPOSE: Colorectal cancer (CRC) is the third leading cause of cancer death in Taiwan; it ranks top three in the cancer mortality rate. Curcuminoids are derived from the rhizome of Curcuma longa. It has shown anti-cancer activity and apoptosis induction in a variety of cancer cell lines. This aims to study the potential of Poloxamer 407 as the thermogelling and mucoadhesive polymer for development of a site-targeting delivery system to enhance the localized delivery of curcuminoids to the colorectal cells for CRC chemotherapy. METHODS: The mucoadhesive strength and rheological properties were measured as a function of poloxamer loaded with curcuminoids. RESULTS: The gelation temperature of Poloxamer 407 was found to vary with its concentration and start gelling at 37°C at the concentration of 15.5% (w/v). To ensure gelation at physiological temperature after intra-rectal application, gelation temperature was determined by rheological measurement as well as by its physical appearance. The results indicated that its mucoadhesive strength also shows a dependency on temperature, which appears to be related to the increment in the maximum strength and average strength of the polymer. CONCLUSION: The results have suggested that Poloxamer 407 could be a potential thermogelling and mucoadhesive polymer for the development of a site-targeting colorectal drug delivery system for curcuminoids in colorectal cancer therapy.

[Controling of Paratrioza sinica by bionic glue].

OBJECTIVE: To investigate the controlling effects of bionic glue on Paratrioza sinica. METHOD: P. sinica and bionic glue were chosen as materials to investigate the adhesive rate, mortality rate, and study the effects of behavior of P. sinica and growth of leaves sprayed with bionic glue. RESULT: Spraying of the bionic glue can significantly increase the adhesive rate of P. sinica with no obviously repellency, and it can be used to control the adults of P sinaca in field with no significant effect on the growth of wolfberry leaves. CONCLUSION: Bionic glue has significant controlling effects on adults of P. sinica, it can be used as an eliminator of adults of P. sinica in field at the beginning of the vegetation season to suppress of the development of P. sinica population.

Studies on biodegradable and crosslinkable poly(castor oil fumarate)/poly(propylene fumarate) composite adhesive as a potential injectable biomaterial.

Biodegradable hydroxyl terminated-poly(castor oil fumarate) (HT-PCF) and poly(propylene fumarate) (HT-PPF) resins were synthesized as an injectable and in situ-cross linkable polyester resins for orthopedic applications. An injectable adhesive formulation containing this resin blend, N-vinyl pyrrolidone (NVP), hydroxy apatite, free radical initiator and accelerator was developed. The Composite adhesives containing the ratio of resin blend and NVP, 2.1:1.5, 2.1:1.2 and 2.1:1.0 set fast with tolerable exothermic temperature as a three dimensionally cross linked toughened material. Crosslink density and mechanical properties of the crosslinked composite increase with increase of NVP. The present crosslinked composite has hydrophilic character and cytocompatibility with L929 fibroblast cells.

Evaluation of mucilage of Hibiscus rosasinensis Linn as rate controlling matrix for sustained release of diclofenac.

This article reports the exploitation of novel hydrophilic excipient, that is, mucilage from Hibiscus rosasinensis Linn, for the development of sustained release tablet. Swelling ratio and flow properties analyses of dried mucilage powder were carried out. A 3(2) full factorial design was used. In factorial design, amounts of dried mucilage and dibasic calcium phosphate (DCP) were taken as independent factors and percentage drug release in 60 and 300 min and time for 80% drug release as dependent variables. Matrix tablet containing dried mucilage and diclofenac sodium (DS) was prepared through direct compression techniques. DS tablets were evaluated for hardness, friability, weight variation, in vitro drug release and water uptake, and mass loss study. The dried mucilage powder shows superior swelling capacity and excellent flow properties. Prepared tablets have acceptable hardness, friability, and uniformity in weight. It was found that batch HD8 fulfills all selected criteria. Drug release kinetics from these formulations corresponded best to the zero-order kinetics. Water uptake was independent whereas mass loss was dependent on agitation speed. The concept of similarity factor (f(2)) was used to prove similarity of dissolution profile in distilled water and phosphate buffer and was found to be 90.68. It was concluded that mucilage can be used as release-retarding agent for 12 h when the drug-mucilage ratio was 1:1.5. So, matrix tablet containing dried mucilage is most suitable for sustained release of DS.

Opuntia ficus indica (L.) Mill. mucilages show cytoprotective effect on gastric mucosa in rat.

Opuntia ficus indica cladodes possess a protective action against ethanol-induced ulcer in the rat. The major components of cladodes are carbohydrate polymers, mainly mucilages and pectin. To clarify the cytoprotective effects of cladodes on experimental ethanol-induced ulcer in rat, mucilages and pectin were extracted and were administered instead of cladodes. The above mentioned effects induced by cladodes may be attributed to mucilages, and not significantly to pectin.

Reversing gastric mucosal alterations during ethanol-induced chronic gastritis in rats by oral administration of Opuntia ficus-indica mucilage.

AIM: To study the effect of mucilage obtained from cladodes of Opuntia ficus-indica (Cactaceae) on the healing of ethanol-induced gastritis in rats. METHODS: Chronic gastric mucosa injury was treated with mucilage (5 mg/kg per day) after it was induced by ethanol. Lipid composition, activity of 5'-nucleotidase (a membrane-associated ectoenzyme) and cytosolic activities of lactate and alcohol dehydrogenases in the plasma membrane of gastric mucosa were determined. Histological studies of gastric samples from the experimental groups were included. RESULTS: Ethanol elicited the histological profile of gastritis characterized by loss of the surface epithelium and infiltration of polymorphonuclear leukocytes. Phosphatidylcholine (PC) decreased and cholesterol content increased in plasma membranes of the gastric mucosa. In addition, cytosolic activity increased while the activity of alcohol dehydrogenases decreased. The administration of mucilage promptly corrected these enzymatic changes. In fact, mucilage readily accelerated restoration of the ethanol-induced histological alterations and the disturbances in plasma membranes of gastric mucosa, showing a univocal anti-inflammatory effect. The activity of 5'-nucleotidase correlated with the changes in lipid composition and the fluidity of gastric mucosal plasma membranes. CONCLUSION: The beneficial action of mucilage seems correlated with stabilization of plasma membranes of damaged gastric mucosa. Molecular interactions between mucilage monosaccharides and membrane phospholipids, mainly PC and phosphatidylethanolamine (PE), may be the relevant features responsible for changing activities of membrane-attached proteins during the healing process after chronic gastric mucosal damage.

The flocculation performance of Tamarindus mucilage in relation to removal of vat and direct dyes.

A food grade natural mucilage, extracted from the seeds of Tamarindus indica pods, is used as a flocculant for removal of solubilised vat (golden yellow) and direct dye (direct fast scarlet) in aqueous solutions. The maximum removal obtained was 60% for golden yellow after 2 h and was 25% for direct fast scarlet after 1 h. The optimum mucilage dose was 10 mg/l and 15 mg/l for golden yellow and direct fast scarlet, respectively. The pH values also seem to affect the percent removal of both the dyes significantly. In case of vat dye, the pH value of the test samples affected the percent removal significantly. The change was highly significant between neutral and alkaline pH. In case of direct dye, there was no significant change in percent removal at pH 7 and pH 4 whereas a significant change in percent removal was observed between pH 7 and pH 9.2. The plausible mucilage-dye interaction and flocculation mechanism has been discussed. This new flocculant works better in the case of vat dye removal compared with the direct dye.