Effects of different concentrations of bromelain and papain enzymes on shear bond strength of composite resin to deep dentin using an etch-and-rinse adhesive system.

BACKGROUND: The dentin substrate can be modified by proteolytic agents, which may affect the bonding strength of adhesive systems to the treated dentin surface. Papain, a cysteine protease enzyme with antibacterial and anti-inflammatory properties, can be used for deproteinization of dentin. An alternative deproteinizing enzyme is bromelain. OBJECTIVES: This study aimed to evaluate the impact of deproteinization on the shear bond strength (SBS) of composite resin to deep dentin using different concentrations of bromelain and papain. MATERIAL AND METHODS: Sixty upper premolars were extracted and randomly divided into 5 groups (n = 12 per group). In all groups, the dentin surface was etched with 37% phosphoric acid. Group 1 did not receive any enzyme treatment, group 2 was treated with a 10% papain solution, group 3 was treated with a 15% papain solution, group 4 was treated with a 6% bromelain solution, and group 5 was treated with a 10% bromelain solution. After applying an etch-and-rinse adhesive system, the specimens were restored with composite resin and the SBS was measured. RESULTS: Statistically significant differences were found between groups 2 and 3 (10% papain and 15% papain, p = 0.004), groups 2 and 4 (10% papain and 6% bromelain, p = 0.017), groups 4 and 5 (6% bromelain and 10% bromelain, p = 0.021), and groups 3 and 5 (15% papain and 10% bromelain, p = 0.005). CONCLUSIONS: Deproteinization with papain and bromelain at different concentrations after acid etching did not affect the SBS of composite resin to deep dentin when using an etch-and-rinse adhesive system. However, the group deproteinized with 15% papain demonstrated a higher SBS than the group deproteinized with 10% papain, and the group deproteinized with 6% bromelain showed a higher SBS compared to the group deproteinized with 10% bromelain.

Development of nanocomposites based on chitosan/reduced graphene oxide for wound healing application.

Nanocomposites containing different effective materials have various effects, such as antioxidant, and anti-inflammatory activity, which are desirable for wound dressing. Herein, nanocomposites based on chitosan/reduced graphene oxide (CS/rGO) containing curcumin (CS/rGO/Cur), curcumin and papain (CS/rGO/Cur/Pa), curcumin, papain, and collagen peptide (CS/rGO/CP/Cur/Pa), prepared using ionic gelation method and characterized by Fourier Transform Infrared (FTIR), Differential Light Scattering (DLS), X-ray diffraction (XRD), and Scanning Electron Microscope (SEM). Subsequently, the nanocomposite's potential for wound healing was studied through parameters such as porosity, swelling, degradability, anti-inflammatory, antioxidant, antibacterial, cell viability, and in-vivo. The results of FTIR, XRD, SEM, and DLS showed that the nanocomposites synthesized properly with an almost spherical morphology, an average diameter of below 100 nm (mostly 40-85 nm), and a hydrodynamic diameter of 455-616 nm. The various tests demonstrated the nanocomposite's effectiveness in wound healing. The results showed that CS/rGO/CP/Cur/Pa increased the anti-inflammatory and cell viability up to 99.7 % and 395 %, respectively, which is higher than others. Animal tests on rats showed that CS/rGO/CP/Cur/Pa accelerated the wound healing rate up to 70 %. In conclusion, the results showed that the nanocomposites based on CS/rGO significantly improve wound healing, and the presence of collagen peptides boost their wound healing potency.

Papain exerts an anti-atherosclerosis effect with suppressed MPA-mediated foam cell formation by regulating the MAPK and PI3K/Akt-NF-κB pathways.

BACKGROUND: Papain possesses a potential anti-atherosclerosis (AS) effect. This study aimed to explore the inhibitory effects of papain on the monocyte-platelet aggregates (MPAs)-mediated production of foam cells in vitro and AS in vivo. RESEARCH DESIGN AND METHODS: THP-1 cells were treated by platelet, papain, nuclear factor-κB (NF-κB) inhibitor or activator. An AS rat model was treated with papain. The THP-1 cells, macrophages, and foam cells were detected, and CD36, CD11b and CCR2 (macrophages) and CD14 and CD41 (MPAs) were measured. The levels of inflammatory factors, lipoprotein, and MAPK and PI3K/Akt -NF-κB pathways proteins were determined. Finally, injury of the thoracic aorta of AS rats was observed. RESULTS: Papain reduced macrophage production, lipid accumulation, and foam cell formation in vitro and downregulated the expression of monocyte chemoattractant protein 1 (MCP-1), prostaglandin E2 (PGE2), and cyclooxygenase 2 (COX2), and that of p38, JNK, Akt, and p65. Moreover, NF-κB activator could reversed the inhibitory effects of papain. Similarly, papain alleviated aortic smooth muscle hyperplasia, lipid droplet accumulation, and collagen diffusion and inhibited the expression of inflammatory factors and p38, JNK, Akt, and p65 in vivo. CONCLUSIONS: Papain inhibited MPA-induced foam cell formation by inactivating the MAPK and PI3K/Akt-NF-κB pathways, thereby exerting an anti-AS effect.

A cysteine enzyme hemostat for efficient heparin-tolerant blood coagulation.

It is challenging to stop bleeding effectively in patients treated with heparin which leads to enhanced risk of uncontrolled bleeding during operation. Herein, we report an easy-to-use and heparin-tolerant hemostatic agent based on a thrombin-like cysteine enzyme (papain), which catalyzes the hydrolysis of fibrinogen and cross-linking of fibrin clots. A papain-based hemostat with increased procoagulant activity is developed through immobilizing papain on the cellulose carrier, which displays short clotting time in both normal and heparinized plasmas. The excellent hemostatic performance of the papain-based hemostat is further confirmed with reduced hemostatic time and limited blood loss in a mouse tail amputation model, rabbit auricular artery injury model and rat liver injury model, in which a natural coagulation system fails to function on account of heparin. This bio-hemostat has great potential to reverse the effect of heparin and stop topical hemorrhage rapidly in surgical procedures.

Effects of traditional and novel proteolytic agents on tissue dissolution and dentine microhardness.

The study aimed to evaluate the tissue-dissolving ability of papain and bromelain with respect to that of sodium hypochlorite (NaOCl) at the temperatures of 25°C and 60°C. The study also assessed the effects of these proteolytic agents on radicular dentine microhardness. Warming NaOCl, papain and bromelain solutions resulted in significant tissue dissolution at all time intervals (p < 0.001). At 60°C, bromelain showed significantly higher tissue weight loss at every time interval when compared to NaOCl (p < 0.001). All of the three organic tissue dissolvents reduced the microhardness at 1 hr when compared to their respective baseline values. The reduction in microhardness from the baseline reading was statistically significant only in the papain group at 30 min (p = 0.018) and at 60 min (p = 0.03) when compared to the control group. Hence it was concluded that bromelain exerted superior tissue dissolution action, especially when warmed, with minimal effect on dentine microhardness.

Inhibition of Nematocyst Discharge from Pelagia noctiluca (Cnidaria: Scyphozoa)-Prevention Measures against Jellyfish Stings.

Pelagia noctiluca stings are common in Mediterranean coastal areas and, although the venom is non-lethal, they are painful. Due to its high toxicity and abundance, P. noctiluca is considered a target species for the focus of research on active ingredients to reduce the symptoms of its sting. To determine the effect of 31 substances and formulations on nematocyst discharge, we performed three tests: (1) screening of per se discharge activator solutions, (2) inhibitory test with nematocyst chemical stimulation (5% acetic acid) and (3) inhibitory test quantifying the hemolytic area. Ammonia, barium chloride, bleach, scented ammonia, carbonated cola, lemon juice, sodium chloride and papain triggered nematocyst discharge. All of them were ruled out as potential inhibitors. Butylene glycol showed a reduction in nematocyst discharge, while the formulations of 10% lidocaine in ethanol, 1.5% hydroxyacetophenone in distilled water + butylene glycol, and 3% Symsitive® in butylene glycol inhibited nematocyst discharge. These last results were subsequently correlated with a significant decrease in hemolytic area in the venom assays versus seawater, a neutral solution. The presented data represent a first step in research to develop preventive products for jellyfish stings while at the same time attempting to clarify some uncertainties about the role of various topical solutions in P. noctiluca first-aid protocols.

Enzymes in the time of COVID-19: An overview about the effects in the human body, enzyme market, and perspectives for new drugs.

The rising pandemic caused by a coronavirus, resulted in a scientific quest to discover some effective treatments against its etiologic agent, the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). This research represented a significant scientific landmark and resulted in many medical advances. However, efforts to understand the viral mechanism of action and how the human body machinery is subverted during the infection are still ongoing. Herein, we contributed to this field with this compilation of the roles of both viral and human enzymes in the context of SARS-CoV-2 infection. In this sense, this overview reports that proteases are vital for the infection to take place: from SARS-CoV-2 perspective, the main protease (Mpro ) and papain-like protease (PLpro ) are highlighted; from the human body, angiotensin-converting enzyme-2, transmembrane serine protease-2, and cathepsins (CatB/L) are pointed out. In addition, the influence of the virus on other enzymes is reported as the JAK/STAT pathway and the levels of lipase, enzymes from the cholesterol metabolism pathway, amylase, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, and glyceraldehyde 3-phosphate dehydrogenase are also be disturbed in SARS-CoV-2 infection. Finally, this paper discusses the importance of detailed enzymatic studies for future treatments against SARS-CoV-2, and how some issues related to the syndrome treatment can create opportunities in the biotechnological market of enzymes and the development of new drugs.

Bushen Qiangjin capsule inhibits the Wnt/α-catenin pathway to ameliorate papain-induced knee osteoarthritis in rat.

OBJECTIVE: To evaluate the molecular mechanism underlying the beneficial effect of Bushen Qiangjin capsule (BSQJ), a Traditional Chinese Medicine, on knee osteoarthritis (KOA). METHODS: In the present study, 32 female Sprague-Dawley rats were randomly divided into four groups: control, KOA, high-dose BSQJ (H-BSQJ), and low-dose BSQJ (L-BSQJ). After successfully establishing the KOA model by intra-articular injection of papain, H-BSQJ and L-BSQJ groups were intragastrically administered 0.243 and 0.122 g/kg BSQJ, respectively, daily for 6 weeks. At the end of the experiment, knee articular cartilage tissues of rats were collected for evaluation by hematoxylin and eosin staining, Safranin O-Fast Green staining, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. Serum interleukin-1α and tumor necrosis factor-α levels of rats were detected with an enzyme-linked immunosorbent assay method. Gene expression of Wnt-4, α-catenin, Frizzled-2, glycogen synthase kinase-3ß (GSK-3ß), cysteinyl aspartate-specific proteinases 3 and 9 (caspases 3 and 9), collagen type II alpha 1 (Col2a1), and matrix metalloproteinases 1 and 13 (MMP-1 and MMP-3) of rat knee articular cartilage was quantified by reverse transcription-quantitative polymerase chain reaction analysis. Wnt-4, α-catenin, Frizzled-2, GSK-3ß, cleaved caspase-3, and cleaved caspase-9 protein expression in rat knee articular cartilage was determined by western blot analysis. RESULTS: BSQJ obviously reduced pathological damage and matrix degradation of articular cartilage in KOA rats. Compared with the KOA group, H-BSQJ rats exhibited downregulated mRNA and protein expression of Wnt-4, ß-catenin, Frizzled-2,and caspase-3, as well as upregulated mRNA and protein expression of GSK-3α. In addition, H-BSQJ significantly increased mRNA expression of Col2a1 and decreased mRNA expression of MMP-1 and MMP-13. CONCLUSION: BSQJ exerted a beneficial effect on KOA by a mechanism involving downregulation of the Wnt/α-catenin pathway, which inhibited both cartilage extracellular matrix degradation and chondrocyte apoptosis to ameliorate KOA in rats.

Papain Ameliorates Lipid Accumulation and Inflammation in High-Fat Diet-Induced Obesity Mice and 3T3-L1 Adipocytes via AMPK Activation.

Papain is a proteolytic enzyme present in the leaves, fruits, roots, and latex of the Carica papaya (papaya) plant. Although it exhibits a wide range of activities, there are no reports on the anti-obesity effects of papain. This study examined the anti-obesity effect and obesity-involved anti-inflammatory mechanism of papain in in vivo and in vitro models using high-fat diet (HFD)-induced obese mice and 3T3-L1 preadipocytes. Oral administration of papain reduced HFD-induced weight of the body, liver, and adipose tissues of mice. Papain also reduced hepatic lipid accumulation and adipocyte size. Moreover, serum total cholesterol and triglyceride levels were markedly reduced in papain-treated mice. In addition, papain inhibited the differentiation of preadipocytes and oil accumulation in 3T3-L1 preadipocytes and rat primary preadipocytes. Mechanistically, papain significantly downregulated the protein levels of key adipogenesis regulators and reversed the expression of pro-inflammatory cytokines and adipokines in HFD-induced obese mice and 3T3-L1 preadipocytes. Papain also markedly enhanced activation of the AMP-activated protein kinase pathway in both models. Collectively, these results suggest that papain exerts anti-obesity effects in HFD-induced mice and 3T3-L1 preadipocytes by regulating levels of adipogenic factors involved in lipid metabolism and inflammation; thus, it could be useful in the prevention and treatment of obesity.

Inhibition of Cysteine Proteases by 6,6'-Dihydroxythiobinupharidine (DTBN) from Nuphar lutea.

The specificity of inhibition by 6,6'-dihydroxythiobinupharidine (DTBN) on cysteine proteases was demonstrated in this work. There were differences in the extent of inhibition, reflecting active site structural-steric and biochemical differences. Cathepsin S (IC50 = 3.2 µM) was most sensitive to inhibition by DTBN compared to Cathepsin B, L and papain (IC50 = 1359.4, 13.2 and 70.4 µM respectively). DTBN is inactive for the inhibition of Mpro of SARS-CoV-2. Docking simulations suggested a mechanism of interaction that was further supported by the biochemical results. In the docking results, it was shown that the cysteine sulphur of Cathepsin S, L and B was in close proximity to the DTBN thiaspirane ring, potentially forming the necessary conditions for a nucleophilic attack to form a disulfide bond. Covalent docking and molecular dynamic simulations were performed to validate disulfide bond formation and to determine the stability of Cathepsins-DTBN complexes, respectively. The lack of reactivity of DTBN against SARS-CoV-2 Mpro was attributed to a mismatch of the binding conformation of DTBN to the catalytic binding site of Mpro. Thus, gradations in reactivity among the tested Cathepsins may be conducive for a mechanism-based search for derivatives of nupharidine against COVID-19. This could be an alternative strategy to the large-scale screening of electrophilic inhibitors.

The effects of plant cysteine proteinases on the nematode cuticle.

BACKGROUND: Plant-derived cysteine proteinases of the papain family (CPs) attack nematodes by digesting the cuticle, leading to rupture and death of the worm. The nematode cuticle is composed of collagens and cuticlins, but the specific molecular target(s) for the proteinases have yet to be identified. METHODS: This study followed the course of nematode cuticle disruption using immunohistochemistry, scanning electron microscopy and proteomics, using a free-living nematode, Caenorhabditis elegans and the murine GI nematode Heligmosomoides bakeri (H. polygyrus) as target organisms. RESULTS: Immunohistochemistry indicated that DPY-7 collagen is a target for CPs on the cuticle of C. elegans. The time course of loss of DPY-7 from the cuticle allowed us to use it to visualise the process of cuticle disruption. There was a marked difference in the time course of damage to the cuticles of the two species of nematode, with H. bakeri being more rapidly hydrolysed. In general, the CPs' mode of attack on the nematode cuticle was by degrading the structural proteins, leading to loss of integrity of the cuticle, and finally death of the nematode. Proteomic analysis failed conclusively to identify structural targets for CPs, but preliminary data suggested that COL-87 and CUT-19 may be important targets for the CPs, the digestion of which may contribute to cuticle disruption and death of the worm. Cuticle globin was also identified as a cuticular target. The presence of more than one target protein may slow the development of resistance against this new class of anthelmintic. CONCLUSIONS: Scanning electron microscopy and immunohistochemistry allowed the process of disruption of the cuticle to be followed with time. Cuticle collagens and cuticlins are molecular targets for plant cysteine proteinases. However, the presence of tyrosine cross-links in nematode cuticle proteins seriously impeded protein identification by proteomic analyses. Multiple cuticle targets exist, probably making resistance to this new anthelmintic slow to develop.

Foliar Spray with Pepsin-and Papain-Whey Protein Hydrolysates Promotes the Productivity of Pea Plants Cultivated in Clay Loam Soil.

Papain and pepsin-hydrolyzed whey protein (PAH and PEH, respectively) were prepared and characterized for its degree of hydrolysis, chemical constituents (amino acid and peptides) and antioxidant activity. A field experiment was conducted at El Salheya El Gedida City, Sharqia, Egypt, during the seasons 2019 and 2020, to investigate the biological action of the foliar spray of PAH and PEH on the growth and yield of pea plants cultivated in a clay loam soil. Foliar application of the papain and pepsin-hydrolyzed whey protein (PAH and PEH, respectively) at 1000 and 2000 mg/L was applied three times after 25, 35 and 45 days from planting. All protein foliar spray treatments had significant positive effects on the uptake of N, P and K, simultaneously increasing the contents of all the photosynthetic pigments (Chlorophyll a, Chlorophyll b and Carotenoids) in a concentration-dependent manner. The most conspicuous increase was seen in Chlorophyll b (105% increase), followed by Carotenoids (91% increase). Generally, the favorable increases caused by the second level of application (2000 mg/L) were nearly 2-3 times that of the low level (1000 mg/L). Pod growth and formation indicators, e.g., no. of pod/plant, pod length and no. of seeds/pod, responded more evidently to the hydrolyzed than the intact form of whey protein treatments. Hydrolyzed whey protein foliar spray treatments achieved significantly higher increases in the global field yield components of Pisum sativum plants than the intact form, where peptic hydrolysates were significantly superior to papain hydrolysate. The treatment PEH (2000 mg/L) can be recommended as the most effective bio-stimulating foliar spray treatment for higher plant productivity when applied 25, 35 and 45 days after planting.

Effects of alkali, enzymes, and ultrasound on monosodium glutamate byproduct for a sustainable production of Bacillus subtilis.

Due to the hindrance of flocculated polymers and bacterial cell wall, the production of Bacillus subtilis using monosodium glutamate byproduct (MSGB) was low. With the assistance of scanning electron microscope images, effects of alkali, lysozyme, papain, ultrasound, and their combinations on MSGB were evaluated using the results of soluble protein, carbohydrate, monosaccharides and peptidoglycans. Alkali could dissolve flocculated polymers increasing 21% soluble MSGB, and thus enhanced the subsequent treatments (ultrasound, lysozyme, or papain) to increase 14-17% soluble MSGB. As ultrasound mainly released intercellular components (mannose, and glucose) while lysozyme or papain mainly released cell wall components (peptidoglycans), the combination of alkali, ultrasound, and enzymes led to a highest soluble MSGB (78%), yielding a maximal B. subtilis production of 6.6 × 109 colony-forming units mL-1. This yield was about 33 times that of using untreated MSGB, and the key to improve B. subtilis production was the release of carbohydrate.

Biochemical Properties and Anti-Biofilm Activity of Chitosan-Immobilized Papain.

Chitosan, the product of chitin deacetylation, is an excellent candidate for enzyme immobilization purposes. Here we demonstrate that papain, an endolytic cysteine protease (EC: 3.4.22.2) from Carica papaya latex immobilized on the matrixes of medium molecular (200 kDa) and high molecular (350 kDa) weight chitosans exhibits anti-biofilm activity and increases the antimicrobials efficiency against biofilm-embedded bacteria. Immobilization in glycine buffer (pH 9.0) allowed adsorption up to 30% of the total protein (mg g chitosan-1) and specific activity (U mg protein-1), leading to the preservation of more than 90% of the initial total activity (U mL-1). While optimal pH and temperature of the immobilized papain did not change, the immobilized enzyme exhibited elevated thermal stability and 6-7-fold longer half-life time in comparison with the soluble papain. While one-half of the total enzyme dissociates from both carriers in 24 h, this property could be used for wound-dressing materials design with dosed release of the enzyme to overcome the relatively high cytotoxicity of soluble papain. Our results indicate that both soluble and immobilized papain efficiently destroy biofilms formed by Staphylococcus aureus and Staphylococcus epidermidis. As a consequence, papain, both soluble and immobilized on medium molecular weight chitosan, is capable of potentiating the efficacy of antimicrobials against biofilm-embedded Staphylococci. Thus, papain immobilized on medium molecular weight chitosan appears a presumably beneficial agent for outer wound treatment for biofilms destruction, increasing antimicrobial treatment effectiveness.

Wogonoside attenuates the articular cartilage injury and the infiltration of Th1/Th2-type cytokines in papain-induced osteoarthritis in rat model via inhibiting the NF-κB and ERK1/2 activation.

OBJECTS: Osteoarthritis is the most common joint disease and a major cause of functional limitation and pain in adults. This study aims to investigate the effect of wogonoside (WOG) on the progression of knee osteoarthritis (KOA) in model rats. MATERIALS AND METHODS: Rats KOA models were established and treated with different doses of WOG (10 mg/kg, 20 mg/kg and 30 mg/kg). The degree of cartilage injury was detected by Mankin scores via HE/Alcian blue staining. The levels of IFN-γ and IL-4 in peripheral blood and synovial fluid and the Th1/Th2 ratio were detected by flow cytometry. The model mice were injected with NF-κB p65 or ERK1/2 inhibitors or activators to further investigate the effect of WOG on KOA. RESULTS: WOG significantly improved cartilage tissue damage and reduced the Mankins score. WOG down-regulated the level of IFN-γ while up-regulated the expression of IL-4, which maintained the balance of Th1/Th2 cells. Further studies showed that the expression of NF-κB p65, phosphorylated p65, cytoplasmic ERK1/2 and nuclear ERK1/2 were all inhibited by WOG. The results of reverse verification experiments showed that the activator of NF-κB p65 and ERK1/2 weakened the protective effect of WOG on KOA, and the inhibitor of NF-κB p65ERK1/2 enhanced the protective effect of WOG on KOA. CONCLUSIONS: WOG inhibited the activation of NF-κB and ERK1/2 to alleviate the articular cartilage injury and Th1/th2 cytokine infiltration in KOA rats.

Poly (γ-glutamic acid)/chitooligo-saccharide/papain hydrogel prevents hypertrophic scar during skin wound healing.

Hypertrophic scar, a common skin disorder typically caused by deep burns or scald were usually treated via surgical resection, laser irradiation, and drugs. However, all the approaches were always companied with complications and devastatingly subjected to relapse, which indicated the urgently need of an effective treatment method. In this project, a new hydrogel composed of Poly (γ-glutamic acid) (γ-PGA), Chitooligo-saccharide, and Papain was developed via crosslinker (EDC&NHS), and characterized with good porously three-dimensional network structure, good water absorption, and mechanical properties. Besides, G/C/P hydrogel facilitated cell adhesion and inhibited excessive proliferation of fibroblasts, which indicated the potential of in vivo application. After applied onto skin wound healing in vivo on a rabbit ear skin wound model, G/C/P hydrogel inhibited excessive collagen deposition and the generation of hyperplastic scars effectively during wound healing. The hydrogel described here provide a new platform for regeneration field and hold great promise for solving serious skin disorder.

Region-specific effects of the cysteine protease papain on gastric motility.

BACKGROUND: Papaya is a traditional remedy for gastrointestinal complaints in the folk medicine. On this basis, papain, a cysteine protease of the fruit, is sold as a nutritional supplement, although scientific data on its effects in the gastrointestinal tract are lacking. We aimed to explore the effect of papain on gastric motility in vitro. METHODS: Guinea pig antrum and corpus strips were mounted in organ bath. KEY RESULTS: Papain reversibly increased the amplitude of ongoing phasic contractions in both circular and longitudinal antrum strips without having an effect on the frequency or on the muscle tone. All three tested doses of papain (end cc.: 12.5 mg L-1 , 50 mg L-1 , 100 mg L-1 ) were similarly effective. Contrarily, in the corpus circular and longitudinal muscle strips, papain caused a dose-dependent relaxation, which was preceded by a transient contraction in most tissues. The effect was resistant to tetrodotoxin (1 µM), but diminished by the cysteine protease inhibitor E64 (4.5 µM) in both regions. In the corpus, L-NAME (100 µM) and the protease-activated receptor (PAR)-1 antagonist SCH79797 (5 µM) or the PAR-2 antagonist GB 83 (3 µM) did not change the effect of papain significantly. This demonstrates that the effects of papain are not neurally mediated and nitrergic pathways are not involved in the mechanism. The effects are linked to the enzymatic activity, but not executed via PAR-1 or 2. CONCLUSIONS AND INFERENCES: Papain alters gastric motility in a region-specific manner, which could at least partly explain its claimed beneficial effects in functional gastrointestinal disorders.

Papain immobilization on heterofunctional membrane bacterial cellulose as a potential strategy for the debridement of skin wounds.

We combined the chemical and physical methods of papain immobilization through the aldehyde groups available on oxidized bacterial cellulose (OxBC) to provide high proteolytic activity for future applications as bioactive dressing. Bacterial cellulose (BC) was obtained by the fermentation of Komagataeibacter hansenii in Hestrin-Schramm medium for 5 days, followed by purification and oxidation using NaIO4. Surface response methodology was used to optimize papain immobilization (2%, w/v) for 24 h. The independent variables: pH (3-7) and temperature (5 to 45 °C) were investigated. The mathematically validated optimal conditions of 45 °C and pH 7 had a statistical effect on the immobilization yield (IY) of papain in OxBC (52.9%). These ideal conditions were also used for papain immobilization in BC (unoxidized). The IY of 9.1% was lower than that of OxBC. OxBC-Papain and BC-Papain were investigated using thermal analysis, confocal microscopy, and diffusion testing. The OxBC support exhibited a more interactive chemical structure than the BC support, and was capable of immobilizing papain by covalent bonds (-C-NHR) and adsorption (ion exchange), with 93.3% recovered activity, 49.4% immobilization efficiency, and better thermal stability. Papain immobilized to OxBC by adsorption displayed 53% widespread papain activity. The results indicate the potential of prolonged bioactivity in debrided chronic wounds.

Comparison between conventional and chemomechanical approaches for the removal of carious dentin: an in vitro study.

The present study aimed to evaluate the efficiency, effectiveness, and biocompatibility of two agents used for the chemomechanical removal of carious dentin. Sixty extracted carious human teeth were treated with a conventional bur (CBG) or chemomechanical agents - Papacarie Duo (PG) and Brix 3000 (BG). Treatment efficiency and effectiveness were assessed by the working time for carious dentin removal and Knoop microhardness values, respectively. Human pulp fibroblasts (FP6) were used to evaluate cytotoxicity by incorporating MTT dye, and genotoxicity was evaluated with the micronuclei test. The carious tissue was removed in a shorter time with CBG (median = 54.0 seconds) than the time required for chemomechanical agents (p = 0.0001). However, the time was shorter for Brix 3000 (BG) than that for Papacarie Duo (PG), showing mean values of 85.0 and 110.5 seconds, respectively. Regarding microhardness testing, all approaches tested were effective (p < 0.05). The final mean microhardness values were 48.54 ± 16.31 KHN, 43.23 ± 13.26 KHN, and 47.63 ± 22.40 KHN for PG, BG, and CBG, respectively. PG decreased cell viability compared to that of BG, but it presented no genotoxicity. Brix 3000 may be a good option for chemomechanical dentin caries removal due to its reduced removal time and lower cytotoxicity compared to the other treatment options.