Tracking heterogenous protein aggregation at nanoscale through fluorescence correlation spectroscopy.

Various biophysical techniques have been extensively employed to study protein aggregation due to its significance. Traditionally, these methods detect aggregation at micrometer length scales and micromolar concentrations. However, unlike in vitro, protein aggregation typically occurs at nanomolar concentrations in vivo. Here, using fluorescence correlation spectroscopy (FCS), we captured bromelain aggregation at concentrations as low as ~20 nM, surpassing the detection limit of traditional methods like thioflavin T fluorescence, scattering, and fluorescence microscopy by more than one order of magnitude. Moreover, using thioflavin T fluorescence-based FCS, we have detected larger aggregates at higher bromelain concentrations, which is undetectable in FCS otherwise. Importantly, our study reveals inherent heterogeneity in bromelain aggregation, inaccessible to ensemble-averaged techniques. The presented report may provide a platform for the characterization of premature aggregates at very low protein concentrations, which are thought to be functionally significant species in protein aggregation-induced diseases.

Exploring the Therapeutic Potential of Bromelain: Applications, Benefits, and Mechanisms.

Bromelain is a mixture of proteolytic enzymes primarily extracted from the fruit and stem of the pineapple plant (Ananas comosus). It has a long history of traditional medicinal use in various cultures, particularly in Central and South America, where pineapple is native. This systematic review will delve into the history, structure, chemical properties, and medical indications of bromelain. Bromelain was first isolated and described in the late 19th century by researchers in Europe, who identified its proteolytic properties. Since then, bromelain has gained recognition in both traditional and modern medicine for its potential therapeutic effects.

Interfacial Protein Fibril Polymorphisms Regulate In Vivo Adipose Expansion for Control of Obesity.

Obesity is becoming a worldwide pandemic. Interfacial engineering of food lipid is expected to inhibit diet-induced obesity without damage to the eating enjoyment brought by high-fat diets. Unfortunately, this strategy has not been achieved yet. After screening different plant proteins, bromelain and papain were found to form wormlike and long-straight protein fibrils, respectively. The conversion of long-straight amyloid-like fibrils to wormlike fibrils was demonstrated in the fibrillation of bromelain. Using oil-in-water high internal phase emulsions (HIPEs) as a proof of concept, bromelain fibrils showed dramatically stronger interfacial stabilization capabilities than papain fibrils with high application potentials in the real-world formulation of high-fat food products such as mayonnaise. Compared with papain fibrils, oral administration of HIPEs stabilized by bromelain fibrils resulted in substantially higher fecal lipid contents and significantly decreased expression levels of the genes related to lipid absorption and transport in the intestine, including CD36, FATP-2, FATP-4, and APOA-4, without a difference in intervening gut microbiota. Consequently, dramatically less lipid absorption in the small intestine, markedly smaller chylomicron particles in the plasma, lower serum triglycerides, and controlled energy and lipid metabolism, as well as the inhibition of adipose expansion and overweight, were observed in the group with gavage of HIPEs stabilized by the bromelain fibrils rather than the papain fibrils. Furthermore, with the same calorie, substitution of all the fat in the standard high-fat feed of mice with the HIPEs emulsified by the bromelain fibrils showed a significantly stronger effect than the ones prepared by the papain fibrils on preventing high-fat-diet (HFD)-induced obesity including alleviation of adipose expansion and inflammation as well as fatty liver, also via inhibiting the absorption and transport of lipid in the intestine. The effect is ascribed to the suppressed lipolysis caused by a more compact and elastic interfacial layer formed by the wormlike fibrils than that of the long-straight fibrils, which are resistant to gastric environments and replacement by bile acids in digestion. Therefore, we provide an appealing and general strategy for controlling obesity by reducing the supply of free fatty acids (FAs) for absorption in the enteric lumen through protein fibril polymorphisms at the interface.

A review on the immobilization of bromelain.

This review shows the endeavors performed to prepare immobilized formulations of bromelain extract, usually from pineapple, and their use in diverse applications. This extract has a potent proteolytic component that is based on thiol proteases, which differ depending on the location on the fruit. Stem and fruit are the areas where higher activity is found. The edible origin of this enzyme is one of the features that determines the applications of the immobilized bromelain to a more significant degree. The enzyme has been immobilized on a wide diversity of supports via different strategies (covalent bonds, ion exchange), and also forming ex novo solids (nanoflowers, CLEAs, trapping in alginate beads, etc.). The use of preexisting nanoparticles as immobilization supports is relevant, as this facilitates one of the main applications of the immobilized enzyme, in therapeutic applications (as wound dressing and healing components, antibacterial or anticancer, mucus mobility control, etc.). A curiosity is the immobilization of this enzyme on spores of probiotic microorganisms via adsorption, in order to have a perfect in vivo compatibility. Other outstanding applications of the immobilized enzyme are in the stabilization of wine versus haze during storage, mainly when immobilized on chitosan. Curiously, the immobilized bromelain has been scarcely applied in the production of bioactive peptides.

A Nutraceutical Combination of Bromelain and Boswellia Serrata Casperome® in Siben®: Effects on the Postoperative Course of Inguinal Hernioplasty with Mesh at One Year Follow up. A Randomized Multicentric Study.

AIM: We investigated the potential benefits of administering a nutraceutical combination of Bromelain (200 mg) and Boswellia serrata Casperome® (200 mg) on post-operative outcomes of hernioplasty with mesh. METHODS: One hundred eighty patients (27 females, 153 males) were enrolled to undergo open tension-free hernioplasty with the use of Progrip®. Patients were randomized to receive either one tablet of Siben® (study group) or placebo (control group) on an empty stomach, every twelve hours for eleven postoperative days. All patients filled out a medical questionnaire focused on postoperative pain, based on the Visual Analogue Scale (VAS) scale and the Short Form-36 (SF-36) questionnaire, at time T0 (day of surgery) and T28 (28th day after surgery). RESULTS: One-year results showed a significant improvement in the primary postoperative outcome in the study group. Perception of pain was significantly reduced in the Siben® group compared with controls, both on the seventh (p < 0.05) and the twenty-first (p < 0.05) postoperative day. Patients included in the Siben® group also resumed daily activities and returned to work earlier than the controls. Moreover, results of the SF-36 indicated better Quality of Life (QoL) scores in the study group compared to the placebo group. CONCLUSIONS: Our analysis effectively demonstrates that the use of Siben® in open inguinal hernia mesh repair may improve short- and long-term surgical outcomes, contributing to a better QoL.

Optimization and mechanisms of proteolytic enzyme immobilization onto large-pore mesoporous silica nanoparticles: Enhanced tumor penetration.

Immobilization of proteolytic enzymes onto nanocarriers is effective to improve drug diffusion in tumors through degrading the dense extracellular matrix (ECM). Herein, immobilization and release behaviors of hyaluronidase, bromelain, and collagenase (Coll) on mesoporous silica nanoparticles (MSNs) were explored. A series of cationic MSNs (CMSNs) with large and adjustable pore sizes were synthesized, and investigated together with two anionic MSNs of different pore sizes. CMSNs4.0 exhibited the highest enzyme loading capacity for hyaluronidase and bromelain, and CMSNs4.5 was the best for Coll. High electrostatic interaction, matched pore size, and large pore volume and surface area favor the immobilization. Changes of the enzyme conformations and surface charges with pH, existence of a space around the immobilized enzymes, and the depth of the pore structures, affect the release ratio and tunability. The optimal CMSNs-enzyme complexes exhibited deep and homogeneous penetration into pancreatic tumors, a tumor model with the densest ECM, with CMSNs4.5-Coll as the best. Upon loading with doxorubicin (DOX), the CMSNs-enzyme complexes induced high anti-tumor efficiencies. Conceivably, the DOX/CMSNs4.5-NH2-Coll nanodrug exhibited the most effective tumor therapy, with a tumor growth inhibition ratio of 86.1 %. The study provides excellent nanocarrier-enzyme complexes, and offers instructive theories for enhanced tumor penetration and therapy.

Valorization of Pineapple (Ananas comosus) By-Products in Milk Coffee Beverage: Influence on Bioaccessibility of Phenolic Compounds.

The industrial processing of pineapples generates a substantial quantity of by-products, including shell, crown, and core. Bromelain, a proteolytic enzyme found naturally in pineapple, including its by-products, may positively influence the bioaccessibility of phenolics from milk coffee. Therefore, this study aimed to assess how the inclusion of extracts from pineapple by-products, namely shell, crown and core, could impact the bioaccessibility of coffee phenolics when combined with milk. After measuring the proteolytic activity of pineapple by-products, the standardized in vitro digestion model of INFOGEST was employed to evaluate changes in total phenolic content, total antioxidant capacity, and individual phenolic compounds in different coffee formulations. The results showed that incorporating extracts from the crown or core in both black and milk coffee increased the bioaccessibility of total phenolics (from 93 to 114% to 105-129%) and antioxidants (from 54 to 56% to 84-87%), while this effect was not observed for the shell. Moreover, adding core extracts also enhanced the bioaccessibility of caffeoylquinic acids and gallic acid in milk coffee (from 0.72 to 0.85% and 109-155%, respectively). Overall, the findings of this study highlight that bromelain from pineapple core may have a favorable effect on the recovery of phenolic compounds in milk coffee, possibly due to its ability to cleave proteins. These outcomes point out that industrial by-products can be transformed into economic value by being reintroduced into the production process through suitable treatment instead of disposal.

Enhancing the Efficacy of HIPEC Through Bromelain: A Preclinical Investigation in Appendiceal Cancer.

INTRODUCTION: Appendiceal cancer (AC) excessive mucin production is a barrier to heated intraperitoneal chemotherapy (HIPEC) drug delivery. Bromelain is a pineapple stem extract with mucolytic properties. We explored bromelain treatment effects against mucinous AC in a patient-derived tumor organoid (PTO) model and an AC cell line. PATIENTS AND METHODS: PTOs were fabricated from tumor specimens obtained from patients with AC undergoing cytoreductive surgery with HIPEC. PTOs underwent HIPEC treatment with bromelain, cisplatin, and mitomycin C (MMC) at 37 °C and 42 °C with and without bromelain pretreatment. RESULTS: From October 2020 to May 2023, 16 specimens were collected from 13 patients with low-grade (12/16, 75%) and high-grade AC (4/16, 25%). The mucin-depleting effects of bromelain were most significant in combination with N-acetylcysteine (NAC) compared with bromelain (47% versus 10%, p = 0.0009) or NAC alone (47% versus 12.8%, p = 0.0027). Bromelain demonstrated > 31% organoid viability reduction at 60 min (p < 0.001) and > 66% in 48 h (p < 0.0001). Pretreatment with bromelain increased cytotoxicity of both cisplatin and MMC HIPEC conditions by 31.6% (p = 0.0001) and 35.5% (p = 0.0001), respectively. Ki67, CK20, and MUC2 expression decreased after bromelain treatment; while increased caspase 3/7 activity and decreased Bcl-2 (p = 0.009) and Bcl-xL (p = 0.01) suggest induction of apoptosis pathways. Furthermore, autophagy proteins LC3A/B I (p < 0.03) and II (p < 0.031) were increased; while ATG7 (p < 0.01), ATG 12 (p < 0.04), and Becline 1(p < 0.03), expression decreased in bromelain-treated PTOs. CONCLUSIONS: Bromelain demonstrates cytotoxicity and mucolytic activity against appendiceal cancer organoids. As a pretreatment agent, it potentiates the cytotoxicity of multiple HIPEC regimens, potentially mediated through programmed cell death and autophagy.

Addressing the interaction of stem bromelain with different anionic surfactants, below, at and above the critical micelle concentration (cmc) in phosphate buffer at pH 7: Physicochemical, spectroscopic, & molecular docking study.

The structural stability and therapeutic activity of Stem Bromelain (BM) have been explored by unravelling the interaction of stem BM in presence of two different types of anionic surfactants namely, bile salts, NaC and NaDC and the conventional anionic surfactants, SDDS and SDBS, below, at and above the critical micelle concentration (cmc) in aqueous phosphate buffer of pH 7. Different physicochemical parameters like, surface excess (Γcmc), minimum area of surfactants at air water interface (Amin) etc. are calculated from tensiometry both in absence and presence of BM. Several inflection points (C1, C2 and C3) have been found in tensiometry profile of surfactants in presence of BM due to the conformational change of BM assisted by surfactants. Similar observation also found in isothermal titration calorimetry (ITC) profiles where the enthalpy of micellization (ΔH0obs) of surfactants in absence and presence of BM have calculated. Further, steady state absorption and fluorescence spectra monitoring the tryptophan (Trp) emission of free BM and in presence of all the surfactants at three different temperatures (288.15 K, 298.15 K, and 308.15 K) reveal the nature of fluorescence quenching of BM in presence of bile salts/surfactants. Time resolved fluorescence studies at room temperature also support to determine the several quenching parameters. The binding constant (Kb) of BM with all the surfactants and free energy of binding (∆G0 of bile salts/surfactants with BM at different temperatures have been calculated exploiting steady state fluorescence technique. It is observed that, the binding of NaC with BM is greater as compared to other surfactants while Stern-Volmer quenching constant (KSV) is found greater in presence of SDBS as compared with others which supports the surface tension and ITC data with the fact that surface activity of surfactant(s) is decreasing with the binding of the surfactants at the core or binding pocket of BM. Circular Dichroism (CD) study shows the stability of secondary structure of BM in presence of NaC and NaDC below C3, while BM lost its structural stability even at very low surfactant concentration of SDDS and SDBS which also supports the more involvement of bile salts in binding rather than surfactants. The molecular docking studies have also been substantiated for better understanding the several experimental investigations interaction of BM with the bile salts/surfactants.

Burn Wounds and Enzymatic Debridement (ED)-Past, Present, and Future.

INTRODUCTION: Excision of necrotic and devitalized tissues of deep burns is key for optimal care of burn injuries. However, the modality of early tangential excision followed by skin grafting proposed by Zora Janzekovic 5 decades ago was not received initially with great enthusiasm. At present, it developed to become the standard of care (SOC) despite the special expertise it necessitates and the general anesthesia it requires in addition to several drawbacks including excessive blood loss, risk of hypothermia, and most importantly potential excision of normal non-burned tissues. Conservative non-surgical selective enzymatic debridement (ED) at present is becoming more popular as an adjunct or even an alternative approach. METHODS: A systematic review of the PubMed electronic database was conducted to identify all experimental and clinical studies about ED of burn wounds. Additional separate searches were also conducted to identify any reports missed by the initial systematic review. Full texts of 59 reports (42 clinical and 17 experimental studies) were retrieved for analysis. RESULTS: A total of 46 studies (11 experimental and 35 clinical) were about the pineapple extract debriding agent. In total, 23 clinical studies describing promising favorable results with pineapple bromelain-based debridement (BBD) concentrate were published in the last 3 years (2020-2023). CONCLUSION: Though available evidence is not entirely in favor of replacing the current surgical SOC with BBD, it certainly presents ED as a highly advantageous modality for the management of burn wounds. Newly described keratinase and SN514 also are promising new products. They both still await further investigation before being clinically adopted.

Bacterial nanocellulose loaded with bromelain and nisin as a promising bioactive material for wound debridement.

The bacterial nanocellulose (BnC) membranes were produced extracellularly by a novel aerobic acetic acid bacterium Komagataeibacter melomenusus. The BnC was modified in situ by adding carboxymethyl cellulose (CMC) into the culture media, obtaining a BnC-CMC product with denser fibril arrangement, improved rehydration ratio and elasticity in comparison to BnC. The proteolytic enzyme bromelain (Br) and antimicrobial peptide nisin (N) were immobilized to BnC matrix by ex situ covalent binding and/or adsorption. The optimal Br immobilization conditions towards the maximized specific proteolytic activity were investigated by response surface methodology as factor variables. At optimal conditions, i.e., 8.8 mg/mL CMC and 10 mg/mL Br, hyperactivation of the enzyme was achieved, leading to the specific proteolytic activity of 2.3 U/mg and immobilization efficiency of 39.1 %. The antimicrobial activity was observed against Gram-positive bacteria (S. epidermidis, S. aureus and E. faecalis) for membranes with immobilized N and was superior when in situ modified BnC membranes were used. N immobilized on the BnC or BnC-CMC membranes was cytocompatible and did not cause changes in normal human dermal fibroblast cell morphology. BnC membranes perform as an efficient carrier for Br or N immobilization, holding promise in wound debridement and providing antimicrobial action against Gram-positive bacteria, respectively.

Modulation of fried spring roll wrapper quality upon treatment of batter with maltogenic amylase, transglutaminase and bromelain.

BACKGROUND: Fried foods are favored for their unique crispiness, golden color and flavor, but they also face great challenge because of their high oil content, high calories and the existence of compounds such as acrylamide and polycyclic aromatic hydrocarbons. Long-term consumption of fried foods may adversely affect health. Therefore, it is necessary to explore fried foods with lower oil contents and a high quality to meet the demand. RESULTS: A method of enzyme treatment was explored to investigate the effects of maltogenic amylase (MA), transglutaminase (TG) and bromelain (BRO) on the physicochemical properties of the batter and the quality of fried spring roll wrapper (FSRW). The results showed that the MA-, TG- or BRO-treated batters had a significant shear-thinning behavior, especially with an increase in viscosity upon increasing TG contents. FSRW enhanced its fracturability from 419.19 g (Control) to 616.50 g (MA-6 U g-1), 623.49 g (TG-0.75 U g-1) and 644.96 g (BRO-10 U g-1). Meanwhile, in comparison with BRO and MA, TG-0.5 U g-1 endowed batter with the highest density and thermal stability. MA-15 U g-1 and TG-0.5 U g-1 displayed FSRW with uniform and dense pores, and significantly reduced its oil content by 18.05% and 25.02%, respectively. Moreover, compared to MA and TG, BRO-50 U g-1 improved the flavor of FSRW. CONCLUSION: MA, TG or BRO played a key role in affecting the physicochemical properties of the batter and the quality of FSRW. TG-0.5 U g-1 remarkly reduced the oil content of FSRW with a great potential in practical application. © 2024 Society of Chemical Industry.

Assessing the Effect of Enzymatic Debridement on the Scar Quality in Partial-Thickness Burns to Deep Dermal Burns of the Hand: A Long-Term Evaluation.

Background and Objectives: Burn surgery on the hands is a difficult procedure due to the complex anatomy and fragility of the area. Enzymatic debridement has been shown to effectively remove burn eschar while minimizing damage to the surrounding tissue and has therefore become a standard procedure in many burn centers worldwide over the past decade. However, surprisingly, our recent literature review showed limited valid data on the long-term scarring after the enzymatic debridement of the hands. Therefore, we decided to present our study on this topic to fill this gap. Materials and Methods: This study analyzed partial-thickness to deep dermal burns on the hands that had undergone enzymatic debridement at least 12 months prior. Objective measures, like flexibility, trans-epidermal water loss, erythema, pigmentation, and microcirculation, were recorded and compared intraindividually to the uninjured skin in the same area of the other hand to assess the regenerative potential of the skin after EDNX. The subjective scar quality was evaluated using the patient and observer scar assessment scale (POSAS), the Vancouver Scar Scale (VSS), and the "Disabilities of the Arm, Shoulder, and Hand" (DASH) questionnaire and compared interindividually to a control group of 15 patients who had received traditional surgical debridement for hand burns of the same depth. Results: Between January 2014 and December 2015, 31 hand burns in 28 male and 3 female patients were treated with enzymatic debridement. After 12 months, the treated wounds showed no significant differences compared to the untreated skin in terms of flexibility, trans-epidermal water loss, pigmentation, and skin surface. However, the treated wounds still exhibited significantly increased blood circulation and erythema compared to the untreated areas. In comparison to the control group who received traditional surgical debridement, scarring was rated as significantly superior. Conclusions: In summary, it can be concluded that the objective skin quality following enzymatic debridement is comparable to that of healthy skin after 12 months and subjectively fares better than that after tangential excision. This confirms the superiority of enzymatic debridement in the treatment of deep dermal burns of the hand and solidifies its position as the gold standard.

An Evaluation of the Effects of Pineapple-Extract and Bromelain-Based Treatment after Mandibular Third Molar Surgery: A Randomized Three-Arm Clinical Study.

A three-arm, randomized, placebo-controlled clinical study was conducted to assess the impact of lyophilized pineapple extract with titrated bromelain (Brome-Inf®) and purified bromelain on pain, swelling, trismus, and quality of life (QoL) following the surgical extraction of the mandibular third molars. Furthermore, this study examined the need for Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) by comparing their effects with a placebo group. This study enrolled 42 individuals requiring the extraction of a single mandibular third molar under local anesthesia. The patients were randomly assigned to receive Brome-Inf®, purified bromelain, or a placebo orally, initiating treatment on the day of surgery and continuing for the next 7 days. The primary outcome measured was the requirement for NSAIDs in the three groups. Pain, swelling, and trismus were secondary outcome variables, evaluated postoperatively at 1, 3, and 7 days. This study also assessed the comparative efficacy of freeze-dried pineapple extract and single-component bromelain. Ultimately, the placebo group showed a statistically higher need for ibuprofen (from days 1 to 7) at the study's conclusion (p < 0.0001). In addition, reductions in pain and swelling were significantly higher in both the bromelain and pineapple groups (p < 0.0001 for almost all patients, at all intervals) than in the placebo group. The active groups also demonstrated a significant difference in QoL compared to the placebo group (p < 0.001). A non-significant reduction in trismus occurred in the treatment groups compared to the placebo group. Therefore, the administration of pineapple extract titrated in bromelain showed significant analgesic and anti-edema effects in addition to improving QoL in the postoperative period for patients who had undergone mandibular third molar surgery. Moreover, both bromelain and Brome-Inf® supplementation reduced the need for ibuprofen to comparable extents, proving that they are good alternatives to NSAIDs in making the postoperative course more comfortable for these patients. A further investigation with larger samples is necessary to assess the pain-relieving and anti-inflammatory impacts of the entire pineapple phytocomplex in surgical procedures aside from mandibular third molar surgery.

Forward Light Scattering of the Vitreous Gel After Enzymatic Aging: An In Vitro Model to Study Vitreous Opacification.

Purpose: Symptomatic vitreous opacifications, so-called floaters, are difficult to objectively assess majorly limiting the possibility of in vitro studies. Forward light scattering was found previously to be increased in eyes with symptomatic floaters. Using an objective setup to measure forward light scattering, we studied the effects of enzymatically digesting the components of the vitreous body on straylight to develop an in vitro model of vitreous opacifications. Methods: Fifty-seven porcine vitreous bodies were digested using hyaluronidase, collagenase, trypsin, and bromelain, as well as using a combination of hyaluronidase + collagenase and hyaluronidase + bromelain. A modified C-Quant setup was used to objectively assess forward light scattering. Results: Depletion of hyaluronic acid majorly increased vitreous straylight (mean increase 34.4 deg2/sr; P = 0.01), whereas primarily digesting the vitreous gel with collagenase or trypsin did not significantly affect straylight. When collagenase or bromelain is applied in hyaluronic acid depleted vitreous gels, the increase in forward light scattering is reversed partially. Conclusions: The age-related loss of hyaluronic acid primarily drives the increase in vitreous gel straylight induced by conglomerates of collagen. This process can be reversed partially by digesting collagen. This in vitro model allows the objective quantification and statistical comparison of straylight burden caused by vitreous opacities and, thus, can serve as a first testing ground for pharmacological therapies, as demonstrated with bromelain.

Evaluation of Stain Removal Efficacy and Color Stability of Three Different Dentifrices on Artificially Stained Enamel Surface-An In Vitro Study.

AIM: The aim of the present study was to assess the stain removal ability and color stability of three distinct dentifrices on artificially stained enamel surface. MATERIALS AND METHODS: This study included 75 intact, healthy premolars free of dental caries that were extracted during orthodontic therapy. The samples were allowed to dry for 6 hours after being submerged in the prepared tea solution for roughly 18 hours every day. Then this procedure was repeated for seven successive days. All samples were randomly divided into three experimental groups with 25 samples in each group. Group I: control dentifrice, group II: dentifrice containing hydrogen peroxide, group III: dentifrice containing papain and bromelain. A specially designed toothbrushing simulator was used to brush every sample in the relevant group. Using a spectrophotometer and a measurement program, color measurement was evaluated after staining process after 4 weeks and 8 weeks of teeth cleaning. Using a profilometer, the surface roughness values (Ra) were assessed. RESULTS: After 8 weeks of brushing of stained samples, the color stability was better in dentifrice containing hydrogen peroxide (1.14 ± 0.11) followed by dentifrice containing papain and bromelain (1.22 ± 0.08) and control group (1.30 ± 0.09). And after 8 weeks of brushing of stained samples, the surface roughness was more in dentifrice containing hydrogen peroxide (0.237 ± 0.02) followed by dentifrice containing papain and bromelain (0.229 ± 0.13) and control group (0.207 ± 0.05). CONCLUSION: The present study concluded that the dentifrice containing hydrogen peroxide showed a superior whitening effect on the stained enamel surface than dentifrice containing papain and bromelain and control dentifrice. CLINICAL SIGNIFICANCE: The development of various dentifrice products has been greatly aided by the increased demand for an improved esthetic appearance. Teeth's natural color and any external stains that could accumulate on the tooth surface combine to determine a tooth's color. Additionally, the use of whitening dental pastes to remove external stains has grown in favor. With the development of these whitening toothpastes, dentifrices' ability to lessen or eliminate extrinsic dental stains has increased. How to cite this article: Mishra D, Kamath DG, Alagla M, et al. Evaluation of Stain Removal Efficacy and Color Stability of Three Different Dentifrices on Artificially Stained Enamel Surface-An In Vitro Study. J Contemp Dent Pract 2024;25(1):68-71.

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.