Anti-inflammatory Properties of Bioactive Peptide Derived from Gastropod Influenced by Enzymatic Hydrolysis

Anti-inflammatory peptide therapeutics and the role of sulphur containing amino acids (cysteine and methionine) in inflammation suppression: A review

BACKGROUND

Inflammation serves as our body's immune response to combat infections, pathogens, viruses, and external stimuli. Inflammation can be classified into two types: acute inflammation and chronic inflammation. Non-steroidal anti-inflammatory medications (NSAIDs) are used to treat both acute and chronic inflammatory disorders. However, these treatments have various side effects such as reduced healing efficiency, peptic ulcers, gastrointestinal toxicities, etc. METHOD: This review assesses the potential of anti-inflammatory peptides (AIPs) derived from various natural sources, such as algae, fungi, plants, animals, and marine organisms. Focusing on peptides rich in cysteines and methionine, sulphur-containing amino acids known for their role in suppression of inflammation.

RESULT

Due to their varied biological activity, ability to penetrate cells, and low cytotoxicity, bioactive peptides have garnered interest as possible therapeutic agents. The utilisation of AIPs has shown great potential in the treatment of disorders associated with inflammation. AIPs can be obtained from diverse natural sources such as algae, fungi, plants, and animals. Cysteine and methionine are sulphur-containing amino acids that aid in the elimination of free radicals, hence assisting in the treatment of inflammatory diseases.

CONCLUSION

This review specifically examines several sources of AIPs including peptides that contain numerous cysteines and methionine. In addition, the biological characteristics of these amino acids and advancements in peptide delivery are also discussed.

Bioactivities of Garcinia kola enzymatic hydrolysates at different enzyme-substrate ratios

Natural products, such as enzymatic hydrolysates and bioactive peptides from dietary sources, are safe alternatives to synthetic compounds linked to various deleterious effects. The purpose of this study is to determine the in vitro bioactivities (antioxidant and anti-inflammatory activities) of Garcinia kola seeds enzymatic hydrolysates (GKPHs) at different enzyme (pepsin)-substrate ratios. G. kola protein, isolated by alkaline solubilization and acid precipitation, was hydrolyzed with pepsin at varying enzyme-substrate (E:S) ratios. The antioxidant parameters investigated include 1,1-diphenyl-2-picrylhydrazyl (DPPH)-radical scavenging, hydrogen peroxide scavenging and ferrous ion (Fe²⁺) chelating activities. For anti-inflammatory properties, membrane stabilization and protein denaturation activities tests were used. GKPH produced at 1:32 had the highest degree of hydrolysis (66.27 ± 4.21%). All GKPHs had excellent in vitro anti-inflammatory properties. However, only enzymatic hydrolysates produced at 1:16 (E:S) ratio chelated iron (II) and as well had the highest percentage hemolysis inhibition of 84.45 ± 0.007%, percentage protein denaturation inhibition of 53.36 ± 0.01% at maximum concentration and exhibited highest DPPH scavenging activity (87.24 ± 0.10%). The enzymatic hydrolysates had excellent solubility, emulsifying and foaming properties. It could be deduced from this study that pepsin at a ratio of 1:16 of G. kola protein produced the most effective enzymatic hydrolysates in terms of their antioxidant and anti-inflammatory activities. G. kola pepsin enzymatic hydrolysates, thus, have potential in development as functional foods and as therapeutics pharmaceutical industries in the management of diseases associated with oxidative stress and inflammation owing to their excellent functional, antioxidant and anti-inflammatory properties.

In vitro antioxidant and anti-inflammatory properties of Artocarpus altilis (Parkinson) Fosberg (seedless breadfruit) fruit pulp protein hydrolysates

Protein hydrolysates from dietary sources possess many physiological and biological properties. Artocarpus altilis is an evergreen multipurpose plant with many benefits. Therefore, this study evaluates in vitro antioxidant and anti-inflammatory properties of A. altilis protein hydrolysates. Protein was isolated from A. altilis and hydrolysed with pepsin and trypsin separately using different enzyme: substrate ratios (1:8, 1:16, 1:32). Antioxidant properties investigated included Fe²⁺-chelating, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and hydrogen peroxide radical scavenging activities. Anti-inflammatory activities were determined using effects on hypotonic solution-induced cell lysis on red blood cell membrane stabilisation and heat-induced protein denaturation. The degree of hydrolysis of trypsin hydrolysate increased with increasing enzyme-substrate ratio, while pepsin hydrolysate decreased as the enzyme-substrate ratio increased. The dominant amino acids in A. altilis protein and hydrolysates were glutamate, aspartate and leucine. Protein hydrolysates obtained from pepsin and trypsin digestion had DPPH scavenging abilities of 43.0 ± 0.01% and 22.2 ± 0.01%, respectively. However, trypsin-hydrolysed protein had a high Fe²⁺-chelating ability, while pepsin-hydrolysed protein had high hydrogen peroxide scavenging ability. Trypsin-hydrolysed protein showed good membrane stability and inhibition of protein denaturation. The results indicated that A. altilis protein hydrolysates possess significant antioxidant and anti-inflammatory effects and can further lend support to food industries as functional foods.

Peptides and protein hydrolysates exhibiting anti-inflammatory activity: sources, structural features and modulation mechanisms

Inflammation is the response of the immune system to harmful stimuli such as tissue injury, infection or toxic chemicals, which has the aim of eliminating irritants or pathogenic microorganisms and enhancing tissue repair. Uncontrolled long-lasting acute inflammation can gradually progress to chronic, causing a variety of chronic inflammatory diseases that are usually treated with anti-inflammatory drugs, but most of them are inadequate to control chronic responses and are also associated with adverse side effects. Thus, many efforts are being directed to develop alternative and more selective anti-inflammatory therapies from natural products. One main field of interest is the obtaining of bioactive peptides exhibiting anti-inflammatory activity from sustainable protein sources like edible insects or agroindustry and fishing by-products. This work highlighted the structure-activity relationship of anti-inflammatory peptides. Small peptides with molecular weight under 1 kDa and amino acid chain length between 2 to 20 residues are generally the most active because of the higher probability to be absorbed in the intestine and penetrate into cells when compared with the larger size peptides. The presence of hydrophobic (Val, Ile, Pro) and positively charged (His, Arg, Lys) amino acids is another common occurrence for anti-inflammatory peptides. Interestingly, a high percentage (77%) of these bioactive peptides can be found in alternative sustainable protein sources such as Tenebrio molitor or sunflower, apart from its original protein source. However, not all of these peptides with anti-inflammatory potential in vitro achieve good scores by the in silico bioactivity predictors studied. Therefore, it is essential to implement current bioinformatics tools, in order to complement in vitro experiments with prior prediction of potential bioactive peptides.

Fish and Shellfish-Derived Anti-Inflammatory Protein Products: Properties and Mechanisms

The interest in utilizing food-derived compounds therapeutically has been rising. With the growing prevalence of systematic chronic inflammation (SCI), efforts to find treatments that do not result in the side effects of current anti-inflammatory drugs are underway. Bioactive peptides (BAPs) are a particularly promising class of compounds for the treatment of SCI, and the abundance of high-quality seafood processing byproducts (SPB) makes it a favorable material to derive anti-inflammatory BAPs. Recent research into the structural properties of anti-inflammatory BAPs has found a few key tendencies including they tend to be short and of low molecular weight (LMW), have an overall positive charge, contain hydrophobic amino acids (AAs), and be rich in radical scavenging AAs. SPB-derived anti-inflammatory BAPs have been observed to work via inhibition of the NF-κB and MAPK pathways by disrupting the phosphorylation of IκBα and one or more kinases (ERK, JNK, and p38), respectively. Radical scavenging capacity has also been shown to play a significant role in the efficacy of SPB-derived anti-inflammatory BAPs. To determine if SPB-derived BAPs can serve as an effective treatment for SCI it will be important to understand their properties and mechanisms of action, and this review highlights such findings in recent research.

Use of Alcalase in the production of bioactive peptides: A review

This review aims to cover the uses of the commercially available protease Alcalase in the production of biologically active peptides since 2010. Immobilization of Alcalase has also been reviewed, as immobilization of the enzyme may improve the final reaction design enabling the use of more drastic conditions and the reuse of the biocatalyst. That way, this review presents the production, via Alcalase hydrolysis of different proteins, of peptides with antioxidant, angiotensin I-converting enzyme inhibitory, metal binding, antidiabetic, anti-inflammatory and antimicrobial activities (among other bioactivities) and peptides that improve the functional, sensory and nutritional properties of foods. Alcalase has proved to be among the most efficient proteases for this goal, using different protein sources, being especially interesting the use of the protein residues from food industry as feedstock, as this also solves nature pollution problems. Very interestingly, the bioactivities of the protein hydrolysates further improved when Alcalase is used in a combined way with other proteases both in a sequential way or in a simultaneous hydrolysis (something that could be related to the concept of combi-enzymes), as the combination of proteases with different selectivities and specificities enable the production of a larger amount of peptides and of a smaller size.

Anti-inflammatory potential of novel hexapeptide derived from Meretrix meretrix foot and its functional properties

The study aimed to identify bioactive peptide from Meretrix meretrix Linnaeus foot (MMF) and examine its potential of suppressing inflammation. In brief, the anti-inflammatory activity was identified by erythrocyte membrane protection and protein denaturation assay from MMF peptic 9th-h hydrolysate and was separated with three molecular weight cut-off units. The obtained four fractions were testified for activity and the fraction (10-3 kDa) with maximum activity was purified using gel permeation chromatography. Finally, the peptide sequence was identified as Asn-Pro-Ala-Gln-Asp-Cys (647.559 Da) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The hexapeptide was characterised for functional properties at different pH range. The non-toxic hexapeptide was able to reduce the cyclooxygenase (COX)-2 activation, pro-inflammatory cytokines and nitric oxide (NO) production significantly in RAW264.7 macrophage cells. The current results propose that the hexapeptide derived from MMF protein can act as an effective anti-inflammatory against pro-inflammatory cytokines, COX-2 and NO. Moreover, it could be used as an effective alternative source for drugs in pharma and also as an ingredient in food industries.

Anti-Inflammatory Activity of a Peptide from Skipjack (Katsuwonus pelamis)

In this paper, the effect of skipjack (Katsuwonus pelamis) enzymatic peptide (SEP), which was prepared and purified from a byproduct of skipjack, on inflammation, ulcerative colitis and the regulation of intestinal flora was studied in a mouse ulcerative colitis model and a transgenic zebrafish inflammation model. The aggregation of transgenic granulocyte neutrophils in zebrafish from a normal environment and from a sterile environment was calculated, and the anti-inflammatory activity of SEP was evaluated. To evaluate the anti-ulcerative colitis activity of SEP, DSS-induced colitis mice were given SEP, salicylazosulfapyridine (SASP), or SASP + SEP. Then, the concentrations of IL-6, IL-10 and TNF-α in the serum were detected, the HE-stained colon tissue was examined by microscopy the species composition and abundance distribution of the intestinal flora was analyzed. The results showed that 500 μg/mL SEP treatment significantly alleviated neutrophil granulocyte aggregation in the zebrafish inflammation model; Diarrhea, hematochezia and body weight loss were alleviated to a certain extent in mice gavaged with SEP and SASP, and the combination of SASP with SEP was the most effective in mice. The damage to villi in the intestine was completely repaired, and the levels of IL-6, IL-10 and TNF-α, which are associated with inflammation, were all reduced. In addition, the proportion of intestinal probiotics or harmless bacteria increased, while that of pathogenic bacteria decreased, and the effect of the combined treatment was the most pronounced. These results show that SEP could relieve inflammation, cure ulcerative colitis, regulate intestinal flora and enhance the therapeutic effect of the clinical drug SASP. This study provides a theoretical basis for the development of SEP as an anti-inflammatory adjuvant therapy and intestinal flora regulator.

Antioxidant drimane-type sesquiterpenoid from muricid gastropod Chicoreus ramosus attenuates pro-inflammatory 5-lipoxygenase and carbolytic enzymes

The muricid gastropod, Chicoreus ramosus, is a nutrient-enriched food source available along the coastal peninsular of the Indian subcontinent. This study was aimed at bioactivity-directed chromatographic fractionation of the organic extract of C. ramosus to isolate an unprecedented drimane-type sesquiterpenoid Ramosane, characterized as 3-hydroxy-7,9b-dimethyl-5-methylene-8-pentyl-octahydro-1H-cyclopenta[a]naphthalen-9(2H)-one. The compound possessed potential antioxidant activities {2, 2'-diphenyl-1-picryl hydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activities of IC₅₀ 1.42 mM and 1.72 mM, respectively} and was proportionate with those (IC₅₀ 1.39 and 1.69 mM, respectively) exhibited by α-tocopherol. The studied sesquiterpenoid exhibited potential attenuation property countering the pro-inflammatory 5-lipoxygenase (IC₅₀  ~ 4 mM), and its activity was analogous with that exhibited by the anti-inflammatory ibuprofen (IC₅₀ 4.36 mM), whereas its carbolytic α-amylase activity (IC₅₀ 0.96 mM) was commensurate with that displayed by acarbose (IC₅₀ 0.43 mM). The isolated metabolite might anticipate as potential naturally derived bioactive constituent in functional food and pharmaceutical applications. PRACTICAL APPLICATIONS: The edible marine muricid gastropod C. ramosus is a prominently available gastropod species of commercial significance in the coastal regions of Indian Peninsula. An unprecedented drimane-type sesquiterpenoid Ramosane was isolated through the bioactivity-directed chromatographic fractionation of the organic extract of muricidae C. ramosus displaying potential anti-inflammatory and anti-diabetic properties. The present study apprehended the prospective of drimane-type sesquiterpenoid derivative Ramosane purified from C. ramosus as a naturally derived pharmacophore with anti-diabetic and anti-inflammatory potential for utilization in functional food and pharmaceutical formulations to minimize the likelihood of inflammation and hyperglycemic pathologies.

Effect of Enzymatic Digestion of Protein Derivatives Obtained from Mucuna pruriens L. on Production of Proinflammatory Mediators by BALB/c Mouse Macrophages

Inflammation is considered to be a major risk factor for the pathogenesis of chronic non-communicable diseases. Macrophages are important immune cells, which regulate inflammation and host defense by secretion of proinflammatory mediators. Obtaining biopeptides by enzymatic hydrolysis adds value to proteins of vegetative origin, such as Mucuna pruriens L. The present study evaluated the effect of enzymatic digestion of protein derivatives obtained from M. pruriens L. on the production of proinflammatory mediators by BALB/c mouse macrophages. Five different molecular weight peptide fractions were obtained (F > 10, 5-10, 3-5, 1-3, and < 1 kDa, respectively). At 300 μg/mL, F5-10 kDa inhibited 50.26 and 61.00% NO and H₂O₂ production, respectively. Moreover, F5-10 kDa reduced the IL-6 and TNFα levels to 60.25 and 69.54%, respectively. After enzymatic digestive simulation, F5-10 kDa decreased the inflammatory mediators.