Inhibition of α-melanocyte-stimulating hormone-induced melanogenesis and molecular mechanisms by polyphenol-enriched fraction of Tagetes erecta L. flower.

BACKGROUND: The pursuit for safe and efficacious skin-whitening agents has prompted a dedicated exploration of plant-derived compounds. Notably, Tagetes erecta L. flowers have been used as a medicinal extract and possessed in vitro mushroom tyrosinase activity. However, whether polyphenol-enriched fraction extracted from T. erecta L. flowers (TE) regulates melanogenesis within cellular and animal models has not yet been investigated. PURPOSE: This study aimed to investigate the effect of TE as a prospective inhibitor of melanogenesis. METHODS: Through advanced UPLC-QTof/MS analysis, the components of TE were analyzed. Anti-melanogenic effects of TE were evaluated in α-melanocyte-stimulating hormone (α-MSH)-stimulated B16F10 melanoma cells by measuring cell viability assay, extracellular and intracellular melanin biosynthesis, cyclic adenosine monophosphate (cAMP) production, and melanogenesis-related gene and protein expression. Zebrafish larvae were employed for in vivo studies, assessing both heart rate and melanogenesis. Furthermore, molecular docking analyses were employed to predict the interaction between TE components and the melanocortin 1 receptor (MC1R). Direct binding activity of TE components to MC1R was compared with [Nle4, d-Phe7]-MSH (NDP-MSH). RESULTS: TE was found to contain significant phenolic compounds such as patulitrin, quercetagetin, kaempferol, patuletin, and isorhamnetin. This study revealed that TE effectively inhibits melanin biosynthesis in both in vitro and in vivo models. This inhibition was attributed to interference of TE with the cAMP-cAMP response element-binding protein (CREB)-microphthalmia-associated transcription factor (MITF)-tyrosinase pathway, which plays a pivotal role in regulating melanogenesis. Importantly, TE exhibited the remarkable ability to curtail α-MSH-induced melanogenesis in zebrafish larvae without impacting heart rates. Molecular docking analyses predicted that the components of TE possibly interact with the melanocortin 1 receptor, suggesting their role as potential inhibitors of melanin biosynthesis. However, through the direct binding activity compared with NDP-MSH, any TE components did not directly bind to MC1R, suggesting that TE inhibits α-MSH-induced melanogenesis by inhibiting the cAMP-mediated intracellular signaling pathway. The assessment of anti-melanogenic activity, conducted both in vitro and in vivo, revealed that patulitrin and patuletin exhibited significant inhibitory effects on melanin formation, highlighting their potency as major contributors. DISCUSSION: This investigation demonstrated the considerable potential of TE as a natural remedy endowed with remarkable anti-melanogenic properties. The demonstrated capacity of TE to attenuate melanin production by modulating the cAMP-CREB-MITF-tyrosinase pathway underscores its central role in management of disorders associated with excessive pigmentation. Importantly, the implications of these findings extend to the cosmetics industry, where TE emerges as a prospective and valuable ingredient for the formulation of skin-whitening products. The elucidated interactions between TE components and MC1R not only provide insight into a potential mechanism of action but also elevate the significance of this study. In summary, this study not only contributes to our comprehension of pigmentation-related conditions but also firmly establishes TE as a secure and natural strategy for the regulation of melanin production. The innovative aspects of TE propel it into the forefront of potential interventions, marking a noteworthy advancement in the pursuit of effective and safe solutions for pigmentation disorders.

Identification and Growth Characteristics of a Gluten-Degrading Bacterium from Wheat Grains for Gluten-Degrading Enzyme Production.

Immunogenic peptides from wheat gluten can be produced during digestion, which are difficult to digest by gastrointestinal proteases and negatively affect immune responses in humans. Gluten intolerance is a problem in countries where wheat is a staple food, and a gluten-free diet is commonly recommended for its treatment and prevention. Enzyme approaches for degradation of the peptides can be considered as a strategy for its prevention. Here, we isolated a gluten-degrading bacterium, Bacillus amyloliquefaciens subsp. plantarum, from wheat grains. The culture conditions for enzyme production or microbial use were considered based on gluten decomposition patterns. Additionally, the pH range for the activity of the crude enzyme was investigated. The bacterium production of gluten-degrading enzymes was temperature-dependent within 25 °C to 45 °C, and the production time decreased with increasing culture temperature. However, it was markedly decreased with increasing biofilm formation. The bacterium decomposed high-molecular-weight glutenin proteins first, followed by gliadin proteins, regardless of the culture temperature. Western blotting with an anti-gliadin antibody revealed that the bacterium decomposed immunogenic proteins related to α/ß-gliadins. The crude enzyme was active in the pH ranges of 5 to 8, and enzyme production was increased by adding gliadin into the culture medium. In this study, the potential of the B. amyloliquefaciens subsp. plantarum for gluten-degrading enzyme production was demonstrated. If further studies for purification of the enzyme specific to the immunogenic peptides and its characteristics are conducted, it may contribute as a strategy for prevention of gluten intolerance.

Effects of Sodium Alginate on the Physical Properties and Storage Stability of Freeze-Dried Tofu Coagulated with Crab Shell Extract.

The amount of processed by-products such as crab shells is increasing, but industrial utilization is insufficient. In our previous study, crab shell extract (CSE) acted as a coagulant for tofu manufacturing. This study aimed to reduce freeze-dried (FD) tofu breakdown by improving its physical properties through adding sodium alginate (SA). FD state in tofu helps increase storage and availability, but FD tofu frequently fractures during processing, which is a concern for manufacturers. Tofu samples were prepared with either crab shell extract (CSE) or MgCl2, and SA, and freeze-dried. In the yields of FD tofu samples, there were no significant differences (p < 0.05). The brokenness of FD tofu samples was lower in CSE than in MgCl2 and was significantly reduced by SA in both tofu samples, which was affected by hardness. The water-holding capacity decreased after freeze-drying, and CSE reduced this decrease, regardless of SA addition. The microstructures differed depending on the coagulant and were dense upon SA addition. The FD tofu was packed into a multilayer film and stored at 25 °C or 45 °C for 6 months to investigate storage stability. During the storage, brokenness was unchanged in all tofu samples, indicating that they maintained their original structure. There were no significant differences in the volatile base nitrogen and thiobarbituric acid values according to the coagulant type and SA addition (p < 0.05). In conclusion, SA reduced FD tofu breakdown by improving the network structure, which may help increase FD tofu quality and decrease economic loss.

Preparation and Taste Profiling of the Enzymatic Protein Hydrolysate from a by-Product of Red Snow Crab Processing as a Natural Seasoning Compound.

The red snow crab (Chionoecetes japonicus) is the most industrially processed in the Republic of Korea, and the meat is very popular, owing to its savory taste and flavor. Its body meat production comprises a two-step separation to increase meat yield. However, during the secondary separation, broken shell debris is occasionally entrained in the meat products, which is a concern for manufacturers. As the residues from first separation contain 39.9% protein, it can be utilized as an enzymatic protein hydrolysate (FPH) rich in free amino acids (FAAs). A combination of flavourzyme and alcalase (1:1) superiorly hydrolyzed the protein of the residues, and the best hydrolysis condition was suggested at 60 °C for 15 h with fourfold water and 2% enzyme addition, achieving a 57.4% degree of hydrolysis. The EPH was mostly composed of FAAs containing most essential amino acids; however, bitter-tasting amino acids accounted for 46.4% of the FAAs. To reduce the bitter taste, different nonvolatile organic acids were considered as masking agents, and citric and malic acids were effective, though the umami taste is slightly decreased. In conclusion, the crab processing residues can be utilized as an FAA-based natural seasoning compound through enzymatic hydrolysis and organic acid treatment.

Occurrence of Cis-11,12-Methylene-Hexadecanoic Acid in the Red Alga Solieria pacifica (Yamada) Yoshida.

Fatty acids in marine algae have attracted the attention of natural chemists because of their biological activity. The fatty acid compositions of the Solieriaceae families (Rhodophyceae, Gaigartinales) provide interesting information that unusual cyclic fatty acids have been occasionally found. A survey was conducted to profile the characteristic fatty acid composition of the red alga Solieria pacifica (Yamada) Yoshida using gas chromatography-mass spectrometry (GC-MS), infrared spectroscopy (IR), and proton nuclear magnetic resonance spectroscopy (1H-NMR). In S. pacifica, two cyclopentyl fatty acids, 11-cyclopentylundecanoic acid (7.0%), and 13-cyclopentyltridecanoic acid (4.9%), and a cyclopropane fatty acid, cis-11,12-methylene-hexadecanoic acid (7.9%) contributed significantly to the overall fatty acid profile. In particular, this cyclopropane fatty acid has been primarily found in bacteria, rumen microorganisms or foods of animal origin, and has not previously been found in any other algae. In addition, this alga contains a significant amount of the monoenoic acid cis-11-hexadecenoic acid (9.0%). Therefore, cis-11,12-methylene-hexadecanoic acid in S. pacifica was likely produced by methylene addition to cis-11-hexadecenoic acid.

Effects of crab shell extract as a coagulant on the textural and sensorial properties of tofu (soybean curd).

To find an economic use of red snow crab (Chionoecetes japonicus) shell waste, we focused on its high mineral content. To evaluate its usability as a coagulant for tofu making, the effects of the crab shell extracts on the textural and sensorial properties of the tofu samples were investigated. The crab shell powder (CSP) and ash (CSA) were used for their extract preparation, and 1%-5% acetic acid treatment led to an abundance of calcium in the resulting extracts. The tofu yields of all the acetic acid extracts were comparable with those of the commercial coagulants MgCl2 and glucono-δ-lactone (GDL). Furthermore, the results for the textural attributes and sensorial acceptability demonstrated that either the extract from CSP prepared with 3% acetic acid or the extracts from CSA prepared with 1% or 3% acetic acid could be used as coagulants, because all the values of the extracts were statistically equivalent to those of the MgCl2 and GDL (p < 0.05).

Antimicrobial and Antibiofilm Activities of Sulfated Polysaccharides from Marine Algae against Dental Plaque Bacteria.

Dental plaque biofilms cause various dental diseases; therefore, inhibiting the growths of the dental plaque bacteria which produce biofilms can be a strategy for preventing dental disease. Certain sulfated polysaccharides from marine algae exert antimicrobial activities against human bacterial pathogens in addition to their physiological benefits. On the basis of these observations, the antimicrobial and antibiofilm activities of sulfated polysaccharides from different marine algae were evaluated against dental plaque bacteria. Among the sulfated polysaccharides, a fucoidan from Fucus vesiculosus showed notable antimicrobial activities against the selected dental plaque bacteria, including some foodborne pathogenic bacteria. The minimum inhibitory concentrations were of 125 to 1000 µg mL-1. Regarding the antibiofilm activity, the fucoidan at the concentrations of above 250 µg mL-1 completely suppressed the biofilm formations and planktonic cell growths of Streptococcus mutans and S. sobrinus. However, no eliminative effect on the completed biofilm was observed. The fucoidan consisted of almost fucose base polysaccharide containing approximately 14.0% sulfate content. The average molecular weight of the fucoidan was changed by heat treatment (121 °C for 15 min) and it affected the antimicrobial activity.