Luteolin (LT), present in most plants, has potent anti-inflammatory properties both in vitro and in vivo. Furthermore, some of its derivatives, such as luteolin-7-O-glucoside, also exhibit anti-inflammatory activity. However, the molecular mechanisms underlying luteolin-3′-O-phosphate (LTP)-mediated immune regulation are not fully understood. In this paper, we compared the anti-inflammatory properties of LT and LTP and analyzed their molecular mechanisms of action; we obtained LTP via the biorenovation of LT. We investigated the anti-inflammatory activities of LT and LTP in macrophage RAW 264.7 cells. We confirmed from previously reported literature that LT inhibits the production of nitric oxide and prostaglandin E₂, as well as the expression of inducible NO synthetase and cyclooxygenase-2. In addition, expressions of inflammatory genes and mediators, such as tumor necrosis factor-α, interleukin-6, and interleukin-1β, were suppressed. LTP showed anti-inflammatory activity similar to LT, but better anti-inflammatory activity in all the experiments, while also inhibiting mitogen-activated protein kinase and nuclear factor-kappa B more effectively than LT. At a concentration of 10 μM, LTP showed differences of 2.1 to 44.5% in the activity compared to LT; it also showed higher anti-inflammatory activity. Our findings suggest that LTP has stronger anti-inflammatory activity than LT.

A novel cellulase was characterized from a newly isolated marine bacterium, strain J9-3. Phylogenetic analysis based on the 16S rRNA gene revealed that strain J9-3 belonged to the genus Cellulophaga, and thus, it was named Cellulophaga sp. J9-3. An extracellular cellulase was purified from cell-free culture broth of J9-3 cultured in Marine Broth containing 0.2% carboxymethylcellulose. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the protein revealed a single band with an apparent molecular weight (Mw) of 35 kDa. Based on the NH₂-terminal amino acid sequence (N-N-T-E-Q-T-V-V-D-A-Y-G), the gene (named celA_J93) encoding the protein was identified from J9-3 genomic sequencing data. CelA_J93 was expected to be translated into a premature protein (359 amino acids) and then processed to a mature protein (307 amino acids, Mw = 34,951 Da), which is consistent with our results. CelA_J93 had high homology with many uncharacterized putative glycosyl hydrolases of the genus Cellulophaga and it was highly specific for carboxymethylcellulose and cellooligosaccharides under optimum conditions (pH 7.5, 60 °C). Co²⁺ completely recovered CelA_J93 activity that was severely inhibited by ethylenediaminetetraacetic acid (EDTA), indicating that CelA_J93 required Co²⁺ as a cofactor. Thus, CelA_J93 is a Co²⁺-dependent endo-β-1,4-glucanase that can hydrolyze carboxymethylcellulose and cellooligosaccharides into cellobiose at a relatively high temperature.

In the present study, we investigated the anti-inflammatory and anti-melanogenic effects of Leuconostoc mesenteroides subsp. DB-21-derived exosomes (DB-21 exosomes), isolated from Camellia japonica flower in lipopolysaccharide (LPS)-induced RAW 264.7 macrophage cells and melanocyte-stimulating hormone (α-MSH)-induced B16F10 melanoma cells. We confirmed that DB-21 exosomes were not toxic to LPS-induced RAW 264.7 macrophage cells and α-MSH-induced B16F10 melanoma cells. Moreover, we confirmed that DB-21 exosomes inhibit the pro-inflammatory cytokines IL-6, IL-1β, TNF-α, PGE₂, and the expression of inflammatory factors iNOS and COX-2. We also found that DB-21 exosomes have a concentration-dependent ability to inhibit melanin, TRP-1, TRP-2, tyrosinase, and MITF, which are factors involved in melanogenesis. Additionally, it inhibits the phosphorylation of Akt and GSK-3β, and MAP kinase pathway proteins such as ERK, JNK, and p38. We confirmed that DB-21 exosomes inhibit melanin synthesis in B16F10 cells through various pathways, and based on previous results, they may be used as a functional cosmetic material with anti-inflammatory and anti-melanogenic activities.

The formation of atroposelective biaryl compounds in plants and fungi is well understood; however, polyketide aglycone synthesis and dimerization in bacteria remain unclear. Thus, the biosynthetic gene cluster (BGC) responsible for antibacterial setomimycin production from Streptomyces nojiriensis JCM3382 was examined in comparison with the BGCs of spectomycin, julichromes, lincolnenins, and huanglongmycin. The setomimycin BGC includes post-polyketide synthase (PKS) assembly/cycling enzymes StmD (C-9 ketoreductase), StmE (aromatase), and StmF (thioesterase) as key components. The heterodimeric TcmI-like cyclases StmH and StmK are proposed to aid in forming the setomimycin monomer. In addition, StmI (P-450) is predicted to catalyze the biaryl coupling of two monomeric setomimycin units, with StmM (ferredoxin) specific to the setomimycin BGC. The roles of StmL and StmN, part of the nuclear transport factor 2 (NTF-2)-like protein family and unique to setomimycin BGCs, could particularly interest biochemists and combinatorial biologists. α-Glucosidase, a key enzyme in type 2 diabetes, hydrolyzes carbohydrates into glucose, thereby elevating blood glucose levels. This study aimed to assess the α-glucosidase inhibitory activity of EtOAc extracts of JCM 3382 and setomimycin. The JCM 3382 EtOAc extract and setomimycin exhibited greater potency than the standard inhibitor, acarbose, with IC₅₀ values of 285.14 ± 2.04 μg/mL and 231.26 ± 0.41 μM, respectively. Molecular docking demonstrated two hydrogen bonds with maltase-glucoamylase chain A residues Thr205 and Lys480 (binding energy = −6.8 kcal·mol⁻¹), two π–π interactions with Trp406 and Phe450, and one π–cation interaction with Asp542. Residue-energy analysis highlighted Trp406 and Phe450 as key in setomimycin’s binding to maltase-glucoamylase. These findings suggest that setomimycin is a promising candidate for further enzymological research and potential antidiabetic therapy.

Dimethyl itaconate (DMI) exhibits an anti-inflammatory effect. Activation of nuclear factor erythroid 2-related factor 2 (NRF2) is implicated in the inhibition of melanogenesis. Therefore, DMI and itaconic acid (ITA), classified as NRF2 activators, have potential uses in hyperpigmentation reduction. The activity of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB), an important transcription factor for MITF gene promoter, is regulated by glycogen synthase kinase 3β (GSK3β) and protein kinase A (PKA). Here, we investigated the inhibitory effect of ITA and DMI on alpha-melanocyte-stimulating hormone (α-MSH)-induced MITF expression and the modulatory role of protein kinase B (AKT) and GSK3β in melanogenesis in B16F10 mouse melanoma cells. These cells were incubated with α-MSH alone or in combination with ITA or DMI. Proteins were visualized and quantified using immunoblotting and densitometry. Compared to ITA, DMI treatment exhibited a better inhibitory effect on the α-MSH-induced expression of melanogenic proteins such as MITF. Our data indicate that DMI exerts its anti-melanogenic effect via modulation of the p38 mitogen-activated protein kinase (MAPK) and AKT signaling pathways. In conclusion, DMI may be an effective therapeutic agent for both inflammation and hyperpigmentation.