Biorenovation is a microbial enzyme-catalyzed structural modification of organic compounds with the potential benefits of reduced toxicity and improved biological properties relative to their precursor compounds. In this study, we synthesized a novel compound verified as formononetin 7-O-phosphate (FMP) from formononetin (FM) using microbial biotransformation. We further compared the anti-inflammatory properties of FMP to FM in lipopolysaccharide (LPS)-treated RAW264.7 macrophage cells. We observed that cell viabilities and inhibitory effects on LPS-induced nitric oxide (NO) production were greater in FMP-treated RAW 264.7 cells than in their FM-treated counterparts. In addition, FMP treatment suppressed the production of proinflammatory cytokines such as prostaglandin-E₂ (PGE₂), interleukin-6 (IL-6), and interleukin-1β (IL-1β) in a dose-dependent manner and concomitantly decreased the mRNA expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2). We also found that FMP exerted its anti-inflammatory effects through the downregulation of the extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and nuclear factor kappa B (NF-κB) signaling pathways. In conclusion, we generated a novel anti-inflammatory compound using biorenovation and demonstrated its efficacy in cell-based in vitro assays.

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.

Ligularia taquetii (H. Lev. & Vaniot) Nakai has traditionally been used to treat inflammation and skin swelling in the Jeju Island, Korea. The objective of this study was to investigate the anti-inflammatory and anti-adipogenic effects of Ligularia taquetii ethanoic extract (LTE), in lipopolysaccharide (LPS)-stimulated RAW264.7 cells and 3T3-L1 adipocytes. Lipopolysaccharide-induced inflammation was reduced by LTE in a concentration-dependent manner, via the nuclear factor-κB signaling pathway. Ligularia taquetii ethanoic extract (100 µg/mL) inhibited the LPS-induced production of nitric oxide (NO) and inducible nitric oxide synthase (iNOS), by 60% and 100%, respectively. In comparison, 200 and 100 µg/mL LTE suppressed the LPS-stimulated production of prostaglandin-2 (PGE₂) and cyclooxygenase-2 by 50% and 80%, respectively. Ligularia taquetii ethanoic extract also inhibited the secretion of interleukin-1β and interleukin-6 at 300 and 100 μg/mL by 15% and 30%, respectively. High-performance liquid chromatography-photodiode array analysis, combined with mass analysis, revealed chlorogenic acid (CGA) as the anti-inflammatory constituent of LTE. Conversely, 25, 50, 100, and 200 μg/mL LTE lowered the lipid accumulation by 6%, 8%, 25%, and 60%, respectively, while simultaneously increasing cell viability by 7%, 14%, 34%, and 78%. The anti-adipogenic effect of LTE at 100 µg/mL was equivalent to that of CGA at 50 µg/mL. However, LTE treatment promoted cell proliferation by about 30% compared to its CGA-treated counterpart. These results suggest the potential of LTE as a new resource in the discovery of anti-inflammatory and anti-obesity drugs.

The anti-inflammatory activity and non-toxicity of Sonchus oleraceus extract (J6) were tested by measuring its effect on the levels of nitric oxide (NO), prostaglandin E2 (PGE2), and the pro-inflammatory cytokines, interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. We treated the RAW264.7 cells with various concentrations (50, 100, or 200 μg/mL) of J6. Our results showed that J6 inhibited the production of NO, PGE2, and pro-inflammatory cytokines in a concentration-dependent manner, without compromising cell viability. In addition, we provided supporting evidence that the inhibitory activity of J6 on the production of NO and PGE2 occurred via the downregulation of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), respectively. Our findings suggest that J6 is a new source for anti-inflammatory drugs and ingredients for healthcare products that include functional cosmetics.

The increased interest in anti-whitening dyes has enhanced the research interest to identify efficient melanogenic activators. Melanogenesis is the process of melanin production by melanocytes in the hair follicles and skin, which is mediated by several enzymes, such as microphthalmia-associated transcription factor (MITF), tyrosinase (TYR), tyrosinase-related protein (TRP)-1, and TRP-2. This study investigated the melanogenesis-stimulating effect of 4-Methylumbelliferone (4MUMB) and its synthetic derivatives, 7-acetoxy-4-methylcoumarin (7A4MC) and 4-methylheriniarin (4MH) in B16F10 melanoma cells. The cytotoxicity of these compounds was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, followed by the assessment of the melanin content and the intracellular TYR activity. Finally, the expression levels of the key enzymes involved in melanogenesis were investigated. 7A4MC increased melanin production in B16F10 cells relative to that by 4MUMB and 4MH treated cells in a dose-dependent manner without significant cytotoxicity. Concomitantly, 7A4MC significantly increased TYR activity and enhanced the expression of MITF, which significantly induced the expression of TRP-1, TRP-2, and TYR. Furthermore, 7A4MC stimulated melanogenesis via increased phosphorylation of c-Jun N-terminal kinases (JNK) and reduced phosphorylation of protein kinase B (AKT). These results confirmed the melanogenesis-inducing effects of 7A4MC and indicated its potential use as an anti-hair bleaching agent in cosmetics industries.

Tyrosinase ultimately controls the melanogenesis rate of the skin, and tanning and haircare products generally induce the activation of tyrosinase. Moreover, various enzymes, including tyrosinase, tyrosinase-related protein 1 (TRP1), and tyrosinase-related protein 2 (TRP2), mediate melanogenesis in which microphthalmia-associated transcription factor (MITF) is a master regulator. One coumarin family member 7,8-dihydroxy-4-methylcoumarin (DHMC) shows extensive biological activities with beneficial health effects; however, it also induces cytotoxicity and its melanogenic effect has not been reported yet. Therefore, we first synthesized DHMC derivatives via methylation to obtain 7,8-dimethoxy-4-methylcoumairn (DMMC), and investigated the pro- or anti-melanogenic effects of DHMC and DMMC in B16-F10 melanoma cells as well as the underlying mechanism. DHMC showed cytotoxicity at all tested concentrations, whereas DMMC did not reduce cell viability, even at the high concentration. DMMC also drives the significant increase in intracellular melanin and tyrosinase activity. Moreover, DMMC induced MITF expression by significantly increasing tyrosinase activity, which activates the gene expression of TRP1 and TRP2. Western blotting confirmed that DMMC induced the activation of mitogen-activated protein kinase (MAPK) signaling by the phosphorylation of C-Jun N-terminal kinase (JNK), resulting in the increased melanin production and the decreased phosphorylation of protein kinase B. Collectively, this study showed the pro-melanogenic effect of DMMC and its potential as a safe tanning and dyeing agent.