A polyphenol‐enriched fraction (PEF) from Acalypha wilkesiana, whose leaves have been traditionally utilized for the treatment of diverse medical ailments, was investigated for the anti‐inflammatory effect and molecular mechanisms by using lipopolysaccharide‐ (LPS‐) stimulated RAW 264.7 macrophages and acetaminophen‐ (APAP‐) induced liver injury mouse model. Results showed that PEF significantly attenuated LPS‐induced nitric oxide (NO) and prostaglandin E₂ (PGE₂) production and suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX‐2) in RAW 264.7 macrophages. PEF also reduced the secretion of proinflammatory cytokines including tumor necrosis factor‐α (TNF‐α), interleukin‐ (IL‐) 1β, and IL‐6 in LPS‐stimulated RAW 264.7 macrophages. Moreover, PEF potently inhibited LPS‐induced phosphorylation of mitogen‐activated protein kinases (MAPKs) as well as the activation of nuclear factor‐κB (NF‐κB) by preventing the degradation of inhibitor κB‐α (IκB‐α). In vivo, PEF pretreatment ameliorated APAP‐induced liver injury and hepatic inflammation, as presented by decreased hepatic damage indicators and proinflammatory factors at both plasma and gene levels. Additionally, PEF pretreatment remarkably diminished Toll‐like receptor 3 (TLR3) and TLR4 expression and the subsequent MAPKs and NF‐κB activation. HPLC analysis revealed that two predominantly polyphenolic compounds present in PEF were geraniin and corilagin. These results indicated that PEF has an anti‐inflammatory effect, and its molecular mechanisms may be involved in the inactivation of the TLR/MAPK/NF‐κB signaling pathway, suggesting the therapeutic potential of PEF for inflammatory diseases.

It is well established that certain carboxylic acid compounds can effectively inhibit tyrosinase activity. This study investigated the mechanisms by which four carboxylic acid compounds—3-phenyllactic acid, lactic acid, L-pyroglutamic acid, and malic acid—inhibit tyrosinase and melanogenesis. IC₅₀ values for mushroom tyrosinase inhibition ranged from 3.38 to 5.42 mM, with 3-phenyllactic acid (3.50 mM), lactic acid (5.42 mM), and malic acid (3.91 mM) exhibiting mixed-type inhibition, while L-pyroglutamic acid (3.38 mM) showed competitive inhibition, as determined by enzymatic kinetic analysis. Additionally, the acidification effects of lactic acid, L-pyroglutamic acid, and malic acid contributed to the reduction in tyrosinase activity. Furthermore, all four carboxylic acid compounds effectively inhibited DOPA auto-oxidation (IC₅₀ = 0.38–0.66 mM), ranking in potency as follows: malic acid (0.38 mM) > lactic acid (0.57 mM) > 3-phenyllactic acid (0.63 mM) > L-pyroglutamic acid (0.66 mM). These compounds also demonstrated a dose-dependent reduction in melanin production in B16-F10 cells. Proteomic analysis further revealed that these compounds not only inhibit key proteins involved in melanin synthesis, such as tyrosinase, tyrosinase-related protein 1, and tyrosinase-related protein 2, but also potentially modulate other genes associated with melanogenesis and metabolism, including Pmel, Slc45a2, Ctns, Oca2, and Bace2. Network toxicology analysis indicated that these four compounds exhibit a low risk of inducing dermatitis. These findings suggest that these compounds may indirectly regulate melanin-related pathways through multiple mechanisms, highlighting their potential for further applications in cosmetics and pharmaceuticals.

The fruit of Rosa laevigata Michx. (FR), a traditional Chinese herb utilized for the treatment of a variety diseases, has notably diverse pharmacological activities including hepatoprotective, anti-oxidant, and anti-inflammatory effects. Despite ongoing research on illustrating the underlying anti-inflammatory mechanism of FR, the principal mechanism remained inadequately understood. In this study, we investigated in depth the molecular mechanism of the anti-inflammatory actions of the ethanol extract of FR (EFR) and its potential targets using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages in vitro. We showed that EFR effectively ameliorated the overproduction of inflammatory mediators and cytokines, as well as the expression of related genes. It was further demonstrated that LPS-induced activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) were significantly inhibited by pretreatment with EFR, accompanied by a concomitant decrease in the nuclear translocation of the p65 subunit of NF-κB and activator protein 1 (AP-1). In addition, EFR pretreatment potently prevented LPS-induced decreased phosphorylation of adenosine monophosphate-activated protein kinase (AMPK). Our data also revealed that the activation of AMPK and subsequent inhibition of the mammalian target of the rapamycin (mTOR) signaling pathway was probably responsible for the inhibitory effect of EFR on LPS-induced inflammatory responses, evidenced by reverse changes observed under the condition of AMPK inactivation following co-treatment with the AMPK-specific inhibitor Compound C. Finally, the main components with an anti-inflammatory effect in EFR were identified as madecassic acid, ellagic acid, quinic acid, and procyanidin C1 by LC–MS and testified based on the inhibition of NO production and inflammatory mediator expression. Taken together, our results indicated that EFR was able to ameliorate inflammatory responses via the suppression of MAPKs/NF-κB signaling pathways following AMPK activation, suggesting the therapeutic potential of EFR for inflammatory diseases.

Background: Tea (Camellia sinensis L.) flowers will compete with tea leaves in nutrition and are abandoned as an undesirable by-product. In this study, the biological efficacy of tea flowers was investigated. Further exploration of its antifungal activity was explained. Methods: Tea flowers harvested from China were characterized in term of component, antioxidant ability, tyrosinase inhibition, and antifungal ability. Chemical compounds of tea flowers were analyzed by LC-MS. Disinfectant compounds were identified in tea flowers, and 2-ketobutyric acid exhibited antifungal activity against Aspergillus flavusCCTCC AF 2023038. The antifungal mechanism of 2-ketobutyric acid was further investigated by RNA-seq. Results: Water-soluble tea flower extracts (TFEs) exhibited free radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS) as well as a high ferric-reducing ability. However, no inhibition of tyrosinase activity was observed. In the antifungal test, 6.4 mg/mL TFE reached 71.5% antifungal rate and the electrical conductivity of the culture broth increased with increasing concentration of TFE, implying that it damaged the fungal cell membrane by the TFE. Several disinfectants were identified in TFE by LC-MS, and 2-ketobutyric acid was also confirmed to be capable of fungal inhibition. Propidium iodide (PI) staining indicated that 2-ketobutyric acid caused damage to the cell membrane. RNA-seq analysis revealed that 3,808 differentially expressed genes (DEGs) were found in A. flavus CCTCC AF 2023038 treated by 2-ketobutyric acid, and more than 1,000 DEGs involved in the integral and intrinsic component of membrane were affected. Moreover, 2-ketobutyric acid downregulated aflatoxin biosynthesis genes and decreased the aflatoxin production. Conclusions: Overall, TFE exhibited excellent antioxidant ability and fungal inhibition against A. flavus CCTCC AF 2023038 due to its abundant disinfectant compounds. As a recognized food additive, 2-ketobutyric acid is safe to use in the food industry and can be utilized as the basis for the research and development of strong fungicides.

In traditional Chinese medicine, the root bark and leaves of Schima argentea are utilized to treat dysentery, parasitic infections, and digestive disorders. In this study, the n-butanol extract of S. argentea (NBA) exhibited potent antioxidant properties, protecting HaCaT cells from UVB-induced damage, and was abundant in phenolic and flavonoid compounds. Using UPLC-QTOF-MS analysis, several antioxidants within NBA were identified. Among these, 3,4-dihydroxybenzoic acid, (+)-catechin, and procyanidin B2 effectively reduced ROS levels after 1 h post-UVB treatment (225 mJ/cm²). Notably, all three compounds significantly decreased the phosphorylation of p38 and JNK in a dose-dependent manner. Additionally, the cell survival rate of these compounds was assessed after 12 h post-UVB treatment (225 mJ/cm²). Both 3,4-dihydroxybenzoic acid and (+)-catechin significantly prevented UVB-induced apoptosis in HaCaT cells, as evidenced by MTT, Hoechst, Calcein/PI staining, and flow cytometry analyses. Proteomic analysis revealed that 3,4-dihydroxybenzoic acid achieved photoprotection by downregulating c-Fos and Jun and modulating cell cycle proteins, while (+)-catechin promoted cell repair through the PI3K-Akt and Wnt signaling pathways. These results demonstrated that both compounds can directly absorb UVB, scavenge ROS, and provide cell photoprotection by modulating multiple signaling pathways. The n-butanol extract of S. argentea holds promising potential for future medical applications.