Abietic acid (AA) is known to have beneficial effects on inflammation, photoaging, osteoporosis, cancer, and obesity; however, its efficacy on atopic dermatitis (AD) has not been reported. We investigated the anti-AD effects of AA, which was newly isolated from rosin, in an AD model. To achieve this, AA was isolated from rosin under conditions optimized by response surface methodology (RSM), and its effects on cell death, iNOS-induced COX-2 mediated pathway, inflammatory cytokine transcription, and the histopathological skin structure were analyzed in 2,4-dinitrochlorobenzene (DNCB)-treated BALB/c mice after treatment with AA for 4 weeks. AA was isolated and purified through isomerization and reaction-crystallization under the condition (HCl, 2.49 mL; reflux extraction time, 61.7 min; ethanolamine, 7.35 mL) established by RSM, resulting in AA with a purity and extraction yield of 99.33% and 58.61%, respectively. AA exhibited high scavenging activity against DPPH, ABTS, and NO radicals as well as hyaluronidase activity in a dose-dependent manner. The anti-inflammatory effects of AA were verified in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages through amelioration of the inflammatory response, including NO production, iNOS-induced COX-2 mediated pathway activation, and cytokine transcription. In the DNCB-treated AD model, the skin phenotypes, dermatitis score, immune organ weight, and IgE concentration were significantly ameliorated in the AA cream (AAC)-spread groups compared to the vehicle-spread group. In addition, AAC spread ameliorated DNCB-induced deterioration of skin histopathological structure through the recovery of the thickness of the dermis and epidermis and the number of mast cells. Furthermore, activation of the iNOS-induced COX-2 mediated pathway and increased inflammatory cytokine transcription were ameliorated in the skin of the DNCB+AAC-treated group. Taken together, these results indicate that AA, newly isolated from rosin, exhibits anti-AD effects in DNCB-treated AD models, and has the potential to be developed as a treatment option for AD-related diseases.

Scytosiphon lomentaria (SL) is a brown seaweed with antioxidant and anti-inflammatory properties; however, its effects on obesity are unknown. In this research, we investigated the anti-obesity properties and underlying mechanisms of the SL extract in vitro and in vivo. In 3T3-L1 preadipocytes, SL extract inhibited lipid accumulation, decreased the expression of Acc1, C/ebpa, Pparg mRNA and p-ACC1, and increased the expression of Ucp1 mRNA, UCP1 and p-AMPK. In animal experiments, mice were fed a chow diet, a high-fat diet (HF; 60% of calories as fat), and high-fat diet with SL extract (150 and 300 mg/kg body weight) for eight weeks (n = 10/group). SL extract reduced HF-induced weight gain, epididymal fat weight, fat cell size, LDL-C, leptin, fasting glucose, and glucose tolerance. In addition, SL extract had comparable effects on mRNA expression in WAT and liver to those observed in vitro, thereby inhibiting p-ACC1/ACC1 and increasing p-AMPK/AMPK and UCP1 expression. Furthermore, SL extract decreased HF-induced Firmicutes/Bacteroidetes ratio and reversed HF-reduced Bacteroides spp., Bacteroides vulgatus, and Faecalibacterium prausnitzii. These findings suggest that SL extract can aid in weight loss in mice fed a high-fat diet by altering adipogenic and thermogenic pathways, as well as gut microbiota composition.

Ulcerative colitis (UC), an inflammatory bowel disease (IBD) linked to colon cancer, needs effective natural preventive and therapeutic strategies to alleviate its clinical course. This study investigated the combined effects of phlorotannins (TAs) isolated from Eisenia bicyclis (E. bicyclis) and Lactobacillus casei (LC) on inflammatory markers in UC, with a focus on the aryl hydrocarbon receptor (AhR) axis. In vitro experiments revealed anti-inflammatory effects of the phlorotannin fraction isolated from E. bicyclis, especially in synergy with LC. In vivo experiments showed that a synbiotic combination of TAs and LC mitigated DSS-induced colitis and reduced intestinal shortening and splenic hypertrophy. The TA and LC combination suppressed inflammatory factors (IL-6, TNF-α, Lipocalin 2), while activating tight junction genes (Muc2, Zo-1, Occludin, and Claudin1) and enhancing antioxidant capacity (Nrf2 and Nqo1 genes). Activation of the AhR pathway, which is crucial for regulating intestinal inflammation via IL-22, was evident with both phlorotannin alone and synbiotic administration. The combination of TAs and LC amplified the synergistic effect on intestinal immunity and microbiota, favoring beneficial species and optimizing the Firmicutes/Bacteroidetes ratio. Overall, synbiotic use demonstrated superior preventive effects against UC, suggesting its potential benefits for improving the gut immune system through gut microbiota-derived metabolites.

Aloe vera (A. vera) has been studied as a treatment option for ulcerative colitis (UC), but there is a lack of scientific evidence showing whether treatment with Aloe saponaria (A. saponaria) can also be beneficial. To investigate the therapeutic potential of A. saponaria as a treatment for UC, clinical symptoms, histopathological characteristics of the colon, inflammatory response, and toxicity were analyzed in dextran sulfate sodium (DSS)-induced UC mice after administration of aqueous extracts of A. saponaria (AAS) for 7 days. The total polyphenol and tannin content of AAS was 272 µg/g and 163 µg/g, respectively. AAS exhibited significant antioxidant activity. Several clinical symptoms, including body weight, colon length, and hematochezia, remarkably improved in the DSS+AAS treated group compared to the DSS+Vehicle-treated group. In addition, similar improvements were detected in the histopathological characteristics and mucin-secreting ability in the colon of DSS-induced UC mice after the administration of AAS. The levels of infiltrated inflammatory cells and cytokine expression were significantly decreased in a dose-dependent manner in the colon of the DSS+AAS-treated group. These alterations in inflammatory response were accompanied by a significant recovery of the protein kinase C/extracellular signal-regulated kinase (PKC/ERK) and phosphatidylinositol-3-kinase/serine-threonine protein kinase (PI3K/Akt) signaling pathways. However, the levels of key markers for hepatotoxicity and nephrotoxicity consistently remained between those of the DSS+AAS-treated and the No groups. Therefore, the results of the present study provide novel evidence that AAS may improve the clinical symptoms and attenuate the inflammatory response in DSS-induced UC mice and does not have any significant hepatotoxicity or nephrotoxicity.

Basil (Ocimum basilicum L.) has been traditionally used in various cultures for its medicinal properties. This study evaluated the antioxidant and antimicrobial activities of basil essential oil (BEO) and identified its key bioactive compounds. Antioxidant activity testing, as determined by DPPH and ABTS assays, returned EC₅₀ values of 115.36 and 54.77 µg/mL, respectively. BEO demonstrated significant antimicrobial effects against Gardnerella vaginalis, Fannyhessea vaginae, Chryseobacterium gleum, and Candida albicans, with inhibition zones of up to 25.88 mm and MIC values ranging from 31 to 500 µg/mL. GC-MS (gas chromatography–mass spectrometry) identified monoterpene, phenylpropene, and sesquiterpene derivatives in BEO. In addition, Fraction 3 (Fr. 3) obtained by preparative HPLC had the highest antimicrobial activity, and methyl trans-cinnamate was identified as the primary active compound in this fraction. BEO had no toxic effect on Lactobacillus crispatus or human dermal fibroblasts. These findings support the traditional use of basil and highlight its potential as a safe, natural therapeutic agent with antioxidant and antimicrobial properties.

Ulcerative colitis (UC) is a chronic inflammatory disease of the colon that is associated with dysbiosis in the gut microbiota. Eisenia bicyclis, a marine alga, is known for its anti-inflammatory, antioxidant, and gut microbiota-modulating properties. This study explored the mechanisms by which a 70% ethanol extract of E. bicyclis may alleviate UC, through both in vitro and in vivo experiments. LC-MS/MS analysis revealed eckol, 7-phloroeckol, dieckol, phlorofucofuroeckol A, and fucofuroeckol as key phenolic compounds present in the extract. The administration of E. bicyclis significantly improved symptoms in a dextran sulfate sodium (DSS)-induced colitis mouse model by reducing intestinal shortening, splenomegaly, and histological scores. Both cell and animal studies demonstrated that E. bicyclis suppressed the release of inflammatory cytokines, downregulated the mRNA expression of genes related to the mTOR pathway, and reduced the p-mTOR/mTOR ratio. Microbiota analysis revealed that, while the Firmicutes/Bacteroidetes ratio was elevated in UC mice, E. bicyclis administration normalized this imbalance, with a notable increase in the abundance of beneficial probiotics such as Bifidobacterium bifidum. In conclusion, a phenolic-rich extract of E. bicyclis demonstrates significant potential as a dietary supplement to prevent and mitigate UC by modulating both the mTOR signaling pathway and gut microbiota composition.