Background Disruptions of the intestinal epithelial barrier (IEB) are frequently observed in various digestive diseases, including irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). This study assessed the improvement in the IEB during the laxative activity of phlorotannin (Pt) harvested from Ecklonia cava in constipation by examining the changes in the expression of the regulatory proteins for the tight junction (TJ) and adherens junction (AJ), and inflammatory cytokines in Sprague Dawley (SD) rats with loperamide (Lm)-induced constipation after a Pt treatment. Results The Pt treatment induced laxative activity, including the improvement of feces-related parameters, gastrointestinal transit rate, and histological structure of the mid colon in Lm-treated SD rats. In addition, significant recovery effects were detected in the histology of IEB, including the mucus layer, epithelial cells, and lamina propria in the mid colon of Lm + Pt treated SD rats. The expression levels of E-cadherin and p120-catenin for AJ and the ZO-1, occludin, and Claudin-1 genes for TJ in epithelial cells were improved remarkably after the Pt treatment, but the rate of increase was different. Furthermore, the Pt treatment increased the expression level of several inflammatory cytokines, such as TNF-α, IL-6, IL-1β, IL-13, and IL-4 in Lm + Pt treated SD rats. Conclusions These results provide the first evidence that the laxative activity of Pt in SD rats with Lm-induced constipation phenotypes involve improvements in the IEB.

Natural products with significant antioxidant activity have been receiving attention as one of the treatment strategies to prevent age-related macular degeneration (AMD). Reactive oxygen intermediates (ROI) including oxo-N-retinylidene-N-retinylethanolamine (oxo-A2E) and singlet oxygen-induced damage, are believed to be one of the major causes of the development of AMD. To investigate the therapeutic effects of methanol extracts of Dipterocarpus tuberculatus Roxb. (MED) against blue light (BL)-caused macular degeneration, alterations in the antioxidant activity, apoptosis pathway, neovascularization, inflammatory response, and retinal degeneration were analyzed in A2E-laden ARPE19 cells and Balb/c mice after exposure of BL. Seven bioactive components, including 2α-hydroxyursolic acid, ε-viniferin, asiatic acid, bergenin, ellagic acid, gallic acid and oleanolic acid, were detected in MED. MED exhibited high DPPH and ABTS free radical scavenging activity. BL-induced increases in intracellular reactive oxygen species (ROS) production and nitric oxide (NO) concentration were suppressed by MED treatment. A significant recovery of antioxidant capacity by an increase in superoxide dismutase enzyme (SOD) activity, SOD expression levels, and nuclear factor erythroid 2–related factor 2 (NRF2) expression were detected as results of MED treatment effects. The activation of the apoptosis pathway, the expression of neovascular proteins, cyclooxygenase-2 (COX-2)-induced inducible nitric oxide synthase (iNOS) mediated pathway, inflammasome activation, and expression of inflammatory cytokines was remarkably inhibited in the MED treated group compared to the Vehicle-treated group in the AMD cell model. Furthermore, MED displayed protective effects in BL-induced retinal degeneration through improvement in the thickness of the whole retina, outer nuclear layer (ONL), inner nuclear layer (INL), and photoreceptor layer (PL) in Balb/c mice. Taken together, these results indicate that MED exhibits protective effects in BL-induced retinal degeneration and has the potential in the future to be developed as a treatment option for dry AMD with atrophy of retinal pigment epithelial (RPE) cells.

Antioxidants are an important strategy for treating photoaging because excessive reactive oxygen species (ROS) are produced during UV irradiation. The therapeutic effects of methanol extracts of Hygrophila erecta (Brum. F.) Hochr. (MEH) against UV-induced photoaging were examined by monitoring the changes in the antioxidant defense system, apoptosis, extracellular matrix (ECM) modulation, inflammatory response, and melanin synthesis in normal human dermal fibroblast (NHDF) cells and melanoma B16F1 cells. Four bioactive compounds, including 4-methoxycinnamic acid, 4-methoxybenzoic acid, methyl linoleate, and asterriquinone C-1, were detected in MEH, while the DPPH free radical scavenging activity was IC50 = 7.6769 µg/mL. UV-induced an increase in the intracellular ROS generation, NO concentration, SOD activity and expression, and Nrf2 expression were prevented with the MEH treatment. Significant decreases in the number of apoptotic cells, the ratio of Bax/Bcl-2, and cleaved Cas-3/Cas-3 were observed in MEH-treated NHDF cells. The MEH treatment induced the significant prevention of ECM disruption and suppressed the COX-2-induced iNOS mediated pathway, expression of inflammatory cytokines, and inflammasome activation. Finally, the expression of the melanin synthesis-involved genes and tyrosinase activity decreased significantly in the α-melanocyte-stimulating hormone (MSH)-stimulated B16F1 cells after the MEH treatment. MEH may have an antioxidative role against UV-induced photoaging by suppressing ROS-induced cellular damage.

This study investigated the anti-obesity effects of Cucumis melo var. gaettongchamoe (CG) in mice fed a high-fat diet (HFD). The mice received CG water extract (CGWE) treatment for 8 weeks, and changes in body weight and serum lipid levels were analyzed. The HFD + vehicle group showed a significant increase in body weight compared to the control group, while the HFD + CGWE and HFD + positive (orlistat) groups exhibited reduced body weight. Lipid profile analysis revealed lower levels of total cholesterol, triglycerides, high-density lipoprotein, and low-density lipoprotein cholesterol in the HFD + CGWE group compared to the HFD + vehicle group. The HFD + vehicle group had increased abdominal fat weight and fat content, whereas both HFD + CGWE groups showed significant reductions in abdominal fat content and adipocyte size. Additionally, CGWE administration downregulated mRNA expression of key proteins involved in neutral lipid metabolism. CGWE also promoted hepatic lipolysis, reducing lipid droplet accumulation in hepatic tissue and altering neutral lipid metabolism protein expression. Furthermore, CGWE treatment reduced inflammatory mediators and suppressed the activation of the mitogen-activated protein kinase pathway in hepatic tissue. In conclusion, CGWE shows promise as a therapeutic intervention for obesity and associated metabolic dysregulation, including alterations in body weight, serum lipid profiles, adipose tissue accumulation, hepatic lipolysis, and the inflammatory response. CGWE may serve as a potential natural anti-obesity agent.

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.