Atopic dermatitis (AD) is a chronic inflammatory disease. Combretum quadrangulare (C. quadrangulare) is used as a traditional medicine to improve various pathologies in Southeast Asia. In this study, we investigated the effects of C. quadrangulare ethanol extract (CQ) on 1-chloro-2,4-dinitrobenzene (DNCB)-induced AD like skin lesions in BALB/c mice. After administration with CQ (100, 200, and 400 mg/kg) for 6 weeks, AD symptoms, protein expression, immunoglobulin E (IgE), thymus and activation-regulated chemokine (TARC), and ceramidase level were measured in skin lesions of DNCB-induced BALB/c mice. CQ group improved the dermatitis score, skin pH, transepidermal water loss (TEWL), and skin hydration. Furthermore, histological analysis revealed that CQ attenuated the increased epidermal thickness and infiltration of mast cells caused by DNCB. CQ also increased the expression of filaggrin, and reduced the expression of ceramidase, serum IgE level, and the number of eosinophils. CQ effectively inhibited cytokines and chemokines such as interleukin (IL)-6, IL-13, TARC, and thymic stromal lymphopoietin (TSLP) at the mRNA levels, as well as the activation of mitogen-activated protein kinase (MAPK), including extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase (JNK), and p38 in the skin lesions. Taken together, these findings demonstrate that CQ may be an effective treatment of AD-like skin lesions by inhibiting the expression of inflammatory mediators via the MAPK signaling pathways.

Amomum tsao-ko Crevost et Lemaire (Zingiberaceae) is a medicinal herb found in Southeast Asia that is used for the treatment of malaria, abdominal pain, dyspepsia, etc. The aim of this study was to investigate the effect of an ethanol extract of Amomum tsao-ko (EAT) on obesity and hyperlipidemia in C57BL/6 mice fed a high-carbohydrate diet (HCD). First, the mice were divided into five groups (n = 6/group) as follows: normal diet, HCD, and HCD+EAT (100, 200, and 400 mg/kg/day), which were orally administered with EAT daily for 84 days. Using microcomputed tomography (micro-CT) analysis, we found that EAT inhibited not only body-weight gain, but also visceral fat and subcutaneous fat accumulation. Histological analysis confirmed that EAT decreased the size of fat tissues. EAT consistently improved various indices, including plasma levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein, high-density lipoprotein, atherogenic index, and cardiac risk factors, which are related to dyslipidemia—a major risk factor for heart disease. The contents of TC and TG, as well as the lipid droplets of HCD-induced hepatic accumulation in the liver tissue, were suppressed by EAT. Taken together, these findings suggest the possibility of developing EAT as a therapeutic agent for improving HCD-induced obesity and hyperlipidemia.

In our search for novel plant-derived inhibitors of nitric oxide (NO) with potential for treating inflammatory diseases, the phytochemicals of Amomum tsao-ko fruits were investigated, leading to the isolation of one bicyclic nonane (1), three menthene skeleton monoterpenoids (2–4), and two acyclic monoterpenoids (5 and 6). Their structures were identified using one- and two-dimensional nuclear magnetic resonance spectroscopy, and mass spectrometry. To the best of our knowledge, compounds 2–5 were obtained from the genus Amomum for the first time. All isolates were tested for their ability to inhibit lipopolysaccharide-stimulated NO overproduction in RAW264.7 cells. Compound 4 was found to inhibit NO production. Western blotting analysis indicated that active compound 4 can regulate inducible NO synthase expression. In addition, lipopolysaccharide-induced interleukin 1 beta and interleukin-6 overproduction was reduced in a concentration-dependent manner.

Tetracera loureiri (T. loureiri) is a woody climber inhabiting open deciduous or evergreen forests in Southeast Asia. A decoction comprising its stem and other herbs is a traditional Thai remedy for fatigue and jaundice, as well as to promote overall health. Anti-inflammatory effects induced by T. loureiri extract have not been reported. In this study, we investigated the anti-inflammatory effect of an ethanol extract of T. loureiri (ETL) on lipopolysaccharide (LPS)-induced inflammatory response in RAW264.7 macrophages. We found that ETL treatment inhibited the production of nitric oxide (NO) in LPS-stimulated RAW264.7 cells, without affecting cell viability. The effect of ETL on the expression of various pro-inflammatory mediators was analyzed using reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA). We observed that ETL inhibited the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the mRNA and protein levels and decreased the production of prostaglandin E₂ (PGE₂) by COX-2 in RAW264.7 macrophages. ETL dose-dependently reduced the production of pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in LPS-induced RAW264.7 cells, in a dose-dependent manner. Furthermore, ETL suppressed the LPS-induced nuclear translocation of the nuclear factor, NF-κB. Additionally, ETL was found to inhibit the activation of mitogen-activated protein kinases (MAPK), such as extracellular signal-regulated kinase, c-Jun-N-terminal kinase, and p38 MAPK. In conclusion, our findings demonstrate that ETL inhibits the expression of pro-inflammatory mediators and cytokines, thereby downregulating NF-κB and MAPK signaling pathways in LPS-stimulated macrophages, Consequently, ETL is a potential therapeutic agent for the treatment of inflammatory diseases.

Smilax sieboldii, a climbing tree belonging to Smilacaceae, has been used in traditional oriental medicine for treating arthritis, tumors, leprosy, psoriasis, and lumbago. To evaluate the anti-obesity effects of S. sieboldii (Smilacaceae), we screened methylene chloride (CH₂Cl₂), ethyl acetate (EtOAc), aqueous-saturated n-butanol, and ethanol (EtOH) extracts of the whole plant at various concentrations to inhibit adipogenesis in adipocytes. The 3T3-L1 cell line with Oil red O staining with the help of fluorometry was used as an indicator of anti-obesity activity. Bioactivity-guided fractionation of the EtOH extract and subsequent phytochemical investigation of the active CH₂Cl₂- and EtOAc-soluble fractions resulted in the isolation of 19 secondary metabolites (1–19), including a new α-hydroxy acid derivative (16) and two new lanostane-type triterpenoids (17 and 18). The structures of these compounds were characterized using various spectroscopic methods. All the isolated compounds were screened for adipogenesis inhibition at a concentration of 100 μM. Of these, compounds 1, 2, 4–9, 15, and 19 significantly reduced fat accumulation in 3T3-L1 adipocytes, especially compounds 4, 7, 9, and 19, showing 37.05 ± 0.95, 8.60 ± 0.41 15.82 ± 1.23, and 17.73 ± 1.28% lipid content, respectively, at a concentration of 100 μM. These findings provide experimental evidence that isolates from S. sieboldii extracts exert beneficial effects regarding the regulation of adipocyte differentiation.