Lasia spinosa (L.) Thwaites was used as a traditional medicine to treat many inflammatory diseases for centuries. However, its effects on the inflammatory response are not yet characterized. In this study, we investigated the anti-inflammatory activities of L. spinosa leaf extract in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. We found that ethanol extracts of L. spinosa leaves showed anti-oxidant activity due to the presence of high levels of polyphenolic compounds. Treatment with the leaf extract significantly repressed the production of inflammatory mediators such as nitric oxide and reactive oxygen species and the expression of pro-inflammatory cytokines in the LPS-stimulated RAW 264.7 cells. Moreover, L. spinosa leaf extract treatment prevented activation of the nuclear factor-kappa B pathway by inhibiting nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) degradation. Furthermore, the mitogen-activated kinase and phosphoinositide-3-kinase/protein kinase B (PI3K/Akt) pathways were suppressed upon treatment with the leaf extract. In addition to suppressing inflammatory factors, the extract also activated the nuclear factor erythroid 2-related factor 2/heme-oxygenase-1 pathway. We propose that L. spinosa leaf extract has the potential as an effective therapeutic agent for alleviating oxidative stress and excessive inflammation.

Launaea sarmentosa has been extensively used as a nutrient herb in traditional Vietnamese remedies for the treatment of various diseases, especially inflammatory diseases. However, no detailed research has been conducted examining the molecular mechanisms involved in the suppression of inflammatory response. Here, we studied the effects of L. sarmentosa methanol extract on lipopolysaccharide (LPS)-induced inflammation using RAW 264.7 macrophages. The extract demonstrated potent antioxidant activity owing to the presence of polyphenolic and flavonoid components. Pretreatment with the extract inhibited LPS-mediated secretion of nitric oxide, reactive oxygen species, and tumor necrosis factor-α as well as the expression of inflammatory cytokines. Furthermore, the activation of the nuclear factor-kappa B pathway and phosphoinositide-3-kinase/protein kinase B pathways was blocked by the extract by inhibiting Akt phosphorylation. Additionally, the mitogen-activated protein kinase pathway was suppressed, and endoplasmic reticulum stress was attenuated. Furthermore, the extract promoted the activity of nuclear factor erythroid-2-related factor 2 resulting in the up-regulation of heme oxygenase-1 pathway, leading to the suppression of oxidative stress and inflammatory response. Taken together, the results indicate that L. sarmentosa exhibits anti-inflammatory effects, and hence, can be further developed as a novel drug for the treatment of diseases associated with excessive inflammation.

Blast disease and sheath blight disease caused by infection with Pyricularia oryzae and Rhizoctonia solani, respectively, are serious fungal diseases in paddy fields. Although synthetic fungicides have been used to control these diseases, the development of ecologically friendly alternatives is required because fungicides can cause health problems and environmental pollution. Natural herbs possessing antifungal activities are among the candidates as alternatives. Ageratum conyzoides is known to contain antifungal compounds, such as precocene II and polymethoxyflavones. Here, we report the antifungal activities of five compounds isolated after ethanol extraction from Ageratum conyzoides against Pyricularia oryzae and Rhizoctonia solani in vitro. Further, we demonstrated the protective effect of the extract on rice from Pyricularia oryzae infection by field trial testing in a shaded net-house.

Bacterial leaf blight and blast diseases caused by the bacterium Xanthomonas oryzae pv. oryzae and the fungus Pyricularia oryzae, respectively, are among the most important infectious diseases affecting rice. We evaluated the antimicrobial effects of compounds derived from Praxelis clematidea on Xanthomonas oryzae and Pyricularia oryzae. The dried aerial parts of Praxelis clematidea were subjected to ethanol extraction, separated by solvent partitioning using hexane, chloroform, ethyl acetate, and water. In vitro assays demonstrated that the main antibacterial and antifungal activities were distributed in the ethyl acetate and chloroform fractions, respectively. These fractions were further separated using silica gel chromatography and reversed-phase chromatography. Finally, we isolated five compounds, 1–5, that inhibited the growth of Xanthomonas oryzae in vitro and four compounds, 6–9, that exhibited in vitro antifungal activity against Pyricularia oryzae. We evaluated their antimicrobial activities and identified their chemical structures by NMR and mass spectrometry analyses. This is the first study to isolate compound 2 (4,4′,4″-nitrilotriphenol) as an alternative microbial from natural resources and evaluate its physiological activity. Moreover, this is the first report to demonstrate antibacterial activity in comparison with flavonoids. Praxelis clematidea extracts plausibly exert both antibacterial and antifungal effects, which should be further validated in field trials.

In bioconjugation chemistry, achieving a target-specific reaction for a non-modified amino acid is challenging. Here, we report a novel nucleobase-involved native chemical ligation (NbCL) that allows a site-specific oligonucleotide–peptide conjugation via a new S–N acyl transfer reaction between an oxanine nucleobase and N-terminal cysteine.