Clinacanthus nutans (Burm.f.) Lindau is a Southeast Asian medicinal plant traditionally used for treating skin inflammation and infections. This study evaluated its wound-healing potential through anti-inflammatory, cytoprotective, and antiviral mechanisms. HPLC-DAD analysis identified schaftoside as the major flavonoid in the 95% ethanolic leaf extract. In the lipopolysaccharide (LPS)-stimulated murine macrophage cell line (RAW 264.7), both C. nutans extract (5 and 50 μg/mL) and its flavonoid schaftoside (5 and 20 μg/mL) significantly downregulated the expression of pro-inflammatory genes, including cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and prostaglandin E2 (PGE2), under both pre-treatment and post-treatment conditions. ELISA confirmed dose-dependent inhibition of human COX-2 enzymatic activity, reaching up to 99.3% with the extract and 86.9% with schaftoside. In the endothelial cell models (CCL-209), the extract exhibited low cytotoxicity and effectively protected cells from LPS-induced apoptosis, preserving vascular integrity critical to tissue regeneration. Antiviral assays demonstrated suppression of HSV-2 replication, particularly during early infection, which may help prevent infection-related delays in wound healing. Collectively, these findings suggest that C. nutans and schaftoside promote wound repair by attenuating inflammatory responses, supporting endothelial survival, and controlling viral reactivation. These multifunctional properties highlight their potential as natural therapeutic agents for enhancing wound-healing outcomes.
Environmental factors and climate are the primary factors influencing the microbial colonization and deterioration of cultural heritage in outdoor environments. Hence, it is imperative to investigate seasonal variations in microbial communities and the biodeterioration they cause. This study investigated the surfaces of sandstone sculptures at Wat Umong Suan Phutthatham, Chiang Mai, Thailand, during wet and dry seasons using culture-dependent and culture-independent approaches. The fungi isolated from the sandstone sculptures were assessed for biodeterioration attributes including drought tolerance, acid production, calcium crystal formation, and calcium precipitation. The results show that most of the fungal isolates exhibited significant potential for biodeterioration activities. Furthermore, a culture-independent approach was employed to investigate the fungal communities and assess their diversity, interrelationship, and predicted function. The fungal diversity and the communities varied seasonally. The functional prediction indicated that pathotroph–saprotroph fungi comprised the main fungal guild in the dry season, and pathotroph–saprotroph–symbiotroph fungi comprised the dominant guild in the wet season. Remarkably, a network analysis revealed numerous positive correlations among fungal taxa within each season, suggesting a potential synergy that promotes the biodeterioration of sandstone. These findings offer valuable insights into seasonal variations in fungal communities and their impacts on the biodeterioration of sandstone sculptures. This information can be utilized for monitoring, management, and maintenance strategies aimed at preserving this valuable cultural heritage.
16 June 2026 in Journal of Agricultural and Food Chemistry
Auxinic herbicides remain essential for weed control, yet metabolic resistance to these herbicides is poorly understood. Here we show that catalytically promiscuous CYP81A P450s from Echinochloa phyllopogon detoxify auxinic herbicides. Arabidopsis thaliana expressing CYP81A12 or CYP81A21 showed decreased sensitivity to quinclorac. In an Escherichia coli whole-cell assay, these enzymes produced a putative hydroxylated quinclorac metabolite. Docking and 300 ns molecular dynamics simulations indicated that active CYP81As maintain quinclorac in a productive pose close to the heme, with pocket geometry and water exclusion enabling precise substrate–heme alignment, whereas the inactive CYP81A18 retains quinclorac farther from the catalytic center. Consistent with resistant E. phyllopogon, transgenic Arabidopsis expressing CYP81A12 or CYP81A21 produced less ethylene after quinclorac treatment, linking detoxification to suppressed auxinic phytotoxic responses. CYP81As also conferred resistance to florpyrauxifen-benzyl and 2,4-D, highlighting cross-resistance across auxinic chemistries. These findings reveal a structural basis for CYP81A-mediated catalytic promiscuity underlying metabolic resistance to auxinic herbicides.
Auxinic herbicides are critically important tools for weed control in modern agriculture. Although resistant weed populations have been increasing in recent years, the underlying mechanisms remain largely unknown. In a multiple-herbicide resistant line of the paddy weed Echinochloa phyllopogon , overexpression of catalytically promiscuous CYP81A P450 enzymes has been shown to confer resistance to diverse herbicides. Here, we investigated the role of these P450s in quinclorac resistance in E. phyllopogon . Arabidopsis thaliana plants expressing CYP81A12 and CYP81A21 genes, previously demonstrated to metabolize other herbicides, showed low but detectable levels of quinclorac resistance. A similar activity was also observed for CYP81A24, another promiscuous enzyme present in E. phyllopogon . Moreover, Escherichia coli strains expressing these genes produced putative hydroxylated metabolites of quinclorac. In silico analyses revealed that quinclorac binds stably near the catalytic heme center of CYP81A12, CYP81A21, and CYP81A24, but not CYP81A18, the importance of spatial alignment between the substrate recognition site and the heme center in determining metabolic activity and resistance potential. Consistent with the phenotype of resistant E. phyllopogon , A. thaliana expressing CYP81A12 and CYP81A21 produced significantly less ethylene following quinclorac treatment, linking P450-mediated metabolism to the suppression of quinclorac-induced phytotoxic responses. Finally, we demonstrated that CYP81A enzymes also confer resistance to other auxinic herbicides, florpyrauxifen-benzyl and 2,4-D. These findings provide new insights into the molecular basis of auxinic herbicide resistance and underscore the role of CYP81A P450s in metabolic detoxification and the prevention of herbicide-induced phytotoxic responses.