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.

Medicinal plants in the Acanthaceae family have long been used in Thai traditional medicine. In this study, ethanolic extracts of four plant species, Andrographis paniculata, Thunbergia laurifolia, Acanthus ebracteatus, and Rhinacanthus nasutus, were prepared and their phytochemical and pharmacological properties were evaluated. Total phenolic and flavonoid content assays were used to investigate phytochemical content and phytochemical profiles were characterized with LC-MS, while antioxidant activities were assessed via colorimetric methods. The extracts were also tested for antibacterial activity against several skin pathogens, such as Pseudomonas aeruginosa, Cutibacterium acnes, Micrococcus luteus, Staphylococcus aureus, and methicillin-resistant S. aureus, using agar well diffusion and broth dilution methods. Cytotoxic effects on the RAW 264.7 macrophage cell were assessed using the MTT assay. The extracts were further evaluated for anti-inflammatory activity in an LPS-stimulated RAW 264.7 cell. Inflammatory gene expression was assessed by quantifying the mRNA levels of iNOS, COX-2, TNF-α, IL-1β, IL-6, and NF-κB genes using RT-qPCR. The results revealed that among the four species, T. laurifolia extract showed the highest phenolic and flavonoid levels, consistent with the greatest antioxidant activity. Moreover, LC-MS profiling annotated a range of secondary metabolites in the extracts. The inhibition zones were observed for all plant extracts when tested against the skin pathogenic bacteria except C. acnes, and A. paniculata did not inhibit P. aeruginosa, indicating the antibacterial activity of the extracts. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values differed across the extracts and bacterial strains. T. laurifolia exhibited the most potent activity against various bacterial pathogens, while A. paniculata was most effective against C. acnes at 0.98 mg/mL. In addition, all plant extracts reduced nitric oxide production and downregulated the expression of inflammatory genes. Among all plant species, A. paniculata showed the most potent activity with the highest NO inhibition of 65.68% at 60 µg/mL. Therefore, these findings support the antioxidant, antibacterial, and anti-inflammatory potential of A. paniculata, T. laurifolia, A. ebracteatus and R. nasutus, which are traditionally used in folk medicine.