Anti-inflammatory activity of lupinifolin and Derris reticulata crude extract in lipopolysaccharide and recombinant receptor-binding domain of SAR-CoV-2 induced macrophage cells

Derris reticulata has been used in traditional Thai medicines and uses for fever and skin diseases treatment [ 1 ]. This herb was reported as α-glucosidase inhibitory, antibacterial, and antioxidant [ 2 ]. The major compound of stem parts is lupinifolin, prenylated naringenin derivative. Currently, SAR-CoV-2 pandemic has been occurred which involved immunity and respiratory systems. From these pharmacological activities of this herb, we aimed to investigate anti-inflammatory activity using lipopolysaccharide (LPS) or receptor-binding domain (RBD) of SAR-CoV2 [ 3 ] induced nitric oxide (NO) production in RAW 264.7 macrophage cell line [ 4 ] and co-treatment with lupinifolin and stem crude extracts of D. recticulata . We used RT-PCR to investigate gene expression and proved mechanism of action. The results showed inhibition of LPS- and RBD-induced NO production were 50 μM lupinifolin (46.85 and 79.52%, respectively) and 1000 μg/mL stem extract (66.42 and 77.61%, respectively). Both LPS- and RBD-induced related inflammatory genes expression as inducible nitric oxide synthase ( iNOS ), cyclooxygenase-2 ( COX-2 ), interleukin-6 ( IL-6 ) and 5-lipoxygenase ( 5-LOX ) genes in RAW 264.7 cells. All treatment samples significantly suppressed inflammatory genes expression from inducer. Stem extract downregulated iNOS , IL-6 and 5-LOX genes from LPS-induction (2.2, 2.8 and 13.0-fold, respectively). RBD-induced iNOS , COX-2 , IL-6 and 5-LOX genes expression were suppressed (1.9, 3.5, 7.5 and 3.6-fold, respectively). Lupinifolin inhibited COX-2 gene from LPS induction (2.3-fold). Lupinifolin and stem crude extracts of D. reticulata might be used for anti-inflammation in macrophage. However, it is necessary to quantify and identify standard compounds in extracts, as well as conduct in vivo studies to investigate their effects. Publication History Article published online: 05 March 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany