Bioactive compound schaftoside from Clinacanthus nutans attenuates acute liver injury by inhibiting ferroptosis through activation the Nrf2/GPX4 pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Clinacanthus nutans (Burm. f.) Lindau, a traditional herb renowned for its anti-tumor, antioxidant, and anti-inflammatory properties, has garnered considerable attention. Although its hepatoprotective effects have been described, there is still limited knowledge of its treatment of acute liver injury (ALI), and its mechanisms remain unclear. AIM OF THE STUDY: To assess the efficacy of Clinacanthus nutans in ALI and to identify the most effective fractions and their underlying mechanism of action. METHODS: Bioinformatics was employed to explore the underlying anti-hepatic injury mechanisms and active compounds of Clinacanthus nutans. The binding ability of schaftoside, a potential active ingredient in Clinacanthus nutans, to the core target nuclear factor E2-related factor 2 (Nrf2) was further determined by molecular docking. The role of schaftoside in improving histological abnormalities in the liver was observed by H&E and Masson's staining in an ALI model induced by CCl4. Serum and liver biochemical parameters were measured using AST, ALT and hydroxyproline kits. An Fe2+ kit, transmission electron microscopy, western blotting, RT-qPCR, and DCFH-DA were used to measure whether schaftoside reduces ferroptosis-induced ALI. Subsequently, specific siRNA knockdown of Nrf2 in AML12 cells was performed to further elucidate the mechanism by which schaftoside attenuates ferroptosis-induced ALI. RESULTS: Bioinformatics analysis and molecular docking showed that schaftoside is the principal compound from Clinacanthus nutans. Schaftoside was shown to diminish oxidative stress levels, attenuate liver fibrosis, and forestall ferroptosis. Deeper investigations revealed that schaftoside amplified Nrf2 expression and triggered the Nrf2/GPX4 pathway, thereby reversing mitochondrial aberrations triggered by lipid peroxidation, GPX4 depletion, and ferroptosis. CONCLUSION: The lead compound schaftoside counters ferroptosis through the Nrf2/GPX4 axis, providing insights into a novel molecular mechanism for treating ALI, thereby presenting an innovative therapeutic strategy for ferroptosis-induced ALI.

Schaftoside inhibits 3CLpro and PLpro of SARS-CoV-2 virus and regulates immune response and inflammation of host cells for the treatment of COVID-19.

It is an urgent demand worldwide to control the coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The 3-chymotrypsin-like protease (3CLpro) and papain-like protease (PLpro) are key targets to discover SARS-CoV-2 inhibitors. After screening 12 Chinese herbal medicines and 125 compounds from licorice, we found that a popular natural product schaftoside inhibited 3CLpro and PLpro with IC50 values of 1.73 ± 0.22 and 3.91 ± 0.19 µmol/L, respectively, and inhibited SARS-CoV-2 virus in Vero E6 cells with EC50 of 11.83 ± 3.23 µmol/L. Hydrogen-deuterium exchange mass spectrometry analysis, quantum mechanics/molecular mechanics calculations, together with site-directed mutagenesis indicated the antiviral activities of schaftoside were related with non-covalent interactions with H41, G143 and R188 of 3CLpro, and K157, E167 and A246 of PLpro. Moreover, proteomics analysis and cytokine assay revealed that schaftoside also regulated immune response and inflammation of the host cells. The anti-inflammatory activities of schaftoside were confirmed on lipopolysaccharide-induced acute lung injury mice. Schaftoside showed good safety and pharmacokinetic property, and could be a promising drug candidate for the prevention and treatment of COVID-19.

[Main components in different varieties of Xihuangcao by UPLC-Q-TOF-MS and UPLC-DAD].

This study established an ultra-high performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry(UPLC-Q-TOF-MS) method to analyze the main components in different varieties of Xihuangcao and established a UPLC-DAD method to simultaneously determine the five active components(caffeic acid, rosmarinic acid, schaftoside, isoschaftoside, and oridonin).The chromatographic separation was performed on a Waters ACQUITY UPLC BEH C_(18) column(2.1 mm×100 mm, 1.7 µm) with a gradient elution of methanol(B)-water containing 0.1% formic acid(A) at a flow rate of 0.3 mL·min~(-1).The column temperature was 30 ℃.The Q-TOF-MS discriminant analysis was performed under positive electrospray ion mode and the split ratio was 1∶1. Quantitative analysis was carried out by UPLC-DAD.The determination wavelength was set at 245 nm.Thirty-two main components of Xihuangcao were separated and identified by UPLC-Q-TOF-MS, where 19 were identified in Rabdosia serra, nine in R.nervosa, 10 in R.lophanthoides, 15 in R.lophanthoides var.graciliflora, 10 in R.lophanthoides var.gerardianus, and seven in R.stracheyi.The UPLC-DVD method was developed for simultaneously determining five active components in different varieties of Xihuangcao.The standard curves for five compounds showed good linearity with correlation coefficients higher than 0.999 0.The precision, repeatability, and stability were good.The average recoveries(n=6) were between 97.01% and 102.7% with RSD<3.0%.The results of UPLC-Q-TOF-MS analysis provided a scientific basis for the use of R.stracheyi as a medicinal material of Xihuangcao and the equivalent use of R.lophanthoides var.gerardianus with R.lophanthoides var.graciliflora to some extent.The UPLC-DAD method for simultaneously determining five active components is simple, rapid, and accurate.This study can provide the basis for the quality control of different varieties of Xihuangcao.

Anti-Inflammatory Effects of Phytochemical Components of Clinacanthus nutans.

Recent studies on the ethnomedicinal use of Clinacanthus nutans suggest promising anti-inflammatory, anti-tumorigenic, and antiviral properties for this plant. Extraction of the leaves with polar and nonpolar solvents has yielded many C-glycosyl flavones, including schaftoside, isoorientin, orientin, isovitexin, and vitexin. Aside from studies with different extracts, there is increasing interest to understand the properties of these components, especially regarding their ability to exert anti-inflammatory effects on cells and tissues. A major focus for this review is to obtain information on the effects of C. nutans extracts and its phytochemical components on inflammatory signaling pathways in the peripheral and central nervous system. Particular emphasis is placed on their role to target the Toll-like receptor 4 (TLR4)-NF-kB pathway and pro-inflammatory cytokines, the antioxidant defense pathway involving nuclear factor erythroid-2-related factor 2 (NRF2) and heme oxygenase 1 (HO-1); and the phospholipase A2 (PLA2) pathway linking to cyclooxygenase-2 (COX-2) and production of eicosanoids. The ability to provide a better understanding of the molecular targets and mechanism of action of C. nutans extracts and their phytochemical components should encourage future studies to develop new therapeutic strategies for better use of this herb to combat inflammatory diseases.

Costus spiralis extract restores kidney function in cisplatin-induced nephrotoxicity model: Ethnopharmacological use, chemical and toxicological investigation.

ETHNOPHARMACOLOGICAL RELEVANCE: Costus spiralis (Jacq.). Roscoe (Costaceae) is traditionally used in Brazil for the treatment of kidney diseases such as pyelonephritis, urethra inflammation, kidney stones, and inflammatory conditions. There are reports of its use by Brazilian Indians since the 17th century when it was known as "pacocatinga." Currently, the use of the Costus species in Brazil is widespread, which was evidenced by the inclusion of the genus in the Brazilian National List of Medicinal Plants of Interest to the Unified Health System (RENISUS). AIM OF THE STUDY: This study aimed to confirm the ethnopharmacological use of Costus spiralis in the treatment of kidney diseases, toxicity study using animal models, and the phytochemistry of the species. MATERIALS AND METHODS: The chemical profile of Costus spiralis leaves extract (CSLE) was obtained for the hydroethanolic extract by ultra-performance liquid chromatography coupled to a mass spectrometer and ultraviolet detector with diode array (UPLC-UV/DAD-ESI-MS). The acute oral toxicity of the extract was predicted using the neutral red uptake cytotoxicity assay. Wistar rats were used in a model in vivo for confirmation of acute oral toxicity (2000 mg/kg p.o. for 14 days.) and determination of the effect on a cisplatin-induced nephrotoxicity model. RESULTS: The analysis by UPLC-UV/DAD-ESI-MS showed that the chemical composition of the extract is mostly di-glycosylated flavones of apigenin. In the extract were identified the flavones vicenin II and schaftoside. The quantification of total flavonoids by spectrometry showed 0.880%. CSLE proved to be safe for acute oral administration (2000 mg/kg) with an IC50 value of 222.9 µg/mL and predicted oral toxic dose of 523.82 µg/mL in a neutral red uptake cytotoxicity assay. The absence of death allows the classification of the extract in class 5 according to OECD 423 guidelines and therefore it can be considered as a high acute safety product, which is highly relevant, considering the wide popular use of the species. In the cisplatin-induced nephrotoxicity model, C. spiralis extract (5, 15, and 30 mg/kg) significantly improved renal function, reversing almost completely the effects on plasma creatinine levels and creatinine clearance (p < 0.001). CONCLUSIONS: This study demonstrates that oral administration of Costus spiralis extract leaves is safe and effective in restoring the renal function in rats in a cisplatin-induced nephrotoxicity. It is suggested that the observed activity is related to the flavonoids present. This hypothesis should be confirmed, and the participation of other secondary metabolites should be investigated in the future.

Dissection of the general two-step di-C-glycosylation pathway for the biosynthesis of (iso)schaftosides in higher plants.

Schaftoside and isoschaftoside are bioactive natural products widely distributed in higher plants including cereal crops and medicinal herbs. Their biosynthesis may be related with plant defense. However, little is known on the glycosylation biosynthetic pathway of these flavonoid di-C-glycosides with different sugar residues. Herein, we report that the biosynthesis of (iso)schaftosides is sequentially catalyzed by two C-glycosyltransferases (CGTs), i.e., CGTa for C-glucosylation of the 2-hydroxyflavanone aglycone and CGTb for C-arabinosylation of the mono-C-glucoside. The two enzymes of the same plant exhibit high homology but remarkably different sugar acceptor and donor selectivities. A total of 14 CGTa and CGTb enzymes were cloned and characterized from seven dicot and monocot plants, including Scutellaria baicalensis, Glycyrrhiza uralensis, Oryza sativa ssp. japonica, and Zea mays, and the in vivo functions for three enzymes were verified by RNA interference and overexpression. Through transcriptome analysis, we found homologous genes in 119 other plants, indicating this pathway is general for the biosynthesis of (iso)schaftosides. Furthermore, we resolved the crystal structures of five CGTs and realized the functional switch of SbCGTb to SbCGTa by structural analysis and mutagenesis of key amino acids. The CGT enzymes discovered in this paper allow efficient synthesis of (iso)schaftosides, and the general glycosylation pathway presents a platform to study the chemical defense mechanisms of higher plants.

Schaftoside alleviates HFD-induced hepatic lipid accumulation in mice via upregulating farnesoid X receptor.

ETHNOPHARMACOLOGY RELEVANCE: The farnesoid X receptor (FXR) is a therapeutic target of for the treatment of non-alcoholic fatty liver disease (NAFLD) owing to its regulatory role in lipid homeostasis. Schaftoside (SS) is a bioactive compound of Herba Desmodii Styracifolii, which has traditionally been used to treat hepatitis and cholelithiasis. However, the potential hepatoprotective effect of SS against NAFLD and the underlying mechanisms remain unknown. AIM OF THE STUDY: We investigated whether SS could improve NAFLD-induced liver injury by decreasing lipid accumulation via the activation of FXR signalling. MATERIALS AND METHODS: In vivo, the effects of SS on high-fat diet (HFD)-induced lipid accumulation in the liver of mice were evaluated by serum biochemical parameters and histopathological analysis. In vitro, the intracellular triglyceride (TG) level and Oil Red O staining were used to evaluate the lipid removal ability of SS in Huh-7 cells or FXR knockout mouse primary hepatocytes (MPHs) induced by oleic acid (OA). Moreover, FXR/sterol regulatory element-binding protein 1 (SREBP1) mRNA and protein expression levels were detected. RESULTS: SS reduced HFD-induced lipid accumulation in the liver, as indicated by decreased aspartate aminotransferase (AST), cholesterol (Ch), and TG levels in serum and TG levels in liver tissue, and subsequently resulting in attenuation of liver histopathological injury. Gene expression profiles demonstrated that SS dose-dependently prevented HFD-induced decrease of FXR expression and inversely inhibited SREBP1 expression in the nucleus. Furthermore, SS significantly suppressed excessive TG accumulation and decreased intracellular TG level in Huh-7 cells or MPHs via the upregulation of FXR and inhibition of SREBP1 expression in the nucleus. CONCLUSION: Our results suggest that SS ameliorates HFD-induced NAFLD by the decrease of lipid accumulation via the control of FXR-SREBP1 signalling.

Antioxidant activity and polyphenol composition of sugarcane molasses extract.

The antioxidant activity of sugarcane molasses ethanol extract (ME) and its fraction (ME-RBF) was evaluated using ABTS, ORAC 6.0 and CAA assays and ME-RBF demonstrated 26-fold, 12-fold and 2-fold higher values, respectively than ME. Likewise, total polyphenol and flavonoid concentration in ME-RBF are more than 10-fold higher than ME, that suggested antioxidant activity is correlated with polyphenol composition. Quantitative analysis of 13 polyphenols (chlorogenic acid, caffeic acid, sinapic acid, syringic acid, vanillin, homoorientin, orientin, vitexin, swertisin, diosmin, apigenin, tricin and diosmetin) was carried out by LCMS. MS/MS analysis allowed the tentative identification of seven apigenin-C-glycosides, three methoxyluteolin-C-glycosides and three tricin-O-glycosides some of which have not been reported in sugarcane before to the best of our knowledge. The results demonstrated that sugarcane molasses can be used as potential source of polyphenols that can be beneficial to health.

Identification and quantitative analysis of phenolic glycosides with antioxidant activity in methanolic extract of Dendrobium catenatum flowers and selection of quality control herb-markers.

Recently, the flowers of Dendrobium catenatum (D. officinale) have been approved as new food ingredient. This study aimed to investigate the herb-markers and their antioxidant activities in methanolic extracts of D. catenatum flowers, and to establish the quality evaluation methods for raw materials and their products of flower by HPLC. The methanolic extract of 11 strains of D. catenatum flowers were found to contain a high content of total phenol and flavonoids, and they possessed potential antioxidant capacities based on DPPH radical scavenging assay. A total of 21 phenolic herb-markers were selected according to the similarity and principal component analysis of the chromatographic fingerprinting profiles. Their structures were further elucidated by UV, HPLC-DAD-ESI-QTOF-MS/MS and NMR analyses. The identified compounds included 2 phenylpropanoids, 11C-glycosylflavones and 6 O-glycosylflavones, which could be employed as the indicators for quantitative evaluation of the quality and authenticity of the flowers. Based on the pre-column DPPH/ABTS+-HPLC analysis, the major compounds contributed to the antioxidative activity were identified as 1-O-caffeoyl-ß-D-glucoside, rutin and isoquercitrin, all of which, were also the most abundant constituents in the methanolic extract. The results suggest the potential of D. catenatum flowers as a new antioxidant resources for medicinal and food products.

Costus spiralis (Jacq.) Roscoe: A Novel Source of Flavones with α-Glycosidase Inhibitory Activity.

Costus spiralis, a plant used in traditional Brazilian medicine for the treatment of complications in diabetes, was investigated. Assay of hexane, ethyl acetate, methanol, and aqueous fractions obtained by partition of a crude methanol extract of dried leaves of C. spiralis revealed that AGI activity was confined to the ethyl acetate fraction. Purification of this fraction yielded schaftoside and isoschaftoside. The AGI activities of the two flavones were lower than, but comparable with, that of the anti-diabetic drug acarbose. In contrast, the IC50 value of the ethyl acetate fraction was 1.95-, 2.34-, and 2.22-fold higher than those of acarbose, schaftoside, and isoschaftoside, respectively. The results demonstrate for the first time that schaftoside and isoschaftoside are responsible, in part, for the AGI activity of C. spiralis. Our study suggests that further investigations into C. spiralis may lead to the discovery of additional compounds with antihyperglycemic activity.