Explore the vast range of titles available.

Safety concerns surrounding skin-lightening agents have intensified following chemical leukoderma linked to rhododendrol. Here, we performed an in vitro safety and hazard profiling comparison of raspberry ketone (RK) and a total anthraquinone fraction from Fallopia multiflora var. cillinerve (Polygonum cillinerve) using an immortalized keratinocyte–melanocyte co-culture model (human HaCaT keratinocytes and murine B10.BR melanocytes, 3:1). Rhododendrol and arbutin were included as contextual references. Following viability-guided range finding, cells were exposed for 48 h and evaluated for melanocyte stress and injury, including ROS generation, UPR/ER-stress activation (PERK/eIF2α–ATF4-associated readouts: ATF4, Hmox1, GADD45a; and IRE1 phosphorylation), IL-8-related chemokine output (CXCL1/KC, a murine functional homolog of IL-8), cell-cycle perturbation, and Caspase-3-associated apoptosis. In parallel, targeted LC–MS metabolomics was performed to resolve pathway-level perturbations. High-dose RK elicited a rhododendrol-like in vitro stress/toxicity signature, characterized by elevated ROS, robust UPR engagement, inflammatory chemokine induction, cell-cycle dysregulation, and pro-apoptotic responses; under viability-adjusted conditions, these effects remained more evident than with arbutin. Metabolomics revealed convergent disturbances between RK and rhododendrol, highlighting purine metabolism as a prominent perturbed pathway and suggesting purine-related metabolites as candidate indicators associated with leukoderma-relevant cellular stress in vitro. In contrast, the anthraquinone fraction did not trigger oxidative or ER stress within the tested range and exhibited a more favorable in vitro safety profile, including reduced ROS.

The anticancer, anti-inflammatory and antioxidant properties of Purpurin were generated from in vitro studies, and no scientific reports were found on its safety and efficacy, related to their in vivo studies; thus, the present study was focused on acute oral toxicity of purpurin in female Wistar rats as per the OECD 423 guidelines. In this study, purpurin was administered at starting dosage of 300 mg/kg followed by 2000 mg/kg, p.o, and animals were observed for toxic signs at 24 h and for the next 14 days to different animal groups. Animals were observed for mortality, behavioral changes, biochemistry, hematological parameters, and histopathological examination after a follow up on the 14th day. The oral lethal dose for mice was greater than 2000 mg/kg, b.wt. in female rats and classified under category 5 as per the acute oral toxicity study. It was found that there were no significant differences in body weight changes, food/water intake, hematology, and clinical biochemistry. The histopathological study directly depicted that there were no pathological changes observed in the vital organs of rats treated with the different dose of Purpurin. The present work advocates that an acute oral administration of Purpurin was found to be a non-toxic and safe drug in the tested experimental conditions.

Emodin, rhein, aloe-emodin, physcion, and chrysophanol are five representative anthraquinones (AQs) in rhubarb. They exhibit diverse pharmacological activities, including antitumor, anti-inflammatory, antibacterial, and antioxidant effects, and are widely used in traditional Chinese medicines (TCMs), dietary supplements, and functional foods. However, with their increasing application, the potential toxicity of AQs has become increasingly prominent. Moreover, their toxic mechanisms and metabolism-related toxicities remain incompletely elucidated, which has limited their clinical development and safe application to a certain extent. This paper systematically reviews the toxicological characteristics, toxic mechanisms, and metabolism-related toxicity of the five major AQs in rhubarb, and explores research strategies for AQs toxicity based on advanced technologies, aiming to provide new insights and references for their safe application and further studies. A comprehensive search was conducted in PubMed, Google Scholar, Web of Science, and CNKI for peer-reviewed research articles and reviews published in the past 15 years. The research progress of the five major rhubarb AQs and the applications of cutting-edge technologies in their toxicity studies were summarized. The toxicities of AQs mainly target the liver, kidney, heart, reproductive system, and nervous system. Their toxic mechanisms involve multiple pathways, including mitochondrial apoptosis, oxidative stress, death receptor pathway, endoplasmic reticulum (ER)-related apoptosis, caspase-dependent apoptosis, autophagy, inflammation, DNA damage, and bilirubin metabolism. The in vivo metabolism of AQs is complicated, and both Phase I and Phase II metabolites are linked to toxicity. The diverse metabolites can interconvert and undergo various reactions in vivo, posing great challenges for toxicity research. In the future, the application of advanced technologies, such as multi-omics and single-cell sequencing, artificial intelligence (AI) and computer simulation, microfluidics, and mass spectrometry imaging (MSI) will provide strong support for accurately elucidating toxic mechanisms, enabling toxicity prediction, and optimizing detoxification strategies, and will become effective approaches to advance toxicity studies of rhubarb AQs. The intrinsic toxicity and complex metabolic processes of rhubarb AQs restrict their clinical application. Current studies on the toxic mechanisms, metabolism-toxicity relationships, and multifactorial regulation of AQs still require further in-depth investigation. Future research should focus on the metabolism-toxicity relationship, key toxic targets, and detoxification strategies of AQs, and establish an integrated toxicity research system combined with advanced technologies, so as to provide robust support for the safe application and clinical development of rhubarb AQs.

This research investigated the discoloration and mineralization of Reactive Blue 19 (RB19) anthraquinone dye by single ozonation, single UV radiation and ozonation jointed with UV radiation (O3/UV). The problem was approached from two points of view: with the objective of color removal or the mineralization of solution. In each case, the optimum operating conditions were different. Ozonation was the most effective treatment for color removal, while the combined O3/UV treatment was for mineralization. Major intermediates of the dye degradation were identified by gas chromatography/mass spectrometry and a degradation pathway was proposed. In addition, a clear decrease of the toxicity of the dye was achieved at the end of the experiments. The effect of initial dye concentration, pH, ozone dose, and UV radiation on the degradation of the dye and decrease of total organic carbon was investigated, in order to establish the optimal operating conditions to achieve discoloration, mineralization or a combination of both.

Objective: This study was conducted to evaluate the acute and subchronic toxicity of anthraquinone. An acute toxicity test was performed in female Sprague Dawley (SD) rats, and the oral median lethal dose (LD50) of anthraquinone was estimated to be >5000 mg/kg body weight (BW). In the subchronic study, groups of 10 male and 10 female rats were dosed with anthraquinone by gavage at 0, 1.36, 5.44, 21.76, and 174.08 mg/kg BW, 7 days/week for 90 days followed by a recovery period of 28 days. No appreciable toxic-related changes were observed in the 1.36 mg/kg BW group. When the animals received 5.44 mg/kg BW or more of anthraquinone, hyaline droplet accumulation in the renal tubules was observed in both the male and female rats, and anemia was observed in the females. When the anthraquinone dose reached 174.08 mg/kg BW, mild hepatocellular hypertrophy around the central vein of the hepatic lobule and hypothyroidism were observed in the female rats. During the recovery period, changes in clinical symptoms and parameters were considerably alleviated. Based on the results of this study, the no observed adverse effect level (NOAEL) for anthraquinone in rats was set at 1.36 mg/kg BW, and the lowest observed adverse effect level (LOAEL) was 5.44 mg/kg BW.

A striking and clinically relevant virulence trait of the human fungal pathogen Candida albicans is its ability to grow and switch reversibly among different morphological forms. Inhibition of yeast-to-hypha transition in C. albicans represents a new paradigm for antifungal intervention. We have previously demonstrated the novel antifungal activity of purpurin against Candida fungi. In this study, we extended our investigation by examining the in vitro effect of purpurin on C. albicans morphogenesis and biofilms. The susceptibility of C. albicans biofilms to purpurin was examined quantitatively by 2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide reduction assay. Hyphal formation and biofilm ultrastructure were examined qualitatively by scanning electron microscopy (SEM). Quantitative reverse transcription-PCR (qRT-PCR) was used to evaluate the expression of hypha-specific genes and hyphal regulator in purpurin-treated fungal cells. The results showed that, at sub-lethal concentration (3 µg/ml), purpurin blocked the yeast-to-hypha transition under hypha-inducing conditions. Purpurin also inhibited C. albicans biofilm formation and reduced the metabolic activity of mature biofilms in a concentration-dependent manner. SEM images showed that purpurin-treated C. albicans biofilms were scanty and exclusively consisted of aggregates of blastospores. qRT-PCR analyses indicated that purpurin downregulated the expression of hypha-specific genes (ALS3, ECE1, HWP1, HYR1) and the hyphal regulator RAS1. The data strongly suggested that purpurin suppressed C. albicans morphogenesis and caused distorted biofilm formation. By virtue of the ability to block these two virulence traits in C. albicans, purpurin may represent a potential candidate that deserves further investigations in the development of antifungal strategies against this notorious human fungal pathogen in vivo.

Anthracyclines such as doxorubicin are used extensively in the treatment of cancers. Anthraquinone-related angucyclines also exhibit antiproliferative properties and have been proposed to operate via similar mechanisms, including direct genome targeting. Here, we report the chemical synthesis of marmycin A and the study of its cellular activity. The aromatic core was constructed by means of a one-pot multistep reaction comprising a regioselective Diels–Alder cycloaddition, and the complex sugar backbone was introduced through a copper-catalysed Ullmann cross-coupling, followed by a challenging Friedel–Crafts cyclization. Remarkably, fluorescence microscopy revealed that marmycin A does not target the nucleus but instead accumulates in lysosomes, thereby promoting cell death independently of genome targeting. Furthermore, a synthetic dimer of marmycin A and the lysosome-targeting agent artesunate exhibited a synergistic activity against the invasive MDA-MB-231 cancer cell line. These findings shed light on the elusive pathways through which anthraquinone derivatives act in cells, pointing towards unanticipated biological and therapeutic applications. Marmycin A is an anthraquinone natural product with antiproliferative properties. Now the chemical synthesis of marmycin A—through a Diels–Alder cycloaddition, an Ullmann aromatic amination and a Friedel–Crafts cyclization—has enabled a study of its biological activity. Fluorescence microscopy reveals that marmycin A accumulates in lysosomes and promotes cell death independently of genome targeting.

Considering the toxicity of the impurities of synthesized anthraquinone, this study clarified new catalytic compounds for kraft cooking with improved carbohydrate yield and delignification and less mutagenicity, which are important for ensuring the safety of paper products in contact with food. The 2-methylanthraquinone contents of teak (Tectona grandis) woods were 0.18–0.21%. Acetone extracts containing 2-methylanthraquinone from Myanmar and Indonesia teak woods as additives improved lignin removal during kraft cooking of eucalyptus wood, which resulted in kappa numbers that were 2.2–6.0 points lower than the absence of additive. Myanmar extracts and 2-methylanthraquinone improved carbohydrate yield in pulps with 1.7–2.2% yield gains. Indonesia extracts contained more deoxylapachol and its isomer than 2-methylanthraquinone. The residual content of 2-methylanthraquinone in the kraft pulp was trace. Although Ames tests showed that the Indonesia and Myanmar extracts were mutagenic to Salmonella typhimurium, 2-methylanthraquinone was not. The kraft pulp obtained with the additives should be safe for food-packaging applications, and the addition of 0.03% 2-methylanthraquinone to kraft cooking saves forest resources and fossil energy in industries requiring increased pulp yield.

Aurantio-obtusin is an anthraquinone derived from Cassia obtusifolia (cassiae semen). It is also used as a tool and a detection index for the identification of cassiae semen, as stipulated by the Chinese Pharmacopoeia. Anthraquinones, the main components in cassiae semen, have been reported to show hepatotoxicity. This study investigates the hepatotoxicity of aurantio-obtusin in male Sprague–Dawley rats. We randomly divided the animals into a blank control group and treated three test groups with different doses of aurantio-obtusin: Low dose (4 mg/kg), medium dose (40 mg/kg), and high dose (200 mg/kg). Each group was treated with aurantio-obtusin for 28 days, whereas the control group was administered an equal volume of 0.5% carboxymethyl cellulose sodium salt (CMC-Na) aqueous solution. Subsequently, we conducted biochemical, hematological, and pathological investigations and determined the weight of different organs. We used serum metabolomics to identify possible biomarkers related to hepatotoxicity. The low-dose group showed no significant liver injury, whereas the medium- and high-dose groups manifested obvious liver injury. Compared with the control group, the test groups showed an increase in alanine transaminase, aspartate transaminase, and alkaline phosphatase levels. The liver organ coefficient also significantly increased. Additionally, we found significant changes in the hematological indices. Metabolomics analysis showed that aurantio-obtusin induced 28 endogenous markers related to liver injury. Our data indicate that aurantio-obtusin induces hepatotoxicity in rat liver in a dose-dependent manner and is mediated by pathways involving bile acids, fatty acids, amino acids, and energy metabolism. In particular, changes in bile acid content during treatment with therapeutic agents containing aurantio-obtusin deserve increased attention.

Inflammatory bowel disease (IBD) is an immune disorder that develops due to chronic inflammation in several cells. It is known that colorectal and T cells are mainly involved in the pathogenesis of IBD. Chrysophanol is an anthraquinone family member that possesses several bioactivities, including anti-diabetic, anti-tumor, and inhibitory effects on T cell activation. However, it is unknown whether chrysophanol suppresses the activity of colorectal cells. In this study, we found that chrysophanol did not induce cytotoxicity in HT-29 colorectal cells. Pre-treatment with chrysophanol inhibited the mRNA levels of pro-inflammatory cytokines in tumor necrosis factor-α (TNF-α)-stimulated HT-29 cells. Western blot analysis revealed that pre-treatment with chrysophanol mitigates p65 translocation and the mitogen-activated protein kinase (MAPK) pathway in activated HT-29 cells. Results from the in vivo experiment confirmed that oral administration of chrysophanol protects mice from dextran sulfate sodium (DSS)-induced IBD. Chrysophanol administration attenuates the expression of pro-inflammatory cytokines in colon tissues of the DSS-induced IBD model. In addition, we found that oral administration of chrysophanol systemically decreased the expression of effector cytokines from mesenteric lymph nodes. Therefore, these data suggest that chrysophanol has a potent modulatory effect on colorectal cells as well as exhibiting a beneficial potential for curing IBD in vivo.