Emodin Concentration Research Articles

Natural Sunlight-Mediated Emodin Photoinactivation of Aeromonas hydrophila.

Aeromonas hydrophila can be a substantial concern, as it causes various diseases in aquaculture. An effective and green method for inhibiting A. hydrophila is urgently required. Emodin, a naturally occurring anthraquinone compound, was exploited as a photo-antimicrobial agent against A. hydrophila. At the minimum inhibitory concentration of emodin (256 mg/L) to inactivate A. hydrophilia in 30 min, an 11.32% survival rate was observed under 45 W white compact fluorescent light irradiation. In addition, the antibacterial activity under natural sunlight (0.78%) indicated its potential for practical application. Morphological observations demonstrated that the cell walls and membranes of A. hydrophila were susceptible to damage by emodin when exposed to light irradiation. More importantly, the photoinactivation of A. hydrophila was predominantly attributed to the hydroxyl radicals and superoxide radicals produced by emodin, according to the trapping experiment and electron spin resonance spectroscopy. Finally, a light-dependent reactive oxygen species punching mechanism of emodin to photoinactivate A. hydrophila was proposed. This study highlights the potential use of emodin in sunlight-mediated applications for bacterial control, thereby providing new possibilities for the use of Chinese herbal medicine in aquatic diseases prevention.

The role of chitosan in enhancing the solubility and antibacterial activity of emodin against drug-resistant bacteria

Similar to most anthraquinone compounds, the pharmacological properties of emodin are limited because of its low water solubility. In this study, the formulation of chitosan and emodin (EMD/CS) was prepared by a bottom-up method with precipitation and sonication steps in order to enhance the solubility of emodin. Thanks to the interactions of oxygen-and nitrogen-containing groups in chitosan with emodin molecules, the solubility of emodin in the formulation was remarkably increased to 0.5 mg/mL. The EMD/CS particles were well dispersed and distributed in a range of sub-micrometer with an average particle size of 342 nm. The EMD/CS formulation exhibited synergic antibacterial activity of emodin and chitosan, against drug-resistant bacterial strains, namely Methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli O157:H7 (E. coli O157:H7). When the compositions of emodin and chitosan increased, the antibacterial effectiveness of the EMD/CS formulation increased. The EMD/CS formulation with compositions of 0.5 mg/mL of emodin and 9.0 mg/mL of chitosan could significantly inhibit the proliferation of E. coli O157:H7. Meanwhile, the EMD/CS formulation with a lower concentration of emodin (0.4 mg/mL) and chitosan (7.2 mg/mL) could cause an extermination effect on MRSA. The enhanced solubility of EMD/CS formulation suggests that this formulation can be a potential candidate for the treatment of infectious diseases caused by drug-resistant bacterial pathogens.

Fabrication of microspheres and characterization of antimicrobial and anti-inflammatory activity isolated fraction from total alcoholic extract of Cassia Fistula (Linn.) in carrageenan-Type-IV induced inflammatory rats

The Cassia fistula Linn is known as the golden shower tree. It’s also referred to as a "disease killer" in Ayurvedic medicine. The current study investigates the effect and estimate of antimicrobial and Anti-inflammatory activity guided fraction isolated from alcoholic extract of Cassia fistula (Linn.) root on carrageenan-Type IV induced Inflammatory rats for using Column fraction of alcoholic extract of root of Cassia fistula (Linn.) An in vivo carrageenan-induced paw edoema model was used to confirm further the anti-inflammatory effect of the fraction aloe-emodin and physcion-loaded microspheres. This study was designed first time for the isolation of alcoholic fraction of aloe emodin and Physcion by root extract and screening of pharmacological activities of Cassia fistula. Aloe-emodin and Physcion fraction demonstrated antibacterial and antifungal effectiveness against the studied pathogens in a dose-dependent manner, according to anti-microbial activity. 50 mg/ml concentration of Physcion-containing microspheres and aloe emodin's antibacterial efficacy against tested pathogens. The anti-inflammatory activity of Aloe emodin and Physcion was found in an equal manner. Both Microsphere samples were found capable of controlling the inflammation till 6 hours. According to the findings of this research, the chosen plant extracts have an immediate anti-inflammatory effect. There are three stages during which carrageenan-induced inflammation mediators are released.

In vitro study of emodin-induced nephrotoxicity in human renal glomerular endothelial cells on a microfluidic chip

Emodin is an effective component of rhubarb with positive pharmacological effects on human health. However, it is also toxic to different cells or tissues to varying degrees. The effects of emodin on glomerular endothelial cells (GECs) remain to be tested, and the documented works were always performed in vitro and hardly reflect the real physiological situation. To study the effects of emodin on GECs in a biomimetic environment, we utilized a microfluidic chip to assess the physiological reaction of human renal glomerular endothelial cells to various concentrations of emodin in this work. The results showed that emodin caused cytotoxicity, impaired glomerular filtration barrier integrity to macromolecules, and increased barrier permeability in a dose-dependent manner. With the increase in emodin concentration, the concentration of the pro-inflammatory cytokine tumor necrosis factor-α, interleukin (IL)-6, transforming growth factor-β1, and monocyte chemoattractant protein (MCP-1) increased while the production of inflammatory cytokine IL-6 first increased and then decreased with the increase in emodin concentration. Our findings shed new light on emodin-induced nephrotoxicity and provide insights for the application of microfluidic chip devices to reveal drug-cell interactions.

Pharmacokinetic characteristics of emodin in polygoni Multiflori Radix Praeparata

Ethnopharmacological relevancePolygoni Multiflori Radix Praeparata (Zhiheshouwu) has been a Wudang Taoist medicine for tonifying the liver and kidney, resolving turbidity and reducing lipid. Emodin is one of the active anthraquinones in Zhiheshouwu. Our previous studies showed that emodin (EM) and the other anthraquinones in Zhiheshouwu extract (HSWE) exerted similar inhibitory effects on liver cancer cells in vitro. However, it is still unknown if the other anthraquinones enhance pharmacokinetics (PK) of EM in HSWE in vivo. Aim of the studyIn this study, we compared the PK characteristics of EM alone with that in Zhiheshouwu aiming to explore which anthraquinones in HSWE contribute to the changed PK of EM in rats. Materials and methodsQuality control of HSWE was determined using high performance liquid chromatography (HPLC). The ratios of emodin to other anthraquinones, physcion (PH), chrysophanol (CH), rhein (RH), aloe-emodin (AE), emodin-8-O-β-D-glycoside (EMG), physcion-1-O-β-D-glycoside (PHG) and chrysophanol-8-O-β-D-glycoside (CHG) in HSWE were determined and analyzed using UPLC combined with tandem mass spectrometry (UPLC/MS). The PK parameters and intestinal tissue concentration of EM alone, EM in HSWE, or with other anthraquinones in SD rats were analyzed using UPLC/MS. ResultsThe quality of the Zhiheshouwu samples met the quality standard of the Chinese Pharmacopoeia (Version 2020). The PK results showed that compared with EM alone, Cmax (239.90 ± 146.71 vs. 898.46 ± 291.62, P < 0.001), Tmax (0.26 ± 0.15 vs. 12.55 ± 1.33, P < 0.001), AUC0-t (1575.09 ± 570.46 vs. 12154.96 ± 5394.25, P < 0.001), and AUC0-∞ (4742.51 ± 1837.62 vs. 37131.34 ± 21647.39, P < 0.001) of EM in HSWE were decreased due to PH and EMG, while the values of Vd (380.75 ± 217.74 vs. 11.75 ± 7.35, P < 0.001), T1/2 (10.81 ± 1.99 vs. 6.65 ± 2.76, P < 0.05) and CL (19.30 ± 7.82 vs. 2.78 ± 1.88, P < 0.001) of EM in HSWE were increased due to PH and AE. In addition, the intestinal tissue concentration of emodin in HSWE was decreased compared with that of EM alone in 20 and 780 min (25.37 ± 5.98 vs. 43.29 ± 4.16 and 26.72 ± 4.03 vs. 43.40 ± 14.19, respectively. P < 0.05) dominantly due to RH and PH. ConclusionIn conclusion, compared with treatment of EM alone, the AUC0-t value of EM in HSWE was decreased with different ways in rats. PH shortened Tmax, and increased Vd and CL. While AE prolonged T1/2 of EM. This indicated that the other anthraquinones in HSWE changed the PK of EM in rats and participated in the complex effects of EM on liver cancer. Besides the other anthraquinones, other components (e.g., 2,3,5,4′-tetrahydroxystilbene-2-O-β-D-glucoside) in Zhiheshouwu may contribute in the pharmacokinetic and pharmacodynamic interactions with EM for anti-liver cancer.

Optimization and Application of A Bionic System of Dynamic Co-Culture with Hepatocytes and Renal Cells Based on Microfluidic Chip Technique in Evaluating Materials of Health Food.

We aimed to explore the optimization and application of a bionic system of dynamic co-culture with hepatocytes and renal cells based on the microfluidic chip technique in evaluating emodin, which might replace the conventionally cytological evaluation technique of health food. After optimal experiments, the improved bionic system was composed of human hepatocellular carcinoma cells (HepG2), human renal glomerular endothelial cells (HRGECs), rat tail collagen type I, and gelatin with optimized concentrations (1.3 mg/mL + 7.5%). The applicability of the bionic system indicated that the growth stability was appropriate (CV: 7.36%), and the cell viability of that gradually decreased with the increasing of emodin concentration from 0-100 μM, which statistic significances were at 50 and 100 μM (p &lt; 0.05), and the stained results of dead/live cells also showed the same trend. The LDH level appeared rising trend after decline between 0 μM and 100 μM emodi, and the level of that at 100 μM emodin was significantly higher than that at 25 μM and 50 μM emodin, respectively. The BUN level continuously and significantly declined with the increasing of emodin concentration (p &lt; 0.05). Our research realized the application of this optimized bionic system in evaluating emodin, and provided a useful platform and reference for further in vitro alternative research with regard to evaluating the efficacies of health food in the future.

Effects of methyl jasmonate, salicylic acid and phenylalanine on aloe emodin and aloin in diploid and tetraploid Aloe barbadensis

Aloe vera is one of the most famous medicinal plants. Aloin and aloe emodin are the most important active compounds in this plant. The purpose of this research was the comparison of aloin and aloe emodin production after the elicitation by methyl jasmonate, salicylic acid, and phenylalanine in diploid and tetraploid Aloe vera plants in greenhouse conditions. The plants were treated with the concentrations of 25, 50, and 100 µM. The amounts of aloin and aloe emodin were determined 24 and 48 hours after application of the treatment. HPLC analysis showed that the leaves of the control diploid plants (without applying elicitors) had more aloin (1.20 fold) and aloe emodin (1.14 fold) than the control tetraploid plants. The maximum concentration of aloin (1.15 ± 0.07 µg mg-1 dry weight) was obtained after the elicitation by 25 µM methyl jasmonate, 24 hours after treatment, in diploid plants) 6.36 fold compared to the control (0.18 µg mg-1 dry weight (. In addition, the maximum concentration of aloe emodin (0.28 µg mg-1 dry weight) was obtained after the elicitation by 25 µM salicylic acid, 24 hours after treatment, in diploid plants) 6.18 fold compared to the control (0.04 µg mg-1 dry weight)). The long-term effect of three studied elicitors (after 240 days) on plant health and survival was also studied. This investigation showed that only methyl jasmonate at a concentration of 100 µM was resulted in the death of Aloe vera plants.

Construction and Application of Hepatocyte Model Based on Microfluidic Chip Technique in Evaluating Emodin.

The current cytological evaluation technique of health food raw materials does not entirely meet the needs of evaluating health food. Our study adopted the microfluidic chip technique for the first time to construct a hepatocyte model of evaluating emodin, which was composed of a human hepatocellular carcinoma cell (HepG2) and microfluidic chip. The mixed glue of a model with rat tail collagen type I (1.3 mg/mL) + gelatin (7.5%) was used to simulate the microenvironment of a cell. The validity of this model was evaluated by cell proliferation activity and cell staining, and the toxicity of emodin was evaluated by a series of metabolic indicators on this model. The results indicated that the repeatability of the constructed hepatocyte model was favorable, with a coefficient of variation (CV) of 2.8%. After emodin continuously was exposed for 48 h, the cell inhibition was obvious at 100 and 200 μM, and the number of dead cells gradually increased with the increasing of emodin concentration, and the difference of BUN was significant between the emodin group and blank group (p < 0.05). The constructed model has a favorable applicability in evaluating emodin. This study provides an important platform and a potential in vitro alternative model for assessing and predicting the health effects of health food.

Adsorption Characteristics and Enrichment of Emodin from Marine-Derived Aspergillus flavipes HN4-13 Extract by Macroporous Resin XAD-16.

Emodin, a hydroxyanthraquinone derivative, has been used as medicine for more than 2000 years due to its extensive pharmacological activities. Large-scale production of emodin has been achieved by optimizing the fermentation conditions of marine-derived Aspergillus flavus HN4-13 in a previous study. However, the fermentation broth contained complex unknown components, which adversely affected the study of emodin. Herein, the conditions for the enrichment of emodin from A. flavipes HN4-13 extract using XAD-16 resin were optimized, and a separation method with high efficiency, simple operation, a low cost, and a large preparative scale was established. The adsorption process of emodin on the XAD-16 resin conformed to pseudo-second-order kinetics and Langmuir models. The optimal conditions for the adsorption process were as follows: An emodin concentration, flow rate, and loading volume of 0.112 mg/mL, 2 BV/h, and 10 BV, respectively. For desorption, 50% ethanol was used to elute impurities and 80% ethanol was used to desorb emodin. After enrichment with XAD-16 resin, the emodin content increased from 1.16% to 11.48%, and the recovery rate was 75.53% after one-step treatment. These results demonstrate the efficiency of the simple adsorption–desorption strategy, using the XAD-16 resin for emodin enrichment.

Prospects of Antiviral Drugs Derived from Natural Products: Targeting SARS-CoV Entry and Replication

: The recent coronavirus disease (COVID-19) pandemic outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its rapid spread from continent to continent pose a global health emergency. Researchers are making headway to combat the ongoing COVID-19 to prevent further losses. Many natural antiviral compounds have been explored for their potential application in treating viral infections, including those caused by SARS- and MERS-CoV. This review focuses on natural compounds that have been showing promising results against SARS-CoV, SARS-CoV-2 and MERS-CoV, along with their mechanism of action. The entry and replication of CoV are among the major mechanism for the spread of COVID-19. In this context, natural compounds inhibiting the proteins essential for SARS-CoV-2 entry and replication in the nanomolar (nicotianamine) and micromolar (baicalin, baicalein, scutellarein, dihydromyricetin, quercetagetin, myricetin, amentoflavone, herbacetin, isobavachalcone, quercetin 3‐β‐d‐glucoside, helichrysetin, hirsutenone, hirsutanonol, oregonin, rubranol, rubranoside B, rubranoside A, tanshinones, emodin, and griffithsin) concentration could be potential sources of new anti-SARS-CoV-2 drugs.

Emodin protects knee joint cartilage in rats through anti-matrix degradation pathway: An in vitro and in vivo study

AimsOsteoarthritis (OA) is a common joint disease and the main cause of disability. We sought to determine the effective concentration of emodin on chondrocytes and to identify the dosage of emodin that induces a comparable therapeutic effect with the COX-2 inhibitor drug, celecoxib that is currently used to treat OA. Material and methodsIn vitro experiments induced inflammation of chondrocytes by IL-1β, and an osteoarthritis model was established in vivo by cutting rat anterior cruciate ligament. Western Blot, Real-time PCR, HE staining, Safranin O-green staining and immunohistochemistry were performed to detect MMP-3, MMP-13, ADAMTS-4, iNOS and COL2A1 on the chondrocytes or the tibial plateau. The cytokine activity and content in serum of six groups of rats were measured by kit. ResultsIt was found that the surface layer of the cartilage was thicker and smoother after the administration of emodin. Tissue expression of MMP-3, MMP-13, ADAMTS-4 and iNOS were significantly (p < 0.05) decreased in chondrocytes and cartilage treated with different doses of emodin, and the content of COL2A1 was reversed. Emodin also significantly decreased the blood levels of COX-2 and PGE2. The effective emodin in vitro was 5 μmol/L, whereas emodin at 80 mg/kg was equivalent to celecoxib in vivo. ConclusionEmodin reduces the expression of cartilage matrix degradation biomarkers, thereby reducing the degradation of cartilage matrix and protecting the knee joint cartilage. Emodin at 5 μmol/L shows the best concentration to treat chondrocytes, and the protective effect of emodin at 80 mg/kg is comparable to that of celecoxib.

Investigation of Effect of Phytoconstituents Aloe Emodin and Quercetin on Bioavailability of Albendazole

Abstract: Background/Aim: Albendazole is a drug with benzimidazole nucleus and is poorly absorbed from the gastrointestinal tract due to its low aqueous solubility. The objective of present work was to study the effect of two phytoconstituents aloe emodin and quercetin on the bioavailability of albendazole. Materials and Methods: Estimation was done through UV spectroscopy and HPLC analysis using different concentration of both the phytoconstituents. In-vivo study was conducted to investigate the pharmacokinetics and pharmacodynamic parameters. Results: Results revealed no change in Tmax of albendazole and significant changes were observed in Cmax values. The Cmax was maximum i.e. 0.138 μg/ml when 20mg/kg of quercetin was added as compared to aloe-emodin. The increase in bioavailability of Albendazole was due to the presence of flavonoids in quercetin. The retention time of albendazole as estimated through HPLC chromatogram was found to be 3.2 minutes with acetonitrile and phosphate buffer as the mobile phase. However; albendazole was not detectable in 24 hr plasma sample and values of AUC were found to be zero in all the concentration of aloe emodin and quercetin. Conclusion: Thus, the phytoconstituents rich in flavonoids could be used to increase the bioavailability of poor soluble drugs. Key words: Albendazole, Aloe emodin, Quercetin, Bioavailability, Pharmacokinetics.

Modulation of activated murine peritoneal macrophages functions by emodin, aloe-emodin and barbaloin isolated from Aloe barbadensis

Activated murine macrophages produce high level of nitric oxide by inducible nitric oxide synthase (iNOS), which is an important mechanism in macrophage-induced inflammation. In the present study, we isolated emodin, aloe-emodin and barbaloin compounds from Aloe barbadensis and investigated their inhibitory effects on the production of nitric oxide (NO), tumor necrosis factor-α (TNF-α) and interleukin (IL-12) from murine macrophages activated by lipopolysaccharide (LPS) and interferon-gamma (IFN-γ). Our results showed that the 50% inhibition concentration (IC50) of emodin, aloe-emodin and barbaloin on NO, TNF-α and IL-12 from activated peritoneal macrophages were 120, 30 and 200 μM respectively. Our experimental results showed that reduction of NO level by emodin might inhibit both at the pretreated LPS/IFN-γ activation and post-LPS/IFN-γ activation pathway. Activities of aloe-emodin and barbaloin could be caused by inhibition at the pretreated LPS/IFN-γ activation event. Chemical structures of all the isolated components were identified by comparison of NMR, mass spectral data and melting points with those reported in literature.

The Effect and Mechanism of Emodin on the NO Secretion of Human Umbilical Vein Endothelial Cells (HUVECs) Induced by High Glucose

Objective. To investigate the effects of emodin on nitric oxide (NO) secretion induced by high glucose in human umbilical vein endothelial cells (HUVECs) through the p-Akt signaling pathway. Methods. Sensitivity of cells to emodin was determined by MTT assay to establish the experimental concentrations; then, HUVECs were treated with high-dose (33.3 mmol/L) glucose (HG), HG + emodin (HG + E), HG + the Akt phosphorylation inhibitor LY294002 (HG + LY), or HG + E + LY. The p-Akt (Ser 473) expression in 48 h was analyzed using Western blot. NO effect on the secretion of HUVECs was analyzed using nitrate reductase assay. Results. The sensitive emodin concentration for HUVECs growth was 10 mol/L (P&lt;0.05). Compared with the HG group, NO secretion was significantly higher in the HG + E group (P&lt;0.05), whereas it was lowest in the HG + LY group (P&lt;0.05). Compared with the HG + LY group, NO secretion was increased in the HG + E + LY group (P&lt;0.05). The p-Akt protein expression was decreased in the HG + LY group when compared to the HG group (P&lt;0.05), while it significantly increased in the HG + E group (P&lt;0.05). Compared with HG + LY group, p-Akt protein expression was significantly higher in the HG + E + LY group (P&lt;0.05). Conclusion. Emodin could improve the NO secretion of HUVECs by high glucose through the p-Akt signaling pathway.

Emodin Induces Death in Human Cervical Cancer Cells Through Mitotic Catastrophe

Anthraquinones, including emodin, are compounds with numerous pharmacological properties, including anticancer properties. The aim of this study experiment was to examine the effect of emodin, a natural compound present in the roots and rhizomes of Rheum palmatum, on the induction of mitotic catastrophe in cervical cancer cells. HeLa celIs were treated with different emodin concentrations for 48 h, and cell growth was measured with 3-(4-,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolyl. The cell-cycle distribution and the level of apoptosis were determined by means of flow cytometry, using annexin V-fluorescein isothiocyanate staining and propidium iodide. Morphological changes in the mitotic apparatus were evaluated using optical and confocal microscopy techniques. Emodin induced an increase in the number of polymorphonuclear cells, giant cells, cells with micronuclei, cells with abnormal mitosis and damaged spindle. The reorganization of F-actin depended on the concentration of emodin. With the increase in emodin concentration, inhibition of mitotic activity was demonstrated, which was manifested by a decrease in the mitotic index, mainly in metaphase of the mitotic process and an increase in the number of cells inhibited in the G2/M phase. At the same time, an increase in the number of apoptotic cells was found. Emodin leads to death of cervical cancer cells by induction of a mitotic catastrophe.

Green synthesis of β-cyclodextrin metal–organic frameworks and the adsorption of quercetin and emodin

Cyclodextrin metal–organic frameworks (K-CD-MOFs) based on renewable β-cyclodextrin molecules (β-CD) and alkali metals (K) was prepared by modified methanol vapor diffusion method at temperature of 50 °C for 6 h, and this can shorten the reaction time compared with the previous reported. Then the quercetin and emodin were selected to investigate the loading characteristics of K-CD-MOFs and drugs adsorption behavior was studied by changing the reaction time, temperatures, MOFs quality, initial drugs concentration and pH. In results, the crystals showed high adsorption (150.2 and 199.8 mg/g) when the reaction time both at 48 h, the temperatures of 35 and 45 °C, 30 mg K-CD-MOFs, the initial concentration of quercetin and emodin was 3.2 and 2.3 mg/ml and pH 6. Furthermore, the adsorption kinetics of drugs matched a pseudo-second-order model well and chemisorption of quercetin and emodin. Most importantly, XRD pattern analysis showed that the drug loading process did not destroy the crystallinity of the material. In summary, on the basis of optimizing the synthesis of K-CD-MOFs, the crystal stability and drugs adsorption properties were evaluated, which provided a basis for the potential drug delivery.

Emodin Successfully Inhibited Invasion of Brucella abortus Via Modulting Adherence, Microtubule Dynamics and ERK Signaling Pathway in RAW 264.7 Cells.

The aim of this work is to investigate the protective efficacy of emodin, an active, naturally-occurring anthraquinone derivative of several traditional Chinese herbs, against Brucella abortus infection in macrophages. Brucella were incubated with different concentrations of emodin and showed that bacterial survival rates were markedly reduced in a dose-dependent manner at increasing incubation time points. Through bacterial infection assay, the highest non-cytotoxic concentration of emodin demonstrated attenuated invasion of Brucella into macrophages, however it did not inhibit the growth of these pathogens within the host cells. On the other hand, emodin effectively decreased the number of bacteria that adhered to host cells, which indicated its potential as an anti-adhesin agent. Furthermore, using immunoblotting and FACS assay for detecting MAPK signaling proteins and F-actin polymerization, respectively, the results showed that the emodin-incubated cells displayed modest reduction in the phosphorylation levels of ERK1/2 and inhibition of F-actin polymerization as compared to control cells. These findings indicate the potential use of emodin as a naturally-occurring alternative method for the prevention of animal brucellosis although this requires confirmation of safe clinical doses.

Evaluation of an antiparasitic compound extracted from Polygonum cuspidatum against Ichthyophthirius multifiliis in grass carp

Ichthyophthirius multifiliis is a ciliated parasite that infests almost all freshwater fish species and causes great economic losses to the aquaculture industry. In this study, a compound with anti-I. multifiliis activity was isolated from Polygonum cuspidatum and identified as emodin. In vitro anti-I. multifiliis results showed that emodin at 1 mg/L killed all I. multifiliis theronts for 96.0 min, and at 0.5 mg/L or lower concentrations could not kill all I. multifiliis theronts, but could significantly reduce the infectivity of theronts after pretreatment with emodin at the low concentrations mentioned above for 2 h. Additionally, emodin at 1 mg/L and 2 mg/L completely terminated the reproduction of nonencysted and encysted tomonts, respectively. In vivo tests, emodin at 0.5 mg/L could cure infected grass carp and protect naive fish from I. multifiliis infection by continuous adding emodin for 10 days. The 96 h median lethal concentration (LC50) of emodin to grass carp was 3.15 mg/L, which were approximately 18 and 7 times the median effective concentration (EC50) of emodin for killing theronts (0.18 mg/L) and nonencysted tomonts (0.45 mg/L), respectively. On the basis of these results, emodin is an effective compound for the development of a new drug against I. multifiliis.

Characterization and Deer-Repellent Property of Chrysophanol and Emodin from Sicklepod Weed

Deer, particularly white-tailed deer (Odocoileus virginianus), damage row crops such as soybean (Glycine max L.) and are a perceived problem in the continental US. Currently, the only widely used technique to control deer from crop browsing is establishment of fences, which is expensive, labor intensive, and most of the time ineffective. Studies have shown that sicklepod, Senna obtusifolia (L.), contains anthraquinone derivatives, which in separate studies were shown to be toxic to cattle, rats, rabbits, and horses, and repel herbivores primarily birds. However, information of the deer-repelling property of anthraquinone in sicklepod is lacking. Field tests conducted at our Captive Deer Facility at MississippiStateUniversity(MSU) confirmed the deer-repelling property of anthraquinone extracts from sicklepod. Soybean plants applied with control treatment (water) were browsed by deer, while plants applied with sicklepod anthraquinone extracts were avoided. Using chromatography techniques, we found the levels of anthraquinone derivatives (chrysophanol, emodin) in sicklepod plant parts in the order: root > fruit > stem/leaf. Hydrolysis of water extracts of sicklepod seed produced high emodin concentration, suggesting emodin glycoside as the main form of anthraquinone glycoside in sicklepod seed. Deer-repelling compounds can be extracted in its pure form from sicklepod and applied on soybean to increase its repelling efficacy on deer, and at the same time protect soybean yields.

Bioconcentration and Metabolism of Emodin in Zebrafish Eleutheroembryos.

Emodin is a major active anthraquinone of various herbal laxatives, which can exert many pharmacological effects. However, chronic use of anthranoid laxatives, even at low dosages, may cause melanosis coli (MC). It has been suggested that the accumulation of anthraquinones is a risk factor in the MC process. To investigate the accumulation of emodin, we conducted a bioconcentration study of emodin in zebrafish eleutheroembryos. Based on the economic cooperation and development (OECD) 305 test, zebrafish eleutheroembryos were exposed to emodin at a constant concentration for 48 h, before the test media were replaced by the blank medium for 24 h of depuration. To eliminate the effect of metabolism of emodin for assessment of the bioconcentration factor (BCF), we also conducted a modified test for which zebrafish eleutheroembryos were exposed to the non-renewed test media, whose emodin concentration decreased with time. At different exposure time points, zebrafish eleutheroembryos and exposure media were sampled for analysis of emodin concentration using HPLC-MS/MS. The results showed rapid accumulation of emodin in zebrafish eleutheroembryos to reach a steady-state concentration within 24 h. Meanwhile, emodin was actively metabolized by zebrafish eleutheroembryos to result in 29.5–40.7% of its elimination. In the groups with high or low concentrations of emodin, the standardized BCF (sBCF) values in the standard test were 24.0 and 20.0, while those in the modified test were 50.4 and 52.0. These results showed that emodin could accumulate in zebrafish eleutheroembryos when used for 48 h and beyond, suggesting that the accumulation of anthraquinones may be a risk factor in the MC process. Accordingly, emodin should be unsuitable for long-term use due to its accumulation.