Diacerein mitigates renal ischemia/reperfusion injury via inhibition of renal inflammation, dendritic cells maturation and apoptosis: the role of TLR4/NF-kB/NLRP3/IL-1beta signaling pathway / La diacereína mitiga la lesión por isquemia/reperfusión renal a través de la inhibición de la inflamación renal, la maduración de las células dendríticas y la apoptosis: el papel de la vía de señalización TLR4/NF-kB/NLRP3/IL-1beta

SUMMARY: One of the reasons for acute kidney damage is renal ischemia. Nevertheless, there are limited protective and therapeutic approaches for this problem. Diacerein is an anti-inflammatory drug characterized by numerous biological activities. We aimed to determine the ameliorative impact of diacerein on renal ischemia/reperfusion injury (I/R) condition, exploring the underlying mechanisms. Twenty-four male rats were allotted into four groups (n= 6): sham group; Diacerein (DIA) group; I/R group, in which a non-crushing clamp occluded the left renal pedicle for 45 min, and the right kidney was nephrectomized for 5 min before the reperfusion process; I/R + diacerein group, injected intraperitoneally with 50 mg diacerein/kg i.m 30 minutes prior to I/R operation. Ischemia/ reperfusion was found to affect renal function and induce histopathological alterations. The flow cytometry analysis demonstrated an elevated expression of innate and mature dendritic cells in I/R renal tissues. Moreover, upregulation in the expression of the inflammatory genes (TLR4, Myd88, and NLRP3), and overexpression of the pro-inflammatory cytokines (IL-1β), apoptotic (caspase-3) and pyroptotic (caspase-1) markers were observed in I/R-experienced animals. The aforementioned deteriorations were mitigated by pre-I/R diacerein treatment. Diacerein alleviated I/R-induced inflammation and apoptosis. Thus, it could be a promising protective agent against I/R.

La isquemia renal es una de los motivos del daño renal agudo. Sin embargo, los enfoques protectores y terapéuticos para este problema son limitados. La diacereína es un fármaco antiinflamatorio caracterizado por numerosas actividades biológicas. Nuestro objetivo fue determinar el impacto de mejora de la diacereína en la condición de lesión por isquemia/ reperfusión renal (I/R), explorando los mecanismos subyacentes. Veinticuatro ratas macho se distribuyeron en cuatro grupos (n= 6): grupo simulado; grupo de diacereína (DIA); grupo I/R, en el que una pinza no aplastante ocluyó el pedículo renal izquierdo durante 45 min, y el riñón derecho fue nefrectomizado durante 5 min antes del proceso de reperfusión; Grupo I/R + diacereína, inyectado por vía intraperitoneal con 50 mg de diacereína/kg i.m. 30 min antes de la operación I/R. Se encontró que la isquemia/ reperfusión afecta la función renal e induce alteraciones histopatológicas. El análisis de citometría de flujo demostró una expresión elevada de células dendríticas innatas y maduras en tejidos renales I/R. Además, se observó una regulación positiva en la expresión de los genes inflamatorios (TLR4, Myd88 y NLRP3) y una sobreexpresión de las citoquinas proinflamatorias (IL-1β), marcadores apoptóticos (caspasa-3) y piroptóticos (caspasa-1) en animales con experiencia en I/R. Los deterioros antes mencionados fueron mitigados por el tratamiento previo a la diacereína I/R. La diacereína alivió la inflamación y la apoptosis inducidas por I/R. Por lo tanto, podría ser un agente protector prometedor contra I/R.

Rubiadin exerts an acute and chronic anti-inflammatory effect in rodents / A Rubiadina exerce um efeito anti-inflamatório agudo e crônico em roedores

Rubiadin is identified as a bioactive anthraquinone that exists in some quinone rich plants. The current research was carried out to evaluate the potential anti-inflammatory impact of Rubiadin in acute and chronic inflammation test models in rodents. The anti-inflammatory activity of Rubiadin was examined in cotton pellet-induced granuloma and carrageenan-induced edema as chronic and acute inflammation models in rats. TNF-α level and histopathological changes were assessed using sampled foot tissue of rat in the acute model. Also, the IL-1β level was assessed in the chronic model. One-way ANOVA (post hoc Tukey’s) analysis was used for comparing the groups. Rubiadin (0.5 mg/kg, i.p.) induced a significant reduction in TNF α level and the paw edema compared to the control group in carrageenan test. Also, it was observed that the anti-inflammatory activity of Rubiadin (0.5 mg/kg, i.p.) is comparable to mefenamic acid (30 mg/kg, i.p.) as the standard drug. Rubiadin was effective in granuloma induced by cotton pellet concerning the granuloma and transudate formation amount. Rubiadin's anti-inflammatory effects were associated with a significant IL-1β decrease in this model. The results suggest that Rubiadin as a natural compound can possess significant peripheral anti-inflammatory impacts.

A rubiadina é identificada como uma antraquinona bioativa que existe em algumas plantas ricas em quinonas. A presente pesquisa foi realizada para avaliar o potencial impacto anti-inflamatório da rubiadina em modelos de teste de inflamação aguda e crônica em roedores. A atividade anti-inflamatória da rubiadina foi examinada em granuloma induzido por pellet de algodão e edema induzido por carragenina como modelos de inflamação crônica e aguda em ratos. O nível de TNF-α e as alterações histopatológicas foram avaliados usando amostra de tecido do pé de rato no modelo agudo. Além disso, o nível de IL-1β foi avaliado no modelo crônico. A análise ANOVA de uma via (post hoc de Tukey) foi usada para comparar os grupos. A rubiadina (0,5 mg / kg, i.p.) induziu uma redução significativa no nível de TNF α e no edema da pata em comparação com o grupo de controle no teste de carragenina. Além disso, foi observado que a atividade anti-inflamatória da rubiadina (0,5 mg / kg, i.p.) é comparável ao ácido mefenâmico (30 mg/kg, i.p.) como o fármaco padrão. A rubiadina foi eficaz no granuloma induzido por pellet de algodão no que diz respeito à quantidade de granuloma e formação de transudato. Os efeitos anti-inflamatórios da rubiadina foram associados a uma redução significativa de IL-1β nesse modelo. Os resultados sugerem que a rubiadina como um composto natural pode ter impactos anti-inflamatórios periféricos significativos.

Chondroitin sulfate-functionalized lipid nanoreservoirs: a novel cartilage-targeting approach for intra-articular delivery of cassic acid for osteoarthritis treatment.

Novel intra-articular nanoreservoirs were implemented employing different cartilage targeting approaches to improve cartilage bioavailability of a chondroprotective drug, cassic acid (CA), for effective amelioration of cartilage deterioration off-targeting CA gastrointestinal disorders. Herein, we compared active cartilage-targeting approach via chondroitin sulfate (CHS) functionalization versus passive targeting using positively charged nanoparticles to target negatively charged cartilage matrix. Firstly, CA integrated nanoreservoirs (CA-NRs) were fabricated based on ionic conjugation between CA and cationic hydrophobic surface modifier octadecylamine (ODA) and were further functionalized with CHS to develop CHS-CA-NRs. Confocal laser microscope was used to visualize the accumulation of nanoparticles into the cartilage tissue. Both targeting approaches promoted CA local cartilage availability and prolonged its residence time. Compared to passive targeted CA-NRs, active targeted CHS-CA-NRs showed higher fluorescence signals in proximity to and inside chondrocytes which lasted for up to 21 days. In MIA-osteoarthritic rats, CHS-CA-NRs showed superior antiosteoarthritic activity, exhibiting highest cartilage repair compared to CA-NRs. Additionally, CHS-CA-NRs significantly inhibited OA inflammatory cytokine, degradation enzyme and oxidative stress and improved cartilage matrix biosynthesis. Conclusively, CHS-CA-NRs improved OA repair showing a superior efficacy for articular cartilage targeting with CHS which could be a potential advance for OA therapy.

HRPIF data mining based on data-dependent/independent acquisition for Rhei Radix et Rhizoma metabolite screening in rats.

In traditional Chinese medicine (TCM), components with identical nuclei often share structural similarity, indicating the possibility of similar second-level mass spectrometry (MS/MS) fragments. High-resolution product-ion filter (HRPIF) technique can be utilized to identify metabolites, with similar fragments, in vivo. In principle, this technique applies to TCM; however, its application has been restricted due to the limitations of traditional MS/MS data acquisition. Therefore, a novel analysis strategy, based on data-dependent acquisition (DDA) and data-independent acquisition (DIA) datasets, has been developed for the determination of template product ions and efficient non-targeted identification of TCM-related components in vivo by HRPIF and background subtraction (BS). This DDA-DIA combination strategy, taking Rhei Radix et Rhizoma as a test case, identified 71 anthraquinone prototype components in vitro (36 of which were discovered for the first time), and 45 related components in vivo, confirming glucuronidation and sulfation as the main reactions. The developed strategy could rapidly identify TCM-related components in vivo with high sensitivity, indicating the immense importance of this novel HRPIF data mining technology in TCM analysis.

A systematic comparison of the effect of topically applied anthraquinone aglycones to relieve psoriasiform lesion: The evaluation of percutaneous absorption and anti-inflammatory potency.

The anthraquinones derived from rhubarb are reported to have anti-inflammatory activity. The present study aimed to assess the topical application of rhubarb anthraquinone aglycones for psoriasis treatment. The antipsoriatic effect of five anthraquinones, including aloe-emodin, rhein, emodin, physcion, and chrysophanol, was compared to elucidate a structure-permeation relationship. Molecular modeling was employed to determine the physicochemical properties. Both macrophages (differentiated THP-1) and keratinocytes (HaCaT) were used to examine the anti-inflammatory activity in the cell-based study. The in vitro pig skin absorption showed that chrysophanol was the compound with the highest cutaneous accumulation. Topically applied rhein was detected to be largely delivered to the receptor compartment. The absorption of rhein was increased by 5-fold in the barrier-deficient skin as compared to intact skin. By stimulating macrophages with imiquimod (IMQ) to model the inflammation in psoriasis, it was found that the anthraquinones significantly reduced IL-6, IL-23, and TNF. The cytokine inhibition level was comparable for the five compounds. The anthraquinones suppressed cytokines by inhibiting the activation of MAPK and NF-κB signaling. The anthraquinones also downregulated IL-6, IL-8, and IL-24 in the inflammatory keratinocytes stimulated with TNF. Rhein and chrysophanol were comparable to curtail the STAT3 phosphorylation in keratinocytes induced by the conditioned medium of stimulated macrophages. The IMQ-induced psoriasiform mouse model demonstrated the improvement of scaling, erythema, and epidermal hyperplasia by topically applied rhein or chrysophanol. The epidermal acanthosis evoked by IMQ was reduced with rhein and chrysophanol by 3-fold. The histological profiles exhibit that both anthraquinone compounds diminished the number of macrophages and neutrophils in the lesional skin, skin-draining lymph node, and spleen. Rhein and chrysophanol showed multifunctional inhibition, by regulating several targets for alleviating psoriasiform inflammation.

Preparation of a Self-Assembled Rhein-Doxorubicin Nanogel Targeting Mitochondria and Investigation on Its Antihepatoma Activity.

Mitochondria are involved in the regulation of apoptosis, making them a promising target for the development of new anticancer drugs. Doxorubicin (DOX), a chemotherapeutic drug, can induce reactive oxygen species (ROS)-mediated apoptosis, improving its anticancer effects. Herein, Rhein, an active ingredient in rhubarb, with the capability of self-assembly and mitochondrial targeting, was used in conjunction with DOX to form efficient nanomaterials (Rhein-DOX nanogel) capable of sustained drug release. It was self-assembled with a hydrogen bond, π-π stacking interactions, and hydrophobic interactions as the main driving force, and its loading efficiency was up to 100%. Based on its self-assembly characteristics, we evaluated the mechanism of this material to target mitochondria, induce ROS production, and promote apoptosis. The IC50 of the Rhein-DOX nanogel (3.74 µM) was only 46.3% of that of DOX (11.89 µM), and the tumor inhibition rate of the Rhein-DOX nanogel was 79.4% in vivo, 2.3 times that of DOX. This study not only addresses the disadvantages of high toxicity of DOX and low bioavailability of Rhein, when DOX and Rhein are combined for the treatment of hepatoma, but it also significantly improved the synergistic antihepatoma efficacy of Rhein and DOX, which provides a new idea for the development of long-term antihepatoma agents with low toxicity.

Development of a novel anti-liver fibrosis formula with luteolin, licochalcone A, aloe-emodin and acacetin by network pharmacology and transcriptomics analysis.

CONTEXT: Xiaoyaosan decoction (XYS), a classical Traditional Chinese Medicine (TCM) formula is used to treat liver fibrosis in clinics. OBJECTIVE: This study explores defined compound combinations from XYS decoction to treat liver fibrosis. MATERIALS AND METHODS: Network pharmacology combined with transcriptomics analysis was used to analyze the XYS decoction and liver depression and spleen deficiency syndrome liver fibrosis. From the constructed XYS-Syndrome-liver fibrosis network, the top 10 active formulas were developed by topological analysis according to network stability. The most active formula was determined by in vitro study. The anti-fibrosis effect was evaluated by in vitro and in vivo studies. RESULTS: According to the network XYS-Syndrome-liver fibrosis network, 8 key compounds and 255 combinations were predicted from in XYS. Luteolin, licochalcone A, aloe-emodin and acacetin formula (LLAAF) had a synergistic effect on the proliferation inhibition of hepatic stellate cells compared to individual compounds alone. The treatment of XYS and LLAAF showed a similar anti-liver fibrotic effect that reduced histopathological changes of liver fibrosis, Hyp content and levels of α-SMA and collagen I in CCl4-induced liver fibrosis in rats. Transcriptomics analysis revealed LLAAF regulated PI3K-Akt, AMPK, FoxO, Jak-STAT3, P53, cell cycle, focal adhesion, and PPAR signalling. Furthermore, LLAAF was confirmed to regulate Jak-STAT and PI3K-Akt-FoxO signalling in vitro and in vivo. CONCLUSIONS: This study developed a novel anti-liver formula LLAAF from XYS, and demonstrated its anti-liver fibrotic activity which may be involved in the regulation of Jak-STAT and PI3K-Akt-FoxO signalling.

Fabrication, in vitro and ex vivo evaluation of proliposomes and liposomal derived gel for enhanced solubility and permeability of diacerein.

The present study is associated with the development of proliposomes and liposomal derived gel for enhanced solubility and permeability of diacerein. Proliposomes were developed by thin film hydration method and converted into the liposomal derived gel using carbopol-934 as a gelling agent. Formulations with varied lecithin to cholesterol ratios were investigated to obtain the optimal size, entrapment efficiency, and enhanced in vitro dissolution. Dynamic light scattering analysis revealed the particle size and zeta potential in the range of 385.1±2.45-762.8±2.05 nm and -22.4±0.55-31.2±0.96mV respectively. Fourier transform infrared (FTIR) spectroscopic analysis depicted the physicochemical compatibility, powdered x-ray diffraction (PXRD) analysis predicted the crystalline nature of pure drug and its transition into amorphous form within formulation. The differential scanning calorimetry (DSC) demonstrated the thermal stability of the formulation. The in vitro drug release study using dialysis membrane displayed the enhanced dissolution of diacerein due to the presence of hydrophilic carrier (Maltodextrin) followed by sustained drug release due to the presence of lipid mixture (lecithin and cholesterol). Ex vivo permeation studies depicted 3.50±0.27 and 3.21±0.22 folds enhanced flux of liposomal gels as compared to control. The acute oral toxicity study showed safety and biocompatibility of the system as no histopathological changes in vital organs were observed. These results suggests that proliposomes and liposomal derived gel are promising candidates for the solubility and permeability enhancement of diacerein in the management of osteoarthritis.

Decrease in dysbaric osteonecrosis severity as a result of 45-minute oxygen pre-breathe.

Sudden decompression can result in bubble formation as the result of nitrogen gas (N2) dissolved in tissue during disabled submarine escape (DISSUB). This may cause dysbaric osteonecrosis (DON), a condition in long bones where bubbles in fatty marrow result in ischemia and necrosis. Previous research has shown that oxygen (O2) pre-breathe of two hours resulted in a reduction of DON; however, effects of shorter O2 pre-breathe remain uncertain. This study's aim was to understand the effect of shorter lengths of O2 pre-breathe. Eight adult Suffolk ewes (89.5± 11.5 kg) were exposed to 33 feet of seawater (fsw) for 24 hours. They were placed randomly into four groups and exposed to either 45, 30 or 15 minutes of O2 (91-88%) pre-breathe; the controls received none. They were then rapidly decompressed. Alizarin complexone was later injected intravenously to visualize the extent of DON in the right and left long bones (radii, tibiae, femur and humeri). The 30- and 15-minute pre-breathe groups saw the greatest deposition. There was significant decrease of variance in the 45-minute group when compared with all other treatments, suggesting that 45 minutes of O2 pre-breathe is required to effectively increase confidence in the reduction of DON. Similar confidence was not reflected in the 30-minute and 15-minute groups: 45 minutes of pre-breathe was the minimum amount needed to effectively prevent against DON in DISSUB escape at 33 fsw. However, future research is needed to determine how to calculate effective dosages of O2 pre-breathe to prevent DON in any given scenario.

Aloe-emodin, a hydroxyanthracene derivative, is not genotoxic in an in vivo comet test.

Aloe-emodin, one of the molecules belonging to the group of hydroxyanthracene derivatives, was recently described as genotoxic in vivo. Indeed, the EFSA judged that aloe-emodin, together with other similar molecules (emodin and danthron) and extracts from the leaf of Aloe species containing hydroxyanthracene derivatives, could represent a risk factor for colorectal cancer mediated by a genotoxic effect. Given the marked uncertainty regarding the conclusions in the opinion of the EFSA ANS Panel and conflicts in the epidemiological data on which the opinion is based, a new in vivo study (in vivo alkaline comet assay in mice - OECD 489) was conducted to test the potential genotoxicity of aloe-emodin at doses of 250, 500, 1000 and 2000 mg/kg bw/day on preparations of single cells from the kidney and colon of treated male mice. Following treatment with the test item, no clinical signs were observed in animals in any treatment group. Slight body-weight loss was randomly observed in all groups treated with the test item and was more evident in the groups dosed at 1000 and 2000 mg/kg bw/day. Under these experimental conditions, aloe-emodin showed no genotoxic activity. Possible oxidative damage to colon tissues could not be excluded based on the results obtained after repair enzyme treatment.

Erythrocyte-Camouflaged Mesoporous Titanium Dioxide Nanoplatform for an Ultrasound-Mediated Sequential Therapies of Breast Cancer.

BACKGROUND: The hypoxic microenvironment promotes tumor resistance to most treatments, especially highly oxygen-dependent sonodynamic therapy (SDT). METHOD AND RESULTS: In view of the aggravation of hypoxia by oxygen consumption during SDT, a biomimetic drug delivery system was tailored to integrate SDT with hypoxia-specific chemotherapy. In this system, mesoporous titanium dioxide nanoparticles (mTNPs) were developed to deliver the hypoxia-activated prodrug AQ4N with high loading efficiency. Subsequently, a red blood cell (RBC) membrane was coated onto the surface of mTNP@AQ4N. RBC-mTNPs@AQ4N inherited the immune escape ability from RBC membranes, thus efficiently reducing the immunological clearance and improving the work concentration. Upon activation by ultrasound (US), mTNPs as sonosensitizers generate reactive oxide species (ROS), which not only induce apoptosis and necrosis but also disrupt RBC membranes to achieve the US-mediated on-demand release of AQ4N. The released AQ4N was activated by hypoxia to convert into toxic products, which effectively supplemented the inefficiency of SDT in hypoxic tissues. Importantly, SDT-aggravated hypoxia further potentiated this hypoxia-specific chemotherapy of AQ4N. CONCLUSION: Based on the sequential strategy, RBC-mTNPs@AQ4N exhibited an excellent synergistic therapeutic effect, thus potentially advancing the development of SDT in cancer treatments.

Biosynthesis of gold nanoparticles for the treatment of osteoarthritis alone or in combination with Diacerein® in a rat model.

Gold (Au) compounds were used as an effective therapeutic agent for various inflammatory diseases; however, the use of Au compounds becomes limited because of its association with several side effects. Hence, gold nanoparticles (AuNPs) were developed as a new option for the medical proposes. However, the safety evaluation of gold nanoparticles (AuNPs) in osteoarthritis (OA) treatment remains vague. This study aimed to biosynthesize, characterize and evaluate the therapeutic effects of biosynthesized AuNPs and/or Diacerein® (DIA) in experimental OA. OA was induced by a single injection of monosodium iodoacetate (3 mg/joint) in the intra-articular knee of female rats. Normal rats (N-rats) and OA-rats were treated orally for 5 weeks as follow: untreated N-rats; untreated OA-rats; N-rats received DIA (50 mg/kg b.w); N-rats received AuNPs (30 µg/kg b.w.); N-rats received AuNPs plus DIA; OA-rats received DIA; OA-rats received AuNPs, and OA-rats received AuNPs plus DIA. Blood, knee cartilage, liver and kidney samples were collected for biochemical and histological analysis. The synthesized AuNPs were nearly spherical with average size of 20 nm and zeta potential of 33 mV. AuNPs and DIA induced a significant improvement in serum inflammatory cytokines, biochemical parameters, estrogen level, hepatic and renal oxidative markers, hepatic DNA fragmentation, genomic template stability and cartilage joint histology of OA-rats. AuNPs were more effective than DIA and the combined treatment was more effective than the single treatment. It could be concluded that AuNPs are promising for the treatment of OA alone or in combination with DIA.

Chrysophanol Attenuates Manifestations of Immune Bowel Diseases by Regulation of Colorectal Cells and T Cells Activation In Vivo.

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.

Near-Infrared Photo-controlled Permeability of a Biomimetic Polymersome with Sustained Drug Release and Efficient Tumor Therapy.

Synthetic polymersomes have structure similarity to bio-vesicles and could disassemble in response to stimuli for "on-demand" release of encapsulated cargos. Though widely applied as a drug delivery carrier, the burst release mode with structure complete destruction is usually taken for most responsive polymersomes, which would shorten the effective drug reaction time and impair the therapeutic effect. Inspired by the cell organelles' communication mode via regulating membrane permeability for transportation control, we highlight here a biomimetic polymersome with sustained drug release over a specific period of time via near-infrared (NIR) pre-activation. The polymersome is prepared by the self-assembling amphiphilic diblock copolymer P(OEGMA-co-EoS)-b-PNBOC and encapsulates the hypoxia-activated prodrug AQ4N and upconversion nanoparticle (PEG-UCNP) in its hydrophilic centric cavity. Thirty minutes of NIR pre-activation triggers cross-linking of NBOC and converts the permeability of the polymersome with sustained AQ4N release until 24 h after the NIR pre-activation. The photosensitizer EoS is activated and aggravates environmental hypoxic conditions during a sustained drug release period to boost the AQ4N therapeutic effect. The combination of sustained drug release with concurrent hypoxia intensification results in a highly efficient tumor therapeutic effect both intracellularly and in vivo. This biomimetic polymersome will provide an effective and universal tumor therapeutic approach.

Improved oral bioavailability and anti-chronic renal failure activity of chrysophanol via mixed polymeric micelles.

AIMS: This study was designed to prepare chrysophanol-loaded micelles (CLM) to improve the oral bioavailability, targetability and anti-chronic renal failure (CRF) activity of chrysophanol (CH). METHODS: The preparation of CLM was achieved via thin-film dispersion technique. The in vitro release of CLM compared with free CH was measured in phosphate buffer solution (PBS) containing 0.5%w/v sodium dodecyl sulphate (pH 6.8) while the pharmacokinetic and anti-CRF activity study was also conducted in rats. Moreover, the tissue distribution of CLM was investigated in the mice. RESULTS: The CLM had particle size (PS) of 29.64 ± 0.71 nm, and encapsulation efficiency (EE) of 90.48 ± 1.22%w/w. The cumulative release rate of CH from the micellar system was significantly higher than that of the free CH (86%m/m vs. 15%m/m, p < 0.01). In vivo pharmacokinetic studies showed that the bioavailability of CLM after oral administration was substantially improved (about 3.4 times) compared with free drugs (p < 0.01). Also, it was observed that CLM accumulated well in the liver and brain. Moreover, in vitro renal podocytes study showed that CLM had better protection against renal podocyte damage than the free CH. In addition, CLM significantly (p < 0.01) reduced levels of blood urea nitrogen (BUN), kidney injury molecule-1 (Kim-1), and serum creatinine (SCr), which obviously improved kidney damage in rats with CRF. CONCLUSIONS: Collectively, these findings suggest that mixed micelles may be used as a promising drug delivery system for oral bioavailability improvement and concomitantly enhance the anti-CRF activity of CH, as well as provide a basis for the clinical application of CH.

Diacerein solid dispersion loaded tablets for minimization of drug adverse effects: statistical design, formulation, in vitro, and in vivo evaluation.

Diacerein is a BCS class II drug employed in osteoarthritis management. The acid/base hydrolysis of the unabsorbed diacerein in the colon is responsible for its laxative effect. Therefore, this work aimed to enhance the solubility, dissolution, and oral bioavailability of diacerein. Such enhancement means lower doses and fewer gastrointestinal adverse effects. A 41.31.21 full factorial design was adopted to prepare 24 solid dispersion formulae. Solid-state characterization showed the dissolution of diacerein crystals as metastable amorphous or microcrystalline forms in a matrix system that enhanced the drug dissolution. Desirability factor suggested compounding an optimized formula (F1) of Pluronic®F68 with 1:3 drug:carrier ratio using rotavap that showed higher drug solubility (187.61 µg/mL) than drug powder (22.5 µg/mL). It achieved higher dissolution efficiency (4.04-fold) and rate (6.6-fold) as well as 100% release in 2 min. F1 was compressed into tablets recording greater dissolution efficiency (1.24-fold) and rate (12.5-fold) than the marketed product. The prepared tablet accomplished a 2.66-fold enhancement in diacerein bioavailability compared to the marketed product. In conclusion, the formulation of diacerein as solid dispersion loaded tablets could be of added value for the treatment of osteoarthritis in terms of enhanced patient compliance. Solid dispersion is an easy and scalable technique.

Development of orally disintegrating tablets containing solid dispersion of a poorly soluble drug for enhanced dissolution: In-vitro optimization/in-vivo evaluation.

Diacerein (DCN), a potent anti-inflammatory API used to treat osteoarthritis yet, it suffers from poor water solubility which affects its oral absorption. Unabsorbed colonic DCN is converted into rhein, which is responsible for laxation as a main side effect of DCN treatment. Therefore, in this study orally disintegrating tablets (ODTs) loaded with optimized DCN solid dispersion system were prepared using different co-processed excipients (Prosolv® ODT, Pharmaburst® 500 and F-melt®), aiming to achieve improved solubility, rapid absorption and consequently limited amount of rhein reaching the colon. Prepared ODTs were evaluated for physical characteristics, in-vitro drug release, disintegration and wetting times. Dissolution parameters; dissolution efficiency percent at 10 (DE (10 min)%) and 30 (DE (30 min)%) min and mean dissolution time (MDT) were determined. The optimized ODT showed 1.50 and 1.12 fold increase in DE (10 min)% and DE (30 min)%, respectively and 2 fold decrease in MDT, compared to Diacerein® capsules. In-vivo anti-inflammatory effect of optimized ODT, using rat paw edema revealed significant increase in edema inhibition (p < 0.0465) and promoted onset of action compared to Diacerein® capsules at 0.5 hr. It could be concluded that optimized ODT could be promising for enhanced dissolution and rapid absorption of DCN from the oral cavity.

The Effects of Rhein and Honokiol on Metabolic Profiles in a Mouse Model of Acute Pancreatitis.

BACKGROUND Acute pancreatitis (AP) is generally a self-limiting inflammatory disease, but is associated with a high mortality rate when severe. The present study aimed to investigate the effects of rhein and honokiol on AP. MATERIAL AND METHODS Thirty mice were randomly divided into 5 groups (n=6 per group): blank control, AP model, AP+rhein, AP+honokiol, and AP+rhein+honokiol. The AP model was prepared by intraperitoneal injection of cerulein and lipopolysaccharide (LPS). We observed the pathological changes of the pancreas by hematoxylin and eosin (H&E) staining. A mouse amylase kit was utilized to detect the level of amylase content in serum. Gas chromatography mass spectrometer analysis was performed to detect the differences in metabolites among the blank control, AP model, and AP+rhein+honokiol groups. RESULTS The serum amylase level was significantly higher in the AP model, which suggested that the AP model was constructed successfully. The AP+rhein+honokiol group had significantly reduced interstitial edema, inflammatory cell infiltration, hemorrhage, and necrosis. In addition, the rhein and honokiol treatment influenced some of the metabolic pathways in AP, including riboflavin metabolism, glycerophospholipid metabolism, linoleic acid metabolism, and the pentose and glucuronate interconversions pathway. CONCLUSIONS This study showed that the combination of rhein and honokiol ameliorated pathological changes in the pancreas of mice with AP.

Chrysophanol ameliorates renal interstitial fibrosis by inhibiting the TGF-ß/Smad signaling pathway.

Renal interstitial fibrosis (RIF) is a major pathological feature of chronic kidney disease at middle and end stages. Chrysophanol (CP), 1,8-dihydroxy-3-methyl-9,10-anthraquinone, is an anthraquinone isolated from Rheum palmatum L. with a variety of pharmacological activities including the suppression of RIF. However, the effect of CP on renal fibrosis and its potential mechanism have not been elucidated. We conducted a comprehensive study by determining the expression levels of fibrotic markers and proteins including TGF-ß1, α-SMA, and Smad3 related to transforming growth factor-beta/Smad (TGF-ß/Smad) pathway in unilateral ureteral obstruction (UUO) mice and TGF-ß1-stimulated HK-2 cells with the treatment of CP using western blotting and RT-qPCR analyses. Using small interfering RNA and co-immunoprecipitation, we evaluated the influences of CP on the interactions between Smad3 and Smad7 proteins and also on TGF-ß RI and TGF-ßR II. We found that CP administration significantly ameliorated UUO-induced kidney damage by reversing abnormal serum and urine biochemical parameters and decreasing the production of fibrotic markers including collagen I, collagen III, fibronectin, and α-SMA. Our results showed that TGF-ß1 and phospho-Smad3 (p-Smad3) expression was significantly down-regulated and Smad7 expression was up-regulated by CP in UUO mice compared to the model group; however, the expression of Smad2, Smad4, and TGF-ß receptors was not affected. Furthermore, CP modulated these fibrotic markers as well as p-Smad3 and Smad7 in TGF-ß1-induced HK-2 cells. The inhibitory effect of CP was markedly reduced in TGF-ß1-treated HK-2 cells transfected with Smad3 siRNA. Additionally, co-immunoprecipitation analysis indicated that CP blocked the interaction between Smad3 and TGF-ß receptor I to suppress p-Smad3 expression. These findings demonstrated that CP alleviated RIF by inhibiting Smad3 phosphorylation, which provides a molecular basis for a new drug candidate for the treatment of RIF.

The inhibitory effects of shikonin and ß,ß-dimethylacrylshikonin on tramadol metabolism in vitro and in vivo.

OBJECTIVES: The objective of this study was to investigate the possible interaction of shikonin and ß,ß-dimethylacrylshikonin (DSK) with tramadol. METHODS: Human liver microsome (HLM) and rat liver microsome (RLM) incubation experiments were carried out to assess the half-maximal inhibitory concentration (IC50 ) and inhibitory mechanism of shikonin and DSK on tramadol metabolism in vitro. And pharmacokinetics experiments containing low and high doses of shikonin and DSK were performed to confirm the inhibitory effects on tramadol metabolism in vivo. KEY FINDINGS: The IC50 of shikonin on tramadol metabolism was 5.66 ± 1.2 µmol/l in HLM and 3.35 ± 1.1 µmol/l in RLM, while that of DSK on tramadol metabolism was 14.33 ± 1.1 µmol/l in HLM and 8.24 ± 1.26 µmol/l in RLM. Moreover, shikonin and DSK showed non-competitive inhibition of the cytochrome P450 enzyme in both HLM and RLM. Oral administration of 10 and 30 mg/kg shikonin inhibited tramadol metabolism in a dose-dependent manner. Furthermore, a dose of 30 mg/kg DSK inhibited the metabolism of tramadol in rats, while the lower dose of 10 mg/kg showed no inhibitory effect. CONCLUSIONS: The results of this study suggest that shikonin and DSK can inhibit tramadol metabolism both in vitro and in vivo.