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.

Production of monoclonal antibodies against a major purgative component, sennoside B, their characterization and use in ELISA.

For immunization, sennoside B was conjugated with bovine serum albumin. The hapten density in the antigen conjugate was determined to be 3 mol mol(-1) protein by matrix-assisted laser desorption-ionization TOF mass spectrometry. A hybridoma secreting monoclonal antibody against sennoside B was produced by fusing splenocytes from mouse immunized with the sennoside B conjugate and mouse myeloma cells. Weak cross-reactivities occurred with sennoside A which is a stereochemical isomer, and a monomer of sennoside B, rhein, but no cross-reactivity was observed with other related anthraquinones and phenolics. The range of the assay extended from 0.5 ng ml(-1) to 15 ng ml(-1) of sennoside B, and good correlation between ELISA and HPLC methods was obtained when crude extracts of rhubarb were analyzed.

Radioimmunoassay for mitoxantrone, a new antitumor agent.

A sensitive and specific radioimmunoassay for mitoxantrone in serum has been developed. The procedure allows direct measurement of mitoxantrone in unextracted serum samples, by using antisera from rabbits immunized with mitoxantrone-BSA antigen. Tritiated mitoxantrone of high specific radioactivity (ca. 15 Ci/mmol) was used as a radio-tracer ligand. The assay allows the detection of as little as 50 pg/ml and the quantitation of 75 pg/ml in 0.5 ml serum samples. Standard curves were linear in the concentration range of 75-2500 pg/ml, at antiserum dilutions of 1:15,000. The assay shows good reproducibility: coefficients of variation of 3-6% were obtained by analyzing five samples/concentration at 75, 100, 250, 500, and 1000 pg/ml. There was no cross reactivity with the major metabolite in human serum, having concentrations of up to 10,000 pg/ml. Serum samples collected at various time intervals from rats dosed intravenously with mitoxantrone (0.5 mg/kg), were analyzed for unchanged mitoxantrone by RIA. The drug concentrations decreased from 32 ng/ml at 0.5 h to 0.45 ng/ml by 24 h after dosing. Mitoxantrone, a dihydroxyanthracenedione derivative (1), is an antitumor agent currently used in clinical trials with very encouraging results, especially in metastatic breast cancer, and low incidence of adverse reactions (2-4). The drug is being administered intravenously at doses up to 14 mg/m2. Preliminary pharmacokinetic studies (to be published separately) indicate rapid distribution, followed by slow clearance rates from the tissues. The sensitivity of the currently available (HPLC) methods (5, 6) is of about 5-20 ng/ml in serum.(ABSTRACT TRUNCATED AT 250 WORDS)