The Nephroprotective Effect of Zizyphus lotus L. (Desf.) Fruits in a Gentamicin-Induced Acute Kidney Injury Model in Rats: A Biochemical and Histopathological Investigation

Zizyphus lotus L. (Desf.) (Z. lotus) is a medicinal plant largely distributed all over the Mediterranean basin and is traditionally used by Moroccan people to treat many illnesses, including kidney failure. The nephrotoxicity of gentamicin (GM) has been well documented in humans and animals, although the preventive strategies against it remain to be studied. In this investigation, we explore whether the extract of Zizyphus lotus L. (Desf.) Fruit (ZLF) exhibits a protective effect against renal damage produced by GM. Indeed, twenty-four Wistar rats were separated into four equal groups of six each (♂/♀ = 1). The control group was treated orally with distilled water (10 mL/kg); the GM treated group received distilled water (10 mL/kg) and an intraperitoneal injection of GM (80 mg/kg) 3 h after; and the treated groups received ZLF extract orally at the doses 200 or 400 mg/kg and injected intraperitoneally with the GM. All treatments were given daily for 14 days. At the end of the experiment, the biochemical parameters and the histological observation related the kidney function was explored. ZLF treatment has significantly attenuated the nephrotoxicity induced by the GM. This effect was indicated by its capacity to decrease significantly the serum creatinine, uric acid, urea, alkaline phosphatase, gamma-glutamyl-transpeptidase, albumin, calcium, sodium amounts, water intake, urinary volume, and relative kidney weight. In addition, this effect was also shown by the increase in the creatinine clearance, urinary creatinine, uric acid, and urea levels, weight gain, compared to the rats treated only with the GM. The hemostasis of oxidants/antioxidants has been significantly improved with the treatment of ZLF extract, which was shown by a significant reduction in malondialdehydes levels. Histopathological analysis of renal tissue was correlated with biochemical observation. Chemical analysis by HPLC-DAD showed that the aqueous extract of ZLF is rich in phenolic compounds such as 3-hydroxycinnamic acid, catechin, ferulic acid, gallic acid, hydroxytyrosol, naringenin, p- coumaric Acid, quercetin, rutin, and vanillic acid. In conclusion, ZLF extract improved the nephrotoxicity induced by GM, through the improvement of the biochemical and histological parameters and thus validates its ethnomedicinal use.

Probable role of Brain Natriuretic Peptide (BNP) in lung hypertension secondary to scleroderma

BACKGROUND Scleroderma, when complicated with pulmonary hypertension (PHT), presents a worse prognosis; recently treatment with new drugs seems to offer good perspectives, especially in early diagnosis and treatment. The standard approach for diagnosing PHT consists in measurement of the pulmonary artery pressure (PAP) by means of echodoppler. AIM OF INVESTIGATION Aim of this work is evaluating the significance of the NT-proBNP parameter, matched to echodoppler, in diagnosing scleroderma PHT. MATERIALS AND METHODS Sixty (60) patients, who came to observation for progressive systemic sclerosis underwent echodoppler in order to measure the PAP (normal values up to 30 mmHg). NT-proBNP was determined on serum sample using ECLIA method by Modular E170 (Roche Diagnostics); manufacturer reference values for age and gender were used. Forty-three (43) patients underwent a further NT-proBNP sampling 5 days later in order to assess parameter stability. RESULTS PHT and non- PHT patients showed statistically different (p < 0,001) medians (126 vs 69 pg/ml). No pathologic values of NT-proBNP were measured in the group with PAP < 30 mmHg, while 27% of cases who had PAP between 30 and 40 showed pathologic concentrations. The positivity ratio increases to 57% in patients showing PAP > 40 mmHg. No relevant correlation (r = 0,2) was found between PAP and NT-proBNP. Mean average between the two sampling groups was 31%. CONCLUSIONS In scleroderma patients, combination of NT-proBNP and PAP seems to improve the diagnosis of pulmonary hypertension, especially in presence of borderline pulmonary pressure values. We therefore propose the biochemical observation of NT-proBNP when PAP is > 30 mmHg and in monitoring the evolution of the pathology.

Heparin-Induced Hepatotoxicity

Heparin-induced hepatotoxicity is well described in the literature, but rarely recognized clinically. Two cases were recently encountered. In the first case, elevated aminotransferase levels occurred after four days of heparin therapy. In the second case, enzyme levels increased after only 8 h of heparin treatment. To the authors' knowledge, this short time interval between the administration of heparin and liver enzyme elevations has not been described. The objective of this report is to increase the clinical awareness of this interesting and under-recognized biochemical observation.

Activating Phosphorylation of the Kin28p Subunit of Yeast TFIIH by Cak1p

ABSTRACT Cyclin-dependent kinase (CDK)-activating kinases (CAKs) carry out essential activating phosphorylations of CDKs such as Cdc2 and Cdk2. The catalytic subunit of mammalian CAK, MO15/Cdk7, also functions as a subunit of the general transcription factor TFIIH. However, these functions are split in budding yeast, where Kin28p functions as the kinase subunit of TFIIH and Cak1p functions as a CAK. We show that Kin28p, which is itself a CDK, also contains a site of activating phosphorylation on Thr-162. The kinase activity of a T162A mutant of Kin28p is reduced by ∼75 to 80% compared to that of wild-type Kin28p. Moreover, cells containing kin28T162A and a conditional allele of TFB3 (the ortholog of the mammalian MAT1 protein, an assembly factor for MO15 and cyclin H) are severely compromised and display a significant further reduction in Kin28p activity. This finding provides in vivo support for the previous biochemical observation that MO15-cyclin H complexes can be activated either by activating phosphorylation of MO15 or by binding to MAT1. Finally, we show that Kin28p is no longer phosphorylated on Thr-162 following inactivation of Cak1p in vivo, that Cak1p can phosphorylate Kin28p on Thr-162 in vitro, and that this phosphorylation stimulates the CTD kinase activity of Kin28p. Thus, Kin28p joins Cdc28p, the major cell cycle Cdk in budding yeast, as a physiological Cak1p substrate. These findings indicate that although MO15 and Cak1p constitute different forms of CAK, both control the cell cycle and the phosphorylation of the C-terminal domain of the large subunit of RNA polymerase II by TFIIH.

Ameliorative Effect of an Urinary Preparation on Acetaminophen and D-galactosamine Induced Hepatotoxicity in Rats

The effect of oral administration of a preparation of human urine (PHU) on acute liver injury was examined in rats intoxicated with acetaminophen and D-galactosamine. The results indicated that PHU protected the liver from acetaminophen and D-galactosamine-induced injury as judged by morphological and biochemical observation. An increase in lipid peroxide concentrations and decrease in protein concentrations occurred in the liver by D-galactosamine injection, PHU administration significantly prevented these changes.

Effect of Pretreatment of Rats with an Urinary Preparation on Liver Injuries Induced by Carbon Tetrachloride and α-Naphthylisothiocyanate

The effect of oral administration of a preparation of human urine (PHU) on the progression of acute liver injury was examined in rats intoxicated with carbon tetrachloride (CCl4) and α-naphthylisothiocyanate (ANIT). PHU protected the liver from CCl4-induced injury as judged by morphological and biochemical observations. In contrast, PHU aggravated ANIT-induced injury as judged also by morphological and biochemical observation. PHU prevented the increase in hepatic glutathione (GSH) and lipid peroxidation induced by CCl4. But PHU enhanced the increase in hepatic GSH caused by ANIT. These results indicate that the effect of PHU on hepatic GSH concentrations is through an indirect pathway. Clinical application of PHU on hepatitis should be explored further.

Biochemical aspects of bupivacaine-induced acute muscle degradation

A single injection of a local anaesthetic, bupivacaine, into the soleus muscle of adult rat has a severe mytoxic effect, i.e. rapid dissolution of myofilaments and degradation of myofibrillar proteins shortly after injection. Increased lysosomal enzymes were observed in homogenates of affected muscle. The activity of potent proteolytic enzyme, cathepsins B and L (assayed against a new synthetic substrate succinyl-Tyr-Met-naphthylamide), gradually increased and reached a plateau value that was 11-fold greater than the control 48 h after bupivacaine injection. The chronological change in the activity of cathepsins B and L was reflected in the myofibrillar protein pattern in bupivacaine-treated muscle. To determine whether the increase in lysosomal peptide hydrolases is due to activation of muscle lysosomes or not, mononuclear cells were separated from both injected and control muscles. The activity of cathepsins B and L in the lysate from injured muscle was 180-fold higher than the control. Affinity-purified antibody was used to study the intracellular localization of cathepsin B by immunohistochemical procedures. The results were consistent with the biochemical observation that the main source of cathepsin B in muscle homogenates was infiltrated mononuclear cells. Therefore, we conclude that the increased lysosomal enzymes may be derived mainly from mononuclear cells (macrophages), not from muscle lysosomes, in bupivacaine-induced acute muscle degeneration.