A histological study of the effect of exogenous melatonin on gentamicin induced structural alterations of proximal tubules in rats

Cinnamic acid ameliorate gentamicin-induced liver dysfunctions and nephrotoxicity in rats through induction of antioxidant activities

This study was the first to evaluate the possible protective effects of cinnamic acid (CA) against Gentamicin (GM) induced liver and kidney dysfunctions in rats. Adult male Wistar rats were randomly assigned to 4 equal groups (n = 8): Control group (saline, 0.5 ml/day), CA group (CA, 50 mg/kg/day), GM group (GM, 100 mg/kg/day), and GM + CA group (100 & 50 mg/kg/day). Following 12 days of treatments, blood and 24 h urine samples were collected and kidneys were taken out for biochemical, histopathological, and molecular studies. Following CA treatment, renal function markers and transaminases activities including serum urea (59.92%) and creatinine (50.41%), protein excretion rate (43.67%), and serum activities of aspartate aminotransferase (AST) (54.34%) and alanine aminotransferase (ALT) (47.26%) significantly reduced in the treated group as compared with the GM group (P < 0.05). Also, CA could significantly ameliorate the levels of triglyceride (29.70%), cholesterol (13.02%), very low-density lipoprotein (29.69%) and high-density lipoprotein-cholesterol (7.28%). CA could also attenuate oxidative stress through a decrease of serum malondialdehyde (MDA) (50.86%) and nitric oxide (NO) (0.85%) and an increase of renal catalase (CAT) (196.14%) and glutathione peroxidase (GPX) activities (45.88%) as well as GPX mRNA expression (44.42-fold) as compared with the GM group (P < 0.05). Moreover, histopathological evaluations revealed attenuated tubular damages and reduced inflammatory cellular infiltration in CA treated animals. Overall, CA alleviates GM-induced nephrotoxicity and alterations in transaminases activities in rats through its antioxidant activities.

Evaluation of Preclinical and Clinical Studies Published in Medical Journals of Bosnia and Herzegovina: Methodology Issues

INTRODUCTION

Results of preclinical and clinical studies in medicine could be trusted only if their design and statistical analysis were appropriate.

AIM

The aim of our study was to investigate whether preclinical and clinical studies published in medical journals of Bosnia and Herzegovina satisfy basic requirements for appropriate design and statistical interpretation of data.

METHODS

Preclinical and clinical studies published in medical journals of Bosnia and Herzegovina were retrieved from the PubMed database, and the sample for analysis was randomly chosen from the retrieved publications. Implementation rate of basic principles of experimental design (local control, randomization and replication) and rate of the most common errors in design of clinical/observational studies was established by careful reading of the sampled publications and their checking against predefined criteria.

RESULTS

Our study showed that only a minority of experimental preclinical studies had basic principles of design completely implemented (7%), while implementation rate of single aspects of appropriate experimental design varied from as low as 12% to as high as 77%. Only one of the clinical/observational studies had none of the errors searched for (2%), and specific errors rates varied from 10% to 89%. Average impact factor of the surveyed studies was around one, and average publication date recent, less than 5 years ago.

CONCLUSION

Prevalence of preclinical studies that did not follow completely basic principles of research design, and that of clinical/observational studies with errors are high, raising suspicion to validity of their results. If incorrect and not protected against bias, results of published studies may adversely influence future research.

Therapeutic potential of Origanum vulgare leaf hydroethanolic extract against renal oxidative stress and nephrotoxicity induced by paraquat in rats

Objective:

Paraquat is a herbicide with potent toxicity in humans and animals. This study aimed to evaluate the protective effects of Origanum vulgare (O. vulgare) leaf extract on the acute nephrotoxicity and renal oxidative stress caused by paraquat.

Materials and Methods:

We randomly assigned forty male rats into five groups (G1-G5). The G1 was used as control; G2 only received paraquat (25 mg/kg body weight (bw)/day, po); and G3, G4 and G5 received 25 mg/kg b.w/day oral doses of paraquat and O. vulgare hydroethanolic leaf extract (200, 400, 800 mg/kg bw/day, po, respectively). After 2 weeks, superoxide dismutase (SOD), renal catalase (CAT), vitamin C levels, histopathological changes, and tumor necrosis factor-α (TNF-α) gene expression as well as serum levels of urea, creatinine (Cr), and protein carbonyl (PC) were determined.

Results:

In G2, oral administration of paraquat significantly increased (p<0.05) serum Cr, urea, PC, and renal TNF-α gene expression relative to those of the control group. Renal catalase, superoxide dismutase, and vitamin C levels were decreased significantly (p<0.05) in G2 as compared to G1. Administration of O. vulgare leaf extract not only increased the renal vitamin C, CAT, and SOD but also decreased the renal TNF-α gene expression, malondialdehyde (MDA), serum urea and creatinine in paraquat-induced nephrotoxicity in rats.

Conclusion:

Our results show that O. vulgare leaf extract has protective effects against nephrotoxicity induced by paraquat in rats. It seems that the nephroprotective effects of O. vulgare extract may be related to its antioxidant and anti-inflammatory effects.

Novel Peptide Vaccine GV1001 Rescues Hearing in Kanamycin/Furosemide-Treated Mice

The cell-penetrating peptide GV1001 has been investigated as an anticancer agent and recently demonstrated anti-oxidant and anti-inflammatory effects. It has shown a protective effect on a kanamycin (KM)-induced ototoxicity mouse model. In the present study, we administered GV1001 at different time points after inducing hair cell damage, and examined if it rescues hair cell loss and restores hearing. A deaf mouse model was created by intraperitoneal injection of KM and furosemide. First, to test the early temporal change of hearing and extent of hair cell damage after KM and furosemide injection, hearing and outer hair cells (OHCs) morphology were evaluated on day 1, day 2 and day 3 after injection. In the second experiment, following KM and furosemide injection, GV1001, dexamethasone, or saline were given for three consecutive days at different time points: D0 group (days 0, 1, and 2), D1 group (days 1, 2, and 3), D3 group (days 3, 4, and 5) and D7 group (days 7, 8, and 9). The hearing thresholds were measured at 8, 16, and 32 kHz before ototoxic insult, and 7 days and 14 days after KM and furosemide injection. After 14 days, each turn of the cochlea was imaged to evaluate OHCs damage. GV1001-treated mice showed significantly less hearing loss and OHCs damage than the saline control group in the D0, D1 and D3 groups (p < 0.0167). However, there was no hearing restoration or intact hair cell in the D7 group. GV1001 protected against cochlear hair cell damage, and furthermore, delayed administration of GV1001 up to 3 days rescued hair cell damage and hearing loss in KM/furosemide-induced deaf mouse model.

Nephroprotective and Anti-Inflammatory Effects of Pistacia atlantica Leaf Hydroethanolic Extract Against Gentamicin-Induced Nephrotoxicity in Rats

Gentamicin in overdose can lead to tubular injury and kidney dysfunction. Some antioxidants can protect kidneys against nephrotoxicity. This study was undertaken to evaluate the protective effects of Pistacia atlantica (P. atlantica) leaf hydroethanolic extract against gentamicin-induced nephrotoxicity in rats. Forty rats were divided into five groups: the first group received a daily intraperitoneal (i.p.) injection of normal saline. The second group received gentamicin (120 mg/kg, i.p.). The third, fourth, and fifth groups were orally treated with 200, 400, and 800 mg/kg of P. atlantica leaf hydroethanolic extract, respectively, and they also received gentamicin (120 mg/kg, i.p.). After seven days, serum malondialdehyde (MDA), creatinine (Cr), urea, uric acid, lipids profile, protein carbonyl (PC), and tumor necrosis factor-α (TNF-α) were determined. Also, a piece of kidney was used to determine catalase (CAT) and superoxide dismutase (SOD) activities, vitamin C, the gene expression of TNF-α, and for subsequent histopathological studies. Treatment with P. atlantica leaf hydroethanolic extract resulted in a significant increase (p < 0.05) in CAT, SOD, vitamin C, and high-density lipoprotein cholesterol, and significantly decreased (p < 0.05) the levels of Cr, urea, uric acid, MDA, PC, triglyceride, total cholesterol, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, TNF-α protein, and the gene expression of TNF-α compared with the untreated group. Histopathological studies show that in lymphocyte infiltration, remarkable reduction was observed in P. atlantica leaf hydroethanolic extract-treated groups, compared with the untreated group. The present study suggests that P. atlantica leaf hydroethanolic extract has protective effects against gentamicin-induced nephrotoxicity.