The nephroprotective properties of taurine-amikacin treatment in rats are mediated through HSP25 and TLR-4 regulation

The renoprotective activity of amikacin-gamma-amino butyric acid-chitosan nanoparticles: a comparative study

The development of nanoparticles (NPs) with active components with upgraded stability, and prolonged release helps in enhanced tissue regeneration. In addition, NPs are feasible strategy to boost antibiotic effectiveness and reduce drug side effects. Our study focuses on the use of amikacin (AMK) and gamma amino butyric acid (GABA) unloaded combinations or loaded on chitosan nanoparticles (CSNPs) for kidney protection. The AMK-GABA-CSNPs were prepared with the ionic gelation method, the morphology was studied using transmission electron microscopy (TEM), zetasizer and the Fourier transform-infrared spectroscopy (FT-IR) spectrum of the synthesized NPs was observed. The average size of AMK-GABA-CSNPs was 77.5 ± 16.5 nm. Zeta potential was + 38.94 ± 2.65 mV. AMK-GABA-CSNPs revealed significant in vitro antioxidant, anti-coagulation, non-hemolytic properties and good cell compatibility. To compare the effects of the unloaded AMK-GABA combination and AMK-GABA-CSNPs on the renal tissue, 42 healthy Sprague-Dawley rats were divided into seven groups. G1: normal control (NC), normal saline; G2: low-dose nephrotoxic group (LDN), AMK (20 mg/kg/day; i.p.); G3: unloaded AMK (20 mg/kg/day; i.p.) and GABA (50 mg/kg/day; i.p.); G4: AMK-GABA-CSNPs (20 mg/kg/day; i.p.); G5: high-dose nephrotoxic group (HDN), AMK (30 mg/kg/day; i.p.); G6: unloaded AMK (30 mg/kg/day; i.p.) and GABA (50 mg/kg/day; i.p.) and G7: AMK-GABA-CSNPs (30 mg/kg/day; i.p.). The results showed that AMK-GABA-CSNPs formulation is superior to unloaded AMK-GABA combination as it ameliorated kidney functions, oxidative stress and displayed a significant homeostatic role via suppression of inflammatory cytokines of Th1, Th2 and Th17 types. Hence, AMK-GABA-CSNPs could afford a potential nano-based therapeutic formula for the management of AMK-nephrotoxicity.

Possible correlated signaling pathways with chronic urate nephropathy: A review

Hyperuricemia nephropathy, also known as gouty nephropathy, refers to renal damage induced by hyperuricemia caused by excessive production of serum uric acid or low excretion of uric acid. the persistence of symptoms will lead to changes in renal tubular phenotype and accelerate the progress of renal fibrosis. The existence and progressive aggravation of symptoms will bring a heavy burden to patients, their families and society, affect their quality of life and reduce their well-being. With the increase of reports on hyperuricemia nephropathy, the importance of related signal pathways in the pathogenesis of hyperuricemia nephropathy is becoming more and more obvious, but most studies are limited to the upper and lower mediating relationship between 1 or 2 signal pathways. The research on the comprehensiveness of signal pathways and the breadth of crosstalk between signal pathways is limited. By synthesizing the research results of signal pathways related to hyperuricemia nephropathy in recent years, this paper will explore the specific mechanism of hyperuricemia nephropathy, and provide new ideas and methods for the treatment of hyperuricemia nephropathy based on a variety of signal pathway crosstalk and personal prospects.

Anti-apoptotic effect of HeidihuangWan in renal tubular epithelial cells via PI3K/Akt/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Heidihuang Wan (HDHW) is a classic Chinese herbal formula, which was first recorded in the "Suwen Bingji Qiyi Baoming Collection" written by Liu Wansu during the Jin Dynasty (1115-1234 AD). It is commonly used clinically for the treatment of kidney diseases and its curative effect is stable. Previous animal experiments have confirmed that HDHW can effectively improve renal fibrosis. However, the underlying pharmacological mechanism remains unclear.

AIMS OF THIS STUDY

Renal tubular epithelial cell (RTEC) apoptosis is one of the main pathological features of renal fibrosis. This study aimed to observe the effect and underlying mechanism of HDHW on the apoptosis of RTECs to further explore the pathological mechanism of HDHW against renal fibrosis.

MATERIALS AND METHODS

We examined the HDHW composition in rat serum. In vitro, we first screened out the optimal intervention concentration of HDHW on RTECs using the MTT assay. Hypoxia/reoxygenation was then used to induce apoptosis of RTECs (H/R-RTECs), which were divided into H/R-RTEC, astragaloside IV (positive control), HDHW, and RTECs groups. After 48 h of drug intervention, apoptosis of RTECs was detected using flow cytometry and protein expression was detected by western blotting. The 5/6 nephrectomy rat model was constructed and divided into the normal control, 5/6 nephrectomy, HDHW, and astragaloside IV groups. After 8 weeks of treatment, TUNEL staining was used to detect cell apoptosis, and western blotting was used to detect protein expression.

RESULTS

HDHW downregulated the expression of pro-apoptotic proteins Bax and Caspase3, up-regulated the expression of anti-apoptotic protein Bcl-2, activated the PI3K/Akt/mTOR signaling pathway, and reversed the early apoptosis of RTECs, thereby resisting the apoptosis of RTECs.

CONCLUSION

HDHW inhibits apoptosis of RTECs by modulating the PI3K/Akt/mTOR signaling pathway. This study provides experimental evidence for the anti-fibrotic effect of HDHW on the kidneys and partially elucidates its pharmacological mechanism of action.

Antioxidative and Anti-Inflammatory Protective Effects of β-Caryophyllene against Amikacin-Induced Nephrotoxicity in Rat by Regulating the Nrf2/AMPK/AKT and NF-κB/TGF-β/KIM-1 Molecular Pathways

Herein, the molecular pathogenic pathways implicated in renal injury triggered by amikacin (AK), together with the alleviating actions of β-caryophyllene (BCP), were investigated. Adult male Wistar rats (n = 32) were disseminated to the four following groups (n = 8/group): normal group, positive control animals (PC) that received AK intraperitoneal injections for 14 days (500 mg/kg/day), and rats that received AK simultaneously with small (200 mg/kg/day) and high doses (400 mg/kg/day) of BCP. The PC renal tissues revealed abnormal histology alongside increased apoptosis and significantly elevated serum creatinine and urea with marked proteinuria and oliguria relative to the normal rats. Moreover, renal tissues from the PC animals also showed substantial upregulations in NF-κB/TGF-β/KIM-1, whilst Nrf2/AMPK/AKT/PCNA declined, at the gene and protein levels in comparison to the normal rats. Additionally, the levels of markers of oxidative stress (MDA/H₂O₂/protein adducts) and inflammation (TNF-α/IL-1β/IL-6/IL-18/TLR/HSP25) were substantially higher in the PC renal specimens, whereas the antioxidants (GSH/GPx/SOD1/CAT) and interleukin-10 decreased, relative to the NC group. Both BCP protocols improved the biochemical markers of renal functions, alleviated renal histopathology and apoptosis, and decreased NF-κB/TGF-β/KIM-1 alongside the concentrations of oxidative stress and proinflammatory markers, whilst promoting Nrf2/AMPK/AKT/IL-10/PCNA and the targeted antioxidants. However, the improving effects in the high-dose regimen were markedly stronger than those observed in animals treated with low dose of BCP. In conclusion, the present report is the first to connect NF-κB/TGF-β/KIM-1 proinflammatory and Nrf2/AMPK/AKT antioxidative stress pathways with the pathogenesis of AK-induced nephrotoxicity. Additionally, the current report is the first to disclose alleviating activities for BCP against AK-triggered nephrotoxicity by modulating multiple antioxidative stress with anti-inflammatory molecular pathways.

Endoplasmic reticulum stress and mitochondrial injury are critical molecular drivers of AlCl3-induced testicular and epididymal distortion and dysfunction: protective role of taurine

Aluminum, the third most plentiful metal in the Earth's crust, has potential for human exposure and harm. Oxidative stress plays an essential role in producing male infertility by inducing defects in sperm functions. We aimed to investigate the role of endoplasmic reticulum (ER) stress and mitochondrial injury in the pathogenesis of aluminum chloride (AlCl3)-induced testicular and epididymal damage at the histological, biochemical, and molecular levels, and to assess the potential protective role of taurine. Forty-eight adult male albino rats were separated into four groups (12 in each): negative control, positive control, AlCl3, and AlCl3 plus taurine groups. Testes and epididymis were dissected. Histological and immunohistochemical (Bax and vimentin) studies were carried out. Gene expression of vimentin, PCNA, CHOP, Bcl-2, Bax, and XBP1 were investigated via quantitative real-time polymerase chain reaction (qRT-PCR), besides estimation of malondialdehyde (MDA) and total antioxidant capacity (TAC). Light and electron microscopic examinations of the testes and epididymis revealed pathological changes emphasizing both mitochondrial injury and ER stress in the AlCl3 group. Taurine-treated rats showed a noticeable improvement in the testicular and epididymal ultrastructure. Moreover, they exhibited increased gene expression of vimentin, Bcl-2, and PNCA accompanied by decreased CHOP, Bax, and XBP1 gene expression. In conclusion, male reproductive impairment is a significant hazard associated with AlCl3 exposure. Both ER stress and mitochondrial impairment are critical mechanisms of the deterioration in the testes and epididymis induced by AlCl3, but taurine can amend this.

Urinary Metabolomics from a Dose-Fractionated Polymyxin B Rat Model of Acute Kidney Injury

BACKGROUND

Polymyxin B treatment is limited by kidney injury. We sought to identify Polymyxin B related urinary metabolomic profile modifications for early detection of polymyxin-associated nephrotoxicity.

METHODS

Samples were obtained from a previously conducted study. Male Sprague-Dawley rats received dose-fractionated polymyxin B (12mg/kg/day) once daily (QD), twice daily (BID), and thrice daily (TID) for three days with urinary biomarkers and kidney histopathology scores determined. Daily urine was analysed for metabolites via 1H NMR. Principal Components Analyses identified spectral data trends with orthogonal Partial Least Square Discriminant Analysis applied to classify metabolic differences. Metabolomes were compared across groups (i.e., those receiving QD, BID, TID, and control) using a mixed-effects models. Spearman correlation was performed for injury biomarkers and the metabolome.

RESULTS

A total of 25 rats were treated with Polymyxin B, and n=2 received saline, contributing 77 urinary samples. Pre-dosing samples clustered well, characterized by higher amounts of citrate, 2-oxoglutarate, and hippurate. Day 1 samples showed higher taurine; day 3 samples had higher lactate, acetate, and creatine. Taurine was the only metabolite significantly increased in both BID and TID compared to QD group. Day 1 taurine correlated with increasing histopathology scores (rho=0.4167, P=0.038) and KIM-1 (rho =0.4052, P=0.036); whereas KIM-1 on day one and day 3 did not reach significance with histopathology (rho=0.3248, P=0.11 and rho=0.3739, P=0.066).

CONCLUSIONS

Polymyxin B causes increased amounts of urinary taurine on day 1 which then normalizes to baseline concentrations. Taurine may provide one of the earlier signals of acute kidney damage caused by polymyxin B.

Taurine loaded chitosan-pectin nanoparticle shows curative effect against acetic acid-induced colitis in rats

Owing to the poor outcomes and adverse side effects of existing ulcerative colitis drugs, the study aimed to develop an alternative nano-based treatment approach. The study was designed to characterize the in vitro and in vivo properties of taurine, taurine-loaded chitosan pectin nanoparticles (Tau-CS-PT-NPs) and chitosan pectin nanoparticles (CS-PT-NPs) in the therapy of acetic acid (AA)-induced colitis in rats. CS-PT-NPs and Tau-CS-PT-NPs were prepared by ionic gelation method then in vitro characterized, including transmission electron microscopy (TEM), polydispersity index (PDI), zeta potential, Fourier transform infrared (FTIR) spectroscopy, encapsulation efficiency (EE), and drug release profile. Following colitis induction, rats were orally administrated with free taurine, Tau-CS-PT-NPs, and CS-PT-NPs once per day for six days. The sizes of Tau-CS-PT-NPs and CS-PT-NPs were 74.17 ± 2.88 nm and 42.22 ± 2.41 nm, respectively. EE was about 69.09 ± 1.58%; furthermore, 60% of taurine was released in 4 h in simulated colon content. AA-induced colitis in untreated rats led to necrosis of colon tissues and a significant increase in interleukin-1beta (IL-1β), Tumor Necrosis Factor-alpha (TNF-α), myeloperoxidase (MPO), and malondialdehyde (MDA) levels associated with a remarkable reduction in glutathione (GSH) level in colon tissue in comparison to control group. Treatment with taurine, Tau-CS-PT-NPs, and CS-PT-NPs partly reversed these effects. The present study demonstrated that the administration of free taurine, CS-PT-NPs, and Tau-CS-PT-NPs exerted beneficial effects in acetic acid-induced colitis by their anti-inflammatory and antioxidant activities. The best therapeutic effect was observed in animals treated with taurine-loaded chitosan pectin nanoparticles.