Nephro-protective effect of a novel formulation of unopened coconut inflorescence sap powder on gentamicin induced renal damage by modulating oxidative stress and inflammatory markers

Natural products for the prevention of antibiotic-associated kidney injury

Drug-induced acute kidney injury (AKI), especially from exposure to antibiotics, has a high prevalence secondary to their frequent prescription. Typically, drug-induced AKI results from acute tubular necrosis or acute interstitial nephritis. While some risk factors for the development of AKI in individuals treated with antibiotics are modifiable, others such as concomitant drug therapies to treat comorbidities, age, and pre-existing chronic kidney disease are not modifiable. As such, there is an urgent need to identify strategies to reduce the risk of AKI in individuals requiring antibiotic therapy. Natural products, especially those rich in active constituents possessing antioxidant properties are an attractive option to mitigate AKI risk. Given that mitochondrial dysfunction precedes AKI and natural products can restore mitochondrial health and counter the oxidative stress secondary to mitochondrial damage investigating their utility warrants further attention. The following review summarizes the available preclinical and clinical evidence that provides a foundation for future study.

Protective Effect of Honey and Propolis against Gentamicin-Induced Oxidative Stress and Hepatorenal Damages

Bee products are a promising source of phenolic compounds with strong antioxidant activity. The present study was designed to explore the protective effect of honey, propolis, and their combination on gentamicin-induced oxidative stress and hepatorenal dysfunction. This study was conducted on male Wistar rats by intraperitoneal injections of gentamicin (120 mg/kg BW/day, i.p.) or normal saline (1 ml/kg BW/day, i.p.) for 10 consecutive days. Honey (2 g/kg BW), propolis (100 mg/kg BW), or their combination were given daily by gavage to normal and gentamicin groups. Honey and propolis samples were evaluated for their phytochemical composition and antioxidant capacity. The in vitro investigations showed that the evaluated samples especially propolis extract have high antioxidant power associated with the presence of several phenolic compounds such as flavonoids, flavan-3-ols, hydroxybenzoic acids, hydroxycinnamic acids, and stilbenes, while honey contains only hydroxybenzoic acids and hydroxycinnamic acids. It was also shown that simultaneous treatment with honey or propolis extract alone or in association prevented changes caused by gentamicin administration and improved hepatic and renal functions. Changes caused by gentamicin administration, observed by in vivo experiments, include significant elevation of uric acid, urea, creatinine, and hepatic enzyme levels (ALT, AST, and ALP) and kidney biochemical changes (an increase of urea, uric acid, and creatinine and a decrease of albumin and total protein) as well as remarkable changes of renal and liver oxidative stress markers (CAT, GPx, and GSH) and elevation of MDA levels. Overall, it can be concluded that honey and propolis might be useful in the management of liver and renal diseases induced by xenobiotics.

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.

Benefits of D-005, a lipid extract from Acrocomia crispa fruits, in the prevention of acute kidney injury induced by nephrotoxicity in rats

INTRODUCTION

Aminoglycoside-induced acute kidney injury (AKI) is a pathology closely linked to oxidative and inflammatory reactions. Taking into account the previous reported antioxidant and anti-inflammatory effects of D-005, a lipid extract obtained from Cuban palm Acrocomia crispa (Arecaceae) fruits, this work aimed to evaluate the effects of D-005 on kanamycin-induced AKI.

METHODS

Male Wistar rats were divided into 7 groups: negative control (vehicle, Tween 65/H2O) and six groups treated with kanamycin to induce AKI: positive control (vehicle), D-005 (25, 100, 200, and 400 mg/kg) and grape seed extract (GSE, 200 mg/kg). D-005, vehicle, and GSE oral treatments were administered once daily for seven days, 1 h before kanamycin (500 mg/kg, i.p.). Serum uric acid and urea concentrations, renal histopathology, and oxidative markers (malondialdehyde (MDA), sulfhydryl (SH) groups, and catalase (CAT) activity) were assessed.

RESULTS

D-005 significantly reduced uric acid and urea levels, starting from D-005 100 mg/kg. Histopathologically, D-005, at all the tested doses, protected renal parenchyma structures (glomeruli, proximal tubules, and interstitium). These findings were accompanied by a significant reduction of MDA and SH group concentrations as well as restoration of CAT activity. The highest percentages of inhibition were obtained with the dose of 400 mg/kg. GSE, the reference substance, also prevented kanamycin-induced biochemical and histopathological changes, as well as reduced MDA and SH groups and restored CAT activity.

CONCLUSION

The administration of repeated oral doses of D-005 significantly protected against kanamycin-induced AKI, which could be associated with the antioxidant and anti-inflammatory effects of this extract.

Aqueous Extract from Cinnamomum zeylanicum (Lauraceae) Stem Bark Ameliorates Gentamicin-Induced Nephrotoxicity in Rats by Modulating Oxidative Stress and Inflammatory Markers

Nephropathies and especially nephrotoxicity have become one of the serious causes of life-threatening conditions because of intensive exposure to xenobiotic whether by environmental pollution or by drug abuse. The present study was undertaken to assess the protective effects of Cinnamomum zeylanicum stem bark aqueous extract (AECZ) on gentamicin-induced nephrotoxicity. AECZ was prepared by maceration in water and tested orally at the doses of 200 and 400 mg/kg/day to prevent gentamicin-induced nephropathies in male Wistar rats. Gentamicin (100 mg/kg/day) was administered for 14 consecutive days by intraperitoneal route, concomitantly with AECZ or silymarin (50 mg/kg/day) used as reference drug. Animal body weight was monitored during the treatment. After the last treatment on the 14th day, animals were sacrificed. Blood was collected for the evaluation of hematological and renal function biomarkers. The homogenate of one kidney was used to assess oxidative stress markers and proinflammatory cytokines, while the other one was fixed in formaldehyde for histopathological studies. Gentamicin decreased body weight, serum total proteins, and calcium level but increased kidneys' relative weight, serum creatinine, urea, and uric acid. Moreover, the levels of reduced glutathione, catalase, and superoxide dismutase activities were decreased, while an increase in malondialdehyde, proinflammatory cytokines (TNF-α, IL-1β, and IL-6), and nitrites was observed in the negative control group as compared to normal control. Histological analysis of the kidney revealed the presence of tubular necrosis, glomerular degeneration, and macrophage infiltration in the gentamicin-treated group. All these impairment parameters were prevented by AECZ and silymarin treatments. AECZ has a protective effect against gentamicin-induced nephrotoxicity. The antioxidant and anti-inflammatory potentials of this extract may highly contribute to its nephroprotective activity.

Protective effects of natural products against drug-induced nephrotoxicity: A review in recent years

Drug-induced nephrotoxicity (DIN) is a major cause of kidney damage and is associated with high mortality and morbidity, which limits the clinical use of certain therapeutic or diagnostic agents, such as antineoplastic drugs, antibiotics, immunosuppressive agents, non-steroidal anti-inflammatory drugs (NSAIDs), and contrast agents. However, in recent years, a number of studies have shown that many natural products (NPs), including phytochemicals, various plants extracts, herbal formulas, and NPs derived from animals, confer protective effects against DIN through multi-targeting therapeutic mechanisms, such as inhibition of oxidative stress, inflammation, apoptosis, fibrosis, and necroptosis, regulation of autophagy, maintenance of cell polarity, etc., by regulating multiple signaling pathways and novel molecular targets. In this review, we summarize and discuss the protective effects and mechanisms underlying the action of NPs against DIN found in recent years, which will contribute to the development of promising renal protective agents.

Ameliorative effect of Neera, nonfermented coconut inflorescence sap, on cisplatin-induced renal toxicity by abating oxidative stress

Objectives Neera, nonfermented coconut inflorescence sap (NFCIS) from unopened spadix of Cocos nucifera L., is a well-known traditional beverage. But, scientific reports on its health benefits are limited. NFCIS is reported to exhibits free radical scavenging activity, and its chemical composition is found promising. In the present study, the effect of NFCIS on alleviating cisplatin-induced nephrotoxicity was analyzed in mice. Methods The renal toxicity was induced by cisplatin (16 mg/kg b.wt. ip) in Swiss albino mice. The antioxidant activity of NFCIS was evaluated by nitric oxide radical scavenging assay and phorbol-12-myristate-13-acetate-induced superoxide radical generation in mice peritoneal macrophages. Total polyphenolic content of sap was determined using Folin-Ciocalteu reagent. The phytochemicals present in NFCIS was identified using Fourier transform infrared (FT-IR) spectroscopy. Results NFCIS was found to scavenge nitric oxide (NO) radicals (IC50 = 32 ± 2.47 μL/mL) and shown to inhibit superoxide (SO) generation (53.5 ± 2.1%) in macrophages. High polyphenolic content (193 µg gallic acid/mL) was determined in the sap. The FT-IR spectrum of NFCIS revealed the presence of several phytochemicals indicate its pharmaceutical and nutritional value. Cisplatin-induced hike in urea, creatinine and lipid peroxidation was significantly decreased to 65.16, 87.74 and 53.41% by NFCIS, respectively. Hb (42.37%) and total count (72.81%) were also found to be increased. Additionally, the activity of antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase and reduced glutathione was enhanced to 53.06, 40, 52.22 and 38.49%, respectively. Conclusions Results indicate that NFCIS effectively alleviates cisplatin-mediated renal toxicity by its antioxidant activity.

Reno-protective effects of ursodeoxycholic acid against gentamicin-induced nephrotoxicity through modulation of NF-κB, eNOS and caspase-3 expressions

Gentamicin (GNT) is a potent aminoglycoside antibiotic widely used to treat life-threatening bacterial infections. We aim to investigate the potential protective effect of ursodeoxycholic acid (UDCA) against GNT-induced nephrotoxicity. In this study, 24 male Wistar rats were used and randomly divided into four groups of six animals each. Control group received 0.5% carboxymethyl cellulose orally for 15 days, GNT group received GNT 100 mg/kg/day i.p. for 8 days, UDCA group received UDCA orally for 15 consecutive days at a dose of 60 mg/kg/day suspended in 0.5% carboxymethyl cellulose and UDCA-pretreated group received UDCA orally for 7 days then co-administered with GNT i.p. for 8 days at the same fore-mentioned doses. Serum levels of kidney function parameters (urea, creatinine, uric acid and albumin) were measured. Renal tissues were used to evaluate oxidative stress markers; malonaldehyde (MDA), reduced glutathione (GSH) and the anti-oxidant enzyme superoxide dismutase (SOD) activities and nuclear factor kappa light-chain enhancer of activated B cells (NF-κB) and kidney injury molecule-1 (KIM-1) mRNA levels. Immunohistochemical expression of endothelial nitric oxide synthase (eNOS) and caspase-3 and histological and ultrastructural examination were performed. Treatment with GNT increased the serum levels of renal function parameters and renal MDA, NF-κB and KIM-1 mRNA levels, while it decreased GSH and SOD activities. Marked immunohistochemical expression of caspase-3 was observed after GNT administration while it decreased eNOS expression. Histological and ultrastructural alterations were also evident in renal corpuscles and tubules. In contrast, pretreatment with UDCA reversed changes caused by GNT administration. These results suggest that UDCA ameliorates GNT-induced kidney injury via inhibition of oxidative stress, inflammation and apoptosis.

Intravenous rAAV2/9 injection for murine cochlear gene delivery

Gene therapy for genetic deafness is a promising approach by which to prevent hearing loss or to restore hearing after loss has occurred. Although a variety of direct approaches to introduce viral particles into the inner ear have been described, presumed physiological barriers have heretofore precluded investigation of systemic gene delivery to the cochlea. In this study, we sought to characterize systemic delivery of a rAAV2/9 vector as a non-invasive means of cochlear transduction. In wild-type neonatal mice (postnatal day 0-1), we show that intravenous injection of rAAV2/9 carrying an eGFP-reporter gene results in binaural transduction of inner hair cells, spiral ganglion neurons and vestibular hair cells. Transduction efficiency increases in a dose-dependent manner. Inner hair cells are transduced in an apex-to-base gradient, with transduction reaching 96% in the apical turn. Hearing acuity in treated animals is unaltered at postnatal day 30. Transduction is influenced by viral serotype and age at injection, with less efficient cochlear transduction observed with systemic delivery of rAAV2/1 and in juvenile mice with rAAV2/9. Collectively, these data validate intravenous delivery of rAAV2/9 as a novel and atraumatic technique for inner ear transgene delivery in early postnatal mice.