The Effect of Dexpanthenol on Ototoxicity Induced by Cisplatin

Protective effect of dexpanthenol against methotrexate-induced liver oxidative toxicity in rats

Methotrexate is a familiar chemotherapeutic preferred in a wide range of clinical fields such as leukemia, psoriasis, rheumatoid arthritis, neoplastic and autoimmune disorders. However, methotrexate therapy has limitations as it causes severe side effects from which liver damage is the most important one. Several antioxidant compounds have been studied against methotrexate related liver toxicity, but dexpanthenol has not been experienced. Vitamin B5-derived dexpanthenol is a usual therapeutic having a potent anti-inflammatory and antioxidant effect. In this study, we aimed to evaluate the ameliorating effect of dexpanthenol against methotrexate-induced hepatotoxicity. We performed our experiments on Wistar albino rats divided randomly into four groups involving control, dexphantenol, dexpanthenol + methotrexate and methotrexate applied animals. After this experimental work on rats, for the first time, we showed dexpanthenol improvement effect on ROS-caused hepatotoxicity initiated by methotrexate administration in terms of liver tissue antioxidant/oxidant enzymes, liver function tests, and histological changes. We suggest that dexpanthenol might be applied during methotrexate treatment in order to reduce the liver toxicity. However, further studies are needed to find out the optimal dose regimen and to understand the mechanism of action.

Neuroprotective Effects of Dexpanthenol on Rabbit Spinal Cord Ischemia/Reperfusion Injury Model

OBJECTIVE

Dexpanthenol (DXP) reportedly protects tissues against oxidative damage in various inflammation models. This study aimed to evaluate its effects on oxidative stress, inflammation, apoptosis, and neurological recovery in an experimental rabbit spinal cord ischemia/reperfusion injury (SCIRI) model.

METHODS

Rabbits were randomized into 5 groups of 8 animals each: group 1 (control), group 2 (ischemia), group 3 (vehicle), group 4 (methylprednisolone, 30 mg/kg), and group 5 (DXP, 500 mg/kg). The control group underwent laparotomy only, whereas other groups were subjected to spinal cord ischemia by aortic occlusion (just caudal to the 2 renal arteries) for 20 min. After 24 h, a modified Tarlov scale was employed to record neurological examination results. Malondialdehyde and caspase-3 levels and catalase and myeloperoxidase activities were analyzed in tissue and serum samples. Xanthine oxidase activity was measured in the serum. Histopathological and ultrastructural evaluations were also performed in the spinal cord.

RESULTS

After SCIRI, serum and tissue malondialdehyde and caspase-3 levels and myeloperoxidase and serum xanthine oxidase activities were increased (P < 0.05-0.001). However, serum and tissue catalase activity decreased significantly (P < 0.001). DXP treatment was associated with lower malondialdehyde and caspase-3 levels and reduced myeloperoxidase and xanthine oxidase activities but increased catalase activity (P < 0.05-0.001). Furthermore, DXP was associated with better histopathological, ultrastructural, and neurological outcome scores.

CONCLUSIONS

This study was the first to evaluate antioxidant, anti-inflammatory, antiapoptotic, and neuroprotective effects of DXP on SCIRI. Further experimental and clinical investigations are warranted to confirm that DXP can be administered to treat SCIRI.

Pharmacological treatment with annexin A1-derived peptide protects against cisplatin-induced hearing loss

Cisplatin is an antineoplastic agent widely used, and no effective treatments capable of preventing cisplatin-induced ototoxicity and neurotoxicity in humans have yet been identified. This study evaluated the effect of the anti-inflammatory annexin A1 (AnxA1)-derived peptide Ac_2-26 in a cisplatin-induced ototoxicity model. Wistar rats received intraperitoneal injections of cisplatin (10mg/kg/day) for 3 days to induce hearing loss, and Ac_2-26 (1mg/kg) was administered 15minutes before cisplatin administration. Control animals received an equal volume of saline. Hearing thresholds were measured by distortion product otoacoustic emissions (DPOAE) before and after treatments. Pharmacological treatment with Ac_2-26 protected against cisplatin-induced hearing loss, as evidenced by DPOAE results showing similar signal-noise ratios between the control and Ac_2-26-treated groups. These otoprotective effects of Ac_2-26 were associated with an increased number of ganglion neurons compared with the untreated cisplatin group. Additionally, Ac_2-26 treatment produced reduced immunoreactivity on cleaved caspase 3 and phosphorylated ERK levels in the ganglion neurons, compared to the untreated group, supporting the neuroprotective effects of the Ac_2-26. Our results suggest that Ac_2-26 has a substantial otoprotective effect in this cisplatin-induced ototoxicity model mediated by neuroprotection and the regulation of the ERK pathway.

Demonstration of the protective effect of ghrelin in the livers of rats with cisplatin toxicity

Despite the various and newly developed chemotherapeutic agents in recent years, cisplatin is still used very frequently as a chemotherapeutic agent, even though cisplatin has toxic effects on many organs. The aim of our study is to show whether ghrelin reduces the liver toxicity of cisplatin in the rat model. Twenty-eight male Sprague Dawley albino mature rats were chosen to be utilized in the study. Group 1 rats (n = 7) were taken as the control group, and no medication was given to them. Group 2 rats (n = 7) received 5 mg/kg/day cisplatin and 1 ml/kg/day of 0.9% NaCl, Group 3 rats (n = 7) received 5 mg/kg/day cisplatin and 10 ng/kg/day ghrelin, Group 4 rats (n = 7) received 5 mg/kg/day cisplatin and 20 ng/kg/day ghrelin for 3 days. Glutathione, malondialdehyde (MDA), superoxide dismutase (SOD), plasma alanine aminotransferase (ALT) levels, and liver biopsy results were measured in rats. It was determined that, especially in the high-dose group, the MDA, plasma ALT, and SOD levels increased less in the ghrelin group as compared to the cisplatin group, and the glutathione level decreased slightly with a low dose of ghrelin, while it increased with a higher dose. In histopathological examination, it was determined that the toxic effect of cisplatin on the liver was reduced with a low dose of ghrelin, and its histopathological appearance was similar to normal liver tissue when given a high dose of ghrelin. These findings show that ghrelin, especially in high doses, can be used to reduce the toxic effect of cisplatin.

Protective effect of dexpanthenol on cisplatin induced nephrotoxicity in rats

Cisplatin (CIS) is an antineoplastic agent used for treating solid organ tumors. Toxic side effects of CIS treatment include nephrotoxicity, neurotoxicity, ototoxicity, myelosuppression and hepatotoxicity. Dexpanthenol (DEX) exhibits antioxidant and anti-inflammatory effects and protective effects against free oxygen radicals. We investigated the protective effects of DEX on CIS induced nephrotoxicity. Animals were divided into four groups of 10. The control group was given saline. The DEX group was treated with DEX for 10 days. The CIS group was treated with a single dose of CIS. The DEX + CIS group was given a single dose of CIS followed by DEX for 10 days. We found increased levels of malondialdehyde (MDA), blood urea nitrogen (BUN) and creatinine, while superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and myeloperoxidase (MPO) levels were decreased in the CIS group. MDA, BUN and creatinine levels were decreased, while SOD, CAT, GPx and MPO levels were increased in the DEX + CIS group. Renal tubule damage, inflammation and histopathology scores were significantly higher in the CIS group than the control. The DEX + CIS group exhibited less renal tubule damage and inflammation, and lower histopathological assessment scores than the CIS group. Significant cortical tubule damage and interstitial inflammation were observed in the CIS group. Tubule damage was slightly less, and mild tubule dilation and less cast formation were observed in the DEX + CIS group; also, inflammation was less severe than for the CIS group. DEX may have therapeutic potential for treating CIS induced nephrotoxicity due to its antioxidant and anti-inflammatory properties.

Up-regulation of autophagy and apoptosis of cochlear hair cells in mouse models for deafness

INTRODUCTION

Hearing loss is one of the most common sensory disorders. Recent findings have shown that the apoptotic program and autophagy are related to hearing loss. The aim of the study was to explore the effects of noise and cisplatin exposure on apoptosis and autophagy in the hair cells of the cochleae.

MATERIAL AND METHODS

C57BL/6 mice were randomly divided into 3 groups (n = 10 for each): the control group, the noise model group and the cisplatin model group. Auditory brainstem response (ABR) measurements were used to detect the hearing thresholds. TUNEL assay was used to evaluate cell apoptosis. Western blot and immunofluorescence were performed to examine the apoptosis- and autophagy-related proteins.

RESULTS

The mice exhibited substantial hearing loss after noise and cisplatin exposure. Additionally, more TUNEL positive cells were observed in the mice after noise and cisplatin exposure compared with the control group. Moreover, the protein expression levels of Beclin-1, LC3-II, Bax and cleaved caspase-3 were significantly increased, while the expression of Bcl-2 was notably decreased in the cochlea after noise (p = 0.0278, 0.0075, 0.0142, 0.0158, 0.0131 respectively) and cisplatin (p = 0.0220, 0.0075, 0.0024, 0.0161, 0.0452 respectively) exposure compared with the control group. Besides, the ratio of LC3-II/LC3-I was substantially higher in the mice treated by cisplatin (p = 0.0046) and noise (p = 0.0220) compared with the control group.

CONCLUSIONS

Our findings demonstrated for the first time that noise and cisplatin exposure promoted apoptosis and autophagy in the hair cells of the cochleae. This study provides new insights into the mechanisms of noise- or cisplatin-induced hearing loss.

Protective effect of dexpanthenol against cisplatin-induced hepatotoxicity

The aim of the present study was to investigate the protective effect of dexpanthenol (Dexp) against cisplatin (Cis)-induced hepatotoxicity. Thirty-two Sprague Dawley rats were divided into four groups: Control group (n=8), Dexp group (n=8, 500 mg/kg/ip/daily single dose/3 days Dexp), Cis group (n=8, 7 mg/kg/ip/single dose Cis) and Cis+Dexp group (n=8, 500 mg/kg/ip/daily single dose/3 days Dexp +7 mg/kg/ip/single dose Cis). MDA, CAT, GSH, GSH-Px, TOS, TAS, OSI, Total Nitrit, IL-1β, IL-6 and TNF-α levels were analyzed in liver tissue samples. After paraffinization of liver tissue samples, histopathological (congestion, loss of glycogen, number of Kupffer cells) and immunohistochemical (caspase-3 expression) parameters were assessed on the paraffinized liver sections. GSH, TAS, TOS, OSI, Tot Nit, L-Arginine, ADMA and SDMA levels were measured in the serum samples. Statistically significant differences were found between the groups in terms of all liver tissue biochemical parameters, with the exception of IL-1β and TNF-α levels. GSH, CAT, GSH-Px, TAS and Tot Nit levels were significantly higher in the Cis+Dexp group compared to the Cis group, whereas MDA, TOS, OSI and IL-6 levels were higher in the Cis group. Similarly, serum GSH, TAS, Tot Nit levels were higher in the Cis+Dexp group whereas TOS, L-Arginine, ADMA and SDMA levels were higher in Cis group. There were statistically significant differences between Control and Cis groups in terms of congestion increase, increase of glycogen loss, increase of Kupffer cell number and increase of caspase-3 expression (P<0.001). There was a statistically significant difference between the Cis and the Cis+Dexp groups in terms of histopathologic parameters, with the exception of congestion (P<0.001). To conclude, histopathological, immunohistochemical, and biochemical results of this study demonstrated that Dexp has a protective effect against Cis-induced hepatotoxicity.

Innovative pharmaceutical approaches for the management of inner ear disorders

The sense of hearing is essential for permitting human beings to interact with the environment, and its dysfunctions can strongly impact on the quality of life. In this context, the cochlea plays a fundamental role in the transformation of the airborne sound waves into electrical signals, which can be processed by the brain. However, several diseases and external stimuli (e.g., noise, drugs) can damage the sensorineural structures of cochlea, inducing progressive hearing dysfunctions until deafness. In clinical practice, the current pharmacological approaches to treat cochlear diseases are based on the almost exclusive use of systemic steroids. In the last decades, the efficacy of novel therapeutic molecules has been proven, taking advantage from a better comprehension of the pathological mechanisms underlying many cochlear diseases. In addition, the feasibility of intratympanic administration of drugs also permitted to overcome the pharmacokinetic limitations of the systemic drug administration, opening new frontiers in drug delivery to cochlea. Several innovative drug delivery systems, such as in situ gelling systems or nanocarriers, were designed, and their efficacy has been proven in vitro and in vivo in cochlear models. The current review aims to describe the art of state in the cochlear drug delivery, highlighting lights and shadows and discussing the most critical aspects still pending in the field.