Effects of compound injection of Pyrola rotundifolia L and Astragalus membranaceus Bge on experimental guinea pigs' gentamicin ototoxicity

Use of the traditional Chinese medicine "compound healthy ear agent" to protect against age-related hearing loss in mice: A proteomics study

Background

Previous studies have shown that the traditional Chinese medicine (TCM) called "compound healthy ear agent" (CHEA) had anti-apoptosis effects in cochlear hair cells and spiral ganglion neurons, and could protect mice hearing against presbycusis or age-related hearing loss (AHL), as well as aminoglycoside antibiotic-induced ototoxicity. Because its mechanisms of action are still unclear, we investigated the mechanism of action of CHEA against AHL in mice using proteomics techniques.

Methods

Eighteen C57BL/6J mice at 1 month of age were randomly divided into three groups: (A) drinking water until 2 months of age, K2M); (B) drinking water until 7 months of age to induce AHL, K7M; (C) drinking water containing CHEA daily until 7 months of age as treatment group, Z7M. At 2 or 7 months mice were sacrificed and their cochleae were removed for proteomics analysis.

Results

The numbers of proteins with a false discovery rate (FDR) < 1% were respectively 5873 for qualitative and 5492 for quantitative statistics. The numbers of proteins with differential enrichment at least 1.5-fold (p < 0.05) were respectively 351 for K7M vs K2M groups, 52 for Z7M vs K7M groups, 264 for Z7M vs K2M groups. The differentially expressed proteins in the Z7M group were involved in synaptic molecular transmission, energy metabolism, immune response, antioxidant defenses, and anti-apoptosis.

Conclusion

The TCM CHEA played a protective role against AHL in mice by regulating the expression of specific proteins and genes in cochlear hair cells and spiral ganglion neurons. Besides the pathways expected to be involved (antioxidant and anti-apoptosis), proteins related to immune response is a new finding of the present study.

Cystatin C in Evaluating Renal Function in Ureteral Calculi Hydronephrosis in Adults

BACKGROUND

Serum cystatin C (CysC) is still becoming used as a marker of renal function but is far from being commonly used worldwide. The purpose of this study was to characterize the ureteral calculi patients with hydronephrosis-caused CysC changes in renal function.

METHODS

To better reflect the changes of renal function, we constructed models of ureteral obstruction in rats to mimic the hydronephrosis caused by human ureteral calculi. Moreover, our study included 200 patients diagnosed with ureteral calculi in our hospital between June 2017 and 2018. We compared the estimated glomerular filtration rate using different equations based on CysC and/or serum creatinine (SCr).

RESULTS

We found that the expression of CysC and SCr increased with the prolonged obstruction time by enzyme linked immunosorbent assay. Moreover, quantitative real-time polymerase chain reaction, Western blot and immunohistochemistry further demonstrated that the expression of CysC increases with the degree of hydronephrosis. Among 200 patients with ureteral calculi, 40 (20.0%) had no hydronephrosis, 110 (55.0%) had mild hydronephrosis, 32 (16.0%) had moderate hydronephrosis and 18 (9.0%) had severe hydronephrosis. As the degree of hydronephrosis increased, the expression of neutrophil percentage, CysC, blood urea nitrogen, SCr and serum uric acid also increased. Multivariate analyses demonstrated that only CysC was an independent risk factor for hydronephrosis (p = 0.003). In addition, CysC and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) CysC equation showed the highest veracity in renal function estimation of patients with hydronephrosis caused by ureteral calculus.

CONCLUSION

For patients with hydronephrosis caused by ureteral calculi, CysC better reflects the changes in renal function, and the CKD-EPI CysC equation has the highest accuracy.

An Evaluation of the Protective Effects of Thymoquinone on Amikacin-Induced Ototoxicity in Rats

Objectives

In this study we investigated the probable protective effects of thymoquinone on amikacin-induced ototoxicity in rats.

Methods

Thirty-two healthy rats were divided into four groups (amikacin, amikacin+thymoquinone, thymoquinone, and no treatment). Thymoquinone was fed to the rats via oral gavage in a dose of 40 mg/kg/day throughout the study period of 14 days. Amikacin was given by the intramuscular route in a dose of 600 mg/kg/day. Audiological assessment was conducted by the distortion product otoacoustic emission (DPOAE) and auditory brainstem response (ABR) tests, administered to all rats at the beginning of the study, and also on days 7 and 15. Biochemical parameters were calculated at the termination of the study to evaluate the oxidative status.

Results

There were significant decreases in DPOAE values and significant increases in ABR thresholds of the amikacin group on days 7 and 15, as compared to the amikacin+thymoquinone group. While ABR thresholds of the amikacin group increased significantly on days 7 and 15 as compared to their initial values, there were no significant differences between the initial and the 7th and 15th day values of ABR thresholds in the amikacin+thymoquinone group. Total oxidant status and oxidative stress index values of the amikacin+thymoquinone group were significantly lower than those of the amikacin group. Total antioxidant status values of the amikacin+thymoquinone group were significantly higher than those of the amikacin group.

Conclusion

Our study has demonstrated that the ototoxic effect brought forth by amikacin could be overcome with the concurrent use of thymoquinone.

Changes in cytochemistry of sensory and nonsensory cells in gentamicin-treated cochleas

Effects of a single local dose of gentamicin upon sensory and nonsensory cells throughout the cochlea were assessed by changes in immunostaining patterns for a broad array of functionally important proteins. Cytochemical changes in hair cells, spiral ganglion cells, and cells of the stria vascularis, spiral ligament, and spiral limbus were found beginning 4 days post administration. The extent of changes in immunostaining varied with survival time and with cell type and was not always commensurate with the degree to which individual cell types accumulated gentamicin. Outer hair cells, types I and II fibrocytes of the spiral ligament, and fibrocytes in the spiral limbus showed marked decreases in immunostaining for a number of constituents. In contrast, inner hair cells, type III fibrocytes and root cells of the spiral ligament, cells of the stria vascularis, and interdental cells in the spiral limbus showed less dramatic decreases, and in some cases they showed increases in immunostaining. Results indicate that, in addition to damaging sensory cells, local application of gentamicin results in widespread and disparate disruptions of a variety of cochlear cell types. Only in the case of ganglion cells was it apparent that the changes in nonsensory cells were secondary to loss or damage of hair cells. These results indicate that malfunction of the ear following gentamicin treatment is widespread and far more complex than simple loss of sensory elements. The results have implications for efforts directed toward detecting, preventing, and treating toxic effects of aminoglycosides upon the inner ear.

Amikacin ototoxicity enhanced by Ginkgo biloba extract (EGb 761)

An animal study was realized to investigate the possible beneficial effect of EGb 761 as an antioxidant agent on amikacin ototoxicity by measuring distortion product otoacoustic emissions (DPOAEs). Twenty-eight adult rats were grouped equally as follows. GROUP AMIKACIN: rats received amikacin 600 mg/kg/day intramuscularly between postnatal days (PND) 30 and PND44. Group amikacin/EGb 761: rats received amikacin 600 mg/kg/day intramuscularly between PND30 and PND44 and EGb 761 100 mg/kg/day orally between PND30 and PND50. Group EGb 761: rats received equivolume saline intramuscularly between PND30 and PND44 and EGb 761 100 mg/kg/day orally between PND30 and PND50. NO TREATMENT GROUP: rats received nothing. Group amikacin was found to be affected only on the last measurement day of study (PND57). The frequencies greater than 2002 Hz were significantly reduced compared with the amplitudes of PND30 (P<0.05). Group amikacin/EGb 761 was most and earliest affected by amikacin-induced ototoxicity. DPOAE amplitudes were found in this group to be decreased at 2-6 kHz starting on PND50. The results of Group EGb 761 and No treatment group were not significantly changed. For the DPOAE input/output amplitude thresholds, Group amikacin (P<0.05) and Group amikacin/EGb 761 (P<0.01) had significantly elevated thresholds on PND57, except at 5 kHz for Group amikacin (P=0,06). According to the results of the study, EGb 761 may be regarded as a facilitating drug for the development of amikacin ototoxicity. The results of the present study may warn against concomitant use of aminoglycosides, specifically amikacin, with EGb 761.

Drug-induced otoxicity: current status

We carried out a review of the literature published over the last 10 years on drug-induced ototoxicity by means of a Medline search using the terms 'clinical ototoxicity' for the period January 1990 to September 2000 and found 414 published articles. In order to summarize the content of these articles, we asked ourselves a series of nine questions and answered them based on the most widely-held views and those we considered of greatest interest in the articles reviewed. The questions asked were: what are the most commonly used ototoxic drugs? what is the site of action of ototoxic drugs? what is the importance of the dose and dosing interval? does age influence ototoxicity? are all humans equally prone to the ototoxic effects of drugs? are there substances that are protective against ototoxicity? can hearing loss be monitored? should hearing loss be attributed to ototoxic drugs in all cases? and is ototoxicity in animals the same as in humans?