Telmisartan Attenuates Kanamycin-Induced Ototoxicity in Rats

Association of the protective effect of telmisartan on hearing loss among patients with hypertension

Aim

Hearing loss, affecting a significant portion of the global population, is prevented with peroxisome proliferator-activated receptor γ agonism. Understanding potential protective treatments is crucial for public health. We examine the effect of telmisartan, an antihypertensive drug and partial peroxisome proliferator-activated receptor γ agonist, on hearing loss in patients with hypertension.

Method and results

This retrospective cohort analysis used data from the OMOP Common Data Model database, encompassing information from three tertiary institutions in South Korea. The study included a substantial sample size of 860,103 people diagnosed with hypertension. The study included individuals who had been medically diagnosed with hypertension and had been prescribed antihypertensive drugs, including telmisartan. The study design was established to evaluate the comparative effects of telmisartan and other hypertension medications on hearing loss. We used propensity score matching (PSM) to create a balanced cohort, reducing potential biases between the telmisartan and non-telmisartan groups. From the initial 860,103 patients with hypertension, a propensity score matched cohort was derived from 20,010 patients, with 2,193 in the telmisartan group. After PSM, lower incidence of total hearing loss was observed in the telmisartan group compared to the non-telmisartan group during the 3-year follow-up (0.5% vs. 1.5%, log-rank p = 0.005). In subgroup analysis, this study showed consistent results that lower incidence of total hearing loss was higher in the telmisartan group than in the non-telmisartan group.

Conclusion

Telmisartan was associated with reducing certain types of hearing loss in patients with hypertension. Further research is needed to confirm these findings and understand the mechanisms.

Paklitakselin neden olduğu oksidatif hasara karşı farnesenin otoprotektif etkileri

Amaç: Bu çalışmanın amacı, güçlü serbest radikal süpürücü ve antioksidan özelliklere sahip farnesenin paklitaksel kaynaklı ototoksisite üzerindeki etkilerini biyokimyasal ve fonksiyonel yönden araştırmaktır. Gereç ve Yöntem: On sekiz erkek Wistar albino sıçan, altı sıçandan oluşan üç gruba rastgele ayrıldı. Araştırma boyunca kontrol grubuna paklitaksel veya farnesen verilmedi. Paklitaksel grubuna, 5mg/kg paklitaksel intraperitoneal olarak dört kez (1., 7., 14. ve 21. günlerde) verildi. Farnesen + paklitaksel grubuna, önce 5 mg/kg paklitaksel, 30 dakika sonra 50 mg/kg farnesen intraperitoneal olarak 4 kez (1., 7., 14. ve 21. günlerde) verildi. 0. ve 21. günlerde tüm sıçanların otoakustik emisyon ölçümü yapıldı. Daha sonra hayvanlar sakrifiye edildi ve biyokimyasal testler için kokleaları çıkarıldı. Bulgular: Paklitaksel, önemli ölçüde malondialdehit seviyelerini yükselterek ve glutatyon seviyelerini düşürerek kokleada oksidatif strese neden oldu. Ayrıca paklitaksel grubunun distorsiyon ürünü otoakustik emisyon değerleri diğer gruplara göre anlamlı derecede düşüktü. Farnesen+paklitaksel grubunda ise paklitakselin çeşitli biyokimyasal ve fonksiyonel parametrelerde oluşturduğu hasarda iyileşmeler gözlendi. Sonuç: Çalışma sonuçları doğal bir antioksidan olan farnesen’in sıçanlarda paklitaksel kaynaklı işitme kaybını azalttığını, farnesen ve paklitaksel kombinasyonunun gelecekte klinik kullanım için paklitaksel kaynaklı ototoksisiteden koruyabileceğini göstermektedir.

Pravastatin Administration Alleviates Kanamycin-Induced Cochlear Injury and Hearing Loss

The effect of statins on aminoglycoside-induced ototoxicity is controversial. This study aimed to explore the role of pravastatin (PV) in kanamycin-induced hearing loss in rats. Adult rats were intraperitoneally treated with 20 mg/kg/day of kanamycin (KM) for 10 days. In the PV- and PV + KM-treated rats, 25 mg/kg/day of PV was intraperitoneally administered for 5 days. The auditory brainstem response (ABR) thresholds were measured before and after drug treatment using a smartEP system at 4, 8, 16, and 32 kHz. Cochlear changes in poly ADP-ribose (PAR) polymerase (PARP), PAR, and caspase 3 were estimated using Western blotting. PV administration did not increase the ABR thresholds. The KM-treated rats showed elevated ABR thresholds at 4, 8, 16, and 32 kHz. The PV + KM-treated rats demonstrated lower ABR thresholds than the KM-treated rats at 4, 8, and 16 kHz. The cochlear outer hair cells and spiral ganglion cells were relatively preserved in the PV + KM-treated rats when compared with that in the KM-treated rats. The cochlear expression levels of PARP, PAR, and caspase 3 were higher in the KM-treated rats. The PV + KM-treated rats showed lower levels of PARP, PAR, and caspase 3 than the KM-treated rats. PV protected cochleae from KM-induced hearing loss in rats. The regulation of autophagy and apoptosis mediated the otoprotective effects of PV.