Protective Effect of Astaxanthin on Cardiac Telomere Length in Cigarette Smoke-Exposed Rats (Rattus norvegicus)

Abstract

Telomeres are repetitive nucleotide sequences that protect chromosome ends and serve as biomarkers of cellular aging and oxidative stress. Cigarette smoke accelerates telomere shortening through increased free-radical exposure, particularly in cardiac tissues. Astaxanthin, a potent antioxidant carotenoid, has been proposed to counteract telomere erosion. This study aimed to evaluate the protective effect of astaxanthin on cardiac telomere length in Wistar rats exposed to cigarette smoke.This laboratory experimental research used a Post-test Control Group Design involving 25 male Wistar rats randomly assigned to five groups: Normal, smoke-exposed control, and three treatment groups receiving astaxanthin at 12, 24, or 48 mg/kg body weight. Rats were exposed to Sampoerna Kretek cigarette smoke chronically, and astaxanthin was administered orally for 28 days. Cardiac tissue was collected on Day 29 for telomere length measurement using quantitative PCR (qPCR) based on the telomere-to-single copy gene (T/S) ratio.Cigarette smoke significantly reduced telomere length in the control group (T/S ratio ≈ 0.7; p = 0.001). Astaxanthin showed dose-dependent protection, with the 48 mg/kg dose maintaining telomere length close to normal levels (T/S ratio ≈ 1.0; p = 0.014 vs smoke control). Lower doses produced partial improvement.In conclusion, chronic cigarette smoke exposure accelerates cardiac telomere shortening, while astaxanthin, particularly at 48 mg/kg, effectively preserves telomere integrity, indicating its potential as a natural cardioprotective agent against oxidative DNA damage.