The Human Hair Follicle as Sentinel for Drug Evaluation: Demonstration of Tetracycline Adhesion to Hair Follicle as Proposed Mechanism in Dysfunctional Hair Loss

The study demonstrated that tetracycline, an antibiotic, has a strong affinity for the keratin structure of the hair follicle, which can lead to deleterious effects on the biologically active cells of the follicle's dermal papilla, disrupting metabolism. This was shown using in vitro hair follicles exposed to both liquid and powder forms of tetracycline. The findings support previous research indicating that long-term exposure to tetracycline can damage not only pathogens but also healthy human cells, including those in the hair follicle. The study also referenced a report where the adverse effects of tetracycline on mice with experimentally induced mitochondrial DNA (mtDNA) deficiency were reversed after discontinuing the tetracycline diet for 30 days. The results suggest caution when using tetracycline therapy, especially in the elderly, due to its potential impact on mtDNA, which is associated with aging and age-related diseases.