Citotoxice

Citotoxice is an adjective used in biosciences to describe effects, agents, or cells that can kill or damage cells. The term, related to cytotoxic, derives from cyt- meaning “cell” and toxikos meaning “poisonous.” In literature, citotoxice can refer to toxins, chemotherapeutic drugs, or immune cells that induce cell death. The concept contrasts with cytostatic effects, which inhibit cell division without directly causing cell death.

Mechanisms of cytotoxic action include induction of apoptosis (programmed cell death) or necrosis, disruption of DNA or microtubule function, and perturbation of membranes. In immunology, cytotoxic T lymphocytes and natural killer cells target abnormal or infected cells and kill them via perforin–granzyme pathways or Fas–FasL signaling. Antibody-dependent cellular cytotoxicity can recruit effector cells to kill antibody-coated targets.

In medicine and pharmacology, cytotoxic agents are used to treat cancer and other diseases. These drugs damage DNA, inhibit replication, or interfere with mitosis, leading to tumor cell death but also risking damage to healthy tissues. Side effects include myelosuppression, mucositis, and organ toxicity. Research and clinical practice distinguish cytotoxicity from cytostatic therapy and from non-toxic immunotherapies.

Assays for cytotoxicity in vitro measure loss of viability or membrane integrity after exposure to a substance. Common methods include colorimetric assays such as MTT, XTT, or resazurin-based tests, and luminescent ATP assays or LDH release. These tests help assess safety in drug development and environmental toxicology.