Silymarin as a Promising Potential Therapeutic Agent for Treatment of Patients with Paraquat Poisoning: An Issue that Merits Further Research
Having an extremely toxic compound for humans and most animals, paraquat (PQ) is known as one of the most frequently used herbicides. Accordingly, PQ poisoning has been recognized as a serious medical problem across the world, with a severe case fatality rate (CFR). In this respect; accidental or intentional ingestion of PQ, even in a small amount, can be significantly associated with poor clinical prognosis and increased mortality. Moreover; inherent toxicity of PQ, absence of specific antidotes, as well as lack of effective treatments have been principally attributed to high fatality of PQ poisoning. Once PQ is ingested, it can be absorbed through skin and the digestive and respiratory system and often progresses to multi-organ failure, particularly the lungs as the main target. In this respect, PQ accumulates predominantly in the lungs and can lead to lung fibrosis, pneumonitis, and consequently respiratory failure and death. Given the nonexistence of specific and widely accepted guidelines for treatment of PQ poisoning, a range of conservative therapeutic modalities have been proposed and administered by clinicians to moderate PQ absorption and to prevent organ failure in these patients. In spite of this, PQ-induced mortality rate is high and disappointing.
2. Zhao F, Shi D, Li T, Li L, Zhao M. Silymarin attenuates paraquat-induced lung injury via Nrf2-mediated pathway in vivo and in vitro. Clin Exp Pharmacol Physiol. 2015;42:988-98.
3. Ahmad I, Shukla S, Kumar A, Singh BK, Kumar V, Chauhan AK, et al. Biochemical and molecular mechanisms of N-acetyl cysteine and silymarin-mediated protection against maneb- and paraquat-induced hepatotoxicity in rats. Chem Biol Interact. 2013;201:9-18.
4. Podder B, Kim YS, Zerin T, Song HY. Antioxidant effect of silymarin on paraquat-induced human lung adenocarcinoma A549 cell line. Food Chem Toxicol. 2012;50:3206-14.
5. Valentová K, Vidlář A, Zatloukalová M, Stuchlík M, Vacek J, Šimánek V, et al. Biosafety and antioxidant effects of a beverage containing silymarin and arginine. A pilot, human intervention cross-over trial. Food Chem Toxicol. 2013;56:178-83.