Methylsulfonylmethane (MSM) is a natural organosulfur compound that exhibits 
antioxidative and anti-inflammatory effects. This study was carried out to 
investigate the effect of MSM on paraquat (PQ)-induced acute lung and liver 
injury in mice. A single dose of PQ (50 mg/kg, i.p.) induced acute lung and 
liver toxicity. Mice were treated with MSM (500 mg/kg/day, i.p.) for 5 days. At 
the end of the experiment, animals were euthanized, and lung and liver tissues 
were collected for histological and biochemical analysis. Tissue samples were 
used to determine malondialdehyde (MDA), myeloperoxidase (MPO), catalase (CAT), 
superoxide dismutase (SOD), glutathione (GSH), and tumor necrosis factor-α 
(TNF-α) levels. Blood samples were used to measure plasma alanine transaminase 
(ALT), γ-glutamyl transferase (GGT), and alkaline phosphatase (ALP). 
Histological examination indicated that MSM decreased lung and liver damage 
caused by PQ. Biochemical results showed that MSM treatment significantly 
reduced tissue levels of MDA, MPO, and TNF-α, while increased the levels of SOD, 
CAT, and GSH compared with PQ group. MSM treatment also significantly reduced 
plasma levels of ALT, GGT, and ALP. These findings suggest that MSM as a natural 
product attenuates PQ-induced pulmonary and hepatic oxidative injury.