Sodium Cromolyn Modulates Carrageenan-Induced Acute Inflammation Through the Interleukin-6 Levels

Background: Previous studies have indicated that sodium cromolyn does not negatively affect steroidal and nonsteroidal anti-inflammatory drugs (NSAIDs). Objective: This study aimed to investigate the anti-inflammatory effects of sodium cromolyn on carrageenan-induced paw edema in rats and assess its impact on IL-6, an anti-inflammatory cytokine. Methods: The carrageenan-induced paw edema model is widely used for studying inflammatory mechanisms and evaluating anti-inflammatory drugs. The test groups received intraperitoneal injections of sodium cromolyn at doses of 25, 50, and 100 mg/kg alongside a positive control group (indomethacin at 5 mg/kg) and a negative control group (which received the solvent, saline). Thirty minutes after drug administration, carrageenan (1% w/v) was injected into the right hind paws of the rats. Changes in paw volume were measured using a plethysmometer at 0.5, 1, 2, and 3 hours post-carrageenan injection. Blood and paw tissue samples were collected three hours after carrageenan administration, and IL-6 levels were determined using the standard rat Interleukin-6 ELISA kit. Results: The plasma and tissue IL-6 levels in the group treated with cromolyn (25 mg/kg) were significantly higher than those in the positive control group (indomethacin 5 mg/kg). Sodium cromolyn at a dose of 25 mg/kg had a negligible effect on reducing paw edema and IL-6 levels in serum and paw tissues compared to indomethacin (5 mg/kg). The IL-6 levels in plasma and tissues for the group receiving 50 mg/kg of cromolyn were not significantly different from those in the indomethacin group (5 mg/kg). However, IL-6 levels in the group treated with 100 mg/kg of cromolyn were significantly lower than those in the indomethacin group. Among the groups treated with sodium cromolyn, the highest and lowest IL-6 levels were observed in the groups receiving 25 mg/kg and 100 mg/kg of sodium cromolyn, respectively. The anti-inflammatory effects of sodium cromolyn at doses of 25 mg/kg, 50 mg/kg, and 100 mg/kg were analyzed, revealing that 25 mg/kg of cromolyn sodium was not significantly effective at any time point (P < 0.05). Additionally, no significant differences (P < 0.05) were observed between the 50 mg/kg and 100 mg/kg doses at any study hour. Sodium cromolyn at a 50 mg/kg dose was as effective as indomethacin (5 mg/kg) in significantly reducing paw edema. Conclusions: Sodium cromolyn, at doses of 50 and 100 mg/kg, effectively reduced paw edema and the concentration of serum and paw tissue IL-6 (P < 0.05), demonstrating significant anti-inflammatory activity. Sodium cromolyn at a 50 mg/kg dose is recommended as the anti-inflammatory dose of this drug.