Anti-arthritic and Safety Pharmacological Effects of Gum Extract from Anacardium occidentale in Rats

The antinociceptive and anti-inflammatory activities of a polysaccharide-free extract of the cashew gum obtained from Anacardium occidentale L., Anacardiaceae, in a chronic model of complete Freund’s adjuvant-induced arthritis were investigated, as well as the possible adverse effects caused by continued administration of this extract. The cashew gum extract was obtained after the precipitation and removal of polysaccharides using acetone. The chemical characterization of this extract was performed with liquid chromatography coupled to mass spectrometry and tandem mass spectrometry analyses. In the complete Freund’s adjuvant-induced arthritis model, the experimental groups (number = 8) were orally treated once daily for 15 days with vehicle (5 ml/kg) or extract (75 mg/kg). Pain, edema joint, and cell migration to synovial fluid were assessed. Alterations in the body weight and organ weight of the animals were evaluated and histopathological analyses of the stomach, liver, and kidney were performed. Liquid chromatography coupled to mass spectrometry basically identified and quantified seven anacardic acids as the predominant constituents of the extract. The polysaccharide-free cashew gum reduced the prostration, joint edema, and migration of polymorphonuclear cells; in addition, this extract did not alter body or organ weight. The histopathological analysis showed promoted gastroprotective and hepatoprotective effects against damage caused by adjuvant injection. These findings support the use of cashew gum in popular medicine and demonstrate that part of its effects is independent of the presence of polysaccharides, evidencing its therapeutic potential for the future development of new analgesic and anti-inflammatory drugs. Graphical abstract