Anti-inflammatory and antioxidant activity of a medicinal tincture from Pedilanthus tithymaloides

Pedilanthus tithymaloides (L.) Poit. (Euphorbiaceae) is a low tropical American shrub with a reported wide range of healing properties such as emetic, anti-inflammatory, antibiotic, antiseptic, antihemorrhagic, antiviral, antitumoral, and abortive. In the present study, a tincture from P. tithymaloides collected in Cuba was evaluated for its in vivo anti-inflammatory activity, using the rat paw oedema assay, and for its in vitro scavenging effects on reactive oxygen species (ROS) (HO·, O2·−, HOCl, ROO· and H2O2), reactive nitrogen species (RNS) (ONOO− and ·NO), and DPPH· radical. The protein, free amino acid, and phenolic contents of the tincture were also determined. Pertaining to the anti-inflammatory activity, the intraperitoneal administration of the tincture inhibited carrageenan-induced rat paw oedema, whereas in the scavenging assays the tincture showed to be effective against all the assayed ROS and RNS, specially for HO· (IC50 = 345 ± 77 μg/mL), O2·− (IC50 = 143 ± 7 μg/mL), HOCl (IC50 = 113 ± 20 μg/mL), ONOO− (IC50 = 44 ± 3 μg/mL), and ·NO (IC50 = 54 ± 4 μg/mL), but displayed weak activity in the DPPH. assay. The protein content of the tincture was 0.70%, and twenty free amino acids were identified and quantified. The content of total phenolics was 17.4 ± 0.15 mg of gallic acid equivalents (GAE)/g dry material. These results provide scientific support for the empirical use of P. tithymaloides tincture as an anti-inflammatory medicine.