Topical anti-inflammatory phytomedicine based on Sphagneticola trilobata dried extracts

The aerial parts of Sphagneticola trilobata (L.) Pruski (Asteraceae) are popularly used to treat topical inflammation, but have not been fully investigated.

To identify polar compounds in S. trilobata extracts and develop a new topical phytomedicine based on the kaurenoic acid (KA) content while monitoring and demonstrating its topical anti-inflammatory activity.

Ethanol spray-dried extract of S. trilobata was analysed by LC-MS while the KA content from semisolid was analysed by LC-UV. The extent of ear edema induced by applying 20 μL of croton oil (2.5%), arachidonic acid (AA; 2 mg/ear) and decanoylphorbol-13-acetate (TPA; 2.5 mg/ear) in mice was used to evaluate the biological activity of the semisolids, which were applied 30 min before the phlogistic agents.

Eight phenylpropanoids and four oleanane-type triterpenoid saponins were identified, majority of them reported for the first time in this species, in addition to KA. The semisolid containing 1.0% of dried extract reduced the ear edema induced by croton oil [77.2 ± 4.5%; ID50 = 0.49 (0.28-0.87%)], TPA (81.5 ± 2.4%) and AA (39.1 ± 6.9%), with decreasing effect at higher KA concentrations. This was accompanied by neutrophil migration inhibition as investigated by biochemical and histological assays.

The anti-inflammatory effects were (at least in part) due to the interference in protein kinase C (PKC) activation, AA-cascade products and neutrophil migration inhibition, demonstrating the efficacy of the folk topical usage of this plant. The results support the development of a novel topical anti-inflammatory phytomedicine properly standardized to treat inflammatory dermatological diseases.