Sesquiterpenoids from Carpesium abrotanoides and their anti-inflammatory activity both in vitro and in vivo

Abstract

Twenty-nine sesquiterpenoids, including pseudoguaiane-type (1–11), eudesmane-type (12–23), and carabrane-type (24–29), have been identified from the plant Carpesium abrotanoides. Of them, compounds 1–4, 12–15, and 24–27, namely carpabrotins A–L, are twelve previously undescribed ones. Compound 3 possessed a pseudoguaiane backbone with a rearrangement modification at C-11, C-12 and C-13, while compound 4 suffered a carbon bond break between the C-4 and C-5 to form a rare 4,5-seco-pseudoguaiane lactone. Compounds 1–3, 5, 13–16 and 25–27 exhibited anti-inflammatory activity by inhibiting NO production in LPS-induced RAW264.7 macrophages with IC50 values less than 40 μM, while compounds 1, 2, 5, 13, 14, 16, and 25–27 showed significant inhibitory activity comparable to that of dexamethasone. The anti-atopic dermatitis (AD) effects of compounds 5 and 16 were tested according to 2,4-dinitrochlorobenzene (DNCB)-induced AD-like skin lesions in KM mice, and the results revealed that the major products 5 and 16 improved the histological features of AD-like skin lesions and mast cell infiltration in mice. This study suggested that sesquiterpenoids in C. abrotanoides should play a key role in its anti-inflammatory use.