Studies on the Anti-Inflammatory Activity of Phytopharmaceuticals Prepared from Arnica Flowers[1]

Abstract

Phytopharmaceuticals prepared from flowerheads of Arnica montana of Spanish origin and of the new type ”Arbo”, which can be easily and economically cultivated, were studied for their capability to impair activation of the transcription factors NF-κB and NF-AT. Both proteins are responsible for the transcription of genes encoding various inflammatory mediators. Additionally, their influence on the release of the cytokines IL-1 and TNF-α were examined. The inhibitory activities correlate with their quantitative and qualitative content of sesquiterpene lactones (Sls). Moreover, it was shown that the inhibitory potency of 11α,13-dihydrohelenalin derivatives being the main Sls in the Spanish flowers depend on their esterfication. Compounds with unsaturated acyl moieties, such as methacrylate and tiglinate, exhibited a stronger activity in the NF-κB EMSA as well as in the croton oil ear test in mice than the acetate derivative.

Abbreviations

Arbo tincture:tincture prepared from Arnica flowerheads
type Arbo

AP-1:activator protein 1

BSA:bovine serum albumen

c.p.m.:counts per minute

DTT:dithiothreitol

EDTA:ethylenediaminetetraacetic acid

EGTA:ethylene glycol-bis(β-aminoethyl ether)-
N,N,N′,N′-tetraacetic acid

EMSA:electrophoretic mobility shift assay

FCS:fetal calf serum

HEPES:N-[2-hydroxyethyl]-piperazine-N′-
[2-ethanesulfonic acid]

IL:interleukin

NP-40:nonylphenoxypolyethoxyethanol

NF-AT:nuclear factor of activated T cells

BPS:phosphate buffered saline

PMA:phorbol myristate acetate

PMSF:phenylmethylsulfonyl fluoride

Poly (dI-dC):polydeoxyinosinicdeoxycytidylic acid,
double-stranded alternating copolymer

Spanish tincture:tincture prepared from Spanish Arnica
flowerheads

Sl:sesquiterpene lactone

TNF-α:tumor necrosis factor alpha

Key words

Arnica montana - Asteraceae - anti-inflammatory activity - sesquiterpene lactones - NF-κB - NF-AT - IL-1β - TNF-α - mouse ear edema

1 Partly presented at the 3^rd International Congress on Phytomedicine, 2000, Munich, Germany.

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1 Partly presented at the 3^rd International Congress on Phytomedicine, 2000, Munich, Germany.