Arnica research studies
Arnica montana gel in osteoarthritis of the knee: an open, multicenter clinical trial.
Knuesel O, Weber M, Suter A.
Department of Rheumatology, Valens Clinic for Rheumatism, Valens, Switzerland.
This open multicenter trial investigated the safety and efficacy of an Arnica montana fresh plant gel, applied twice daily, in 26 men and 53 women with mild to moderate osteoarthritis (OA) of the knee. After 3 and 6 weeks, significant decreases in median total scores on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were evident in the intention-to-treat and per-protocol populations (both P < .0001). Scores on the pain, stiffness, and function subscales also showed significant reductions at these timepoints. The overall local adverse-event rate of 7.6% included only one allergic reaction. Sixty-nine patients (87%) rated the tolerability of the gel as "good" or "fairly good," and 76% would use it again. Topical application of Arnica montana gel for 6 weeks was a safe, well-tolerated, and effective treatment of mild to moderate OA of the knee.
Use of Arnica to relieve pain after carpal-tunnel release surgery.
Jeffrey SL, Belcher HJ.
Department of Plastic Surgery of Queen Victoria Hospital in West Sussex, England.
CONTEXT: Arnica is commonly used by the public as a treatment for bruising and swelling. OBJECTIVE: To assess whether Arnica administration affects recovery from hand surgery. DESIGN: Double-blind, randomized comparison of Arnica administration versus placebo. SETTING: Specialist hand surgery unit at the Queen Victoria NHS Trust. PARTICIPANTS: Thirty-seven patients undergoing bilateral endoscopic carpal-tunnel release between June 1998 and January 2000. INTERVENTION: Homeopathic Arnica tablets and herbal Arnica ointment compared to placebos. MAIN OUTCOME MEASURES: Grip strength, wrist circumference, and perceived pain measured 1 and 2 weeks after surgery. RESULTS: No difference in grip strength or wrist circumference was found between the 2 groups. However, there was a significant reduction in pain experienced after 2 weeks in the Arnica-treated group (P<.03). CONCLUSIONS: The role of homeopathic and herbal agents for recovery after surgery merits further investigation.
Jeffrey, SLA and Belcher, HJCR. Use of Arnica to Relieve Pain After Carpal-Tunnel Release Surgery. Alternative Therapies. Mar/Apr 2002, Vol. 8; No. 2:66-68.
After observing that many of their patients were using both homeopathic
preparations and herbal ointments containing arnica (Arnica montana) after wrist
surgery for carpal-tunnel syndrome, the authors conducted a randomized,
double-blind study of arnica versus placebo. The study was conducted at the
Department of Plastic Surgery of Queen Victoria Hospital in West Sussex,
England. Arnica is used traditionally in a topical ointment to treat bruises and
swelling, and, in an oral solution, is recommended by homeopathic practitioners
to relieve bruises, swelling, and pain.
[Arnica: new insights on the molecular mode of action of a traditional medicinal plant]
[Article in German]
Institut fur Pharmazeutische Biologie, Freiburg i.Br., Germany. email@example.com
Preparations from Arnica flowers have been used in traditional medicine since a long time for the treatment of inflammatory diseases. Sesquiterpene lactones are considered as their main active compounds. Previously, it was shown that these natural products attack inflammatory processes at a very central point by inhibiting the transcription factors NF-kappa B and NF-AT at micromolar concentrations. Both transcription factors regulate the transcription of genes encoding for many inflammatory mediators. Thus, these new insights on their molecular mode of action are an important contribution for a better understanding of the antiinflammatory activity of preparations from Arnica. First clinical studies show that they can support the treatment of rheumatic diseases. The agreed use is important to avoid undesirable side effects. Copyright 2003 S. Karger GmbH, Freiburg
Klaas CA, Wagner G, Laufer S, Sosa S, Della Loggia R, Bomme U, Pahl HL, Merfort I.
Institute of Pharmaceutical Biology, University of Freiburg, Freiburg, Germany.
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-kappa B 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-alpha 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 11 alpha,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-kappa B EMSA as well as in the croton oil ear test in mice than the acetate derivative.
Helenalin, an anti-inflammatory sesquiterpene lactone from Arnica, selectively inhibits transcription factor NF-kappaB.
Lyss G, Schmidt TJ, Merfort I, Pahl HL.
Institut fur Pharmazeutische Biologie, Universitat Freiburg, Germany.
Alcoholic extracts prepared form Arnicae flos, the collective name for flowerheads from Arnica montana and A. chamissonis ssp. foliosa, are used therapeutically as anti-inflammatory remedies. The active ingredients mediating the pharmacological effect are mainly sesquiterpene lactones, such as helenalin, 11alpha,13-dihydrohelenalin, chamissonolid and their ester derivatives. While these compounds affect various cellular processes, current data do not fully explain how sesquiterpene lactones exert their anti-inflammatory effect. We show here that helenalin, and, to a much lesser degree, 11alpha,13-dihydrohelenalin and chamissonolid, inhibit activation of transcription factor NF-kappaB. This difference in efficacy, which correlates with the compounds' anti-inflammatory potency in vivo, may be explained by differences in structure and conformation. NF-kappaB, which resides in an inactive, cytoplasmic complex in unstimulated cells, is activated by phosphorylation and degradation of its inhibitory subunit, IkappaB. Helenalin inhibits NF-kappaB activation in response to four different stimuli in T-cells, B-cells and epithelial cells and abrogates kappaB-driven gene expression. This inhibition is selective, as the activity of four other transcription factors, Oct-1, TBP, Sp1 and STAT 5 was not affected. We show that inhibition is not due to a direct modification of the active NF-kappaB heterodimer. Rather, helenalin modifies the NF-kappaB/IkappaB complex, preventing the release of IkappaB. These data suggest a molecular mechanism for the anti-inflammatory effect of sesquiterpene lactones, which differs from that of other nonsteroidal anti-inflammatory drugs (NSAIDs), indomethacin and acetyl salicylic acid.
Wagner S, Suter A, Merfort I.
Institut fur Pharmazeutische Wissenschaften, Lehrstuhl fur Pharmazeutische Biologie, Albert-Ludwigs-Universitat Freiburg, Germany.
Alcoholic preparations of Arnica montana are widely used for the topical treatment of various inflammatory diseases. Sesquiterpene lactones (SLs) are mainly responsible for their anti-inflammatory activity. Here we have studied the penetration kinetics of Arnica tinctures prepared from dried Arnica flowers originating from different chemotypes as well as of their respective dominating SLs, helenalin isobutyrate and 11alpha,13-dihydrohelenalin acetate. Some alcoholic preparations of fresh Arnica flowers and an Arnica fresh plant gel were also included in the study. We used the stripping method with adhesive tape and pig skin as a model and determined the quantity of SLs in the stripped layers of the stratum corneum (SC). Thus, we observed the penetration into and permeation through this uppermost part of the skin. Whereas isolated SLs permeate through the SC only in a very small amount, permeation of SLs was much higher when they were present in the tinctures. Furthermore, differences of permeation were observed between helenalin and dihydrohelenalin derivatives. Permeation through the SC could be determined for the tested Arnica preparations of fresh Arnica flowers with two preparations showing the best penetration behaviour of all the tested substances. Moreover, the effects of incubation time as well as of repeated applications were investigated with one preparation. Altogether, this study shows that a sufficient amount of SLs might permeate the skin barrier by using Arnica preparations to exert anti-inflammatory effects and that the topical use of plant preparations may be advantageous compared to the isolated compounds.
Wong HR, Menendez IY.
Division of Critical Care Medicine, Children's Hospital Research Foundation, Cincinnati, Ohio, 45229, USA.
Nitric oxide (NO) is an important regulator and effector molecule in various inflammatory disease states. High output of NO during inflammation is generated by the inducible isoform of nitric oxide synthase (iNOS). Sesquiterpene lactones are derived from Mexican-Indian medicinal plants and are known to have potent anti-inflammatory properties. The mechanisms by which sesquiterpene lactones exert their anti-inflammatory effects are not fully understood. In the current studies we determined if the sesquiterpene lactones, parthenolide and isohelenin, modulate iNOS gene expression in cultured rat aortic smooth muscle cells (RASMC) treated with lipopolysaccharide and interferon-gamma. Treatment with parthenolide or isohelenin inhibited NO production and iNOS mRNA expression in a concentration-dependent manner. Transient transfection studies with an iNOS promoter-luciferase reporter plasmid demonstrated that parthenolide and isohelenin also inhibited activation of the iNOS promoter. Inhibition of iNOS promoter activation was associated with inhibition of both I-kappaBalpha degradation and nuclear translocation of NF-kappaB. Neither parthenolide nor isohelenin induced the heat shock response in RASMC. We conclude that sesquiterpene lactones inhibit iNOS gene expression by a mechanism involving stabilization of the I-kappaBalpha/NF-kappaB complex. This effect is not related to induction of the heat shock response. The ability of sesquiterpene lactones to inhibit iNOS gene expression may account, in part, for their anti-inflammatory effects. Copyright 1999 Academic Press.