Cat's claw inhibits TNFalpha production and scavenges free radicals: role in cytoprotection.
Cat's claw (Uncaria tomentosa) is a medicinal plant from the Amazon River basin that is widely used for inflammatory disorders and was previously described as an inhibitor of NF-kappaB. Cat's claw was prepared as a decoction (water extraction) of micropulverized bark with and without concentration by freeze-drying. Murine macrophages (RAW 264.7 cells) were used in cytotoxicity assays (trypan blue exclusion) in response to the free radical 1, 1-diphenyl-2-picrilhydrazyl (DPPH, 0.3 microM) and ultraviolet light (UV) light. TNFalpha production was induced by lipopolysaccharide (LPS 0.5 microg/ml). Cat's claw was an effective scavenger of DPPH; the EC(50) value for freeze-dried concentrates was significantly less than micropulverized (18 vs. 150 microg/ml, p <.05). Cat's claw (10 microg/ml freeze-dried) was fully protective against DPPH and UV irradiation-induced cytotoxicity. LPS increased TNFalpha media levels from 3 to 97 ng/ml. Cat's claw suppressed TNFalpha production by approximately 65-85% (p <.01) but at concentrations considerably lower than its antioxidant activity: freeze-dried EC(50) = 1.2 ng/ml, micropulverized EC(50) = 28 ng/ml. In conclusion, cat's claw is an effective antioxidant, but perhaps more importantly a remarkably potent inhibitor of TNFalpha production. The primary mechanism for cat's claw anti-inflammatory actions appears to be immunomodulation via suppression of TNFalpha synthesis.
Sandoval
M
M
Department of Pediatrics and Center for Cardiovascular Sciences, Albany Medical College, Albany, NY 12208, USA. sandovm@mail.amc.edu
Charbonnet
R M
RM
Okuhama
N N
NN
Roberts
J
J
Krenova
Z
Z
Trentacosti
A M
AM
Miller
M J
MJ
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D015764:Bepridil / Q000031:analogs & derivatives / Q000494:pharmacology; D001713:Biphenyl Compounds; D020948:Cat's Claw; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects* / Q000528:radiation effects; D016166:Free Radical Scavengers; D005609:Free Radicals; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D010851:Picrates; D010936:Plant Extracts / Q000494:pharmacology*; D018547:Plant Stems; D010946:Plants, Medicinal; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*; D014466:Ultraviolet Rays
D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D005609:Free Radicals; D008070:Lipopolysaccharides; D010851:Picrates; D010936:Plant Extracts; D014409:Tumor Necrosis Factor-alpha; D015764:Bepridil; C004931:1,1-diphenyl-2-picrylhydrazyl