No abstract

Background: Uncaria tomentosa is a vine commonly known as cat’s claw or ‘uña de gato’ (UG) and is used in traditional Peruvian medicine for the treatment of a wide range of health problems, particularly digestive complaints and arthritis. Purpose: The aim of this study was to determine the proposed anti‐inflammatory properties of cat’s claw. Specifically: (i) does a bark extract of cat’s claw protect against oxidant‐induced stress in vitro, and (ii) to determine if UG modifies transcriptionally regulated events. Methods: Cell death was determined in two cell lines, RAW 264.7 and HT29 in response to peroxynitrite (PN, 300 μM). Gene expression of inducible nitric oxide synthase (iNOS) in HT29 cells, direct effects on nitric oxide and peroxynitrite levels, and activation of NF‐κB in RAW 264.7 cells as influenced by UG were assessed. Chronic intestinal inflammation was induced in rats with indomethacin (7.5 mg/kg), with UG administered orally in the drinking water (5 mg/mL). Results: The administration of UG (100 μg/mL) attenuated (P < 0.05) peroxynitrite‐induced apoptosis in HT29 (epithelial) and RAW 264.7 cells (macrophage). Cat’s claw inhibited lipopolysaccharide‐induced iNOS gene expression, nitrite formation, cell death and inhibited the activation of NF‐κB. Cat’s claw markedly attenuated indomethacin‐enteritis as evident by reduced myeloperoxidase activity, morphometric damage and liver metallothionein expression. Conclusions: Cat’s claw protects cells against oxidative stress and negated the activation of NF‐κB. These studies provide a mechanistic evidence for the widely held belief that cat’s claw is an effective anti‐inflammatory agent.

Sangre de grado is an Amazonian herbal medicine used to facilitate the healing of gastric ulcers and to treat gastritis, diarrhea, skin lesions, and insect stings. This study was designed to evaluate the gastrointestinal applications. Gastric ulcers were induced in rats by brief serosal exposure of the fundus to acetic acid (80%). Sangre de grado was administered in drinking water at 1:1,000 and 1:10,000 dilutions from the postoperative period to day 7. Guinea pig ileum secretory responses to capsaicin, electrical field stimulation, and the neurokinin-1 (NK-1) agonist [Sar(9),Met(O(2))(11)]substance P were examined in Ussing chambers. Sangre de grado facilitated the healing of experimental gastric ulcer, reducing myeloperoxidase activity, ulcer size, and bacterial content of the ulcer. The expression of proinflammatory genes tumor necrosis factor-alpha, inducible nitric oxide synthase (iNOS), interleukin (IL)-1beta, IL-6, and cyclooxygenase-2 was upregulated by ulcer induction but reduced by sangre de grado treatment, particularly iNOS and IL-6. In Ussing chambers, sangre de grado impaired the secretory response to capsaicin but not to electrical field stimulation or the NK-1 agonist. We conclude that sangre de grado is a potent, cost-effective treatment for gastrointestinal ulcers and distress via antimicrobial, anti-inflammatory, and sensory afferent-dependent actions.