Association of various concentrations of cat's claw herb (Uncaria tomentosa) on lymphocyte proliferation and nitric oxide expression: An in-vitro study of osteoarthritis

Uncaria tomentosa, also known as cat’s claw, is an indigenous herb which originates from the Amazon River basin and has proven to be highly effective via case report and limited epidemiological evaluation in the pallative treatment of a number of inflammatory conditions. The herb is particularly preferred on the American market due to its various uses for healing, which provides the impetus for this research. The herb is being used to treat osteoarthritis and claims have been made for its ability to: enhance the repair of deoxyribonucleic acid (DNA), support joint health and improve immune function, enable normal division of cells, and, thus, prevent proliferation of cancer. Various studies have illustrated impacts on: cell death, inducible nitric oxide synthase (iNOS gene) expression induced by lipopolysaccharide, the activation of TNFα, and NFkB, the formation of nitrates, and also the production of hormone prostaglandin (PGE2) (Hardin, 2007; Sandoval et al., 2000; & Valerio & Gonzales, 2005). In this study, its impact on lymphocytes (immunity) and potential long-term use implications to osteoarthritis are explored. The purpose of this study was to examine the association of cat’s claw at various dosages on lymphocyte proliferation and nitric oxide expression in osteoarthritis patients. This has implications for both the long-term safe use of the herb and provides valuable information for osteoarthritis patients who may be currently using pharmaceutical prescriptions to manage the condition. Osteoarthritis patients may have concerns about side effects of those prescription medications and may be considering use of this herb to supplement or replace prescription medications. Further, a brief survey of key demographics often associated with the etiology of osteoarthritis was used to explore any possible relationships between these established risk factors and lymphocyte proliferation and nitric oxide expression at differing treatments of cat’s claw exposure. A total of 25 participants between ages 35 to 65 years old, with osteoarthritis, were recruited as a convenience sample through distributed flyers and outreach at physical therapy centers. Participants having any other immunological diseases were excluded from participation as were individuals taking immunosuppressive drugs. This study was designed using in-vitro cell culture techniques on cases serving as their own controls at the 0 ppm dosage level. Additional treatment groups included 10, 100, 150, 250, and 450 ppm of pharmaceutical grade cat’s claw herb. This was done under both a mitogen stimulated and non-stimulated treatment condition in standard micro-cell well plates. Following incubation, the cells were analyzed through flow cytometry for proliferation counts and through additional assay tagged procedures and flow cytometry for nitric oxide expression. While descriptive findings illustrate some strong directional tendencies between various demographic factors and cell proliferation/nitric oxide expression and simple linear regression illustrated a difference in means, more advanced ANOVA did not illustrate significance. ANOVA tests examining the relationship between decreased lymphocyte proliferation and decreased nitric oxide expression at the various treatment levels did not illustrate a significant relationship. Therefore, the exact biomolecular mechanism of action for cat’s claw herb is not through these modalities. Given the small sample size of this study and trends in the data, larger samples exploring the full panel of both pro and anti-inflammatory cytokines associated with osteoarthritis should be conducted. It also suggests the possibility that the herb may be having direct effects on pain receptors which should also be investigated. ASSOCIATION OF VARIOUS CONCENTRATIONS OF CAT’S CLAW HERB (UNCARIA TOMENTOSA) ON LYMPHOCYTE PROLIFERATION AND NITRIC OXIDE EXPRESSION: AN IN-VITRO STUDY OF OSTEOARTHRITIS A Dissertation Submitted in Partial Fulfillment Of the Requirements for the Degree of