Immunostimulating activity of Uncaria tomentosa in RAW 264.7 macrophages

Abstract

Uncaria tomentosa is a plant native to the Amazon that has immunomodulatory and antitumor properties due to the alkaloids found in the plant, being able to modify the immune response by potentiating or suspending the action of cytokines secreted by macrophages that induce the immune response, either by the classical route (M1) or through the alternative route (M2). Macrophages activated by M1 convert L-arginine into L-citrulline and nitric oxide (NO), whereas macrophages activated by the M2 pathway use the enzymatic activity of arginase to convert the same substrate into L-ornithine and urea. The aim of this work was to evaluate the immunostimulating activity of the crude hydroalcoholic extract from the bark of the U. tomentosa stem in RAW 264.7 macrophages. Concentrations of 0.2, 0.1 and 0.05 mg/mL of U. tomentosa extract associated with LPS, INF-γ and IL-4 inducers were tested by determining NO production and arginase enzyme activity. Nitric oxide production was enhanced by the extract when associated with LPS and LPS + INF-γ inducers. In the activity of the arginase enzyme, the extract decreased the stimulation of IL-4 on the enzyme, mainly at 0.2 mg/mL concentration. Therefore, it is concluded that the crude hydroalcoholic extract of the stem bark of U. tomentosa in RAW 264.7 cells, at a concentration of 0.2 mg/mL, showed considerable pro-inflammatory activity.

Atividade antifúngica de barbatimão (Stryphnodendron adstringens) e unha-de-gato (Uncaria tomentosa) sobre Candida albicans

“…Os extratos das duas plantas testadas apresentaram efeito inibitório nos ensaios de disco-difusão em ágar (tabela 1). Segundo o conhecimento popular soluções aquosas e infusões (chás) de ervas como U. tomentosa e S. adstringens têm sido empregados para diversos fins terapêuticos, sobretudo para o tratamento de processos inflamatórios e doenças infecciosas (Ricardo et al, 2018), o que tem inspirado a realização de várias pesquisas sobre o assunto (Trevisan et al, 2022;Reich et al, 2023;Brito et al, 2023;Melo et al, 2023). No entanto, as evidências que comprovem a eficácia dessas formulações, principalmente no que diz respeito aos efeitos antimicrobianos, precisam ser testadas e validadas, conforme o que foi realizado aqui neste trabalho.…”