Changes in Human Erythrocyte Membrane Exposed to Aqueous and Ethanolic Extracts from Uncaria tomentosa

Abstract

Uncaria tomentosa (Willd.) DC is a woody climber species originating from South and Central America that has been used in the therapy of asthma, rheumatism, hypertension, and blood purification. Our previous study showed that U. tomentosa extracts altered human erythrocyte shape, which could be due to incorporation of the compounds contained in extracts into the erythrocyte membrane. The aim of the present study was to determine how the compounds contained in U. tomentosa extracts incorporate into the human erythrocyte membrane. The study has assessed the effect of aqueous and ethanolic extracts from leaves and bark of U. tomentosa on the osmotic resistance of the human erythrocyte, the viscosity of erythrocyte interior, and the fluidity of erythrocyte plasma membrane. Human erythrocytes were incubated with the studied extracts in the concentrations of 100, 250, and 500 µg/mL for 2, 5, and 24 h. All extracts tested caused a decrease in erythrocyte membrane fluidity and increased erythrocyte osmotic sensitivity. The ethanolic extracts from the bark and leaves increased viscosity of the erythrocytes. The largest changes in the studied parameters were observed in the cells incubated with bark ethanolic extract. We consider that the compounds from U. tomentosa extracts mainly build into the outer, hydrophilic monolayer of the erythrocyte membrane, thus protecting the erythrocytes against the adverse effects of oxidative stress.

An In Vitro Comparative Study of the Effects of Tetrabromobisphenol A and Tetrabromobisphenol S on Human Erythrocyte Membranes—Changes in ATP Level, Perturbations in Membrane Fluidity, Alterations in Conformational State and Damage to Proteins

“…One of the properties of a biological membrane, resulting from its structure and interactions between its components, is fluidity [20]. Using the electron paramagnetic resonance (EPR) method, the placement of 5-DSA and 16-DSA probes in the erythrocyte membrane exposed to TBBPA and TBBPS was assessed.…”

Uncaria tomentosa (Willd. ex Schult.): Focus on Nutraceutical Aspects

“…Among these, the ethanolic extracts of U. tomentosa bark and leaf had the greatest inhibitory effect. The findings of a study demonstrated that the main site of formation of compounds derived from different U. tomentosa extracts is the outer hydrophilic monolayer of the erythrocyte membrane, which means the protection of erythrocytes versus oxidative stress [33].…”

Revisão sistemática sobre os efeitos fitoterápicos da uncaria tomentosa e uncaria guianensis na artrite reumatoide e osteoartrite / Systematic review on the herbal effects of uncaria tomentosa and uncaria guianensis in rheumatoid arthritis and osteoarthritis

“…Os testes in vitro indicaram que U. guianensis e U. tomentosa eram equivalentes na extinção dos radicais DPPH (EC50, 13,6-21,7 mcg / ml), bem como na inibição da produção de TNF-alfa. Duchnowicz, et al (2021), em sua pesquisa avaliou o efeito dos extratos aquosos e etanólicos das folhas e da casca da U. tomentosa na resistência osmótica do eritrócito humano, na viscosidade do interior do eritrócito e na fluidez do plasma eritrocitário membrana. Todos os extratos testados causaram uma diminuição na fluidez da membrana eritrocitária e aumento da sensibilidade osmótica eritrocitária.…”

“…Com base nos resultados obtidos na literatura, descrita por Duchnowicz, et al, (2021), foram considerados que baixas concentrações fisiológicas dos compostos contidos nos extratos de U. tomentosa estarão na monocamada externa da membrana celular e protegerão os eritrócitos contra estresse oxidativo e danos.…”