An extract of the fern Polypodium leucotomos inhibits human peripheral blood mononuclear cells proliferation in vitro

Screening and fractionation of plant extracts with antiproliferative activity on human peripheral blood mononuclear cells

“…The reduced incorporation of tritiated thymidine into lymphocyte DNA was not due to a toxic effect of these extracts on these cells since we observed that the number of viable cells in treated and control cultures remained constant according to the trypan-blue exclusion method (Table III). These results agree with those obtained by Gharagozloo and Ghaderi (2001), Benecia et al (2000) and Rayward et al (1997), in their study of the in vitro immunomodulatory activity of some medicinal plants extracts. Knowing that the inhibition of the proliferative response of human PBMC to mitogens may involve, among other things, the suppression of cytokine production (Shan et al 1999) and direct effects on T lymphocytes and/or macrophages (Rayward et al 1997), our preliminary results encourage us to further investigate the immunomodulatory properties of these extracts and its components.…”

“…Cissampelos sympodialis (Piuvezam et al 1999) inhibited peripheral blood mononuclear cells (PBMC) proliferation due to the presence of bisbenzylisoquinoline alkaloids and flavonoids. Rayward et al (1997) showed that the inhibitory effect of an alcoholic extract of the fern Polypodium leucotomos in this assay was related to a direct effect on T lymphocytes and/or macrophages.…”

Systemic immunomodulatory effects of Polypodium leucotomos as an adjuvant to PUVA therapy in generalized vitiligo: A pilot study

“…In contrast, PUVA + PL therapy normalized the expression of activation markers by Tcells and it suppressed the proliferation of PBMC to mitogens. These effects of the adjuvant use of PL agree with its known biological effects, since PL has demonstrated to have immunomodulatory activity upon T cell activation [9].…”

Immunomodulatory activity of methanol leaf extracts of Cameroonian medicinal plants

“…These extracts could therefore have immunosuppressive property. Similar results were reported by other authors [25,26,27]. This effect may be mediated by the interaction between the active components of the extracts and cell-surface molecules or growth factors involving mitogen activation.…”