Stimulation of Interleukin-2 [IL-2] Release by Rhizophora mangle Bark Aqueous Extracts and Its Fractions

Aims: The objective of the present study was to prepare fractions of polyphenols based on their ability to stimulate release of interleukin-2 (IL-2) from a human T-cell line, Jurkat, in the presence or absence of phorbol myristic acetate (PMA), and to identify the candidate components responsible for this activity.

Study Design: Rhizophora mangle L. [Rhizophoraceae] bark was collected in occident zone of CUBA, was boiled in distilled water and freezer dried for its fractionation.

Methodology: The IL2-releasing the activity of different fractions were quantified using a BD OptEIA Human IL-2 ELISA kit using Jurkat Cells and PMA during the test. The ESI–MS fingerprints of the extracts [ESI-MS/MS] were acquired by the negative ion mode using a Micromass-Waters Q-TOF mass spectrometer.

Results: Guided fractionations from Rhizophora mangle bark aqueous extracts in the evaluation of releasing activity of interleukin 2-stimulated and unstimulated with Jurkat T cells in the presence of PMA showed that the butanolic fraction had an interleukin 2 production of 250 pg mL-1 and an 89.9% yield of procyanidins. Mass spectral studies of the butanolic fraction reflected the presence of compounds that varied between 1000-1333 m/z, indicating the presence of procyanidins up to a tetramer polymerization level linked to glycosides based on monomeric units [epicatechin / catechin]. An increase of IL-2, without prior stimulation with PMA, in the Jurkat T cell model, had not been previously reported for the phenolic compounds.

Conclusion: The compounds characterized preliminarily confirmed the structural diversity of polyphenols present in Rhizophora mangle L plant and its capacity to stimulate release of IL 2.