Background and purpose: Platelets communicate with different immune cells and can activate B-lymphocytes and induce the production of antibodies from these cells. Platelet microparticles (MPs) originate from platelets and express the surface markers of platelets. This study aimed at investigating the ability of these microvesicles on production of antibodies from B-lymphocytes.

Materials and methods: In this experimental study, platelet MPs were isolated from platelet concentrates and B cells were isolated from human whole blood. Then MPs were co-cultured with B-lymphocytes. In different days of culture, the production of IgG antibodies was studied in the supernatants of culture medium using ELISA method. The results were analyzed by paired-samples t-test. P- value < 0.05 was considered statistically significant.

Results: Platelet MPs stimulate the production of antibodies by B-lymphocytes. During 5-day co-culture, significant increase was observed in the production of IgG antibodies in the test samples
(B cells+MPs) compared to the control (B cells in the absence of MPs) (P- value< 0.05).

Conclusion: Platelet MPs can induce IgG production from B cells during in vitro co-culture.

Background and purpose: Avicennia marina (family Acanthaceae) has been used as traditional medicine in Iran to treat some diseases such as ulcers, rheumatism and burns. The present study investigated the in silico and in vitro mutagenicity of the fruit, leaf, seed and stem extracts of Avicennia marina and their effects on human peripheral blood mononuclear cells (PBMC) proliferation.

Materials and methods: In this experimental study, air dried and powdered plant materials were extracted by methanol using maceration. The extracts were evaporated to dryness by rotary evaporator at 40°C and were diluted using different PBS concentrations (50, 100, 500, 1000, and 1500 µg/ml). The effect of the methanol extract of this plant on lymphocyte proliferation was measured using MTT assay. The mutagenicity of these extracts was also investigated using Ames test. In silico analysis of 15 dominant compounds of the plant was performed by Toxtree 2.6.6 software.

Results: The methanol extracts of the leaf and root had the highest and lowest inducing effect on lymphocyte proliferation, respectively. Leaf and stem extracts of Avicennia marina did not show any mutagenicity on this strain. In silico analysis demonstrated that among 15 compounds, four triterpenoids (Taraxerol, Betulin, Lupeol, and Gossypol) had weak mutagenicity.

Conclusion: Avicennia marina showed positive effects on proliferation of lymphocytes and their mutagenicity, therefore, it could be considered as a good candidate in treatment of immunodeficiency diseases.