The phytochemical study of hexane, chloroform and methanol extracts from leaves of Psychotria viridis resulted in the identification of: the pentacyclic triterpenes, ursolic and oleanolic acid; the steroids, 24-methylene-cycloartanol, stigmasterol and β-sitosterol; the glycosylated steroids 3-O-β-D-glucosyl-β-sitosterol and 3-O-β-D-glucosyl-stigmasterol; a polyunsaturated triterpene, squalene; the esters of glycerol, 1-palmitoylglycerol and triacylglycerol; a mixture of long chain hydrocarbons; the aldehyde nonacosanal; the long chain fat acids hentriacontanoic, hexadecanoic and heptadenoic acid; the ester methyl heptadecanoate; the 4-methyl-epi-quinate and two indole alkaloids, N,N-dimethyltryptamine (DMT) and N-methyltryptamine. The chemical structures were determined by means of spectroscopic (IR, 1 H and 13 C NMR, HSQC, HMBC and NOESY) and spectrometric (CG-MS and LCMS-ESI-ITTOF) methods. The study of biologic properties of P. viridis consisted in the evaluation of the acetylcholinesterase inhibition and cytotoxic activities. The hexane, chloroform, ethyl acetate and methanol extracts, the substances 24-methylene-cycloartanol, DMT and a mixture of 3-O-β-D-glucosyl-β-sitosterol and 3-O-β-D-glucosyl-stigmasterol showed cholinesterase inhibiting activity. This activity induced by chloroform and ethyl acetate extracts was higher than 90%. The methanol and ethyl acetate extracts inhibit the growth and/or induce the death of the tumor cells strains B16F10 and 4T1, without damaging the integrity of the normal cells BHK and CHO. DMT also demonstrated a marked activity against tumor cell strains B16F10 and 4T1.

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The Qa-2 has been described as Human Leucocyte Antigen G (HLA-G) murine homolog. This homology is well accepted to gene and protein structure, in different pathology process and embryos implantation. However, in some neoplasm, this homology is questioned, where Qa-2 has been proposed as an immunogenic molecule, associated to tumor rejection. In this way, the aim of this study was to describe the pattern of Qa-2 expression and its relationship with the profile of tumor-infiltrating lymphocytes in solid Ehrlich tumor. The Ehrlich tumor growth was evaluated in Balb/c female mice in different tumor stages. The inflammatory infiltration features were determined by histopathology and, both lymphocyte type and tissue Qa-2 expression by immunohistochemistry. ELISA kit was used to determine soluble Qa-2 in the serum from the animals. We observed that Qa-2 in neoplastic cells increases in intermediate tumor development stages, while, serum Qa-2 increases in the late stage. Qa-2 increasing is correlated with CD3+ increase. Our results suggest that Qa-2 has a role opposite to HLA-G in Ehrlich solid carcinoma, and may be modulating the immune response by attracting the inflammatory infiltrate, especially T CD8+ Lymphocytes.