A murine monoclonal antibody (mAb i3A; IgG1, kappa light chain) was obtained using human red blood cells as immunogen. The antibody showed Fy6 specificity since it agglutinated all but Fy(a-b-)-untreated red cells and failed to agglutinate chymotrypsin-treated cells. An erythrocyte membrane protein of 42-46 kD was revealed as the major component recognized by the antibody on immunoblots. The antibody also bound to 92- to 95- and 200-kD proteins, tentatively identified as oligomers of the 42- to 46-kD monomeric form. The affinity-purified Fy6-active protein was converted to a sharp band of 35 kD after N-glycanase treatment. The molecule appeared as a slightly broadly band after neuraminidase treatment but was not further altered by O-glycanase. The i3A mAb bound to 6,000 +/- 1,000 receptor sites on either Fy(a-b+), Fy (a+b+) and Fy(a+b-) red cells with an affinity constant in the range of 3-6 x 10(8) M-1. No binding was observed to other blood cells nor to several cells (B, T, myelomonocytic and erythro-leukemia cell lines). Also, the bulk of i3A-Fy6 immune complexes could be dissociated from the red cell membrane with as low as 0.2% Triton X-100, showing that the Fy6-active glycoprotein is not tightly associated with the membrane skeleton. Our data obtained with a new monoclonal antibody directed to the Fy6 antigen demonstrate that the blood group Duffy-active component is a red cell-specific glycoprotein carrying one or more N-linked oligosaccharides.

A Ficus umbellata is used to treat cancer. The present work was therefore designed to assess antitumor potentials of F. umbellata extracts in nine different cell lines. Cell cycle, apoptosis, cell migration/invasion, levels of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), caspases activities as well as Bcl-2 and Bcl-xL protein content were assessed in MDA-MB-231 cells. The 7,12-dimethylbenz(a)anthracene (DMBA)-induced carcinogenesis in rats were also used to investigate antitumor potential of F. umbellata extracts. The F. umbellata methanol extract exhibited a CC50 of 180 μg/mL in MDA-MB-231 cells after 24 h. It induced apoptosis in MCF-7 and MDA-MB-231 cells, while it did not alter their cell cycle phases. Further, it induced a decrease in MMP, an increase in ROS levels and caspases activities as well as a downregulation in Bcl-2 and Bcl-xL protein contents in MDA-MB-231 cells. In vivo, F. umbellata aqueous (200 mg/kg) and methanol (50 mg/kg) extracts significantly (p < 0.001) reduced ovarian tumor incidence (10%), total tumor burden (58% and 46%, respectively), average tumor weight (57.8% and 45.6%, respectively) as compared to DMBA control group. These results suggest antitumor potential of F. umbellata constituents possibly due to apoptosis induction mediated through ROS-dependent mitochondrial pathway.

The aim of this work was to determine the chemical profile and assess in vitro the antibacterial activity of the leaves, resin and stem-barks of Dacryodes edulis. The essential oils were analyzed simultaneously by Gas Chromatography and Gas Chromatography coupled to Mass Spectrometry. Agar diffusion well and microdilution methods were used to assay the antibacterial activity. The resin essential oil contained p-cymene (30.32%), α-thujene (28.58%), α-phellandrene (27.14%) and β-phellandrene (10.16%) as the main components; the stembarks essential oil had as abundant components p-cymene (35.14%), trans-carveol (22.60%), α-thujene (14.86%), β-phellandrene (8.65%) and β-elemene (5.22%). The leaves essential oil was distinct with elemol (29.22%), caryophyllene oxide (15.26%), trans-carveol (11.80%) and spathulenol (6.28%) as major components. The leaves essential oil was the most active with MIC and MBC value of 18.75 mg/mL on B. cereus; the most susceptible strain. The stem-barks essential oil had a MIC of 50 mg/mL and MBC of 100 mg/mL on all the strains meanwhile the resin essential oil had a bacteriostatic effect at 200 mg/mL. Based on these results, it emanates that the essential oils of D. edulis represent a potential source of antibacterial substances.