A lactoferrin-derived peptide with cationic residues concentrated in a region of its helical structure induces necrotic cell death in a leukemic cell line (HL-60).

Model studies have shown that peptides derived from the N-terminal region of bovine lactoferrin (Lf-B) exhibit antitumor activity against certain cell lines. This activity is due primarily to the peptides' apoptogenic effect. Several reports indicate that cationic residues clustered in two regions of the peptide sequence can be shuffled into one region and thereby increase cytotoxic activity, although the mechanism of this enhanced cytotoxic effect has not been clarified.

Antiproliferative effect on human cancer cell lines after treatment with nimbolide extracted from an edible part of the neem tree (Azadirachta indica).

Nimbolide, a triterpenoid extracted from the flowers of the neem tree (Azadirachta indica), was found to have antiproliferative activity against some cancer cell lines. Treatment of cells with 0.5-5.

Inhibition of colon cancer (HT-29) cell proliferation by a triterpenoid isolated from Azadirachta indica is accompanied by cell cycle arrest and up-regulation of p21.

Nimbolide, a natural triterpenoid present in the edible parts of the neem tree ( Azadirachta indica), was found to be growth-inhibitory in human colon carcinoma HT-29 cells. Nimbolide treatment of cells at 2.5 - 10 microM resulted in moderate to very strong growth inhibition.

Apoptosis, necrosis and cell proliferation-inhibition by cyclosporine A in U937 cells (a human monocytic cell line).

The immunosuppressive drug cyclosporine A (CsA) has been used in both organ transplantation and the treatment of autoimmune disorders. However, the drug causes adverse effects in the kidney, liver and nervous system, characterized by cellular loss in the affected area. Apoptosis has been shown to play a role in CsA-induced cytotoxicity.

Mahanine, a carbazole alkaloid from Micromelum minutum, inhibits cell growth and induces apoptosis in U937 cells through a mitochondrial dependent pathway.

1 Mahanine, a naturally occurring carbazole alkaloid in some Asian vegetables, has been shown to exhibit antimutagenicity, antimicrobial activity, cytotoxicity, and other biological properties. 2 In the present study, we investigated the effect of mahanine on the activation of the apoptotic pathway in human leukemia U937 cells. Various end points were used to screen for apoptosis: Morphological changes in cells, the relative numbers of viable and apoptotic cells; translocation of membrane bound phosphatidylserine and DNA analysis.

Mechanism of mahanine-induced apoptosis in human leukemia cells (HL-60).

Mahanine, a carbazole alkaloid occurs in the edible part of Micromelum minutum, Murraya koenigii and related species has been found to induce apoptosis in human myeloid cancer cell (HL-60). Concentration of 10 microM mahanine caused a complete inhibition of cell proliferation and the induction of apoptosis in a time dependent manner. Mahanine-induced cell death was characterized with the changes in nuclear morphology, DNA fragmentation, activation of caspase like activities, poly(ADP-ribose) polymerase cleavage, release of cytochrome c into cytosol and stimulation of reactive oxygen species generation.

Prenylated flavanones isolated from flowers of Azadirachta indica (the neem tree) as antimutagenic constituents against heterocyclic amines.

Four prenylated flavanones were isolated from the methanol extract of the flowers of Azadirachta indica (the neem tree) as potent antimutagens against Trp-P-1 (3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole) in the Salmonella typhimurium TA98 assay by activity-guided fractionation. Spectroscopic properties revealed that those compounds were 5,7,4'-trihydroxy-8-prenylflavanone (1), 5,4'-dihydroxy-7-methoxy-8-prenylflavanone (2), 5,7,4'-trihydroxy-3',8-diprenylflavanone (3), and 5,7,4'-trihydroxy-3',5'-diprenylflavanone (4). All isolated compounds were found for the first time in this plant.

Antimutagenic effect of amino acids on the mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG).

The antimutagenic activity of protein-constituting amino acids except histidine on the mutagenicity of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was investigated in vitro using Salmonella typhinurium TA-100 as an indicator bacterium (Ames test), and concentrations (IC50) of amino acids that inhibit 50% of the mutagenecity were measured. Cysteine was found to be most active and glycine, tryptophan, lysine, and arginine were strong antimutagenic amino acids. Other amino acids showed moderate or weak antimutagenic activities, depending on the amino acids.