Synthesis, Characterization and Antitumour Activity of Metal Complexes of 5-Carboxy-2-Thiouracil

Metal complexes of 5-carboxy-2-thiouracil with Mn(ll), Co(ll), Ni(ll), Cu(ll), Zn(ll) and Cd(ll) ions were synthesized, characterized, and subjected to a screening system for evaluation of antitumour activity against Sarcoma-180 (S-180) tumour cells. The complexes were characterized by elemental analysis, infrared, electronic spectra, room temperature magnetic measurements and powder X-ray diffraction. The antitumour activity results indicate that some complexes have antitumour activity both in vivo and in vitro against S-180 tumour cells

Myelopoietic efficacy of orlistat in murine hosts bearing T cell lymphoma: implication in macrophage differentiation and activation.

Orlistat, an inhibitor of fatty acid synthase (FASN), acts as an antitumor agent by blocking de novo fatty acid synthesis of tumor cells. Although, myelopoiesis also depends on de novo fatty acid synthesis, the effect of orlistat on differentiation of macrophages, which play a central role in host's antitumor defence, remains unexplored in a tumor-bearing host. Therefore, the present investigation was undertaken to examine the effect of orlistat administration on macrophage differentiation in a T cell lymphoma bearing host. Administration of orlistat (240 mg/kg/day/mice) to tumor-bearing mice resulted in a decline of tumor load accompanied by an augmentation of bone marrow cellularity and survival of bone marrow cells (BMC). The expression of apoptosis regulatory caspase-3, Bax and Bcl2 was modulated in the BMC of orlistat-administered tumor-bearing mice. Orlistat administration also resulted in an increase in serum level of IFN-γ along with decreased TGF-β and IL-10. BMC of orlistat-administered tumor-bearing mice showed augmented differentiation into macrophages accompanied by enhanced expression of macrophage colony stimulating factor (M-CSF) and its receptor (M-CSFR). The macrophages differentiated from BMC of orlistat-administered mice showed characteristic features of M1 macrophage phenotype confirmed by expression of CD11c, TLR-2, generation of reactive oxygen species, phagocytosis, tumor cell cytotoxicity, production of IL-1,TNF-α and nitric oxide. These novel findings indicate that orlistat could be useful to support myelopoesis in a tumor-bearing host

Synthesis and reactivity studies of mononuclear zinc hydroxo complex

83-87The synthesis of mononuclear zinc hydroxo, Zn(OH)(HB(3-But-5-Pripz) 2 using sterically hindered pyrazolylborate ligand i.e. hydrotris(3-tert-butyl-5-isopropyl-1-pyrazolyl)borate ligand has been described. The structure of 2 is very similar to the active site of the enzyme carbonic anhydrase. The complex 2 is found to stabilize zinc complexes of uracil and its halo derivatives where uracil and its halo derivatives are bound as monodentate ligand via its deprotonated N1. The halogenated uracil complexes have been injected in Dalton's Lymphoma tumour system in mice and it is found that Zn[HB(3-But-5- Pripz)3](5-fluorouracilate) exhibits significant antitumour activity. The complex 2 is a very reactive species and is used as catalyst in ester hydrolysis. The complex 2 is also found to promote the hydrolysis of various esters and the maximum rate of hydrolysis is observed with p-nitrophenylacetate

Effect of orlistat administration to tumor-bearing mice on apoptotic tumor cell population.

<p>Tumor cells (1x10⁶ cells/ml) harvested from control and orlistat administered tumor-bearing mice were analysed for apoptotic cells by Wright-Giemsa (a) and TUNEL assay (b). Values shown in (a) & (b) are mean ± SD of three independent experiments done in triplicate.*<i>p<0</i>.<i>05 </i><i>vs</i>. values of respective control. </p

Protocol for administering orlistat to tumor-bearing mice.

<p>Mice were transplanted DL cells (1x10⁵cells/0.5 ml PBS) on day 0 following administration of Vehicle alone (control) or containing orlistat 240mg/kg body weight/day up to day 14 post tumor transplantation. On day 16 BMC were harvested from femurs.</p

Summary of the suggested mechanisms underlying myelopoietic action of orlistat.

<p>Myelopoietic action of orlistat in tumor bearing hosts leads to augmented differentiation of Mϕ with M₁ phenotype. Modulated expression of cytokines, cell survival and differentiation regulatory molecules play a central role.</p

Effect of orlistat administration to tumor-bearing mice on BMC count, survival and apoptotic population.

<p>Viable cells in BMC harvested from the femur of control and orlistat-administered tumor-bearing mice were enumerated by trypan blue dye exclusion test (a). A differential count of the BMC population was performed by Leishman staining (b). BMC (1x10⁶ cells/ml) of control and orlistat-administered groups were incubated for 24h in 96 well culture plates followed by estimation of cell survival by MTT assay (c). Induction of apoptosis was estimated by Wright Giemsa staining (d) and TUNEL assay (e). Values are mean ± SD of three independent experiments done in triplicate.* <i>p<0.05 vs</i>. values of respective control.</p

Orlistat augments differentiation of BMDM associated with increased expression of M-CSF and M-CSFR.

<p>BMC (1x10⁴ cells/ml) harvested from control or orlistat-administered tumor-bearing mice were cultured in vitro in the presence of L929 culture medium (20%v/v) as a source of M-CSF, for 10 days to allow the BMC to differentiate into colonies. Colonies were counted based on cellular morphology of each colony forming unit (CFU) displaying features of CFU-M, CFU-GM and CFU-G phenotype (a). CFU-M obtained from the BMC of control group displayed lesser number of Mϕ-like cells compared to orlistat-treated group where the colonies were denser with larger macrophage like cells, as indicated by arrows (b). BMC (1x10⁶ cells/ml) obtained from control or orlistat-administered tumor-bearing mice were also processed for RT-PCR to detect expression of mRNA for MCSF and M-CSFR. Bars shown in (e) are densitometric scan of bands shown in (d), which are from a representative experiments out of 3 experiments with similar results. BMDM grown on glass cover slips in petri-dishes were stained with Wright Giemsa stain (c upper panel) and F4/80 FITC-conjugated antibody (c lower panel). As indicated by arrows BMDM of orlistat administered group showed increased size, spreading and cytoplasmic extensions. Plates shown are from a representative experiment. Values shown in (a) are mean ± SD of three independent experiments done in triplicate.*<i>p<0</i>.<i>05 </i><i>vs</i>. values of respective control.</p