Redox cycling of Cu(II) by 6-mercaptopurine leads to ROS generation and DNA breakage: possible mechanism of anticancer activity.

6-Mercaptopurine (6MP) is a well-known purine antimetabolite used to treat childhood acute lymphoblastic leukemia and other diseases. Cancer cells as compared to normal cells are under increased oxidative stress and show high copper level. These differences between cancer cells and normal cells can be targeted to develop effective cancer therapy. Pro-oxidant property of 6MP in the presence of metal ions is not well documented. Redox cycling of Cu(II) to Cu(I) was found to be efficiently mediated by 6MP. We have performed a series of in vitro experiments to demonstrate the pro-oxidant property of 6MP in the presence of Cu(II). Studies on human lymphocytes confirmed the DNA damaging ability of 6MP in the presence of Cu(II). Since 6MP possesses DNA damaging ability by producing reactive oxygen species (ROS) in the presence of Cu(II), it may also possess apoptosis-inducing activity by involving endogenous copper ions. Essentially, this would be an alternative and copper-dependent pathway for anticancer activity of 6MP.

Computational prediction and characterisation of ubiquitously expressed new splice variant of Prkaca gene in mouse.

Prkaca gene of mouse encodes for a cAMP dependent protein kinase catalytic alpha subunit. PKA occurs naturally as a 4-membered structure having two regulatory (R) and two catalytic (C) subunits each encoded by separate gene. Alternatively spliced two transcript variants are known for the Prkaca gene, which encode for two isoforms of PKA C-subunits, namely Cα1 and Cα2. These isoforms arise as a result of alternative splicing of the first coding exon with the internal exons. We have identified a new transcript variant using combinatorial approach of bioinformatics and molecular biology techniques involving RT-PCR, semi-nested PCR and sequencing. The new transcript variant encoding Cα3 isoform has N-terminus that differs from Cα1 and Cα2 isoforms. Cα3 isoform also arise as a result of alternative splicing of first coding exon with the internal exon. Newly identified transcript is expressed ubiquitously in different tissues examined.

Interaction between Cfd1 and Nbp35 proteins involved in cytosolic FeS cluster assembly machinery deciphers a stable complexation in Leishmania donovani.

Leishmania donovani is the causative unicellular parasite for visceral leishmaniasis (VL); and FeS proteins are likely to be very essential for their survival and viability. Cytosolic FeS cluster assembly (CIA) machinery is one of the four systems for the biosynthesis and transfer of FeS clusters among eukaryotes; Cfd1 and Nbp35 are the scaffold components for cytosolic FeS cluster biogenesis. We investigated the role of CIA machinery components and purified Cfd1 and Nbp35 proteins of L. donovani. We also investigated the interactive nature between LdCfd1 and LdNbp35 proteins by in silico analysis, in vitro co-purification, pull down assays along with in vivo immuno-precipitation; which inferred that both LdCfd1 and LdNbp35 proteins are interacting with each other. Thus, our collective data revealed the interaction between these two proteins which forms a stable complex that can be attributed to the cellular process of FeS clusters biogenesis, and transfer to target apo-proteins of L. donovani. The expression of Cfd1 and Nbp35 proteins in Amp B resistant parasites is up-regulated leading to increased amount of FeS proteins. Hence, it favors increased tolerance towards ROS level, which helps parasites survival under drug pressure contributing in Amphotericin B resistance.

Antifertility effect of methanolic extract of Butea monosperma (Lam.) Taub. flower in male albino rats.

Background: Search for an effective, feasible, and safe male contraceptive has been one of the major public health challenges. The present contraceptive methods are either permanent or impractical. Herbal methods are considered safe, and thus, their acceptability is higher than other prospective methods. Aims: In the present study, oral administration of methanolic extract of Butea monosperma (Lam.) Taub. flower was investigated for its potential role in the modulation of fertility in male albino rats. Materials and methods: Healthy male albino rats were randomly distributed into three groups, i.e., a control and two groups administered with 50 and 500 mg/kg body weight/day of methanolic extract of B. monosperma flower for 30, 90, and 180 days, respectively. Fertility records were maintained throughout the experimental period. At the end of experiment, animals were sacrificed and the weight of reproductive organs, sperm characteristics, and histopathology of testicular and epididymal tissues were evaluated. A 45-day withdrawal period was also investigated for parameters as described above for each group. Results: A 40% decline in fertility rate was evident in rats administered with 500 mg/kg of B. monosperma flower extract for 180 consecutive days. A significant reduction in testicular and epididymal weight was observed in these animals. Sperm count, motility, and viability were also reduced significantly in animals treated for 180 days. Histological evaluation of testicular cells indicated distortions in germ cell arrangements at various stages of spermatogenesis. Following 45 days of withdrawal, the resumption of normal functional and histological characteristics was apparent. Conclusion: Based on the abnormalities present in the sperm characteristics and damages in testicular histology, it was confirmed that methanolic extract of B. monosperma flower contain antifertility potential.

Maternal and severe anaemia in delivering women is associated with risk of preterm and low birth weight: A cross sectional study from Jharkhand, India.

BACKGROUND AND OBJECTIVES: Haemoglobin content is the well accepted indicator for anaemia assessment. The high prevalence of anaemia, maternal health care issues and adverse delivery outcome in Jharkhand, we investigated whether delivering women with anaemia would present a modifiable risk of preterm (PTB) and low birth weight (LBW). METHODS: A facility-based cross-sectional study involving pregnant women, with screening for pregnancy endpoints and haemoglobin assay, were conducted. Anaemia was classified according to World Health Organization's definition of anaemia in pregnancy. Confounding variables were adjusted in a logistic model. The adjusted odds ratios (AORs) with 95% confidence intervals (CIs) were used for analyzing the association among maternal anaemia, PTB and LBW. RESULTS: We observed a high prevalence of anaemia (78.45%) in delivering women, whereas high prevalence of preterm birth (34.75%) and LBW (32.81%) in delivering women overall. In the adjusted analysis, overall anaemia in pregnancy was strongly associated with preterm birth (OR, 3.42; 95% CI, 1.98-5.88; P ≤ .0001) as compared to LBW (OR, 1.12; 95% CI, 0.65-1.61; P = .0003). The risk of PTB and LBW were dependent on the stratification of the anaemia group, as the strongest association was observed in severe (OR, 4.86) followed by mild (OR, 3.66) and moderate (OR, 3.18) anaemia in PTB; whereas risk of LBW was found in severe (OR, 2.5) followed by moderate (OR, 1.11) and mild (OR, 0.57) anaemia. The risk of PTB and LBW across six pregnancy haemoglobin groups were compared, haemoglobin of 10-10.9 g/dl (OR, 1.25) and ≤ 8 g/dl (OR, 1.03) have shown association with PTB and LBW, respectively. However, high haemoglobin concentration was not associated with either PTB or LBW. CONCLUSIONS: Anaemia in delivering women was associated with an elevated risk of PTB and LBW and the risk increased with the severity of anaemia in pregnant women.

IGF-I enhances cortisol secretion from guinea-pig adrenal gland: in vivo and in vitro study.

Insulin-like growth factor (IGF)-I is a ubiquitously synthesized peptide that, along with IGF-II, acts via the IGF-R type I receptor. IGF-I and its receptor are expressed in the adrenal gland of humans and bovines, the secretion of which they seem to stimulate. As in humans and cows, the main glucocorticoid hormone secreted by guinea-pig adrenals is cortisol, and hence we have studied the adrenocortical effects of IGF-I in this species. In vivo experiments showed that prolonged IGF-I administration raised the plasma concentration of cortisol in both normal and dexamethasone/captopril-treated guinea pigs, thereby ruling out the possibility that IGF-I may act by activating the hypothalamic-pituitary-adrenal axis and the renin-angiotensin system. In vitro experiments demonstrated that IGF-I enhanced basal, but not maximally agonist [ACTH and angiotensin-II (Ang-II)]-stimulated, cortisol secretion from freshly dispersed guinea-pig inner adrenocortical cells. The IGF-I immuno-neutralization suppressed the IGF-I secretagogue effect, without altering the cortisol response to both ACTH and Ang-II. IGF-I raised cyclic-AMP and inositol triphosphate release from dispersed guinea-pig cells, and the effect was reversed by the adenylate cyclase inhibitor SQ-22536 and the phospholipase-C (PLC) inhibitor U-73122. SQ-22536, U-73122, the protein kinase (PK) A inhibitor H-89 and the PKC inhibitor calphostin-C decreased by approximately 50% the cortisol response of dispersed cells to IGF-I, and the combined exposure to SQ-22536 and U-73122 abolished it. We conclude that IGF-I stimulates glucocorticoid secretion from guinea-pig adrenocortical cells, acting via selective receptors coupled to both the adenylate cyclase/PKA- and PLC/PKC-dependent signaling cascades.