Solanum tuberosum lectin inhibits Ehrlich ascites carcinoma cells growth by inducing apoptosis and G2/M cell cycle arrest.

Recently, a lectin was purified from the potato cultivated in Bangladesh locally known as Sheel. In the present study cytotoxicity of the lectin against Ehrlich ascites carcinoma (EAC) cells was studied by MTT assay in vitro in RPMI-1640 medium and 8.0-36.0 % cell growth inhibition was observed at the range of 2.5-160 µg/ml protein concentration when incubated for 24 h. The lectin-induced apoptosis in EAC cells was confirmed by fluorescence and optical microscope. The apoptotic cell death was also confirmed by using caspase inhibitors. Cells growth inhibition caused by the lectin (36 %) was remarkably decreased to 7.6 and 22.3 % respectively in the presence of caspase-3 and -8 inhibitors. RT-PCR was used to evaluate the expression of apoptosis-related genes Bcl-X, p53, and Bax. An intensive expression of Bcl-X gene was observed in untreated control EAC cells with the disappeared of the gene in Sheel-treated EAC cells. At the same time, Bax gene expression appeared only in Sheel-treated EAC cells and the expression level of the p53 gene was increased remarkable after the treatment of EAC cells with the lectin. The lectin showed strong agglutination activity against EAC cells. Flow cytometry was used to study the cell cycle phases of EAC cells and it was observed that the lectin arrested the G2/M phase. In conclusion, Sheel lectin inhibited EAC cells growth by inducing apoptosis.

Elevated levels of plasma Big endothelin-1 and its relation to hypertension and skin lesions in individuals exposed to arsenic.

Chronic arsenic (As) exposure affects the endothelial system causing several diseases. Big endothelin-1 (Big ET-1), the biological precursor of endothelin-1 (ET-1) is a more accurate indicator of the degree of activation of the endothelial system. Effect of As exposure on the plasma Big ET-1 levels and its physiological implications have not yet been documented. We evaluated plasma Big ET-1 levels and their relation to hypertension and skin lesions in As exposed individuals in Bangladesh. A total of 304 study subjects from the As-endemic and non-endemic areas in Bangladesh were recruited for this study. As concentrations in water, hair and nails were measured by Inductively Coupled Plasma Mass Spectroscopy (ICP-MS). The plasma Big ET-1 levels were measured using a one-step sandwich enzyme immunoassay kit. Significant increase in Big ET-1 levels were observed with the increasing concentrations of As in drinking water, hair and nails. Further, before and after adjusting with different covariates, plasma Big ET-1 levels were found to be significantly associated with the water, hair and nail As concentrations of the study subjects. Big ET-1 levels were also higher in the higher exposure groups compared to the lowest (reference) group. Interestingly, we observed that Big ET-1 levels were significantly higher in the hypertensive and skin lesion groups compared to the normotensive and without skin lesion counterpart, respectively of the study subjects in As-endemic areas. Thus, this study demonstrated a novel dose-response relationship between As exposure and plasma Big ET-1 levels indicating the possible involvement of plasma Big ET-1 levels in As-induced hypertension and skin lesions.

X-Ray analysis of d(CGCGAATTXGCG)(2) containing a 2' or minute-deoxy-N(4)-methoxycytosine residue at X: a characteristic pattern of sugar puckers in the crystalline state of the Dickerson-Drew type DNA dodecamers.

In a series of structural studies on damaged DNA, a modified Dickerson-Drew dodecamer with the sequence d(CGCGAATTmo(4)CGCG), where mo(4)C is 2'-deoxy-N(4)-methoxycytidine, was synthesized and its structure in a new crystal form has been determined by the X-ray diffraction method. The two dodecamers form a B-form duplex, in which the two mo(4)C residues, respectively, form a wobble pair and a Watson-Crick type pair with the guanine residues of the opposite strand. A comparison of the sugar conformations with those of the other related Dickerson-Drew dodecamers indicates a common feature of their puckering patterns. The sugar pucker of the third residue always adopts an intermediate state (C4'-exo-O4'-endo) between the A-form and B-form. This deviation is ascribed to the stacking interaction of the ribose ring at the third residue with the guanine base at the 12th residue, which is brought about by an extra G12:G2 interaction between two duplexes related by a crystallographic 2(1) symmetry.

Antimicrobial and cytotoxic activity of three bitter plants enhydra fluctuans, andrographis peniculata and clerodendrum viscosum.

PURPOSE: In this study, three important medicinal plants (Enhydra fluctuans Lour, Clerodendrum viscosum Vent and Andrographis peniculata Wall) of Bangladesh were investigated to analyze their antimicrobial and cytotoxic activities against some pathogenic microorganisms and Artemia salina (brine shrimp nauplii). METHODS: The coarse powder material of leaves of each plant was extracted separately with methanol and acetone to yield methanol extracts of leaves of Enhydra fluctuans (MLE), Clerodendrum viscosum (MLC) and Andrographis peniculata (MLA), and acetone extracts of leaves of Enhydra fluctuans (ALE), Clerodendrum viscosum (ALC) and Andrographis peniculata (ALA). The disc diffusion method and the method described by Meyer were used to determine the antimicrobial and cytotoxic activities of each plant extract. RESULTS: Among the test samples, MLE and ALE showed comparatively better antimicrobial activity against a number of bacteria and fungi with inhibition zones in the range of 06-15 mm and according to the intensity of activity, the efficacy against microorganisms were found in the order of Enhydra fluctuans > Andrographis peniculata > Clerodendrum viscosum. In cytotoxicity assay, all samples were found to be active against brine shrimp nauplii (Artemia salina) and ALA produced lowest LC50 value (7.03 µg/ml). CONCLUSION: Enhydra fluctuans and Andrographis peniculata possesses significant antimicrobial and cytotoxic activities.