Phytopharmacological evaluation of ethanol extract of Sida cordifolia L.roots

Objective:To investigate the phytochemical screening(group determination)and selected pharmacological activities(antioxidant,antimicrobial and analgesic activity)of the plant Sida cordifolia Linn(S.cordifolia).Methods:Eighty percent concentrated ethanol extract of the roots was used.To identify the chemical constituents of plant extract standard procedures were followed.In phytochemical screening the crude extract was tested for the presence of different chemical groups like reducing sugar,tannins,saponins,steroids,flavonoids,gums,alkaloids and glycosides.The antioxidant property of ethanolic extract of S.cordifolia was assessed by DPPH free radical scavenging activity.Analgesic activity of the extract was tested using the model of acetic acid induced writhing in mice.Diclofenac sodium is used as reference standard drug for the analgesic activity test Antibacterial activity of plant extract was carried out using disc diffusion method with five pathogenic bacteria comparison with kanamycin as a standard.Results:Phytochemical analysis of the ethanolic extract of the roots of S.cordifolia indicated the presence of reducing sugar,alkaloids,steroids and saponins.In DPPH scavenging assay the IC_(50)value was found to be 50 ug/mL which was not comparable to the standard ascorbic acid.The crude extract produced 44.3%inhibition of writhing at the dose of 300 mg/kg body weight which is statistically significant(P>0.001).The in vitro antimicrobial activity of the ethanol extract of the roots of S.cordifolia showed no antimicrobial activity against five types of microorganisms.The experiment was conducted only with five species of bacteria as test species,which do not at all indicate the total inactivity against micro-organisms.Condusions:The obtained results provide a support for the use of this plant in traditional medicine but further pharmacological studies are required.

PLK1 phosphorylation of ZW10 guides accurate chromosome segregation in mitosis

Stable transmission of genetic information during cell division requires faithful chromosome segregation.Mounting evidence has demonstrated that polo-like kinase 1(PLK1)dynamics at kinetochores control correct kinetochore–microtubule attachments and subsequent silencing of the spindle assembly checkpoint.However,the mechanisms underlying PLK1-mediated silencing of the spindle checkpoint remain elusive.Here,we identified a regulatory mechanism by which PLK1-elicited zeste white 10(ZW10)phosphorylation regulates spindle checkpoint silencing in mitosis.ZW10 is a cognate substrate of PLK1,and the phosphorylation of ZW10 at Ser12 enables dynamic ZW10–Zwint1 interactions.Inhibition of ZW10 phosphorylation resulted in misaligned chromosomes,while persistent expression of phospho-mimicking ZW10 mutant caused premature anaphase,in which sister chromatids entangled as cells entered anaphase.These findings reveal the previously uncharacterized PLK1–ZW10 interaction through which dynamic phosphorylation of ZW10 fine-tunes accurate chromosome segregation in mitosis.