No abstract

Objective: Cervical cancer is the second most common cancer as well as one of leading cause of cancer-related death for women worldwide. In regards to that issue, focus of this paper will be on popularly used Piperaceae members including Piper betle L, Piper cf fragile Benth, Piper umbellatum L, Piper aduncum L, Piper pellucidum L. This research was conducted to elucidate the antioxidant, anticancer and apoptosis inducing activities of Piperaceae extracts on cervical cancer cells, namely HeLa cell line. Methods: The anticancer activity was determined by inhibiting the proliferation of cells. Apoptosis inducing was determined by inhibiting proliferation cells and by SubG1 flow cytometry. The antioxidant activity is determined by using superoxide dismutase value and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Results: The highest anticancer activity at 24 h incubation was found for P.pellucidum extract (IC50: 2.85 µg/ml); The anticancer activity at 48 h incubation was more than at 24 h for all extracts. The highest apoptotic activity was found for P.betle (12.5 µg/ml) at both 24 and 48 h incubatio. The highest antioxidant activity was also represented by P.betle extract. Conclusions: All Piperaceae extracts have high anticancer activity; longer incubation increase anticancer activity. P.betle extract has the highest antioxidant property. [J Exp Integr Med 2013; 3(3.000): 225-230

Budding of retroviruses requires the structural precursor polyprotein, Gag, to target the plasma membrane through its N-terminal matrix (MA) domain. For HIV-1, the interaction between membrane signaling molecule phosphatidylinositol 4,5-diphosphate (PIP2) and MA induces the exposure of myristate and promotes membrane binding. Here we studied oligomerization of the naturally unmyristylated equine infectious anemia virus (EIAV) MA and its interaction with PIP2-C4 primarily using solution NMR spectroscopy. The measured 1 H-15 N residual dipolar coupling agrees with the atomic coordinates from the EIAV MA crystal structure. The analytical ultracentrifugation results show a dominant population of monomeric EIAV MA at a concentration of 63 μM and 20 °C, along with a small trimer and a broad distribution of other oligomers. The monomer-trimer equilibrium model and the quaternary packing of the trimer were further established by the concentration-dependent 15 N spin relaxation rates and chemical shifts.Binding of MA to PIP2-C4 was detected by chemical shift mapping (CSM) with an apparent K d of 182 ± 56 μM, a value similar to that reported for HIV-1 MA. The PIP2 binding site includes the Loop region between Helix2 and Helix3 in the EIAV MA. CSM and spin relaxation dispersion reveal a coupling of conformational change and submillisecond dynamics, respectively, between the Loop and trimeric Interface Residues due to PIP2 binding. We infer that PIP2 participates in the initial trimer formation of EIAV MA, but more importantly, the concentration effect is dominant in shifting the equilibrium toward trimer, in line with the entropic switch mechanism proposed for myristylated HIV-1 MA. † This work was supported by the Intramural Research Program of the National Institutes of Health (NIH), National Heart, Lung, and Blood Institute, to N.T. and Grant R01 AI 068463 from National Institute of Allergy and Infectious Diseases of the NIH to C.C. © 2008 American Chemical Society * To whom correspondence should be addressed. N.T.: phone, (301) 402-3029; fax, (301) 402-3405; tjandran@nhlbi.nih.gov. C.C.: phone,(631)632-8801;fax,(631)632-9797; ccarter@ms.cc.sunysb.edu. ‡ Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health. § Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health. || National Institute of Allergy and Infectious Diseases, National Institutes of Health. ⊥ State University of New York. A table of alignment tensor parameters (Table S1), a HSQC spectrum ( Figure S1), an overlay of HSQC spectra showing the trends of chemical shift changes of D50 and V63 with a concentration increase ( Figure S2), profiles of 15 N R 2 /R 1 and heteronuclear NOE in the presence of PIP2-C4 ( Figure S3), a CPMG R 2 profile of EIAV MA alone ( Figure S4), and a binding curve of residue 49 as a function of PIP2 titration to the K49A mutant of EIAV compared to the wild-type protein ( Figure S5). This material is available free of charge via t...

No abstract