Evaluation of Spermicidal Activity of Mi-Saponin A

The seed extracts of Madhuca latifolia were reported to have spermicidal activity. The current investigation identified the spermicidal component of the extracts and evaluated its spermicidal potential in vitro. As characterized by infrared, mass, and nuclear magnetic resonance (NMR) spectral analyses,Mi-saponin A (MSA) was found to be the most potent component among a mixture of saponins. The mean effective concentrations of MSA that induced irreversible immobilization were 320 mg/mL for rat and 500 mg/mL for human sperm, as against the respective concentrations of 350 and 550 mg/mL of nonoxynol 9 (N-9). The mode of spermicidal action was evaluated by a battery of tests including (a) double fluoroprobe staining for spermviability, (b) hypoosmotic swelling test and, assays for 5’ nucleotidase and acrosin for physiological integrity of sperm plasmamembrane, (c) scanning and transmission electron microscopy for sperm membrane ultrastructure, and (d) plasma membrane lipid peroxidation (LPO). The observations, taken together,were interpreted to mean that the spermicidal effect ofMSAinvolved increased membraneLPOleading to structural and functional disintegration of spermplasmamembrane and acrosomal vesicle.Acomparative in vitro cytotoxicity study in human vaginal keratocyte (Vk2/E6E7) and endocervical (End/E6E7) cell lines demonstrated that the 50% cell cytotoxicity (CC50) values, and consequently the safety indices, for MSA were� 8-fold higher as compared to those ofN-9. In conclusion,MSA is a potent spermicidal molecule that may be explored further for its suitability as an effective component of vaginal contraceptive

Quantum states, entanglement and closed timelike curves

We discuss the nature of quantum states (density operators) and entanglement in quantum theory with closed timelike curves. One of the key concepts in the standard quantum theory is that given any mixed state we can always purify it in an enlarged Hilbert space by bringing an ancillary system. The purified state does not depend on the state of any extraneous system with which the mixed state is going to interact and on the physical interaction. Here, we prove that it is not possible to purify a mixed state that traverses a closed time like curve (CTC) and allowed to interact in a consistent way with a causality‐respecting (CR) quantum system. Thus, in general for arbitrary interactions between the CR and the CTC systems there is no universal ‘Church of the larger Hilbert space’ for mixed states with CTC. This shows that in quantum theory with CTCs there can exist ‘proper’ and ‘improper’ mixtures. Also, we suggest what kind of entangled states are allowed in the presence of CTCs. We argue that the nature of entanglement can be different in the presence of such exotic objects. Towards the end we discuss how the no‐hiding theorem in the presence of CTCs may allow quantum information pop‐up