Electrochemical investigations of cholesterol enriched glassy carbon supported thin lipid films

Evaluation of spermicidal activity of saponosides from Saponaria officinalis/Caryophyllaceae, Glycyrrhizia glabra/Fabaceae and Herniaria glabra/Caryophyllaceae

Background and objective

Chemical spermicides currently marketed and widely used are known to have many side effects. Thereby, and in order to look for more tolerated natural spermicidal agents, the aim of this work was to evaluate the spermicidal potential of saponin extracts from the roots of Saponaria officinalis/Caryophyllaceae, Glycyrrhizia glabra/Fabaceae, and Herniaria glabra/Caryophyllaceae by studying their in vitro effects on sperm mobility and vitality.

Methods

Methanolic saponin extracts from the plants roots were performed. Sperm suspensions were prepared by centrifugation on a PureSperm® density gradient (70 and 45%) and incubated with various concentrations of saponin extracts (50, 250, 500 and 750 μg/mL) at 37°C. The spermicidal activity was evaluated by studying the mobility and vitality of spermatozoa at different time intervals ranging from 10 to 240 minutes.

Results

A dose and time dependent effect on sperm mobility and vitality was observed for our extracts.

Extracts from Saponaria officinalis roots induced an irreversible immobilization and a total non-viability of sperm within 10 minutes at a concentration of 750 μg/mL. A similar effect was observed within 30 minutes at 750 μg/mL for Herniaria glabra extract and within 90 minutes at 500 μg/ml for Glycyrrhizia glabra extract.

Conclusion

The results of our study showed that the saponin extracts of our plants roots possess potent in vitro dose and time dependant spermicidal effect. These natural products could therefore represent a safer and better tolerated alternative to chemical spermicides.

[Sperm immobilizing effect of leaves extracts of Cestrum parqui]

OBJECTIVE

The leaves extracts of Cestrum parqui were reported to have spermicidal activity. The current investigation identified the spermicidal component of the extracts and evaluated its spermicidal potential in vitro, particularly the effects on sperm motility and vitality.

METHODS

Sperms were prepared by discontinuous buoyant density gradient centrifugation and incubated with varying concentrations of extract from C. parqui (40-250 μg/ml) at 37°C and 5% CO(2). The mode of spermicidal action was evaluated by sperm motility and vitality at different intervals ranging from 5 to 240 minutes. Morphological changes in human spermatozoa after exposure to the extract were evaluated under transmission electron microscope.

RESULTS

A dose- and time-dependent effect of this extract on sperm motility and viability was observed. The mean effective concentration of extracts that induced irreversible immobilization was 250 μg/ml. Transmission electron microscope revealed a significant damage to sperm membrane in head and acrosomal membranes, notable swelling and disruption.

CONCLUSION

Our study indicates that this natural extract has potential spermicidal effect in vitro. It can adequately replace nonoxynol-9 in vaginal contraceptives to make them more vaginally safe and ecofriendly.

Spermicidal activity of extract from Cestrum parqui

OBJECTIVE

The leaf extract of Cestrum parqui was examined for its effects on sperm motility in vitro.

METHODS

Washed sperm were prepared by discontinuous buoyant density gradient centrifugation and incubated with varying concentrations of extract from C. parqui (40-250 microg/mL) at 37 degrees C and 5% CO(2). Sperm motility and viability were assessed at different intervals ranging from 5 to 240 min. Morphological changes in human ejaculated spermatozoa after exposure to the extract were evaluated under transmission electron microscope.

RESULTS

A dose- and time-dependent effect of this extract on sperm motility and viability was observed. The maximal spermicidal effect was observed with a 250-microg/mL dose of the extract. Transmission electron microscope revealed a significant damage to sperm membrane in both head and acrosomal membranes, notable swelling and disruption.

CONCLUSION

The present study indicates that this natural extract has potential spermicidal effect in vitro.

Interaction of thin wetting films of lecithin with some divalent cations

The impact of some divalent cations on the structure of a model membrane system, comprising wetting lipid films, is assayed in this work. The results from impedimetry suggest prominent structural changes upon the addition of the discussed ions to the electrolyte solution contacting the film. These changes are manifested by the increase of resistivity of the films as well as by the decrease of capacitance dispersion. In accordance with other data in the literature, manganese (Mn(2+)) turned out to have an effect greater than those of Mg(2+) and Ca(2+).

Wetting films of lipids in the development of sensitive interfaces. An electrochemical approach

Solid-supported thin liquid films of lipids, contacting an electrolyte phase, turned out to be a dependable system in the field of bosensors. The investigations of these objects during the past decade reveal some of their intriguing features enabling the application in constructions of receptor part with 'two-dimensional' arrangement. As a model system, complementary to the other artificial analogs of biomembranes, the wetting films of lipids offer certain advantages concerning the compromise between the stability and flexibility of the molecular structures involved in sensing. The basic principles underlaying the techniques of formation, as well as the conditions of the films stability are emphasized in the present consized review. While no limitations are imposed by the way of preparation, the films seem especially profitable in conjunction with methods for electrochemical signal transduction. In this regard some prominent examples are discussed.