Browsing by Author "Ayad, Bashir M."

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    Ameliorative potentials of quercetin against cotinine-induced toxic effects on human spermatozoa
    (Hainan Medical University Journal Publisher, 2016) Goss, Dale; Oyeyipo, Ibukun P.; Skosana, Bongekile T.; Ayad, Bashir M.; Du Plessis, Stefan S.
    Objectives: Cotinine, the principal metabolite of nicotine found in smokers' seminal plasma, has been shown to adversely affect sperm functionality while quercetin, a flavonoid with diverse properties is associated with several in vivo and in vitro health benefits. The aim of this study was to investigate the potential benefits of quercetin supplementation against damage caused by the by-products of tobacco smoke in human sperm cells. Methods: Washed human spermatozoa from 10 normozoospermic donors were treated with nutrient medium (control), quercetin (30 mmol/L) and cotinine (190 mg/mL, 300 ng/mL) with or without quercetin for 60 and 180 min incubation periods. Computer-aided sperm analysis was used to assess sperm motility while acrosomereacted cells were identified under a fluorescent microscope using fluorescein isothiocyanate-labelled Pisum Sativum Agglutinin as a probe, viability was assessed by means of a dye exclusion staining technique (eosin/nigrosin) and oxidative stress by flow cytometry using dihydroethidium as a probe. Values were expressed as mean ± S.E.M. as compared by ANOVA. Results: Higher cotinine concentrations reduced the number of viable cells after 60 and 180 min of exposure while viability of cells was increased in the cotinine aliquots supplemented with quercetin after 180 min of exposure when compared with cotinine only treated group. Conclusion: This study indicates that the ameliorating ability of quercetin on cotinineinduced decline in sperm function is associated with increased number of viable cells.
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    Revisiting the relationship between the ejaculatory abstinence period and semen characteristics
    (Royan Institute, 2018) Ayad, Bashir M.; Van der Horst, Gerhard; Du Plessis, Stefan S.
    ENGLISH ABSTRACT: Variation in the ejaculatory abstinence period suggested by different guidance bodies have resulted in a growing concern among researchers and clinicians over what the precise period of ejaculatory abstinence ought to be for an optimal semen sample. Several studies have thus been undertaken to examine the association between the length of sexual abstinence and semen characteristics. Not all studies, however, have arrived at the same conclusions. This study aims to review all existing literature published during the past few decades pertaining to the influence of ejaculatory abstinence on semen quality. For the purpose of this systematic review, all data related to sexual abstinence duration and seminal parameters were re-analysed to homogenize the current data. Thorough PubMed, MEDLINE and Google Scholar, a literature search was conducted using the keywords “sexual abstinence”, “ejaculatory abstinence”, “semen”, “spermatozoa”, “semen analysis”, “sperm parameters”, “motility”, “reactive oxygen species (ROS)” and “DNA fragmentation”. After carefully reviewing all the literature, 30 relevant papers, both written in English and published between January 1979 and December 2016, were included in this review. The weight of the evidence suggests that the decline in semen volume and sperm concentration with shorter abstinence periods is accompanied by a substantial improvement in sperm motility characteristics, especially progressive motility and velocity. Nevertheless, available data are insufficient to support definitive conclusions regarding the influence of the ejaculatory abstinence period on advanced semen parameters (ROS, DNA fragmentation and seminal plasma antioxidant capacity) and pregnancy rates. In conclusion, taking all data into account, shortening of the abstinence period may be beneficial to sperm quality. Furthermore, we recommend that the current guidelines regarding the prescribed abstinence period should be revisited.