The Experts below are selected from a list of 207 Experts worldwide ranked by ideXlab platform

Yongjun Zhang - One of the best experts on this subject based on the ideXlab platform.

  • zero order release of gossypol improves its Antifertility effect and reduces its side effects simultaneously
    Biomacromolecules, 2018
    Co-Authors: Na Wen, Yansheng Dong, Rui Song, Wenpeng Zhang, Chao Sun, Xiaomei Zhuang, Ying Guan, Qingbin Meng, Yongjun Zhang
    Abstract:

    Gossypol was considered a promising male contraceptive but finally failed due to two side effects: hypokalemia and the irreversibility of its contraceptive effect. Here we demonstrate that sustained zero-order release could be a solution for these problems. The in vitro release of gossypol from gossypol/PEG layer-by-layer films follows a perfect zero-order kinetics. In vivo tests indicate that the films can maintain the plasma drug concentration constant in male SD rats for ∼20 days for a 30-bilayer film. The plasma drug concentration is 2 orders of magnitude lower than the peak plasma drug concentration when administered orally and the daily dose is >50-fold lower than the commonly used contraceptive oral dose. However, significant Antifertility effects were still observed. Furthermore, hypokalemia was not observed, and the Antifertility effects can be reversed after a recovery period. The results suggest that zero-order release can significantly improve the desired Antifertility effect of gossypol and, ...

  • Zero-Order Release of Gossypol Improves Its Antifertility Effect and Reduces Its Side Effects Simultaneously
    2018
    Co-Authors: Na Wen, Yansheng Dong, Rui Song, Wenpeng Zhang, Chao Sun, Xiaomei Zhuang, Ying Guan, Qingbin Meng, Yongjun Zhang
    Abstract:

    Gossypol was considered a promising male contraceptive but finally failed due to two side effects: hypokalemia and the irreversibility of its contraceptive effect. Here we demonstrate that sustained zero-order release could be a solution for these problems. The in vitro release of gossypol from gossypol/PEG layer-by-layer films follows a perfect zero-order kinetics. In vivo tests indicate that the films can maintain the plasma drug concentration constant in male SD rats for ∼20 days for a 30-bilayer film. The plasma drug concentration is 2 orders of magnitude lower than the peak plasma drug concentration when administered orally and the daily dose is >50-fold lower than the commonly used contraceptive oral dose. However, significant Antifertility effects were still observed. Furthermore, hypokalemia was not observed, and the Antifertility effects can be reversed after a recovery period. The results suggest that zero-order release can significantly improve the desired Antifertility effect of gossypol and, meanwhile, significantly reduce its side effects. We envision the drug could be developed to be an effective, safe, and reversible male contraceptive by zero-order release

Na Wen - One of the best experts on this subject based on the ideXlab platform.

  • zero order release of gossypol improves its Antifertility effect and reduces its side effects simultaneously
    Biomacromolecules, 2018
    Co-Authors: Na Wen, Yansheng Dong, Rui Song, Wenpeng Zhang, Chao Sun, Xiaomei Zhuang, Ying Guan, Qingbin Meng, Yongjun Zhang
    Abstract:

    Gossypol was considered a promising male contraceptive but finally failed due to two side effects: hypokalemia and the irreversibility of its contraceptive effect. Here we demonstrate that sustained zero-order release could be a solution for these problems. The in vitro release of gossypol from gossypol/PEG layer-by-layer films follows a perfect zero-order kinetics. In vivo tests indicate that the films can maintain the plasma drug concentration constant in male SD rats for ∼20 days for a 30-bilayer film. The plasma drug concentration is 2 orders of magnitude lower than the peak plasma drug concentration when administered orally and the daily dose is >50-fold lower than the commonly used contraceptive oral dose. However, significant Antifertility effects were still observed. Furthermore, hypokalemia was not observed, and the Antifertility effects can be reversed after a recovery period. The results suggest that zero-order release can significantly improve the desired Antifertility effect of gossypol and, ...

  • Zero-Order Release of Gossypol Improves Its Antifertility Effect and Reduces Its Side Effects Simultaneously
    2018
    Co-Authors: Na Wen, Yansheng Dong, Rui Song, Wenpeng Zhang, Chao Sun, Xiaomei Zhuang, Ying Guan, Qingbin Meng, Yongjun Zhang
    Abstract:

    Gossypol was considered a promising male contraceptive but finally failed due to two side effects: hypokalemia and the irreversibility of its contraceptive effect. Here we demonstrate that sustained zero-order release could be a solution for these problems. The in vitro release of gossypol from gossypol/PEG layer-by-layer films follows a perfect zero-order kinetics. In vivo tests indicate that the films can maintain the plasma drug concentration constant in male SD rats for ∼20 days for a 30-bilayer film. The plasma drug concentration is 2 orders of magnitude lower than the peak plasma drug concentration when administered orally and the daily dose is >50-fold lower than the commonly used contraceptive oral dose. However, significant Antifertility effects were still observed. Furthermore, hypokalemia was not observed, and the Antifertility effects can be reversed after a recovery period. The results suggest that zero-order release can significantly improve the desired Antifertility effect of gossypol and, meanwhile, significantly reduce its side effects. We envision the drug could be developed to be an effective, safe, and reversible male contraceptive by zero-order release

Zhang Jian Wei - One of the best experts on this subject based on the ideXlab platform.

  • recent progress in research on tripterygium a male Antifertility plant
    Contraception, 1995
    Co-Authors: Qian Shao Zhen, Zhang Jian Wei
    Abstract:

    Abstract The discovery of the reversible Antifertility action of an extract from Tripterygium wilfordii both in male rats and in men in 1986 stimulated worldwide interest. International and national collaborations aimed at the bioassay-directed sub-fractionation of materials extracted from the plant was then organized and to date, a series of six male Antifertility diterpene epoxides have been isolated. Their chemical structures have been identified and found to be triptolide, tripdiolide, triptolidenol, tripchlorolide, 16-hydroxytriptolide and T7 19 (structure not yet published). At the ED95 dosage levels, they act mainly on metamorphosing spermatids and testicular and epdidymal spermatozoa with exfoliation and inhibition of basic nuclear protein turnover of late spermatids, delayed spermiation and sperm head-tail separation and microtubule, microfilament and membrane damages. A preliminary toxic evaluation indicated that these compounds were immunosuppressive at dose levels 5–12 times their Antifertility doses. Immuno-suppression is an important weakness for an Antifertility agent, but if the immuno-suppressive dose of a drug is much higher than its Antifertility dose, it could yet be regarded as a safe contraceptive. Therefore, in the safety evaluation of compounds isolated from Tripterygium wilfordii, it warrants our attention to probe deeply into their precise dose/immuno-effect relationship.

Legesse Zerihun - One of the best experts on this subject based on the ideXlab platform.

  • phytochemical screening and pharmacological evaluations for the Antifertility effect of the methanolic root extract of rumex steudelii
    Journal of Ethnopharmacology, 2005
    Co-Authors: Endalk Gebrie, Eyasu Makonnen, Asfaw Debella, Legesse Zerihun
    Abstract:

    The practice of traditional medicine for the control of fertility in most parts of Ethiopia is based on the uses of plant medicines for many years. The fact that herbal medicines have been employed for such a long time does not guarantee their efficacy and safety. The aim of the present study was, therefore, to carry out phytochemical screening, efficacy and safety studies on one of the traditionally used Antifertility plants: Rumex steudelii. The secondary metabolites of the root of this plant were determined. The methanolic extract of the roots of this plant were investigated for their Antifertility activity in female rats and oral LD50 was determined in mice. The identification of the secondary metabolites showed that the roots of the plant contained phytosterols and polyphenols. It was found that the extract reduced significantly (p < 0.01) the number of litters. It also produced Antifertility effect in a dose dependent manner and the contraceptive effect was manifested for a definite period of time. Furthermore, the extract prolonged significantly the estrus cycle (p < 0.05) and the diestrous phase (p < 0.01) of the rats. The wet weights of the ovaries and uterus were shown to be reduced significantly (p < 0.01) and (p < 0.05), respectively. The oral LD50 of the extract was found to be 5 g/kg in mice. All these observations suggest that the extract has Antifertility effect and is safe at the effective Antifertility doses employed in this study.

Yansheng Dong - One of the best experts on this subject based on the ideXlab platform.

  • zero order release of gossypol improves its Antifertility effect and reduces its side effects simultaneously
    Biomacromolecules, 2018
    Co-Authors: Na Wen, Yansheng Dong, Rui Song, Wenpeng Zhang, Chao Sun, Xiaomei Zhuang, Ying Guan, Qingbin Meng, Yongjun Zhang
    Abstract:

    Gossypol was considered a promising male contraceptive but finally failed due to two side effects: hypokalemia and the irreversibility of its contraceptive effect. Here we demonstrate that sustained zero-order release could be a solution for these problems. The in vitro release of gossypol from gossypol/PEG layer-by-layer films follows a perfect zero-order kinetics. In vivo tests indicate that the films can maintain the plasma drug concentration constant in male SD rats for ∼20 days for a 30-bilayer film. The plasma drug concentration is 2 orders of magnitude lower than the peak plasma drug concentration when administered orally and the daily dose is >50-fold lower than the commonly used contraceptive oral dose. However, significant Antifertility effects were still observed. Furthermore, hypokalemia was not observed, and the Antifertility effects can be reversed after a recovery period. The results suggest that zero-order release can significantly improve the desired Antifertility effect of gossypol and, ...

  • Zero-Order Release of Gossypol Improves Its Antifertility Effect and Reduces Its Side Effects Simultaneously
    2018
    Co-Authors: Na Wen, Yansheng Dong, Rui Song, Wenpeng Zhang, Chao Sun, Xiaomei Zhuang, Ying Guan, Qingbin Meng, Yongjun Zhang
    Abstract:

    Gossypol was considered a promising male contraceptive but finally failed due to two side effects: hypokalemia and the irreversibility of its contraceptive effect. Here we demonstrate that sustained zero-order release could be a solution for these problems. The in vitro release of gossypol from gossypol/PEG layer-by-layer films follows a perfect zero-order kinetics. In vivo tests indicate that the films can maintain the plasma drug concentration constant in male SD rats for ∼20 days for a 30-bilayer film. The plasma drug concentration is 2 orders of magnitude lower than the peak plasma drug concentration when administered orally and the daily dose is >50-fold lower than the commonly used contraceptive oral dose. However, significant Antifertility effects were still observed. Furthermore, hypokalemia was not observed, and the Antifertility effects can be reversed after a recovery period. The results suggest that zero-order release can significantly improve the desired Antifertility effect of gossypol and, meanwhile, significantly reduce its side effects. We envision the drug could be developed to be an effective, safe, and reversible male contraceptive by zero-order release