Phytomedicine, Toxicology and Reproductive Biochemistry Research Laboratory, Department of Biochemistry, University of Ilorin, Ilorin, Nigeria.
Department of Chemical Sciences, Bells University of Technology, Ota, Ogun State, Nigeria.
J Integr Med. 2017 Jan;15(1):64-76. doi: 10.1016/S2095-4964(17)60318-2.
The leaves of Parquetina nigrescens have been claimed in folk medicine to be useful for managing sexual dysfunction, but there is inadequate scientific evidence for this claim. This investigation was conducted to assess the effects of aqueous leaf extract of Parquetina nigrescens (AEPN) in rats induced with sexual dysfunction.
Male rats were allocated into various groups after being induced into sexual dysfunction with paroxetine hydrochloride. The groups were treated with distilled water, PowMaxM (reference drug), and the AEPN at 20, 40 and 80 mg/kg body weight (BW) respectively for 7 d. Frequencies of mount (MF), intromission (IF), ejaculation (EF), as well as latencies of mount (ML), intromission (IL) and post-ejaculatory interval (PEI) were progressively monitored with receptive female rats on days 1, 3 and 7. The precentage of mounted, intromitted, and ejaculated rats, intromission ratio (IR), copulatory efficiency (CE) and intercopulatory interval (ICI) were also computed. Standard methods were employed to determine the levels of serum luteinizing and follicle stimulating hormones (LH and FSH), testosterone, nitric oxide (NO) and the activity of phosphodiesterase V (PDE5).
The plant contained alkaloids, saponins, flavonoids, cardiac glycosides, steroids, tannins, phlobatannins, cardenolides, phenolics, anthraquinones and triterpenes with alkaloids (2.32 mg/g) occurring in greatest quantity while flavonoids, anthraquinones and cardenolides (0.01 mg/g, each) were the least. All the 20 standard amino acids were detected in the plant leaf, with the lowest concentration being 0.30 mg/g for methionine and the highest being 2.12 mg/g for cysteine. Furthermore, P. nigrescens leaves contained Na, K, Fe, Mg, Zn, Ca, Cu, Mn, P, Pb, Cd, Ni, Cr, and Co, with Fe present in the highest and Co the lowest concentrations. Paroxetine significantly (P<0.05) reduced MF, IF, EF, percentage mounted , intromitted, ejaculated, IR, CE, serum testosterone, LH, FSH and NO, while ML, IL, PEI, IF and PDE5 were significantly (P<0.05) increased and/or prolonged. The AEPN significantly reversed these paroxetine-treatment-related alterations with most profound activity at the highest dose of 80 mg/kg BW, similar to that of the PowMaxM-treated animals.
The AEPN restored both the physical and biochemical indices of male sexual activity/competence via changes in reproductive hormones, NO and PDE5 activity. The pro-sexual activity, attributed to a myriad of mineral, amino acid and secondary metabolite constituents, was best at 80 mg/kg BW of AEPN.
民间医学声称，黑风藤的叶子可用于治疗性功能障碍，但这一说法缺乏充分的科学证据。本研究旨在评估黑风藤叶水提物（AEPN）对盐酸帕罗西汀诱导的性功能障碍大鼠的影响。
雄性大鼠在盐酸帕罗西汀诱导下发生性功能障碍后，被分配到不同的组中。将这些组分别用蒸馏水、PowMaxM（参比药物）和 AEPN 以 20、40 和 80mg/kg 体重（BW）进行治疗，持续 7 天。在第 1、3 和 7 天，将接受雌性大鼠的接受状态下，对大鼠的交配频率（MF）、插入频率（IF）、射精频率（EF）以及交配潜伏期（ML）、插入潜伏期（IL）和射精后潜伏期（PEI）进行逐步监测。还计算了骑跨、插入和射精的大鼠百分比、插入比（IR）、交配效率（CE）和交配对间隔（ICI）。采用标准方法测定血清促黄体生成素（LH）和促卵泡激素（FSH）、睾酮、一氧化氮（NO）和磷酸二酯酶 V（PDE5）的活性。
该植物含有生物碱、皂苷、类黄酮、强心苷、甾体、单宁、缩合鞣质、卡烯内酯、酚类、蒽醌和三萜类化合物，其中生物碱（2.32mg/g）含量最高，而类黄酮、蒽醌和卡烯内酯（0.01mg/g，每种）含量最低。在植物叶片中检测到 20 种标准氨基酸，最低浓度为 0.30mg/g 的蛋氨酸，最高浓度为 2.12mg/g 的半胱氨酸。此外，黑风藤叶含有 Na、K、Fe、Mg、Zn、Ca、Cu、Mn、P、Pb、Cd、Ni、Cr 和 Co，其中 Fe 的含量最高，Co 的含量最低。盐酸帕罗西汀显著（P<0.05）降低了 MF、IF、EF、骑跨百分比、插入、射精、IR、CE、血清睾酮、LH、FSH 和 NO，而 ML、IL、PEI、IF 和 PDE5 则显著（P<0.05）增加和/或延长。AEPN 显著逆转了这些与盐酸帕罗西汀治疗相关的变化，在 80mg/kg BW 的最高剂量下表现出最显著的活性，与 PowMaxM 治疗的动物相似。
AEPN 通过改变生殖激素、NO 和 PDE5 活性，恢复了雄性动物的性活动/能力的生理和生化指标。这种促进性行为的作用归因于多种矿物质、氨基酸和次生代谢产物的成分，在 80mg/kg BW 的 AEPN 中效果最佳。
