Ero Michael Penfield, Ng Connie M, Mihailovski Tamara, Harvey Nathaniel R, Lewis Brad Howard
Machaon Diagnostics, Oakland, CA, USA.
Altern Ther Health Med. 2013 May-Jun;19(3):16-9.
Nattokinase is a serine protease and is derived from natto, a traditional Japanese, fermented, soybean food meal. Multiple authors have described the significant fibrinolytic, antithrombotic, and antihypertensive effects of natto. Nattokinase has been growing in popularity for use as a dietary supplement for the benefit of cardiovascular health. Little is known regarding the pharmacokinetic and pharmacodynamic properties of this enzyme, and the bioavailability of nattokinase is currently unknown.
This study intended to (1) detect nattokinase directly and immunologically, (2) show that nattokinase and/or its metabolites were detectable in human blood following ingestion of a commercial preparation, and (3) chart a pharmacokinetic dosing effect for nattokinase.
The research team designed the pilot study as an in vivo, human clinical trial. Healthy human subjects responded to an advertisement and were screened. Subjects who satisfied both inclusion and exclusion criteria were enrolled into the study. Subjects were then instructed to orally ingest a single capsule containing a known concentration of nattokinase immediately following a baseline blood draw. Subsequent blood draws occurred over a 24-h period.
This study was conducted in Oakland, California, at a clinical reference laboratory and was performed with the approval of an institutional review board (IRB) to ensure that appropriate ethical standards were met.
Eleven healthy participants (five male, six female, ages 21-65), who met eligibility criteria, were enrolled.
INTERVENTION(S): Administration of nattokinase occurred orally with the ingestion of a single daily dose (2000 FU) of nattokinase. Capsules, each containing approximately 100 mg of nattokinase, in softgel form (NSK-SD, Japan Bio Science Laboratory, Osaka, Japan), were used in the study.
OUTCOME MEASURE(S): Baseline blood samples were collected, and participants were observed swallowing a single capsule of the nattokinase supplement before returning at 2, 4, 8, 12, 24, and 48 h post ingestion for subsequent blood draws. The presence of nattokinase in serum was measured by an enzyme-linked immunosorbent assay (ELISA), using a rabbit, polyclonal, antinattokinase-capture antibody. A pharmacokinetic pattern was observed for nattokinase between baseline and 48 h postdose.
Peak serum levels of nattokinase were observed at approximately 13.3 h ± 2.5 h (mean ± standard error) postdose. Statistically significant increases in binding were detectable from baseline when comparing averaged data at time points t = 2 h-t = 24 h.
These results provided the first evidence that nattokinase can be measured directly in the blood of humans. The results further suggest that a larger, more extensive, pharmacokinetic study of nattokinase is warranted. Additionally, looking for intact enzyme and bioactive nattokinase peptides should be a consideration for future studies investigating the pharmacokinetic profile of nattokinase.
纳豆激酶是一种丝氨酸蛋白酶，源自日本传统发酵大豆食品纳豆。多位作者描述了纳豆具有显著的纤溶、抗血栓和降压作用。纳豆激酶作为一种有益于心血管健康的膳食补充剂，其受欢迎程度一直在不断提高。关于这种酶的药代动力学和药效学特性知之甚少，目前纳豆激酶的生物利用度也未知。
本研究旨在（1）直接通过免疫学方法检测纳豆激酶，（2）证明摄入商业制剂后人体血液中可检测到纳豆激酶及其代谢产物，（3）绘制纳豆激酶的药代动力学给药效应图。
研究团队将该初步研究设计为一项人体体内临床试验。健康人体受试者回应了一则广告并接受了筛查。符合纳入和排除标准的受试者被纳入研究。然后，受试者在基线采血后立即被指示口服一粒含有已知浓度纳豆激酶的胶囊。随后在24小时内进行后续采血。
本研究在加利福尼亚州奥克兰的一家临床参考实验室进行，并在机构审查委员会（IRB）的批准下进行，以确保符合适当的伦理标准。
招募了11名符合资格标准的健康参与者（5名男性，6名女性，年龄21 - 65岁）。
通过口服方式给予纳豆激酶，每日单剂量（2000 FU）纳豆激酶。研究中使用了软胶囊形式的胶囊，每个胶囊约含100毫克纳豆激酶（NSK - SD，日本生物科学实验室，大阪，日本）。
采集基线血样，观察参与者吞服一粒纳豆激酶补充剂胶囊，然后在服药后2、4、8、12、24和48小时返回进行后续采血。使用兔多克隆抗纳豆激酶捕获抗体，通过酶联免疫吸附测定（ELISA）法测定血清中纳豆激酶的存在。观察纳豆激酶在基线至给药后48小时之间的药代动力学模式。
给药后约13.3小时±2.5小时（平均值±标准误差）观察到纳豆激酶的血清峰值水平。比较t = 2小时至t = 24小时时间点的平均数据时，与基线相比，结合有统计学显著增加。
这些结果提供了首个证据，证明纳豆激酶可在人体血液中直接测量。结果进一步表明，有必要对纳豆激酶进行更大规模、更广泛的药代动力学研究。此外，在未来研究纳豆激酶的药代动力学特征时，应考虑寻找完整的酶和具有生物活性的纳豆激酶肽。
