E/C Stack coupled with CYP3A4 inhibitor (Grapefruit Seed Extract)

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    Cool E/C Stack coupled with CYP3A4 inhibitor (Grapefruit Seed Extract)


    Cited from an article from the New York Times:

    Grapefruit juice interferes with the ability of CYP 3A4 to do that, increasing the potency of a drug by letting more of it enter the bloodstream, in effect producing an excessive dose.

    Grapefruit interacts with this enzyme only in the intestines, not in the liver or other places where it is found. As a result, the effect is seen only with medicines taken orally, not with injected drugs

    Interestingly enough...
    Among fruit juices, grapefruit has the strongest effect, but lime juice and orange juice made from Seville oranges similarly inhibit the CYP 3A4 enzyme. With some drugs, apple juice may interact in the same way.

    Anyways, per Wiki...

    Estimates of the turnover rate of human CYP3A4 vary widely. For hepatic CYP3A4, in vivo methods yield estimates of enzyme half-life mainly in the range of 70 to 140 hours, whereas in vitro methods give estimates from 26 to 79 hours.[8] Turnover of gut CYP3A4 is likely to be a function of the rate of enterocyte renewal; an indirect approach based on recovery of activity following exposure to grapefruit juice yields measurements in the 12 to 33 hour range.[8]

    So, my question is how many mg of GSE, since they usually come in 125mg pills, would be a sufficient amount to effectively increase the half life of a substance such as ephedrine, which normally can last from 3.5-7 hours? If the recovery of the CYP3A4 turnover is halted for at least 12-33 hours, does this stand to say that I can expect my pre-workout dosage of E/C to achieve a higher plasma peak concentration (duh?) and extended half life at least double of that of an individual that hasn't inhibited the enzyme?

    Since caffeine is a CYP3A4 substrate, does this stand to say that it will increase the grapefruit juices efficacy with respects to inhibitory actions on CYP3A4? Also, with certain substances like nangarin present in GSE, would the purported increase in half life with respect to caffeine boost the effects I'm looking for even greater? WILL I EVER SLEEP AGAIN!? (j/k)

    Also...

    moderate inhibitors of CYP3A4
    aprepitant[9] (antiemetic)
    some calcium channel blockers
    verapamil[9]
    diltiazem[9]
    some macrolide antibiotics
    erythromycin[9]
    some azole antifungals[19]
    fluconazole[9]
    bergamottin (constituent of grapefruit juice)[9]
    Valerian [21]

    With valerian being a moderately potent inhibitor of the same enzyme, might it be worth it to utilize lower dosages of the two substances in order to achieve an effect greater than that of a singular inhibitor?

    Also, with these two substances having the effect that they do, why is it that most individuals have not incorporated valerian or grapefruit juice into their pre-workout regimens, especially ones utilizing caffeine, as I stated above that nangarin would more than likely decrease the amount of powder needed to achieve the same effects?

    So many questions, so little time. Much thanks people, I appreciate the input.

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    I am not sure the GSE has the enzyme inhibitors that you are looking for. If memory serves, it's naringin/naringinin(sp?) as well as bergamottin that you are after and it has been used with success in products like Drive or RPM. Also, it would be difficult to gauge how much of these compounds you would be getting in run of the mill grapefruit juice.
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    I'd have a mod kick this over into the Supplement Science sub-forum. Awesome question/read.
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    Quote Originally Posted by bioman View Post
    I am not sure the GSE has the enzyme inhibitors that you are looking for. If memory serves, it's naringin/naringinin(sp?) as well as bergamottin that you are after and it has been used with success in products like Drive or RPM. Also, it would be difficult to gauge how much of these compounds you would be getting in run of the mill grapefruit juice.
    After reviewing a bit of literature, I believe your correct. That's a shame, as a gallon of Grapefruit juice costs about the same price as a 100 count of GSE. I've also been attempting to find a standalone nangarin supplement, but haven't been successful as of yet. Maybe I'll be able to locate a pharmacologic breakdown of levels of these substances found in a given grapefruit juice, as I'm sure that they must have looked into this because of its profound effect on some modern medicines. Thanks for the input bioman.

    Glad the subject is interesting to you as well DJ. I wish I was 6` 9 ( D : )

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