socio
Bluelighter
- Joined
- Dec 14, 2009
- Messages
- 342
Supposedly this was a new finding in 2001. I haven't heard of it. Is it correct?
The forums regularly point out that Grapefruit Juice [GJ] potentiates (or at least delays the elimination/metabolism) of benzos & opioids by inhibiting Cytochrome P450 liver enzymes (3A4, and I believe 2A6 and 2D6 [right?], among others responsible for breaking down many benzos and opioids into less-active or inactive metabolites). Cimetidine aka Tagamet does something similar.
I've seen posts about Lemon Juice [LJ] potentiating mushrooms (supposedly due to vitamin c) & poppy tea (supposedly by acidifying).
I've never heard LJ mentioned as a potentiator via liver enzyme inhibition like GJ. But perusing the web, I noticed that there is research claiming that LJ does this almost as well as GJ (a couple other sources as well).
http://www.ncbi.nlm.nih.gov/pubmed/18968322
Application to drug-food interactions of living cells as in vitro model expressing cytochrome P450 activity: enzyme inhibition by lemon juice.
Baltes MR, Dubois JG, Hanocq M. Talanta. 2001 Jun 21;54(5):983-7.
Abstract
Classical inhibitors of human cytochrome P450 3A4 activity, such as ketoconazol and quercetin, are tested to prove the efficiency of a new metabolisation model using living entire cells. Grapefruit juice is a well-known potent inhibitor of cytochrome P450 3A4 activity. With regard to the clinical relevance of grapefruit juice-drug interactions, an investigation of other common juices is undertaken with this in vitro model.... It is demonstrated for the first time that lemon juice significantly inhibits by 60+/-3% the CYP3A4-mediated oxidation. Grapefruit juice inhibits this activity by 82+/-4%. The mechanism of lemon juice inhibition is competitive, whereas it is mixed for grapefruit juice. ...
There are a couple other references out there.
Am I understanding this correctly, LJ is basically 75% (60%/~80%) as effective at 3A4 enzyme inhibition compared to GFJ?
Anyone know what they mean by "competitive" vs. "mixed" inhibition? (My knowledge of this is practical, not based on formal education; I simply try to figure out what will work and get a sense of why.) Would be nice to know if there are more good options available than GJ and Tag, in case they're not around...
The forums regularly point out that Grapefruit Juice [GJ] potentiates (or at least delays the elimination/metabolism) of benzos & opioids by inhibiting Cytochrome P450 liver enzymes (3A4, and I believe 2A6 and 2D6 [right?], among others responsible for breaking down many benzos and opioids into less-active or inactive metabolites). Cimetidine aka Tagamet does something similar.
I've seen posts about Lemon Juice [LJ] potentiating mushrooms (supposedly due to vitamin c) & poppy tea (supposedly by acidifying).
I've never heard LJ mentioned as a potentiator via liver enzyme inhibition like GJ. But perusing the web, I noticed that there is research claiming that LJ does this almost as well as GJ (a couple other sources as well).
http://www.ncbi.nlm.nih.gov/pubmed/18968322
Application to drug-food interactions of living cells as in vitro model expressing cytochrome P450 activity: enzyme inhibition by lemon juice.
Baltes MR, Dubois JG, Hanocq M. Talanta. 2001 Jun 21;54(5):983-7.
Abstract
Classical inhibitors of human cytochrome P450 3A4 activity, such as ketoconazol and quercetin, are tested to prove the efficiency of a new metabolisation model using living entire cells. Grapefruit juice is a well-known potent inhibitor of cytochrome P450 3A4 activity. With regard to the clinical relevance of grapefruit juice-drug interactions, an investigation of other common juices is undertaken with this in vitro model.... It is demonstrated for the first time that lemon juice significantly inhibits by 60+/-3% the CYP3A4-mediated oxidation. Grapefruit juice inhibits this activity by 82+/-4%. The mechanism of lemon juice inhibition is competitive, whereas it is mixed for grapefruit juice. ...
There are a couple other references out there.
Am I understanding this correctly, LJ is basically 75% (60%/~80%) as effective at 3A4 enzyme inhibition compared to GFJ?
Anyone know what they mean by "competitive" vs. "mixed" inhibition? (My knowledge of this is practical, not based on formal education; I simply try to figure out what will work and get a sense of why.) Would be nice to know if there are more good options available than GJ and Tag, in case they're not around...
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