Metabolism and Pharmacokinetics of Phytochemicals in the Human Body

Abstract

Background: Phytochemicals are obtained from various plants and used for the treatment of diseases as both traditional and modern medicines. Poor bioavailability of phytochemicals is a major concern in applying phytochemicals as a therapeutic agent. It is, therefore, necessary to understand the metabolism and pharmacokinetics of phytochemicals for its implication as a therapeutic agent. Methods: Articles on the metabolism of phytochemicals from the PubMed database. The articles were classified into the digestion, absorption, metabolism, excretion, toxicity, and bioavailability of phytochemicals and the effect of gut microbiota on the metabolism of phytochemicals. Results: The metabolism of each phytochemical is largely dependent on the individual's digestive ability, membrane transporters, metabolizing enzymes and gut microbiota. Further, the form of the phytochemical and genetic make-up of the individual greatly influences the metabolism of phytochemicals. Conclusion: The metabolism of phytochemicals is mostly depended on the form of phytochemicals and individualspecific variations in the metabolism of phytochemicals. Understanding the metabolism and pharmacokinetics of phytochemicals might help in applying plant-based medicines for the treatment of various diseases.

Phytochemicals in Cancer Immune Checkpoint Inhibitor Therapy

“…Several clinical trials using phytochemicals have been conducted for various diseases or immune-related activity, but there are currently no clinical trials for phytochemicals with ICI monotherapy or combination agents with other immunomodulatory anti-cancer agents. This may be due to the poor pharmacokinetics and pharmacodynamics features of a large number of phytochemicals [261]. Current ICI therapy is used alone or combined with conventional chemotherapy in patients with certain cancer types, while severe side effects can be accompanied during combination therapy.…”

Methyl Brevifolincarboxylate Attenuates Free Fatty Acid-Induced Lipid Metabolism and Inflammation in Hepatocytes through AMPK/NF-κB Signaling Pathway

“…The metabolism of phytochemicals depends on the individual’s digestive ability, membrane transporters, metabolizing enzymes and gut microbiota. The exogenous compounds (phytochemicals) are metabolize in gut microbiota, and phase I and phase II metabolism through oxidation, hydration, demethylation, hydrogenation, and SH 2 addition, as well as different glucuronide/sulfate conjugates [ 32 ]. A recent study reported that the structurally similar compounds to MBC are orally bioavailable and undergo gut microbiotic metabolism (dehydroxylation and reduction), and phase II metabolism (glucuronidation and sulfation) in healthy humans [ 33 ].…”

Designing a Clinical Study With Dietary Supplements: It's All in the Details

“…Blood collection times of 0.0, 0.5, 1, 2, 4, 6, 8, 12, 24, and 48 h are fairly common, although these can be modified for subject convenience. To be as efficient and practical as possible, a single dose of extract is administered in the morning (with or without food) and blood sampling will span at least 12 h the first day, with subsequent blood draws at 24 and perhaps 48 h. Given that most phytochemicals have fairly short elimination half-lives in humans, samples obtained after 24 h may not be necessary ( 30 , 32 ). A clearly defined biomarker as determined by pre-clinical studies is essential for the clinical PK study.…”