The involvement of multidrug and toxin extrusion protein 1 in the distribution and excretion of berberine

Protoberberine alkaloids: A review of the gastroprotective effects, pharmacokinetics, and toxicity

BACKGROUND

Stomach diseases have become global health concerns. Protoberberine alkaloids (PBAs) are a group of quaternary isoquinoline alkaloids from abundant natural sources and have been shown to improve gastric disorders in preclinical and clinical studies. The finding that PBAs exhibit low oral bioavailability but potent pharmacological activity has attracted great interest.

PURPOSE

This review aims to provide a systematic review of the molecular mechanisms of PBAs in the treatment of gastric disorders and to discuss the current understanding of the pharmacokinetics and toxicity of PBAs.

METHODS

The articles related to PBAs were collected from the Web of Science, Pubmed, and China National Knowledge Infrastructure databases using relevant keywords. The collected articles were screened and categorized according to their research content to focus on the gastroprotective effects, pharmacokinetics, and toxicity of PBAs.

RESULTS

Based on the results of preclinical studies, PBAs have demonstrated therapeutic effects on chronic atrophic gastritis and gastric cancer by activating interleukin-4 (IL-4)/signal transducer and activator of transcription 6 (STAT6) pathway and suppressing transforming growth factor-beta 1 (TGF-β1)/phosphoinositide 3-kinase (PI3K), Janus kinase-2 (JAK2)/signal transducers and activators of transcription 3 (STAT3), and mitogen-activated protein kinase (MAPK) pathways. The major PBAs exhibit similar pharmacokinetic properties, including rapid absorption, slow elimination, and low bioavailability. Notably, the natural organ-targeting property of PBAs may account for the finding of their low blood levels and high pharmacological activity. PBAs interact with other compounds, including conventional drugs and natural products, by modulation of metabolic enzymes and transporters. The potential tissue toxicity of PBAs should be emphasized due to their high tissue accumulation.

CONCLUSION

This review highlights the gastroprotective effects, pharmacokinetics, and toxicity of PBAs and will contribute to the evaluation of drug properties and clinical translational studies of PBAs, accelerating their transfer from the laboratory to the bedside.

Effect of Oregon grape root extracts on P-glycoprotein mediated transport in in vitro cell lines

Purpose: This study aims to investigate the potential of Oregon grape root extracts to modulate the activity of P-glycoprotein. Methods: We performed 3H-CsA or 3H-digoxin transport experiments in the absence or presence of two sources of Oregon grape root extracts (E1 and E2), berberine or berbamine in Caco-2 and MDCKII-MDR1 cells. In addition, real time quantitative polymerase chain reaction (RT-PCR) was performed in Caco-2 and LS-180 cells to investigate the mechanism of modulating P-glycoprotein. Results: Our results showed that in Caco-2 cells, Oregon grape root extracts (E1 and E2) (0.1-1 mg/mL) inhibited the efflux of CsA and digoxin in a dose-dependent manner. However, 0.05 mg/mL E1 significantly increased the absorption of digoxin. Ten µM berberine and 30 µM berbamine significantly reduced the efflux of CsA, while no measurable effect of berberine was observed with digoxin. In the MDCKII-MDR1 cells, 10 µM berberine and 30 µM berbamine inhibited the efflux of CsA and digoxin. Lastly, in real time RT-PCR study, Oregon grape root extract (0.1 mg/mL) up-regulated mRNA levels of human MDR1 in Caco-2 and LS-180 cells at 24 h. Conclusion: Our study showed that Oregon grape root extracts modulated P-glycoprotein, thereby may affect the bioavailability of drugs that are substrates of P-glycoprotein.

Pharmacokinetic of berberine, the main constituent of Berberis vulgaris L.: A comprehensive review

Barberry (Berberis vulgaris L.) is a medicinal plant and its main constituent is an isoquinoline alkaloid named berberine that has multiple pharmacological effects such as antioxidant, anti-microbial, antiinflammatory, anticancer, anti-diabetes, anti-dyslipidemia, and anti-obesity. However, it has restricted clinical uses due to its very poor solubility and bioavailability (less than 1%). It undergoes demethylenation, reduction, and cleavage of the dioxymethylene group in the first phase of metabolism. Its phase two reactions include glucuronidation, sulfation, and methylation. The liver is the main site for berberine distribution. Berberine could excrete in feces, urine, and bile. Fecal excretion of berberine (11-23%) is higher than urinary and biliary excretion routes. However, a major berberine metabolite is excreted in urine greater than in feces. Concomitant administration of berberine with other drugs such as metformin, cyclosporine A, digoxin, etc. may result in important interactions. Thus, in this review, we gathered and dissected any related animal and human research articles regarding the pharmacokinetic parameters of berberine including bioavailability, metabolism, distribution, excretion, and drug-drug interactions. Also, we discussed and gathered various animal and human studies regarding the developed products of berberine with better bioavailability and consequently, better therapeutic effects.

Biodistribution and pharmacokinetic profile of berberine and its metabolites in hepatocytes

BACKGROUND

Berberine has been shown in clinical studies to have many health benefits, including anti-inflammatory and antioxidant properties, along with gut-flora balancing properties. However, its clinical efficacy is hindered by its low oral bioavailability and rapid metabolism.

PURPOSE

This study aims to identify the berberine metabolites' forms and characterize their biodistribution patterns in and out of HepG2 cells.

METHODS

The qualitative analysis of metabolites of berberine in HepG2 cells was performed using the LC/MSⁿ-IT-TOF method. Subsequent cellular pharmacokinetics characterization of intracellular and extracellular berberine and its metabolites was performed by LC-MS/MS analysis.

RESULTS

Berberine's metabolites of phase I metabolism were demethyleneberberine, jatrorrhizine, columbamine, berberrubine, etc., while its phase II metabolites were sulfate and glucuronide conjugates of phase I metabolites. Among the phase I metabolites of berberine, jatrorrhizine+columbamine accounted for over two-thirds of the total, followed by demethyleneberberine, which accounted for about a quarter. The intracellular demethyleneberberine is 25.14 times more enriched than extracellular demethyleneberberine. On the other hand, jatrorrhizine+columbamine and berberrubine were primarily distributed extracellularly, and their extracellular concentrations were 7.13 times and 15.61 times of their intracellular concentrations, respectively. Berberine metabolites produced in phase II metabolism are predominantly sulfate conjugates.

CONCLUSION

Our results show that demethyleneberberine is highly concentrated intracellularly in HepG2, possibly because it is an essential metabolite of berberine that likely contributes to berberine's efficacy. In light of our findings, berberine's poor plasma concentration-effectiveness characteristics have been partially explained.

Organic Cation Transporter Expression and Function in the CNS

The blood-brain barrier (BBB) and blood-cerebrospinal fluid barrier (BCSFB) represent major control checkpoints protecting the CNS, by exerting selective control over the movement of organic cations and anions into and out of the CNS compartment. In addition, multiple CNS cell types, e.g., astrocytes, ependymal cells, microglia, contribute to processes that maintain the status quo of the CNS milieu. To fulfill their roles, these barriers and cell types express a multitude of transporter proteins from dozens of different transporter families. Fundamental advances over the past few decades in our knowledge of transporter substrates, expression profiles, and consequences of loss of function are beginning to change basic theories regarding the contribution of various cell types and clearance networks to coordinated neuronal signaling, complex organismal behaviors, and overall CNS homeostasis. In particular, transporters belonging to the Solute Carrier (SLC) superfamily are emerging as major contributors, including the SLC22 organic cation/anion/zwitterion family of transporters (includes OCT1-3 and OCTN1-3), the SLC29 facilitative nucleoside family of transporters (includes PMAT), and the SLC47 multidrug and toxin extrusion family of transporters (includes MATE1-2). These transporters are known to interact with neurotransmitters, antidepressant and anxiolytic agents, and drugs of abuse. Clarifying their contributions to the underlying mechanisms regulating CNS permeation and clearance, as well as the health status of astrocyte, microglial and neuronal cell populations, will drive new levels of understanding as to maintenance of the CNS milieu and approaches to new therapeutics and therapeutic strategies in the treatment of CNS disorders. This chapter highlights organic cation transporters belonging to the SLC superfamily known to be expressed in the CNS, providing an overview of their identification, mechanism of action, CNS expression profile, interaction with neurotransmitters and antidepressant/antipsychotic drugs, and results from behavioral studies conducted in loss of function models (knockout/knockdown).

A Compositive Strategy to Study the Pharmacokinetics of TCMs: Taking Coptidis Rhizoma, and Coptidis Rhizoma-Glycyrrhizae Radix et Rhizoma as Examples

Pharmacokinetic studies are crucial for elucidating the effective constituents and formula compatibility of traditional Chinese medicines (TCMs). However, studies have usually been limited to single dosages and detection of systemic blood concentrations. To obtain comprehensive pharmacokinetic information, here we propose a multi-dosage and multi-sampling (blood from portal vein or systemic circulation, and liver) strategy to comparatively study the pharmacokinetics of multi-form TCMs, i.e., pure constituents, TCMs, or TCM formula extracts. Based on this strategy, we studied the pharmacokinetics of pure berberine, berberine in Coptidis Rhizoma (CRE), and berberine in Coptidis Rhizoma-Glycyrrhizae Radix et Rhizoma extracts (CR-GRE). After simple calculation and comparison of the obtained area under the curve (AUC) values, the results revealed the drastically different pharmacokinetic properties of pure berberine compared to CRE and CR-GRE. The results contribute to explaining the pharmacological loss of berberine activity after purification and the compatibility of the CR-GR drug pair. The results also innovatively showed that it was intestinal absorption that differentiated the pharmacokinetics of CRE and pure berberine, and CRE and CR-GRE. In conclusion, we propose a composite strategy to comparatively study the pharmacokinetics of TCMs, which could provide sufficient information to obtain a comprehensive view, before follow-up mechanism-of-action studies.