Organic cation transporter and multidrug and toxin extrusion 1 co-mediated interaction between metformin and berberine

Inhibitory effect of flavonoids on multidrug and toxin extrusion protein 1 function: Implications for food/herb-drug interaction and drug-induced kidney injury

Multidrug and toxin extrusion protein 1 (MATE1), an efflux transporter mainly expressed in renal proximal tubules, mediates the renal secretion of organic cationic drugs. The inhibition of MATE1 will impair the excretion of drugs into the tubular lumen, leading to the accumulation of nephrotoxic drugs in the kidney and consequently potentiating nephrotoxicity. Screening and identifying potent MATE1 inhibitors can predict or minimize the risk of drug-induced kidney injury. Flavonoids, a group of polyphenols commonly found in foodstuffs and herbal products, have been reported to cause transporter-mediated food/herb-drug interactions. Our objective was to investigate the inhibitory effects of flavonoids on MATE1 in vitro and in vivo and to assess the effects of flavonoids on cisplatin-induced kidney injury. Thirteen flavonoids exhibited significant transport activity inhibition (>50%) on MATE1 in MATE1-MDCK cells. Among them, the six strongest flavonoid inhibitors, including irisflorentin, silymarin, isosilybin, sinensetin, tangeretin, and nobiletin, markedly increased cisplatin cytotoxicity in these cells. In cisplatin-induced in vivo renal injury models, irisflorentin, isosilybin, and sinensetin also increased serum creatinine and blood urea nitrogen levels to different degrees, especially irisflorentin, which exhibited the most potent nephrotoxicity with cisplatin. The pharmacophore model indicated that the hydrogen bond acceptors at the 3, 5, and 7 positions may play a critical role in the inhibitory effect of flavonoids on MATE1. Our findings provide helpful information for predicting the potential risks of flavonoid-containing food/herb-drug interactions and avoiding the exacerbation of drug-induced kidney injury via MATE1 mediation.

The Role of Natural Products in Diabetic Retinopathy

Diabetic retinopathy (DR) is one of the most severe complications of diabetes mellitus and potentially leads to significant visual impairment and blindness. The complex mechanisms involved in the pathological changes in DR make it challenging to achieve satisfactory outcomes with existing treatments. Diets conducive to glycemic control have been shown to improve outcomes in diabetic patients, thus positioning dietary interventions as promising avenues for DR treatment. Investigations have demonstrated that natural products (NPs) may effectively manage DR. Many types of natural compounds, including saponins, phenols, terpenoids, flavonoids, saccharides, alkaloids, and vitamins, have been shown to exert anti-inflammatory, antioxidant, anti-neovascular, and antiapoptotic effects in vivo and in vitro. Nevertheless, the clinical application of NPs still faces challenges, such as suboptimal specificity, poor bioavailability, and a risk of toxicity. Prospective clinical studies are imperative to validate the therapeutic potential of NPs in delaying or preventing DR.

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.

Study on herb-herb interaction between active components of Plantago asiatica L. seed and Coptis chinensis Franch. rhizoma based on transporters using UHPLC-MS/MS

The combined efficacy in lowering serum lipid levels and increasing kidney protection of Plantago asiatica L. seed (Plantago) and Coptis chinensis Franch. rhizoma (Coptis) is far better than the effects of either herb alone. This finding suggests that there must be some degree of herb-herb interactions (HHI) affect potency. Here, we chose geniposidic acid (GPA), acteoside (ACT), and plantagoamidinic acid A (PLA) as active components in Plantago, and berberine (BBR) as the active component in Coptis, and, using transporter gene-transfected Madin-Darby canine kidney (MDCK) cells in combination with specific substrates and inhibitors, investigated Plantago- Coptis HHIs. We also established a UPLC-MS/MS analytical method to determine substrate content. Results showed that PLA in Plantago was a substrate of rOCT1/2 and rMATE1, and had inhibitory effects on rOCT2 and rMATE1. We also found that ACT is a substrate of rMATE1, but GPA was not a substrate of any transporter that we investigated. When BBR was used as the substrate, the inhibition rate of 10 μM PLA was 53.6% on rOCT2 and 31.5% on rMATE1. The inhibition rates of 30 μM ACT and 30 μM GPA on rMATE1 were 47.0% and 31.0%, respectively. Thus, our findings suggest that GPA, ACT, PLA, and BBR have competitive interactions that are driven by the rOCT2 and rMATE1 transporters. These interactions affect the transport and excretion of compounds and result in efficacy changes after co-administration.

Transporter-mediated Natural Product-Drug Interactions

The increasing use of natural products in clinical practice has raised great concerns about the potential natural product-drug interactions (NDIs). Drug transporters mediate the transmembrane passage of a broad range of drugs, and thus are important determinants for drug pharmacokinetics and pharmacodynamics. Generally, transporters can be divided into ATP binding cassette (ABC) family and solute carrier (SLC) family. Numerous natural products have been identified as inhibitors, substrates, inducers, and/or activators of drug transporters. This review article aims to provide a comprehensive summary of the recent progress on the research of NDIs, focusing on the main drug transporters, such as P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), organic anion transporter 1 and 3 (OAT1/OAT3), organic anion-transporting polypeptide 1B1 and 1B3 (OATP1B1/OATP1B3), organic cation transporter 2 (OCT2), multidrug and toxin extrusion protein 1 and 2-K (MATE1/MATE2-K). Additionally, the challenges and strategies of studying NDIs are also discussed.

The interaction of alkaloids in Coptis chinensis Franch -Tetradium ruticarpum (A. Juss.) T.G. Hartley with hOCT1 and hOCT2

ETHNOPHARMACOLOGICAL RELEVANCE

Zuojin Pill, a traditional poly-herbal drug, comprises Coptis chinensis Franch - Tetradium ruticarpum (A. Juss.) T.G. Hartley (6:1). The significant quantity of alkaloids found in the participating herbs is a key aspect of the Zuojin Pill. According to traditional Chinese medicine (TCM), these numerous alkaloidal compounds within Zuojin Pill have various essential therapeutic effects.

AIM OF THE STUDY

The alkaloids in Tetradium are mainly indole alkaloids, while the alkaloids in Coptis are mostly isoquinoline alkaloids with low bioavailability. Alkaloids and their metabolites are nitrogen-containing compounds or weakly alkaline substances that can be partially ionized under physiological pH conditions. Fortunately, organic cation transporters (OCTs) play a crucial role in the cellular uptake of weakly alkaline compounds. Therefore, we speculated that the alkaloidal compounds might interact with liver cation transporters hOCT1 and kidney cation transporters hOCT2 to alter cell drug disposal. In order to clarify our hypothesis, a series of alkaloids-OCTs interaction experiments were conducted.

MATERIALS AND METHODS

HEK293 cells stably expressing hOCT1 and hOCT2 were modeled and evaluated. Afterward, high-content screening (HCS) was conducted to analyze whether the main alkaloids and their metabolites of Coptis - Tetradium were inhibitors of hOCT1 and hOCT2 transporters. Meanwhile, LC-MS/MS was used to investigate whether the alkaloidal compounds were substrates of hOCT1 and hOCT2 transporters. Finally, drug interactions at the cellular level were assessed by LC-MS/MS after co-administration of berberine and rutacorine.

RESULTS

Berberine, jateorhizine, coptisine, epiberberine, columbamine, demethyleneberberine, and berberrubine could significantly inhibit hOCT1 and hOCT2 activity. Isoquinoline alkaloids, including berberine, jateorhizine, coptisine, epiberberine, columbamine, and palmatine, were substrates of hOCT1 and hOCT2, but not the indole alkaloids evodiamine and rutaecarpine. Furthermore, evodiamine at a concentration of 20 μmol/L had a trivial effect on berberine accumulation in HEK293-hOCT2 cells.

CONCLUSIONS

These results support the idea that alkaloidal compounds within Coptis and Tetradium have hOCT1 and hOCT2 inhibitory activity or be their substrates, and the increased oral bioavailability of berberine in vivo was closely related to the potential interactions of small molecules in Coptis- Tetradium. Overall, our study provides a framework for investigating the potential interactions of small molecules in Coptis- Tetradium.

Advances in Pharmacokinetic Mechanisms of Transporter-Mediated Herb-Drug Interactions

As the use of herbs has become more popular worldwide, there are increasing reports of herb-drug interactions (HDIs) following the combination of herbs and drugs. The active components of herbs are complex and have a variety of pharmacological activities, which inevitably affect changes in the pharmacokinetics of chemical drugs in vivo. The absorption, distribution, metabolism, and excretion of drugs in vivo are closely related to the expression of drug transporters. When the active components of herbs inhibit or induce the expression of transporters, this can cause changes in substrate pharmacokinetics, resulting in changes in the efficacy and toxicity of drugs. In this article, the tissue distribution and physiological functions of drug transporters are summarized through literature retrieval, and the effects of herbs on drug transporters and the possible mechanism of HDIs are analyzed and discussed in order to provide ideas and a reference for further guiding of safe clinical drug use.

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.

The key role of organic anion transporter 3 in the drug-drug interaction between tranilast and methotrexate

Tranilast, N-(3',4'-dimethoxycinnamoyl)-anthranilic acid, is an anti-allergic drug and is considered for use in the treatment of rheumatoid arthritis. Methotrexate, an antimetabolite and folate antagonist to treat some cancers, is also a first-line drug for RA. The aim of this study was to understand whether tranilast could inhibit renal uptake transporters (Oat1, Oat3, and Oct2) and whether MTX combined with TL would have drug-drug interactions. The results of kidney slices and HEK293T-OAT3 cell uptake experiments showed that TL (10 μM) could inhibit the uptake of penicillin G and MTX, which are substrates of OAT3. When TL (10 mg/kg) was combined with MTX (5 mg/kg), the area under the curve and peak concentration of MTX increased by 46.46% and 113.51%, respectively, while the pharmacokinetic process of tranilast (10 mg/kg) was not changed by methotrexate (5 mg/kg). TL could increase plasma exposure of MTX by inhibiting Oat3 in vitro and in vivo.

The effect of Chinese herbal formulas combined with metformin on modulating the gut microbiota in the amelioration of type 2 diabetes mellitus: A systematic review and meta-analysis

To assess and analyse the effectiveness and safety of combined Chinese herbal formula (CHF) and metformin treatment in the modulation of the gut microbiota in the amelioration of type 2 diabetes mellitus(T2DM), all publications addressing the effect of this combination treatment on the quantitative alterations in the gut microbiota and glucose parameters were collected. Rob tool in the Cochrane handbook was performed to evaluate the methodological quality of all included studies. Relevant information and statistics were abstracted and synthesized in Review Manager 5.4 to evaluate the efficacy of combination treatment. Sensitivity analyses and subgroup analyses were used to analyse the sources of heterogeneity. Publication bias analyses were performed by Stata software to assess the robustness and quality of the outcomes. As a result, a total of 12 eligible RCTs with 1307 T2DM participants from 7 electronic databases were included. Combined CHF with metformin treatment showed better efficacies than metformin monotherapy in regulating the structure of the gut microbiota, characterized by increased Bifidobacterium, Lactobacillus and Bacteroidetes and decreased Enterobacteriaceae, Enterococcus, and Saccharomyces along with better decreases in glycated haemoglobin, fasting plasma glucose, 2-hour postprandial blood glucose, fasting insulin and homeostasis model assessment of insulin resistance. Subgroup analyses further analysed the effect of metformin doses and CHF classifications on controlling hyperglycaemia and altering the gut microbiota. In conclusion, our meta-analysis suggested that combined CHF with metformin treatment is promising for the modulation of the gut microbiota along with ameliorating hyperglycemia in T2DM patients. Importantly, more well-designed RCTs are needed to validate the outcomes and verify the treatment value for clinical purposes.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021291524, identifier CRD42021291524.

Pharmacokinetics and Pharmacological Activities of Berberine in Diabetes Mellitus Treatment

Traditional Chinese medicine (TCM) has good clinical application prospects in diabetes treatment. In addition, TCM is less toxic and/or has fewer side effects and provides various therapeutic effects. Berberine (BBR) is isolated as the main component in many TCM kinds (e.g., Rhizoma Coptidis and Berberidis Cortex). Furthermore, BBR can reduce blood sugar and blood fat, alleviate inflammation, and improve the state of patients. Based on the recent study results of BBR in diabetes treatment, the BBR pharmacokinetics and mechanism on diabetes are mainly studied, and the specific molecular mechanism of related experimental BBR is systematically summarized and analyzed. Clinical studies have proved that BBR has a good therapeutic effect on diabetes, suggesting that BBR may be a promising drug candidate for diabetes. More detailed BBR mechanisms and pathways of BBR need to be studied further in depth, which will help understand the BBR pharmacology in diabetes treatment.

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).

Drug-Drug Interactions at Organic Cation Transporter 1

The interaction between drugs and various transporters is one of the decisive factors that affect the pharmacokinetics and pharmacodynamics of drugs. The organic cation transporter 1 (OCT1) is a member of the Solute Carrier 22A (SLC22A) family that plays a vital role in the membrane transport of organic cations including endogenous substances and xenobiotics. This article mainly discusses the drug-drug interactions (DDIs) mediated by OCT1 and their clinical significance.

Efficacy and mechanism of actions of natural antimicrobial drugs

Microbial infections have significantly increased over the last decades, and the mortality rates remain unacceptably high. The emergence of new resistance patterns and the spread of new viruses challenge the eradication of infectious diseases. The declining efficacy of antimicrobial drugs has become a global public health problem. Natural products derived from natural sources, such as plants, animals, and microorganisms, have significant efficacy for the treatment of infectious diseases accompanied by less adverse effects, synergy, and ability to overcome drug resistance. As the Chinese female scientist Youyou Tu received the Nobel Prize for the antimalarial drug artemisinin, antimicrobial drugs developed from Traditional Chinese Medicine are expected to receive increasing attention again. This review summarizes the antimicrobial agents derived from natural products approved for nearly 20 years and describes their efficacy and mode of action. The aim of this unit is to review the current status of antimicrobial drugs from natural products in order to increase the value of natural products as a source of novel drug candidates for infectious diseases.

Pharmacokinetic Interaction between Sorafenib and Atorvastatin, and Sorafenib and Metformin in Rats

The tyrosine kinase inhibitor sorafenib is the first-line treatment for patients with hepatocellular carcinoma (HCC), in which hyperlipidemia and type 2 diabetes mellitus (T2DM) may often coexist. Protein transporters like organic cation (OCT) and multidrug and toxin extrusion (MATE) are involved in the response to sorafenib, as well as in that to the anti-diabetic drug metformin or atorvastatin, used in hyperlipidemia. Changes in the activity of these transporters may lead to pharmacokinetic interactions, which are of clinical significance. The study aimed to assess the sorafenib−metformin and sorafenib−atorvastatin interactions in rats. The rats were divided into five groups (eight animals in each) that received sorafenib and atorvastatin (I_SOR+AT), sorafenib and metformin (II_SOR+MET), sorafenib (III_SOR), atorvastatin (IV_AT), and metformin (V_MET). Atorvastatin significantly increased the maximum plasma concentration (C_max) and the area under the plasma concentration–time curve (AUC) of sorafenib by 134.4% (p < 0.0001) and 66.6% (p < 0.0001), respectively. Sorafenib, in turn, caused a significant increase in the AUC of atorvastatin by 94.0% (p = 0.0038) and its metabolites 2−hydroxy atorvastatin (p = 0.0239) and 4−hydroxy atorvastatin (p = 0.0002) by 55.3% and 209.4%, respectively. Metformin significantly decreased the AUC of sorafenib (p = 0.0065). The AUC ratio (II_SOR+MET group/III_SOR group) for sorafenib was equal to 0.6. Sorafenib did not statistically significantly influence the exposure to metformin. The pharmacokinetic interactions observed in this study may be of clinical relevance in HCC patients with coexistent hyperlipidemia or T2DM.

Identification of a multi-component berberine 11-hydroxylase from Burkholderia sp. strain CJ1

Berberine (BBR) is a protoberberine alkaloid extracted from plants such as Coptis japonica (Ranunculaceae). In a previous report, we demonstrated the existence of a 11-hydroxylation pathway employed by BBR-utilizing bacteria for metabolism of BBR. In the present study, we report the identification of the genes brhA, brhB, and brhC as encoding a multicomponent BBR 11-hydroxylase in Burkholderia sp. strain CJ1. BrhA is belonging to the Rieske non-heme iron oxygenase (RO) family, a class of enzymes known to catalyze the first step in bacterial aromatic-ring hydroxylation. We further demonstrate that BrhA activity requires BrhB (ferredoxin reductase) and BrhC (ferredoxin) as electron transport chain components. A BLAST search revealed that BrhA exhibits 38% and 33% sequence identity to dicamba O-demethylase (DdmC; AY786443) and chloroacetanilide herbicides N-dealkylase (CndA; KJ461679), respectively. To our knowledge, this work represents the first report of a bacterial oxygenase catalyzing the metabolism of a polycyclic aromatic-ring alkaloid.

Abbreviations: BBR: berberine; D-BBR: demethyleneberberine; H-BBR: 11-hydroxyberberine; HD-BBR: 11-hydroxydemethyleneberberine; HDBA: 2-hydroxy-3,4-dimethoxybenzeneacetic acid; PAL: palmatine; H-PAL: 11-hydroxypalmatine; BRU: berberrubine; Fd: ferredoxin; FdR: ferredoxin reductase; ETC: electron transport chain

The Quest to Enhance the Efficacy of Berberine for Type-2 Diabetes and Associated Diseases: Physicochemical Modification Approaches

Berberine is a quaternary isoquinoline alkaloid that has been isolated from numerous plants which are still in use today as medicine and herbal supplements. The great deal of enthusiasm for intense research on berberine to date is based on its diverse pharmacological effects via action on multiple biological targets. Its poor bioavailability resulting from low intestinal absorption coupled with its efflux by the action of P-glycoprotein is, however, the major limitation. In this communication, the chemical approach of improving berberine's bioavailability and pharmacological efficacy is scrutinised with specific reference to type-2 diabetes and associated diseases such as hyperlipidaemia and obesity. The application of modern delivery systems, research from combination studies to preparation of berberine structural hybrids with known biologically active compounds (antidiabetic, antihyperlipidaemic and antioxidant), as well as synthesis approaches of berberine derivative are presented. Improvement of bioavailability and efficacy through in vitro and ex vivo transport studies, as well as animal models of bioavailability/efficacy in lipid metabolism and diabetes targets are discussed.