Effects of saikosaponin-d on CYP3A4 in HepaRG cell and protein-ligand docking study

How Plant Polyhydroxy Flavonoids Can Hinder the Metabolism of Cytochrome 3A4

Background/Objectives: Recent interest in dietary components and their effects on xenobiotic metabolism has highlighted their role in modulating drug pharmacokinetics. Cytochrome P450 3A4, a key isoform of the cytochrome P450 superfamily, is involved in the metabolism of over 50% of xenobiotics. Flavonoids, present in various foods and supplements, exhibit diverse biological activities influenced by the structural modifications in their scaffold. Methods: Fifteen polyhydroxy-flavonoid compounds were firstly tested by a high-throughput fluorimetric method for their ability to inhibit CYP3A4, where scutellarein and gossypetin were assessed for the first time. A molecular docking analysis was performed for the most active inhibitors to gain insight on their interaction with the active site of the enzyme. Results: Baicalein, luteolin, and scutellarein were the most potent flavones, presenting an IC50 of 15 ± 5, 31 ± 10, and 19 ± 7 μmol/L, respectively. Gossypetin, herbacetin, and quercetin were the most potent flavonols with IC50 of 40 ± 8, 32 ± 8, and 23 ± 5 μmol/L, respectively. The molecular docking analysis showed that hydroxyl groups at C6, C7, C8 (ring A), and C3' (ring B) on the flavone structure affect CYP3A4 enzyme catalysis by binding to its substrate-binding site as strong as known antiviral and antifungal drugs. Conclusions: Binding to the enzyme's active site with a strength comparable to known antifungal and antiviral drugs, baicalein and scutellarein were identified as the most active flavonoids. The vicinal hydroxyls in those molecules were pivotal to positioning and stabilization in the catalytic site pocket.

Research progress on the molecular mechanisms of Saikosaponin D in various diseases (Review)

Bupleurum, a Traditional Chinese Medicine (TCM) herb, is widely used in China and other Asian countries to manage chronic liver inflammation and viral hepatitis. Saikosaponin D (SSD), a triterpenoid saponin extracted from Bupleurum, exhibits extensive pharmacological properties, including anti‑inflammatory, antioxidant, anti‑apoptotic, anti‑fibrotic and anti‑cancer effects, making it a therapeutic candidate for numerous diseases. Clarifying the targets and molecular mechanisms underlying TCM compounds is essential for scientifically validating TCM's therapeutic roles in disease prevention and treatment, as well as for identifying novel therapeutic targets and lead compounds. This analysis comprehensively examines SSD's mechanisms across various conditions, such as myocardial injury, pulmonary diseases, hepatic disorders, renal pathologies, neurological disorders, diabetes and cancer. In addition, challenges and potential solutions encountered in SSD research are addressed. SSD is posited as a promising monomer for multifaceted therapeutic applications and this article aims to enhance researchers' understanding of the current landscape of SSD studies, offering strategic insights to guide future investigations.

3D spheroid HepaRG and fluorescent biphasic tracer for CYP3A4-mediated antibiotic interaction monitoring in sepsis

Cytochrome P450 3A4 (CYP3A4) is a crucial enzyme in the metabolism of xenobiotics, particularly in drug metabolism interactions (DDIs), making it a significant factor in clinical drug use. However, current assay techniques are both laborious and costly, making it difficult to construct a high-throughput monitoring method that can be used in conjunction with the clinic. This poses certain safety hazards for drug combination. Therefore, it is crucial to develop a synchronized monitoring method for the inhibition and induction of CYP3A4. In this study, we utilized 3D culture technology to develop a HepaRG cells spheroid model. The CYP450 and transporter expression, the albumin secretion, and urea synthesis capacity characteristics were analyzed. The NEN probe was utilized as a tracer molecule for CYP3A4. The fluorescence intensity of metabolites was characterized by laser confocal technique to determine the inhibition and expression of CYP3A4 in the HepaRG cell spheroid model by the antibiotics for sepsis. The results indicate that the HepaRG sphere model successfully possessed the physiological phenotype of the liver, which could be used for drug interaction monitoring. Through positive drug testing, NEN probe was able to achieve bidirectional characterization of CYP3A4 induction and inhibition. The monitoring method described in this paper was successfully applied to drug interaction monitoring of commonly used antibiotics in sepsis patients, which is a convenient and rapid monitoring method. The proposed method offers a new strategy for monitoring CYP3A4-mediated drug-drug interactions with a high-throughput assay, which will help to improve the safety of clinical drug combination.

Effects of total saikosaponins on CYP3A4 and CYP1A2 in HepaRG cells

Total saikosaponins (TSS) form a group of chemically and biologically active components that can be extracted from Bupleurum, with reported antidepressive, anti-inflammatory, antiviral, antiendotoxin, antitumor, anti-pulmonary fibrosis and anti-gastric ulcer effects. Bupleurum or TSS is frequently utilized in clinical practice alongside other medications (such as entecavir, lamivudine, compound paracetamol and amantadine hydrochloride capsules), leading to an increased risk of drug-drug interactions. The cytochrome P450 (CYP) family serves a critical role in the metabolism of numerous essential drugs (such as tamoxifen, ibuprofen and phenytoin), where the majority of drug interactions involve CYP-mediated metabolism. It is therefore essential to understand the effects of key components of Bupleurum on CYPs when administering combination therapies containing TSS or Bupleurum. The present study aimed to investigate the effects of TSS on the mRNA and protein expression of CYP3A4 and CYP1A2 in HepaRG cells. The effects of TSS on the survival of HepaRG cells was investigated using the Cell Counting Kit-8 (CCK-8) method. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot (WB) analysis were used to assess the effects of different concentrations of TSS (0, 5, 10 and 15 µg/ml) on CYP3A4 and CYP1A2 mRNA and protein expression in HepaRG cells. Based on the CCK-8 assay results, it was observed that the cell viability remained above 80% when treated with 1, 5, 10 and 15 µg/ml TSS. Although there was a statistically significant reduced cell viability at TSS concentrations of 10 and 15 µg/ml compared with the control group, the findings indicated that TSS did not exhibit notable cytotoxic effects at these concentrations. Furthermore, RT-qPCR results revealed that compared with those in the control group, TSS at concentrations of 10 and 15 µg/ml reduced CYP3A4 mRNA expression but increased CYP1A2 mRNA expression in HepaRG cells at concentrations of 15 µg/ml. WB analysis found that TSS at concentrations of 10 and 15 µg/ml downregulated CYP3A4 protein expression in HepaRG cells while increasing CYP1A2 protein expression at concentrations of 15 µg/ml. Results in the present study suggest that TSS can inhibit CYP3A4 mRNA and protein expression, but exerts opposite effects on their CYP1A2 counterparts. These findings suggest that it is necessary to consider drug interactions between clinical preparations containing TSS or Bupleurum and drugs metabolized by CYP3A4 and CYP1A2 to avoid potential adverse drug reactions in clinical practice.

Bupleurum in Treatment of Depression Disorder: A Comprehensive Review

The incidence of depression has been steadily rising in recent years, making it one of the most prevalent mental illnesses. As the pursuit of novel antidepressant drugs captivates the pharmaceutical field, the therapeutic efficacy of Traditional Chinese Medicine (TCM) has been widely explored. Chaihu (Bupleurum) has been traditionally used for liver conditions such as hepatitis, liver inflammation, liver fibrosis, and liver cancer. It is believed to have hepatoprotective effects, promoting liver cell regeneration and protecting against liver damage. In addition, Bupleurum has also been used as a Jie Yu (depression-relieving) medicine in China, Japan, Republic of Korea, and other Asian countries for centuries. This review article aims to summarize the research conducted on the antidepressant properties and mechanisms of Bupleurum, as well as discuss the potential of TCM formulas containing Bupleurum. This review highlights various antidepressant ingredients isolated from Bupleurum, including saikosaponin A, saikosaponin D, rutin, puerarin, and quercetin, each with distinct mechanisms of action. Additionally, Chinese herb prescriptions and extracts containing Bupleurum, such as Chaihu Shugansan, Xiaoyaosan, and Sinisan, are also included due to their demonstrated antidepressant effects. This review reveals that these Bupleurum compounds exhibit antidepressant effects through the regulation of neurotransmitter mechanisms (such as 5-HT and DA), the NMDA (N-methyl-D-aspartate) system, brain-derived neurotrophic factor (BDNF), and other intracellular signaling pathways. Collectively, this comprehensive review provides insights into the multiple applications of Bupleurum in the treatment of depression and highlights its potential as an alternative or complementary approach to traditional therapies. However, it is essential to consider the potential adverse effects and clinical restrictions of Bupleurum despite its promising potential. Further research is needed to elucidate its specific mechanisms of action and evaluate its effectiveness in human subjects.

Three-Dimensional Cell Co-Culture Liver Models and Their Applications in Pharmaceutical Research

As the primary site for the biotransformation of drugs, the liver is the most focused on organ type in pharmaceutical research. However, despite being widely used in pharmaceutical research, animal models have inherent species differences, while two-dimensional (2D) liver cell monocultures or co-cultures and three-dimensional (3D) liver cell monoculture in vitro liver models do not sufficiently represent the complexity of the human liver’s structure and function, making the evaluation results from these tools less reliable. Therefore, there is a pressing need to develop more representative in vitro liver models for pharmaceutical research. Fortunately, an exciting new development in recent years has been the emergence of 3D liver cell co-culture models. These models hold great promise as in vitro pharmaceutical research tools, because they can reproduce liver structure and function more practically. This review begins by explaining the structure and main cell composition of the liver, before introducing the potential advantages of 3D cell co-culture liver models for pharmaceutical research. We also discuss the main sources of hepatocytes and the 3D cell co-culture methods used in constructing these models. In addition, we explore the applications of 3D cell co-culture liver models with different functional states and suggest prospects for their further development.

Saikosaponin D: review on the antitumour effects, toxicity and pharmacokinetics

CONTEXT

Bupleuri Radix, the dried root of Bupleurum chinense DC and Bupleurum scorzonerifolium Willd (Apiaceae), is an important medicinal herb widely used to treat cancers for hundreds of years in Asian countries. As the most antitumour component but also the main toxic component in Bupleuri Radix, saikosaponin D (SSD) has attracted extensive attention. However, no summary studies have been reported on the antitumour effects, toxicity and pharmacokinetics of this potential natural anticancer substance.

OBJECTIVE

To analyse and summarise the existing findings regarding to the antitumour effects, toxicity and pharmacokinetics of SSD.

MATERIALS AND METHODS

We collected relevant information published before April 2021 by conducting a search of literature available in various online databases including PubMed, Science Direct, CNKI, Wanfang database and the Chinese Biological Medicine Database. Bupleurum, Bupleuri Radix, saikosaponin, saikosaponin D, tumour, toxicity, and pharmacokinetics were used as the keywords.

RESULTS

The antitumour effects of SSD were multi-targeted and can be realised through various mechanisms, including inhibition of proliferation, invasion, metastasis and angiogenesis, as well as induction of cell apoptosis, autophagy, and differentiation. The toxicological effects of SSD mainly included hepatotoxicity, neurotoxicity, haemolysis and cardiotoxicity. Pharmacokinetic studies demonstrated that SSD had the potential to alter the pharmacokinetics of some drugs for its influence on CYPs and P-gp, and the oral bioavailability and actual pharmacodynamic substances in vivo of SSD are still controversial.

CONCLUSIONS

SSD is a potentially effective and relatively safe natural antitumour substance, but more research is needed, especially in vivo antitumour effects and pharmacokinetics of the compound.