Extracts of Immature Orange (Aurantii fructus immaturus) and Citrus Unshiu Peel (Citri unshiu pericarpium) Induce P-Glycoprotein and Cytochrome P450 3A4 Expression via Upregulation of Pregnane X Receptor

Flavonoids in natural products for the therapy of liver diseases: progress and future opportunities

The liver is the largest, important organ and the site for essential biochemical reactions in the human body. It has the function to detoxify toxic substances and synthesize useful biomolecules. Liver diseases related complications represent a significant source of morbidity and mortality worldwide, creating a substantial economic burden. Oxidative stress, excessive inflammation, and dysregulated energy metabolism significantly contributed to liver diseases. Therefore, discovery of novel therapeutic drugs for the treatment of liver diseases are urgently required. For centuries, flavonoids and their preparations which have the beneficial health effects in chronic diseases have been used to treat various human illnesses. Flavonoids mainly include flavones, isoflavones, flavanols, dihydroflavones, dihydroflavonols, anthocyanins and chalcones. The primary objective of this review is to assess the efficacy and safety of flavonoids, mainly from a clinical point of view and considering clinically relevant end-points. We summarized the recent progress in the research of hepatoprotective and molecular mechanisms of different flavonoids bioactive ingredients and also outlined the networks of underlying molecular signaling pathways. Further pharmacology and toxicology research will contribute to the development of natural products in flavonoids and their derivatives as medicines with alluring prospect in the clinical application.

Potential herb‒drug interactions between anti-COVID-19 drugs and traditional Chinese medicine

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread worldwide. Effective treatments against COVID-19 remain urgently in need although vaccination significantly reduces the incidence, hospitalization, and mortality. At present, antiviral drugs including Nirmatrelvir/Ritonavir (PaxlovidTM), Remdesivir, and Molnupiravir have been authorized to treat COVID-19 and become more globally available. On the other hand, traditional Chinese medicine (TCM) has been used for the treatment of epidemic diseases for a long history. Currently, various TCM formulae against COVID-19 such as Qingfei Paidu decoction, Xuanfei Baidu granule, Huashi Baidu granule, Jinhua Qinggan granule, Lianhua Qingwen capsule, and Xuebijing injection have been widely used in clinical practice in China, which may cause potential herb-drug interactions (HDIs) in patients under treatment with antiviral drugs and affect the efficacy and safety of medicines. However, information on potential HDIs between the above anti-COVID-19 drugs and TCM formulae is lacking, and thus this work seeks to summarize and highlight potential HDIs between antiviral drugs and TCM formulae against COVID-19, and especially pharmacokinetic HDIs mediated by metabolizing enzymes and/or transporters. These well-characterized HDIs could provide useful information on clinical concomitant medicine use to maximize clinical outcomes and minimize adverse and toxic effects.

Network Analysis of the Herb-Drug Interactions of Citrus Herbs Inspired by the "Grapefruit Juice Effect"

This study was performed to investigate the herb-drug interactions (HDIs) of citrus herbs (CHs), which was inspired by the "grapefruit (GF) juice effect". Based on network analysis, a total of 249 components in GF and 159 compounds in CHs exhibited great potential as active ingredients. Moreover, 360 GF-related genes, 422 CH-related genes, and 111 genes associated with drug transport and metabolism were collected, while 25 and 26 overlapping genes were identified. In compound-target networks, the degrees of naringenin, isopimpinellin, apigenin, sinensetin, and isoimperatorin were higher, and the results of protein-protein interaction indicated the hub role of UGT1A1 and CYP3A4. Conventional drugs such as erlotinib, nilotinib, tamoxifen, theophylline, venlafaxine, and verapamil were associated with GF and CHs via multiple drug transporters and drug-metabolizing enzymes. Remarkably, GF and CHs shared 48 potential active compounds, among which naringenin, tangeretin, nobiletin, and apigenin possessed more interactions with targets. Drug metabolism by cytochrome P450 stood out in the mutual mechanism of GF and CHs. Molecular docking was utilized to elevate the protein-ligand binding potential of naringenin, tangeretin, nobiletin, and apigenin with UGT1A1 and CYP3A4. Furthermore, in vitro experiments demonstrated their regulating effect. Overall, this approach provided predictions on the HDIs of CHs, and they were tentatively verified through molecular docking and cell tests. Moreover, there is a demand for clinical and experimental evidence to support the prediction.

Prospective multifunctional roles and pharmacological potential of dietary flavonoid narirutin

Plant-based phytochemicals are now being used to treat plenty of physiological diseases. Herbal drugs have gained popularity in recent years because of their strength, purity, and cheap cost-effectiveness. Citrus fruits contain significant amounts of flavanones, which falls to the category of polyphenols. Flavanones occupy a major fraction of the total polyphenols present in the plasma when orange juice is taken highly or in moderate states. Narirutin is a disaccharide derivative available in citrus fruits, primarily dihydroxy flavanone. From a pharmacological viewpoint, narirutin is a bioactive phytochemical with therapeutic efficacy. Many experimental researches were published on the use of narirutin. Anticancer activity, neuroprotection, stress relief, hepatoprotection, anti-allergic activity, antidiabetic activity, anti-adipogenic activity, anti-obesity action, and immunomodulation are a couple of the primary pharmacological properties. Narirutin also has antioxidant, and anti-inflammatory activities. The ultimate goal of this review is to provide the current scenario of pharmacological research with narirutin; to make a better understanding for therapeutic potential of narirutin, as well as its biosynthesis strategies and side effects. Extensive literature searches and studies were undertaken to determine the pharmacological properties of narirutin.

Simultaneous Analysis for Quality Control of Traditional Herbal Medicine, Gungha-Tang, Using Liquid Chromatography–Tandem Mass Spectrometry

Gungha-tang (GHT), a traditional herbal medicine, consists of nine medicinal herbs (Cnidii Rhizoma, Pinelliae Tuber, Poria Sclerotium, Citri Unshius Pericarpium, Citri Unshius Pericarpium Immaturus, Aurantii Fructus Immaturus, Atracylodis Rhizoma Alba, Glycyrrhizae Radix et Rhizoma, and Zingiberis Rhizoma Recens). It has been used for various diseases caused by phlegm. This study aimed to develop and verify the simultaneous liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis method, using nine marker components (liquiritin apioside, neoeriocitrin, narirutin, naringin, hesperidin, neohesperidin, liquiritigenin, glycyrrhizin, and 6-shogaol) for quality control of GHT. LC–MS/MS analysis was conducted using a Waters TQ-XS system. All marker analytes were separated on a Waters Acquity UPLC BEH C₁₈ column (2.1 × 100 mm, 1.7 μm) using gradient elution with a distilled water solution (containing 5 mM ammonium formate and 0.1% [v/v] formic acid)–acetonitrile mobile phase. LC–MS/MS multiple reaction monitoring (MRM) analysis was carried out in negative and positive ion modes of an electrospray ionization source. The developed LC–MS/MS MRM method was validated by examining the linearity, limits of detection and quantification, recovery, and precision. LOD and LOQ values of nine markers were calculated as 0.02–8.33 ng/mL and 0.05–25.00 ng/mL. The recovery was determined to be 89.00–118.08% and precision was assessed with a coefficient of variation value of 1.74–8.64%. In the established LC–MS/MS MRM method, all markers in GHT samples were detected at 0.003–16.157 mg/g. Information gathered during the development and verification of the LC–MS/MS method will be useful for the quality assessment of GHT and other herbal medicines.

Flavonoids from Aurantii Fructus Immaturus and Aurantii Fructus: promising phytomedicines for the treatment of liver diseases

Background

Liver diseases and related complications are major sources of morbidity and mortality, which places a huge financial burden on patients and lead to nonnegligible social problems. Therefore, the discovery of novel therapeutic drugs for the treatment of liver diseases is urgently required. Aurantii Fructus Immaturus (AFI) and Aurantii Fructus (AF) are frequently used herbal medicines in traditional Chinese medicine (TCM) formulas for the treatment of diverse ailments. A variety of bioactive ingredients have been isolated and identified from AFI and AF, including alkaloids, flavonoids, coumarins and volatile oils.

Main body

Emerging evidence suggests that flavonoids, especially hesperidin (HD), naringenin (NIN), nobiletin (NOB), naringin (NRG), tangeretin (TN), hesperetin (HT) and eriodictyol (ED) are major representative bioactive ingredients that alleviate diseases through multi-targeting mechanisms, including anti-oxidative stress, anti-cytotoxicity, anti-inflammation, anti-fibrosis and anti-tumor mechanisms. In the current review, we summarize the recent progress in the research of hepatoprotective effects of HD, NIN, NOB, NRG, TN, HT and ED and highlight the potential underlying molecular mechanisms. We also point out the limitations of the current studies and shed light on further in-depth pharmacological and pharmacokinetic studies of these bioactive flavonoids.

Conclusion

This review outlines the recent advances in the literature and highlights the potential of these flavonoids isolated from AFI and AF as therapeutic agents for the treatment of liver diseases. Further pharmacological studies will accelerate the development of natural products in AFI and AF and their derivatives as medicines with tantalizing prospects in the clinical application.

Multi-Component Comparative Pharmacokinetics in Rats After Oral Administration of Fructus aurantii Extract, Naringin, Neohesperidin, and Naringin-Neohesperidin

Citrus × aurantium L., Chinese name: Fructus Aurantii (FA) has been largely used as Qi-invigorating herb in China for centuries. The main components (meranzin hydrate, naringin, neohesperidin, meranzin, nobiletin) have good physiological activity with relatively high abundance in FA. Few multi-component comparative pharmacokinetics are simultaneously accessible for the flavone glycosides, polymethoxy flavones, and coumarins in FA. In this work, a reliable and rapid ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was established and validated to determine the five ingredients in the SD rat plasma, and further applied to the pharmacokinetic studies after oral administration of monomer, drugs in compatibility, and FA extract. After hydrolysis with β-glucuronidase and sulfatase, the concentration of naringin and neohesperidin in rat plasma were expressed respectively by the total concentration of naringenin and hesperitin which was determined by UPLC-MS/MS. Double-peak phenomenon was observed for naringin and neohesperidin, which may be due to the enterohepatic circulation or multiple site absorption of the two flavone glycosides. Meranzin hydrate and meranzin (coumarins) were absorbed rapidly (T_max, about 1.0 h) but eliminated slowly (t_1/2z exceeds 6.5 h). Nobiletin, a typical polymethoxy flavone, was also rapidly absorbed according to T_max and AUC_(0-t). DAS 3.1 software suggests the pharmacokinetic profiles of the five components in rats be depicted as a two-compartment pharmacokinetic model. There were significant differences in pharmacokinetic parameters for naringenin and hesperetin between the compatibility, FA extract group vs monomer group: ① remarkable increases in the values of AUC_(0–∞), AUC_(0–t) and C_max; ② obvious decrease of CL_Z/F; and ③ longer t_max and t_1/2z. The results suggest that compatibility can promote mutual absorption and affect the elimination behaviors.

The Herb-Drug Pharmacokinetic Interaction of Fluoxetine and Its Metabolite Norfluoxetine with a Traditional Chinese Medicine in Rats by LC-MS/MS

Background

Fluoxetine (FLU) is the first-line and widely used medication for depression. The combination of Chaihu Shugan san (CSGS) and FLU is commonly used to enhance antidepressant effects and reduce side effects.

Objective

The primary objective of this study was to investigate the potential pharmacokinetic effect of CSGS on FLU.

Materials and Methods

Thirty-two healthy adult male Sprague-Dawley (SD) rats were randomly divided into four groups, the fluoxetine group and multiple dose groups A, B, and C. The rats in the different groups were orally administered with a combination of FLU and different doses of CSGS for 14 d. On the fifteenth day, serial blood samples were taken from the caudal vein before the administration and at 0.25, 0.5, 0.75, 1, 2, 4, 6, 8, 10, 12, 24, 36, and 48 h after the administration. A liquid-liquid extraction method was applied to extract the analytes from serum. Then, the concentrations of FLU and its metabolite, norfluoxetine (NOF), were determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The pharmacokinetic parameters were calculated by DAS 3.2.8 program and compared by statistic analysis.

Results

Compared with the FLU group, the FLU and NOF area under the plasma concentration-time curve (AUC) (0–∞) in multiple dose group C was significantly increased, while the NOF AUCs (0–∞) in multiple dose group A and multiple dose group B were decreased. Compared with the FLU group, the NOF clearance (CL) in multiple dose group C was decreased, while the CL in multiple dose groups A and B was increased.

Discussion and Conclusion

There were some differences in pharmacokinetic parameters between the FLU group and multiple dose groups, and CSGS can affect the pharmacokinetics of fluoxetine.

Galangin Activates Nrf2 Signaling and Attenuates Oxidative Damage, Inflammation, and Apoptosis in a Rat Model of Cyclophosphamide-Induced Hepatotoxicity

Cyclophosphamide (CP) is a widely used chemotherapeutic agent; however, its clinical application is limited because of its multi-organ toxicity. Galangin (Gal) is a bioactive flavonoid with promising biological activities. This study investigated the hepatoprotective effect of Gal in CP-induced rats. Rats received Gal (15, 30 and 60 mg/kg/day) for 15 days followed by a single dose of CP at day 16. Cyclophosphamide triggered liver injury characterized by elevated serum transaminases, alkaline phosphatase (ALP) and lactate dehydrogenase (LDH), and histopathological manifestations. Increased hepatic reactive oxygen species, malondialdehyde, nitric oxide, and oxidative DNA damage along with declined glutathione and antioxidant enzymes were demonstrated in CP-administered rats. CP provoked hepatic nuclear factor-kappaB (NF-κB) phosphorylation and increased mRNA abundance of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) both expression and serum levels. Gal prevented CP-induced liver injury, boosted antioxidants and suppressed oxidative stress, DNA damage, NF-κB phosphorylation and pro-inflammatory mediators. Gal diminished Bax and caspase-3, and increased B-cell lymphoma-2 (Bcl-2) in liver of CP-administered rats. In addition, Gal increased peroxisome proliferator-activated receptor gamma (PPARγ) expression and activated hepatic nuclear factor erythroid 2-related factor 2 (Nrf2) signaling showed by the increase in Nrf2, NAD(P)H: quinone acceptor oxidoreductase-1 (NQO-1) and heme oxygenase 1 (HO-1) in CP-administered rats. These findings suggest that Gal prevents CP hepatotoxicity through activation of Nrf2/HO-1 signaling and attenuation of oxidative damage, inflammation and cell death. Therefore, Gal might represent a promising adjuvant therapy to prevent hepatotoxicity in patients on CP treatment.

Interaction between phytotherapy and oral anticancer agents: prospective study and literature review

Cancer is becoming more prevalent in elderly patient. Due to polypharmacy, older adults with cancer are predisposed to drug-drug interactions. There is also an increasing interest in the use of complementary and alternative medicine (CAM). Thirty to seventy percent of patients with cancer have used CAM. Through pharmaceutical counseling sessions, we can provide advices on herb-drug interactions (HDI). All the patients seen in pharmaceutical counseling sessions were prospectively included. Information was collected during these sessions: prescribed medication (oral anticancer agents (OAA) and other drugs), CAM (phytotherapy especially), and use of over-the-counter (OTC) drugs. If pharmacist considered an interaction or an intervention clinically relevant, the oncologist was notified. Then, a literature review was realized to identify the potential HDI (no interactions, precautions for use, contraindication). Among 201 pharmacist counseling sessions, it resulted in 104 interventions related to 46 HDI, 28 drug-drug interactions and 30 others (wrong dosage, omission…). To determine HDI, we review 73 medicinal plants which are used by our patients with cancer and 31 OAA. A total of 1829 recommendations were formulated about 59 (75%) medical plants and their interaction with an OAA. Herb-drug interactions should not be ignored by healthcare providers in their management of cancer patients in daily practice.

Two Approaches for Evaluating the Effects of Galangin on the Activities and mRNA Expression of Seven CYP450

Galangin is a marker compound of honey and Alpinia officinarum Hance that exhibits great potential for anti-microbial, anti-diabetic, anti-obesity, anti-tumour and anti-inflammatory applications. Galangin is frequently consumed in combination with common clinical drugs. Here, we evaluated the effects of galangin on cytochrome P450 (CYP)-mediated metabolism, using two different approaches, to predict drug⁻drug interactions. Male Sprague Dawley rats were administered galangin daily for 8 weeks. A "cocktail-probes" approach was employed to evaluate the activities of different CYP450 enzymes. Blood samples of seven probe drugs were analysed using liquid chromatography-tandem mass spectrometry in positive and negative electrospray-ionisation modes. Pharmacokinetic parameters were calculated to identify statistical differences. CYP mRNA-expression levels were investigated in real-time quantitative polymerase chain reaction experiments. The galangin-treated group showed significantly decreased AUC_0⁻∞ and C_max values for CYP1A2, and CYP2B3. The galangin-treated group showed significantly increased AUC_0⁻∞ and C_max values for CYP2C13 and CYP3A1. No significant influences were observed in the pharmacokinetic profiles of CYP2C11, CYP2D4 and CYP2E1. The mRNA-expression results were consistent with the pharmacokinetic results. Thus, CYP450 enzyme activities may be altered by long-term galangin administration, suggesting galangin to be a promising candidate molecule for enhancing oral drug bioavailability and chemoprevention and reversing multidrug resistance.

Inhibitory Effect of Japanese Traditional Kampo Formula Frequently Prescribed in Gynecological Clinics on CYP3A4

Recently, the use of herbal medicines has become popular, and information on drug interactions between herbal medicines and chemical drugs is needed in clinics. In Japan, the number of patients taking Japanese traditional Kampo medicines has been increasing, and the proper drug information about herb-drug interaction is highly demanded. The most established herb-drug interaction is the case of grapefruit juice (GFJ) via the inhibition on CYP3A4 expressed in the small intestine. In the present study, we compared the inhibitory titer on CYP3A4 between the target Kampo products and GFJ used as positive control. We evaluated the inhibitory effects of GFJ and three extracts of Kampo formulas frequently used in gynecological clinics on CYP3A4 in vitro and calculated the related titer of one-time dosage of Kampo formulas to GFJ in order to predict its effect on clinics. Although the extracts of these three Kampo formulas and the most of crude drug components in the formulas exhibited the inhibitory effects on CYP3A4 in some levels, the possibilities of tokishakuyakusan and keishibukuryogan to cause drug interaction can be quite low; however, it is possible that the excessive dosage of kamishoyosan may cause drug interaction with the substrate of CYP3A4 in clinics.

Potential Metabolic Drug-Drug Interaction of Citrus aurantium L. (Rutaceae) Evaluating by Its Effect on 3 CYP450

Aim:Fructus aurantii (FA) is widely used in clinic as an expectorant and digestant herb in traditional Chinese medicine and proven to have a variety of pharmacological functions. FA is close to grapefruit either by botanical taxonomy or by their same components (flavonoids, etc.) and grapefruit has been proven to cause drug-drug interaction when co-administrated with CYP3A4 substrates. Besides, FA contains many compounds, such as flavonoids, which have been reported to impact the expressions of CYP450. However, the effect of FA on CYP450, whose change may affect drug safety and clinical efficacy attributed to drug-drug interaction, still remains unknown. Methods: The protein, mRNA expression and enzyme activity of CYP1A2, CYP3A4, and CYP2E1 in rat were determined by Western Blotting, RT-PCR method, the cocktail method, respectively, after orally administration of FA in succession for 7 days. CYP1A2, CYP3A4, and CYP2E1 mRNA expression were investigated in HepG2 cells following FA-medicated serum incubation for 24 h. Results: In rat, compared to the control group, CYP1A2, CYP3A4 protein, and mRNA expression were significantly induced consistent with the corresponding CYP activities; the protein expression of CYP2E1 was significantly upregulated, while the corresponding mRNA expression and enzyme activity showed no significant change. In HepG2 cells, compared to the control group, the mRNA expression of CYP1A2 and CYP3A4 was up-regulated statistically while CYP2E1 mRNA expression was not significantly induced or inhibited. Conclusion: FA may be a potential slight inducer of CYP1A2 and CYP3A4 and is unlikely to impact CYP2E1 until clinical researches are conducted.

In vitro and in vivo evaluation of systemic and genetic toxicity of Citrus unshiu peel

ETHNOPHARMACOLOGICAL RELEVANCE

The peel of Citrus unshiu Markovich fruits (CUP), called "Jinpi" in Korea, and "Chenpi" in China, has been used for the treatment of respiratory and blood circulation disorders in traditional oriental medicine (TOM). Despite its widespread uses in TOM, no information on the safety of CUP has been reported. Thus, genotoxicity and systemic toxicity of CUP were evaluated in the current studies.

MATERIALS AND METHODS

We conducted a toxicological evaluation of CUP water extracts using acute and subchronic (13-week repeated-dose) toxicity tests and three genotoxicity assays (bacterial reverse mutation, mammalian chromosomal aberration, and micronuclei formation).

RESULTS

In acute and subchronic toxicity tests, both the median lethal dose (LD₅₀) and no-observed-adverse-effect level (NOAEL) were more than 4000mg/kg/day in rats. None of the genotoxicity assays revealed any mutagenicity or clastogenicity in in vitro and in vivo systems.

CONCLUSION

CUP water extracts were found to be nongenotoxic under our testing conditions and had low acute and subchronic toxicity.

Safety, Efficacy, and Mechanistic Studies Regarding Citrus aurantium (Bitter Orange) Extract and p-Synephrine

Citrus aurantium L. (bitter orange) extracts that contain p-synephrine as the primary protoalkaloid are widely used for weight loss/weight management, sports performance, appetite control, energy, and mental focus and cognition. Questions have been raised about the safety of p-synephrine because it has some structural similarity to ephedrine. This review focuses on current human, animal, in vitro, and mechanistic studies that address the safety, efficacy, and mechanisms of action of bitter orange extracts and p-synephrine. Numerous studies have been conducted with respect to p-synephrine and bitter orange extract because ephedra and ephedrine were banned from use in dietary supplements in 2004. Approximately 30 human studies indicate that p-synephrine and bitter orange extracts do not result in cardiovascular effects and do not act as stimulants at commonly used doses. Mechanistic studies suggest that p-synephrine exerts its effects through multiple actions, which are discussed. Because p-synephrine exhibits greater adrenergic receptor binding in rodents than humans, data from animals cannot be directly extrapolated to humans. This review, as well as several other assessments published in recent years, has concluded that bitter orange extract and p-synephrine are safe for use in dietary supplements and foods at the commonly used doses. Copyright © 2017 The Authors Phytotherapy Research Published by John Wiley & Sons Ltd.