Bakuchiol analogs inhibit monoamine transporters and regulate monoaminergic functions

Integrated investigation and discovery of therapeutic targets for 3-hydroxybakuchiol against diabetes based on molecular docking studies and cell experiments

BACKGROUND

Diabetes mellitus is a prevalent endocrine condition. We aimed to investigate the anti-diabetic effects of 3-hydroxybakuchiol (HYD) by exploring its potential targets and molecular mechanisms through bioinformatics analysis and cell experiments.

METHODS

We performed an extensive search and screening of HYD and its potential targets for diabetes mellitus across various databases. Enrichment analyses were conducted using the ClusterProfiler package. PPI networks of the identified genes were constructed using STRING, and topological analysis was performed to identify core targets. The results were further confirmed through molecular docking. To validate the findings of our bioinformatics analysis, we conducted cell experiments using insulin resistance-induced HepG2 cells and C2C12 cells.

RESULTS

We discovered 260 common targets of HYD and diabetes mellitus, which were primarily related to the MAPK signaling pathway, PI3K-Akt signaling pathway, and endocrine resistance. A topological analysis of the PPI network identified four core targets (HSP90AA1, AKT1, SRC, and MAPK1). Molecular docking studies further confirmed the strong binding ability between HYD and these core targets. In cell experiments, we observed that HYD enhanced glucose uptake and suppressed gluconeogenesis in HepG2 cells and C2C12 cells. This resulted in an improvement in glucose metabolism, potentially through the regulation of the PI3K-Akt pathway.

CONCLUSIONS

This study provides valuable insights into the pharmacological effects of HYD on diabetes mellitus, suggesting its potential as a promising treatment option for the disease.

Natural Compounds as Medical Strategies in the Prevention and Treatment of Psychiatric Disorders Seen in Neurological Diseases

Psychiatric disorders are frequently encountered in many neurological disorders, such as Alzheimer’s and Parkinson diseases along with epilepsy, migraine, essential tremors, and stroke. The most common comorbid diagnoses in neurological diseases are depression and anxiety disorders along with cognitive impairment. Whether the underlying reason is due to common neurochemical mechanisms or loss of previous functioning level, comorbidities are often overlooked. Various treatment options are available, such as pharmacological treatments, cognitive-behavioral therapy, somatic interventions, or electroconvulsive therapy. However oral antidepressant therapy may have some disadvantages, such as interaction with other medications, low tolerability due to side effects, and low efficiency. Natural compounds of plant origin are extensively researched to find a better and safer alternative treatment. Experimental studies have shown that phytochemicals such as alkaloids, terpenes, flavonoids, phenolic acids as well as lipids have significant potential in in vitro and in vivo models of psychiatric disorders. In this review, various efficacy of natural products in in vitro and in vivo studies on neuroprotective and their roles in psychiatric disorders are examined and their neuro-therapeutic potentials are shed light.

Traditional Chinese Medicine in Depression Treatment: From Molecules to Systems

Depression is a multigenetic or multifactorial syndrome. The central neuron system (CNS)-orientated, single target, and conventional antidepressants are insufficient and far from ideal. Traditional Chinese Medicine (TCM) has historically been used to treat depression up till today, particularly in Asia. Its holistic, multidrug, multitarget nature fits well with the therapeutic idea of systems medicine in depression treatment. Over the past two decades, although efforts have been made to understand TCM herbal antidepressants at the molecular level, many fundamental questions regarding their mechanisms of action remain to be addressed at the systems level in order to better understand the complicated herbal formulations in depression treatment. In this Mini Review, we review and discuss the mechanisms of action of herbal antidepressants and their acting targets in the pathological systems in the brain, such as monoamine neurotransmissions, hypothalamic–pituitary–adrenal (HPA) axis, neurotropic factor brain-derived neurotrophic factor (BDNF) cascade, and glutamate transmission. Some herbal molecules, constituents, and formulas are highlighted as examples to discuss their mechanisms of action and future directions for comprehensive researches at the systems level. Furthermore, we discuss pharmacological approaches to integrate the mechanism of action from the molecular level into the systems level for understanding of systems pharmacology of TCM formulations. Integration of the studies at the molecular level into the systems level not only represents a trend in TCM study but also promotes our understanding of the system-wide mechanism of action of herbal antidepressant formulations.

Δ3,2-Hydroxybakuchiol Attenuates Depression in Multiple Rodent Models Possibly by Inhibition of Monoamine Transporters in Brain

Δ³,2-Hydroxybakuchiol is isolated from Psoralea corylifolia (L.), which has therapeutic applications in traditional Chinese medicine. Our previous studies have showed that Δ³,2-hydroxybakuchiol inhibited the decreased activity of reserpinized mice, suggestive of its antidepressive potential. In this study, we explored the antidepressant profile of Δ³,2-hydroxybakuchiol in various rodent models and its possible monoamine-modulating mechanism. Δ³,2-Hydroxybakuchiol significantly reduced immobility time of mice in forced swim test and tail suspension test. Δ³,2-Hydroxybakuchiol also significantly increased sucrose consumption in chronic unpredictable mild stress (CUMS) rat model. Furthermore, isotope uptake study showed that Δ³,2-hydroxybakuchiol inhibited the activity of human dopamine transporter (DAT) and norepinephrine transporter (NET) in transporter-overexpressing pheochromocytoma (PC12) cells with IC₅₀ values similar to the potency of bupropion. Microdialysis showed that Δ³,2-hydroxybakuchiol increased dopamine and norepinephrine concentration in rat striatum. In summary, Δ³,2-hydroxybakuchiol exerts antidepressant effects on various types of depression models through a possible mechanism of monoamine transporter inhibition.

Polymorphisms of COMT (c.649G>A), MAO-A (c.1460C>T), NET (c.1287G>A) Genes and the Level of Catecholamines, Serotonin in Patients with Parkinson's Disease

The purpose of this study was to determine the concentration of plasma norepinephrine (NE), epinephrine (E), and serotonin (5-HT) in two collections, after a 30-min supine (I) and 5-min upright position (II), and polymorphisms of genes, COMT (c.649G>A), MAO-A (c.1460C>T), and NET (c.1287G>A), in patients with Parkinson's disease (PD) and other degenerative parkinsonism and controls. The study was performed in 49 PD patients, 19 parkinsonism patients, and 48 controls. The level of NE, E, and 5-HT was determined by HPLC/EC. PCR-RFLP was conducted to analyze the COMT, MAO-A, and NET polymorphisms. Genotypes of COMT, MAO-A, and NET genes occurred with different frequencies in patients with movement disorders and controls. NET AA occurred 4.8 times more frequently in patients with parkinsonism than in PD (p < 0.05). COMT AA genotype was associated with increased E levels [E (I) p < 0.01, E (II) p < 0.05] in PD compared to controls. Patients with parkinsonism with MAO-A TT genotype have a significantly higher level of 5-HT [5-HT (II), p < 0.05] compared to controls. Moreover, PD patients with NET GA genotype have the lowest level of NE (p < 0.05) compared to controls. It appears that COMT, MAO-A, and NET polymorphisms and levels of NE, E, and 5-HT are involved in pathogenesis of PD.

A Potential Alternative against Neurodegenerative Diseases: Phytodrugs

Neurodegenerative diseases (ND) primarily affect the neurons in the human brain secondary to oxidative stress and neuroinflammation. ND are more common and have a disproportionate impact on countries with longer life expectancies and represent the fourth highest source of overall disease burden in the high-income countries. A large majority of the medicinal plant compounds, such as polyphenols, alkaloids, and terpenes, have therapeutic properties. Polyphenols are the most common active compounds in herbs and vegetables consumed by man. The biological bioactivity of polyphenols against neurodegeneration is mainly due to its antioxidant, anti-inflammatory, and antiamyloidogenic effects. Multiple scientific studies support the use of herbal medicine in the treatment of ND; however, relevant aspects are still pending to explore such as metabolic analysis, pharmacokinetics, and brain bioavailability.

Natural polyphenols: Influence on membrane transporters

Accumulated evidence has focused on the use of natural polyphenolic compounds as nutraceuticals since they showed a wide range of bioactivities and exhibited protection against variety of age-related disorders. Polyphenols have variable potencies to interact, and hence alter the activities of various transporter proteins, many of them classified as anion transporting polypeptide-binding cassette transporters like multidrug resistance protein and p-glycoprotein. Some of the efflux transporters are, generally, linked with anticancer and antiviral drug resistance; in this context, polyphenols may be beneficial in modulating drug resistance by increasing the efficacy of anticancer and antiviral drugs. In addition, these effects were implicated to explain the influence of dietary polyphenols on drug efficacy as result of food-drug interactions. However, limited data are available about the influence of these components on uptake transporters. Therefore, the objective of this article is to review the potential efficacies of polyphenols in modulating the functional integrity of uptake transporter proteins, including those terminated the effect of neurotransmitters, and their possible influence in neuropharmacology.

Bakuchiol Is a Phenolic Isoprenoid with Novel Enantiomer-selective Anti-influenza A Virus Activity Involving Nrf2 Activation

Influenza represents a substantial threat to human health and requires novel therapeutic approaches. Bakuchiol is a phenolic isoprenoid compound present in Babchi (Psoralea corylifolia L.) seeds. We examined the anti-influenza viral activity of synthetic bakuchiol using Madin-Darby canine kidney cells. We found that the naturally occurring form, (+)-(S)-bakuchiol, and its enantiomer, (-)-(R)-bakuchiol, inhibited influenza A viral infection and growth and reduced the expression of viral mRNAs and proteins in these cells. Furthermore, these compounds markedly reduced the mRNA expression of the host cell influenza A virus-induced immune response genes, interferon-β and myxovirus-resistant protein 1. Interestingly, (+)-(S)-bakuchiol had greater efficacy than (-)-(R)-bakuchiol, indicating that chirality influenced anti-influenza virus activity. In vitro studies indicated that bakuchiol did not strongly inhibit the activities of influenza surface proteins or the M2 ion channel, expressed in Chinese hamster ovary cells. Analysis of luciferase reporter assay data unexpectedly indicated that bakuchiol may induce some host cell factor(s) that inhibited firefly and Renilla luciferases. Next generation sequencing and KeyMolnet analysis of influenza A virus-infected and non-infected cells exposed to bakuchiol revealed activation of transcriptional regulation by nuclear factor erythroid 2-related factor (Nrf), and an Nrf2 reporter assay showed that (+)-(S)-bakuchiol activated Nrf2. Additionally, (+)-(S)-bakuchiol up-regulated the mRNA levels of two Nrf2-induced genes, NAD(P)H quinone oxidoreductase 1 and glutathione S-transferase A3. These findings demonstrated that bakuchiol had enantiomer-selective anti-influenza viral activity involving a novel effect on the host cell oxidative stress response.

Synthesis of ∆3-2-hydroxybakuchiol analogues and their growth inhibitory activity against rat UMR106 cells

A series of ∆³-2-hydroxybakuchiol analogues have been synthesized and tested for their growth inhibitory activity against rat UMR106 cells by using the MTT method. Some of them exhibit enhanced activities compared with the natural product, and the preliminary SAR profile shows that the chain tail on the natural product could be subtly modified to enhance the activity and the aromatic moiety or the terminal olefin on the main chain can also be modified without any evident loss of activity. The stereo-configuration of the quaternary chiral center has an important influence on the activity.

Polymorphism of the COMT, MAO, DAT, NET and 5-HTT Genes, and Biogenic Amines in Parkinson's Disease

Epinephrine (E) and sympathetic nerve stimulation were described by Thomas Renton Elliott in 1905 for the first time. Dopamine (DA), norepinephrine (NE), E, and serotonin (5-HT) belong to the classic biogenic amines (or monoamines). Parkinson's disease (PD) is among the diseases in which it has been established that catecholamines may account for the neurodegeneration of central and peripheral catecholamine neural systems. PD is a chronic and progressive neurological disorder characterized by resting tremor, rigidity, and bradykinesia, affecting 2% of individuals above the age of 65 years. This disorder is a result of degeneration of DA-producing neurons of the substantia nigra and a significant loss of noradrenergic neurons in the locus coeruleus. In PD and other related neurodegerative diseases, catecholamines play the role of endogenous neurotoxins. Catechol-O-methyltransferase (COMT) and/or monoamine oxidase (MAO) catalyze the metabolism of monoamines. However, the monoamine transporters for DA, NE, and 5-HT namely DAT, NET, and SERT, respectively regulate the monoamine concentration. The metabolism of catecholamines and 5-HT involves common factors. Monoamine transporters represent targets for many pharmacological agents that affect brain function, including psychostimulators and antidepressants. In PD, polymorphisms of the COMT, MAO, DAT, NET, and 5- HTT genes may change the levels of biogenic amines and their metabolic products. The currently available therapies for PD improve the symptoms but do not halt the progression of the disease. The most effective treatment for PD patients is therapy with L-dopa. Combined therapy for PD involves a DA agonist and decarboxylase, MAOs and COMT inhibitors, and is the current optimal form of PD treatment maintaining monoamine balance.

Cynomorium songaricum extracts functionally modulate transporters of gamma-aminobutyric acid and monoamine

Cynomorium songaricum Rupr. (SY) is a central nervous system-oriented herb material that has actions of anti-dementia, anti-epilepsy, and anti-stress. It is unclear whether SY would be biologically active in functionally regulating neurotransmitter transporters. Here, we assessed these potential actions using Chinese hamster ovary cells expressing gamma-aminobutyric acid (GABA) transporter (GAT-1), dopamine transporter (DAT), norepinephrine transporter (NET), or serotonin transporter (SERT) (i.e. G1, D8, N1, or S6 cells, respectively). It was shown that SY extracts, such as SYw, SYa, SYp, SYc, SYe, and SYb (SY water, ethanol, petroleum ether, chloroform, ethyl acetate, and n-butyl alcohol extract, respectively) increased dopamine/norepinephrine (DA/NE) uptake by corresponding D8/N1 cells and decreased gamma-aminobutyric acid/serotoin (GABA/5HT) uptake by corresponding G1/S6 cells; wherein, the potency or efficacy of SYc for up-regulating DA/NE uptake and that of SYb for inhibiting GABA/5HT uptake were relatively stronger. Additionally, GABA/5H-uptake inhibition by SY extracts were also seen in cortical synaptosomes, and DA/NE-uptake enhancement by SYc was dependent on the activity of DAT and NET. Thus, SY extracts especially SYc and SYb are novel neurotransmitter-transporter modulators functioning as DAT/NET activators and/or GAT-1/SERT inhibitors.

Luteolin from Purple Perilla mitigates ROS insult particularly in primary neurons

Increased attention has been paid to the role of oxidant/antioxidant imbalance in neurodegenerative process and pharmaceutical neuroprotective interventions. Food-derived compound luteolin possesses multitarget actions including reactive oxygen species (ROS)-scavenging activity in cultured human endothelial cells or permanent immature rat oligodendrocytes. This study aims to elucidate whether luteolin has a neuroprotective tendency toward ROS-insulted neural cells. The present results showed that luteolin, isolated from the ripe seed of Perilla frutescens (L.) Britt., markedly reversed hydrogen peroxide-induced cytotoxicity in primary culture cortical neurons but not in cultured human neuroblastoma cells. Upon the ROS-insulted primary neurons, luteolin concentration-dependently enhanced neuronal cell survival with efficacy higher than and potency similar to vitamin E. Additionally, luteolin significantly attenuated the increase in ROS production and prevented the decreases in activities of mitochondria, catalase, and glutathione in ROS-insulted primary neurons. Thus, luteolin functions by neuroprotection possibly through a rebalancing of pro-oxidant-antioxidant status. This agent points to possible interventions for preventing neurodegenerative diseases such as cerebral ischemia, Parkinson's disease, and Alzheimer's disease, as well as for improving brain aging.

Caulis Sinomenii Extracts Activate DA/NE Transporter and Inhibit 5HT Transporter

Caulis Sinomenii (QFT) has analgesic, sedative, and anxiolytic-like actions, and is proven effective for improving drug dependence that is known to be associated with abnormal monoaminergic transmission. We assessed whether QFT would be biologically active in functionally regulating monoamine transporters using CHO cells expressing dopamine transporter (DAT), norepinephrine transporter (NET), or serotonin transporter (SERT) (i.e. D8, N1, or S6 cells, respectively). Here, we showed that its primary extracts, such as QA, QC, QE, QD, and QB (QFT ethanol, chloroform, ethyl acetate, alkaloid-free chloroform, and alkaloid-containing chloroform extract, respectively), and secondary extracts, such as QE-2, − 3, − 5, − 7, QD-1, − 2, − 3, − 4, − 5, and QB-1, − 2, − 3, − 4, − 5 (fractioned from QE, QD, and QB, respectively), in differing degrees, either increased DA/ NE uptake by corresponding D8/N1 cells or decreased 5HT uptake by S6 cells; wherein, QE-2, QD-3, and QE-7 were potent DA/NE uptake activators while both QE-7 and QB-5 were potent 5HT uptake inhibitors. Furthermore, the enhancement of DA/NE uptake was dependent of DAT/NET activity, and the inhibition of 5HT uptake was typical of competition. Thus, QFT extracts, especially QE-2 and QE-7 (both with stronger potencies), are novel monoamine transporter modulators functioning as DAT/ NET activators and/or SERT inhibitors, and would likely improve neuropsychological disorders through regulating monoamine transporters.

Safflower extracts functionally regulate monoamine transporters

Safflower (HH), the dry flower of Carthamus tinctorius L., has long been used to empirically treat neuropsychological disorders such as stroke and major depression in traditional Chinese medicine, and recently been proven effective for regulating levels of dopamine and serotonin in new-born rat brain. The present study assessed whether HH would be bioactive for functionally regulating monoamine transporters using in vitro drug-screening cell lines. Our current results showed that all solvent-extracted HH fractions, in different degrees, markedly increased both dopamine uptake by Chinese hamster ovary (CHO) cells stably expressing dopamine transporter (DAT) and norepinephrine uptake by CHO cells expressing norepinephrine transporter (NET), and also showed that chloroform (HC), ethyl acetate (HE), and n-butyl alcohol extract strikingly depressed serotonin uptake by CHO cells expressing serotonin transporter (SERT); wherein, the potencies of ethanol extract, HC, HE, and aqueous extract to up-regulate dopamine/norepinephrine uptake and potency of HE to inhibit serotonin uptake were relatively stronger. Further investigation revealed that the enhancement of dopamine/norepinephrine uptake by HC and HE was dependent of DAT/NET activity, and the HE-induced inhibition of serotonin uptake was typical of competition. Thus, HH extracts are novel monoamine transporter modulators functioning as DAT/NET activators and/or SERT inhibitors, and would likely improve neuropsychological disorders through regulating monoamine-transporter activity.

Bioactive constituents from Chinese natural medicines. XXXIII. Inhibitors from the seeds of Psoralea corylifolia on production of nitric oxide in lipopolysaccharide-activated macrophages

The methanolic extract from the seeds of Psoralea corylifolia was found to inhibit production of nitric oxide (NO) in lipopolysaccharide-activated mouse peritoneal macrophages. Among the isolated compounds, bavachinin (IC(50)=26 microM), isobavachalcone (17 microM), neobavaisoflavone (ca. 29 microM), corylifol A (ca. 21 microM), and psoralidin (ca. 23 microM) significantly inhibited the accumulation of nitrite (NO(2)(-)) as a marker of production of NO. Bakuchiol, which is mainly contained in the extract, also showed weak activity at 10 microM, but cytotoxic effects were observed more than 30 microM.