Pharmacokinetics and brain penetration study of chlorogenic acid in rats

In Vitro and In Silico Anti-Glioblastoma Activity of Hydroalcoholic Extracts of Artemisia annua L. and Artemisia vulgaris L

Glioblastoma, the most aggressive and challenging brain tumor, is a key focus in neuro-oncology due to its rapid growth and poor prognosis. The C6 glioma cell line is often used as a glioblastoma model due to its close simulation of human glioma characteristics, including rapid expansion and invasiveness. Alongside, herbal medicine, particularly Artemisia spp., is gaining attention for its anticancer potential, offering mechanisms like apoptosis induction, cell cycle arrest, and the inhibition of angiogenesis. In this study, we optimized extraction conditions of polyphenols from Artemisia annua L. and Artemisia vulgaris L. herbs and investigated their anticancer effects in silico and in vitro. Molecular docking of the main phenolic compounds of A. annua and A. vulgaris and potential target proteins, including programmed cell death (apoptosis) pathway proteins proapoptotic Bax (PDB ID 6EB6), anti-apoptotic Bcl-2 (PDB ID G5M), and the necroptosis pathway protein (PDB ID 7MON), mixed lineage kinase domain-like protein (MLKL), in complex with receptor-interacting serine/threonine-protein kinase 3 (RIPK3), revealed the high probability of their interactions, highlighting the possible influence of chlorogenic acid in modulating necroptosis processes. The cell viability of rat C6 glioma cell line was assessed using a nuclear fluorescent double-staining assay with Hoechst 33342 and propidium iodide. The extracts from A. annua and A. vulgaris have demonstrated anticancer activity in the glioblastoma model, with the synergistic effects of their combined compounds surpassing the efficacy of any single compound. Our results suggest the potential of these extracts as a basis for developing more effective glioblastoma treatments, emphasizing the importance of further research into their mechanisms of action and therapeutic applications.

The Protective Impact of Aronia melanocarpa L. Berries Extract against Prooxidative Cadmium Action in the Brain-A Study in an In Vivo Model of Current Environmental Human Exposure to This Harmful Element

Cadmium (Cd) is a prooxidant that adversely affects human health, including the nervous system. As exposure of the general population to this heavy metal is inevitable, it is crucial to look for agents that can prevent the effects of its toxic action. An experimental model on female rats of current lifetime human exposure to cadmium (3-24-months' treatment with 1 or 5 mg Cd/kg diet) was used to test whether low-level and moderate intoxication can exert a prooxidative impact in the brain and whether supplementation with a 0.1% extract from the berries of Aronia melanocarpa L. (Michx.) Elliott (AE; chokeberry extract) can protect against this action. Numerous parameters of the non-enzymatic and enzymatic antioxidative barrier, as well as total antioxidative and oxidative status (TAS and TOS, respectively), were determined and the index of oxidative stress (OSI) was calculated. Moreover, chosen prooxidants (myeloperoxidase, xanthine oxidase, and hydrogen peroxide) and biomarkers of oxidative modifications of lipids, proteins, and deoxyribonucleic acid were assayed. Cadmium dysregulated the balance between oxidants and antioxidants in the brain and led to oxidative stress and oxidative injury of the cellular macromolecules, whereas the co-administration of AE alleviated these effects. To summarize, long-term, even low-level, cadmium exposure can pose a risk of failure of the nervous system by the induction of oxidative stress in the brain, whereas supplementation with products based on aronia berries seems to be an effective protective strategy.

Recent Updates on the Therapeutics Benefits, Clinical Trials, and Novel Delivery Systems of Chlorogenic Acid for the Management of Diseases with a Special Emphasis on Ulcerative Colitis

Ulcerative colitis (UC) is a multifactorial disorder of the large intestine, especially the colon, and has become a challenge globally. Allopathic medicines are primarily available for the treatment and prevention of UC. However, their uses are limited due to several side effects. Hence, an alternative therapy is of utmost importance in this regard. Herbal medicines are considered safe and effective for managing human health problems. Chlorogenic acid (CGA), the herbal-derived bioactive, has been reported for pharmacological effects like antiinflammatory, immunomodulatory, antimicrobial, hepatoprotective, antioxidant, anticancer, etc. This review aims to understand the antiinflammatory and chemopreventive potential of CGA against UC. Apart from its excellent therapeutic potential, it has been associated with low absorption and poor oral bioavailability. In this context, colon-specific novel drug delivery systems (NDDS)are pioneering to overcome these problems. The pertinent literature was compiled from a thorough search on various databases such as ScienceDirect, PubMed, Google Scholar, etc., utilizing numerous keywords, including ulcerative colitis, herbal drugs, CGA, pharmacological activities, mechanism of actions, nanoformulations, clinical updates, and many others. Relevant publications accessed till now were chosen, whereas non-relevant papers, unpublished data, and non-original articles were excluded. The present review comprises recent studies on pharmacological activities and novel drug delivery systems of CGA for managing UC. In addition, the clinical trials of CGA against UC have been discussed.

Neuroprotective Properties of Chlorogenic Acid and 4,5-Caffeoylquinic Acid from Brazilian arnica (Lychnophora ericoides) after Acute Retinal Ischemia

Lychnophora is a genus of South American flowering plants in the daisy family, popularly known as "Brazilian arnica". It is used in traditional medicine as an anti-inflammatory and analgesic agent, whose active components are derived from chlorogenic acid (CGA) and C-flavonoids. Since the drugs currently used are ineffective to treat glaucoma, agents with antioxidant and anti-inflammatory properties may represent new alternatives in preventing cellular lesions in retinal ischemia. In this study, we report the neuroprotective effects of CGA and 4,5-di-O-[E]-caffeoylquinic (CQA) acid, isolated from Lychnophora plants, in a rodent glaucoma model. Wistar rats were administered intravitreally with 10 µg CGA or CGA, and then subjected to acute retinal ischemia (ISC) by increasing intraocular pressure (IPO) for 45 minutes followed (or not) by 15 minutes of reperfusion (I/R). Qualitative and quantitative analyses of neurodegeneration were performed using hematoxylin-eosin or Fluoro-Jade C staining protocols. All retinas submitted to ISC or I/R exhibited matrix disorganization, pyknotic nuclei, and pronounced vacuolization of the cytoplasm in the ganglion cell layer (GCL) and inner nuclear layer (INL). Pretreatment with CGA or CQA resulted in the protection of the retinal layers against matrix disorganization and a reduction in the number of vacuolized cells and pyknotic nuclei. Also, pretreatment with CGA or CQA resulted in a significant reduction in neuronal death in the GCL, the INL, and the outer nuclear layer (ONL) after ischemic insult. Our study demonstrated that CGA and CQA exhibit neuroprotective activities in retinas subjected to ISC and I/R induced by IPO in Wistar rats.

Pharmacokinetic study of the main components of Tanreqing capsules and Tanreqing injections in beagles by liquid chromatography-tandem mass spectrometry

BACKGROUND

Tanreqing capsules (TRQCs) and Tanreqing injections (TRQIs) are widely used in the treatment of respiratory diseases. In this study, a simple, rapid, and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous quantification of the main components of Tanreqing, which include chlorogenic acid, ursodeoxycholic acid, chenodeoxycholic acid, and baicalin, in beagle dog plasma to compare their pharmacokinetic parameters.

METHODS

Plasma samples were pretreated with protein precipitation. Chromatographic separation was performed on Waters Acquity UPLC HSS T₃ (2.1 mm × 100 mm, 1.8 μm) column using a gradient elution with (A) 0.1% (v/v) formic acid aqueous solution and (B) acetonitrile. Six healthy beagles were divided into two groups, and a crossover, comparative pharmacokinetic study of TRQC (0.09 g/kg) and TRQI (0.5 mL/kg) after a single-dose administration or daily doses over 7 days was carried out. One group was administrated a single dose of TRQC and followed continuously for 7 days, whereas the other group was treated with TRQI in the same way.

RESULTS

The calibration curves were linear over the ranges of 2.00-1000.00 ng/mL for baicalin, 10.00-5000.00 ng/mL for ursodeoxycholic acid, 1.00-500.00 ng/mLfor chenodeoxycholic acid and chlorogenic acid, respectively. The relative standard deviation of both intra-day and inter-day accuracy is less than 11.23%. The average extraction recovery of all compounds was greater than 82.21%. The major pharmacokinetic parameters of the four compounds were not significantly different between the two formulations (P > 0.05).

CONCLUSIONS

The measured levels of the four major components of TRQCs and TRQIs were comparable in these dogs, providing a reference for the clinical application of TRQCs instead of TRQIs.

Establishment of Quality Evaluation Method for Yinqiao Powder: A Herbal Formula against COVID-19 in China

Yinqiao powder, with significant anti-inflammatory and antiviral effects, is a classical formula for the treatment of febrile diseases in China. During the SARS period in 2003, Yinqiao powder showed a good antipyretic effect. It also plays a major role in the treatment for COVID-19 in China. Although there are many studies on the chemical compositions and pharmacological effects of Yinqiao powder, there are few studies on the quality standard system of it. In our study, a systematic quality evaluation method of Yinqiao powder combining HPLC fingerprint with quantitative analysis of multi-components by single marker (QAMS) based on network pharmacology and UPLC-Q-Exactive-Orbitrap-MS was established for the first time. In the UPLC-Q-Exactive-Orbitrap-MS experiment, a total of 53 compounds were identified in the extract solution of Yinqiao powder. In addition, 33 blood components were characterized, 23 of which were prototypes. The results of network pharmacology analysis showed that Yinqiao powder may inhibit inflammatory responses by suppressing IL-6, CXCL2, TNFα, NF-κB, etc., in the treatment of COVID-19. The HPLC fingerprint analysis of Yinqiao powder was conducted at 237 nm and 29 characteristic peaks were matched, 11 of which were identified. Forsythoside A was selected as the internal standard reference and double-wavelength (237 nm and 327 nm) was established in QAMS experiment. The repeatability was well under different conditions, and the results measured by QAMS were consisted with that of the external standard method (ESM), indicating that the QAMS method was reliable and accurate. The quality evaluation method of Yinqiao powder would be helpful to evaluate the intrinsic quality of Yinqiao powder more comprehensively, which is conducive to improve the quality standard of Yinqiao powder and provide a beneficial guarantee for the clinical treatment of COVID-19.

Neuroprotective Drug Discovery From Phytochemicals and Metabolites for CNS Viral Infection: A Systems Biology Approach With Clinical and Imaging Validation

Background

Recent studies have reported that pulmo-neurotropic viruses can cause systemic invasion leading to acute respiratory failure and neuroinfection. The tetracycline class of secondary metabolites of microorganisms is effective against several migrating neurotropic viral disorders, as Japanese-Encephalitis (JE), Severe-Acute-Respiratory-Syndrome Coronavirus-2 (SARS-COV2), Human-Immunodeficiency-Virus (HIV), and Simian-Immunodeficiency-Virus (SIV). Another microbial secondary metabolite, cephalosporin, can be used for anti-viral combination therapy. However, a substantial public health debacle is viral resistance to such antibiotics, and, thus, one needs to explore the antiviral efficiency of other secondary metabolites, as phytochemicals. Hence, here, we investigate phytochemicals like podophyllotoxin, chlorogenic acid, naringenin, and quercetin for therapeutic efficiency in neurotropic viral infections.

Methods

To investigate the possibility of the afferent neural pathway of migrating virus in man, MRI scanning was performed on human subjects, whereby the connections between cranial nerves and the brain-stem/limbic-region were assessed by fiber-tractography. Moreover, human clinical-trial assessment (n = 140, p = 0.028) was done for formulating a quantitative model of antiviral pharmacological intervention. Furthermore, docking studies were performed to identify the binding affinity of phytochemicals toward antiviral targets as (i) host receptor [Angiotensin-converting Enzyme-2], (ii) main protease of SARS-COV2 virus (iii) NS3-Helicase/Nucleoside triphosphatase of Japanese-encephalitis-virus, and the affinities were compared to standard tetracycline and cephalosporin antibiotics. Then, network pharmacology analysis was utilized to identify the possible mechanism of action of those phytochemicals.

Results

Human MRI-tractography analysis showed fiber connectivity, as: (a) Path-1: From the olfactory nerve to the limbic region (2) Path-2: From the peripheral glossopharyngeal nerve and vagus nerves to the midbrain-respiratory-center. Docking studies revealed comparable binding affinity of phytochemicals, tetracycline, and cephalosporin antibiotics toward both (a) virus receptors, (b) host cell receptors where virus-receptor binds. The phytochemicals effectively countered the cytokine storm-induced neuroinflammation, a critical pathogenic pathway. We also found that a systems-biology-based double-hit mathematical bi-exponential model accounts for patient survival-curve under antiviral treatment, thus furnishing a quantitative-clinical framework of secondary metabolite action on virus and host cells.

Conclusion

Due to the current viral resistance to antibiotics, we identified novel phytochemicals that can have clinical therapeutic application to neurotropic virus infection. Based on human MRI scanning and clinical-trial analysis, we demarcated the anatomical pathway and systems-biology-based quantitative formulation of the mechanism of antiviral action.

Assessment of Low Back Pain in Helicopter Pilots Using Electrical Bio-Impedance Technique: A Feasibility Study

Low back pain (LBP) is known to pose a serious threat to helicopter pilots. This study aimed to explore the potential of electrical bio-impedance (EBI) technique with the advantages of no radiation, non-invasiveness and low cost, which is intended to be used as a daily detection tool to assess LBP in primary aviation medical units. The LBP scales (severity) in 72 helicopter pilots were assessed using a pain questionnaire, while the bilateral impedance measurements of the lumbar muscle were carried out with a high precision EBI measurement system. Results showed that the modulus of lumbar muscle impedance increased with LBP scale whereas the phase angle decreased. For different LBP scales, significant differences were found in the modulus of lumbar muscle impedance sum on both sides (Z_sum), as well as in the modulus and phase angle of lumbar muscle impedance difference between both sides (Z_diff and ϕ_diff), respectively (P < 0.05). Moreover, Spearman’s correlation analysis manifested a strong correlation between Z_sum and LBP scale (R = 0.692, P < 0.01), an excellent correlation between Z_diff and LBP scale (R = 0.86, P < 0.01), and a desirable correlation between ϕ_diff and LBP scale (R = −0.858, P < 0.01). In addition, receiver operator characteristic analysis showed that for LBP prediction, the area under receiver operator characteristic curve of Z_sum, Z_diff, and ϕ_diff were 0.931, 0.992, and 0.965, respectively. These findings demonstrated that EBI could sensitively and accurately detect the state of lumbar muscle associated with LBP, which might be the potential tool for daily detection of LBP in primary aviation medical units.

Apple phenolic extract ameliorates lead-induced cognitive impairment, depression- and anxiety-like behavior in mice through abating oxidative stress, inflammation and apoptosis via miR-22-3p/SIRT1 axis

Lead can lead to neurotoxicity and cognitive impairment. In this study, for the first time, the protective effects and working mechanisms of apple phenolic extract (APE) against lead acetate (Pb(Ac)2)-induced...

Neuroprotective Potential of Mung Bean (Vigna radiata L.) Polyphenols in Alzheimer's Disease: A Review

Mung bean contains various neuroprotective polyphenols, so it might be a healthy food for Alzheimer's disease (AD) prevention. Totally, 19 major phenolic compounds were quantified in mung bean, including 10 phenolic acids and 9 flavonoids. After summarizing their contents and effective doses in rodent AD models, it was speculated that vitexin, isovitexin, sinapic acid, and ferulic acid might be the major bioactive compounds for mung bean-mediated neuroprotection. The mechanisms involved inhibition of β-amyloidogenesis, tau hyperphosphorylation, oxidative stress, and neuroinflammation, and promotion of autophagy and acetylcholinesterase enzyme activity. Notably, the neuroprotective phenolic profile in mung bean changed after germination, with decreased vitexin and isovitexin, and increased rutin, isoquercitrin, isorhamnetin, and caffeic acid detected. However, only studies of individual phenolic compounds in mung bean are published at present. Hence, further studies are needed to elucidate the neuroprotective activities and mechanisms of extractions of mung bean seeds and sprouts, and the synergism between different phenolic compounds.

Beneficial effects of chlorogenic acid treatment on neuroinflammation after deep hypothermic circulatory arrest may be mediated through CYLD/NF-κB signaling

Deep hypothermic circulatory arrest (DHCA) during heart surgery may induce neuroinflammation leading to neurocognitive dysfunction. Chlorogenic acid (CA) is a common phytochemical, which can attenuate neuroinflammation. Nevertheless, the underlying mechanism involved in the anti-inflammatory effect of CA after DHCA is unknown. The present study therefore characterized the anti-inflammatory functions of CA after DHCA using in vivo and in vitro DHCA models. The activation of microglia, inflammatory cytokine levels, and the NF-κB pathway were measured. The results showed that CA treatment ameliorated neurocognitive function and reduced the inflammatory cytokine levels in the brain and circulation. Furthermore, the microglial and NF-κB activations were suppressed after DHCA. CA exerted the same anti-inflammatory effect in hypothermia OGD microglial cells as the in vivo study. Additional studies indicated that the regulation of ubiquitin ligase activity of TRAF6 and RIP1 by CYLD was related to the mechanism involving inhibition of CA in the NF-κB pathway. Together, the results showed that CA may attenuate neuroinflammation after DHCA by modulating the signaling of CYLD/NF-κB.

Real-time monitoring hypoxia at high altitudes using electrical bioimpedance technique: an animal experiment

Hypoxia poses a serious threat to pilots. The aim of this study was to examine the efficacy of electrical bioimpedance (EBI) in detecting the onset of hypoxia in real time in a rabbit hypoxia model. Thirty-two New Zealand rabbits were divided equally into four groups (control group and three hypoxia groups, i.e., mild, moderate, and severe). Hypoxia was induced by simulating various altitudes in the hypobaric oxygen chamber (3,000 m, 5,000 m, and 8,000 m). Both cerebral impedance and blood oxygen (Sp_O2) were monitored continuously. Results showed that the cerebral impedance increased immediately during the period of increasing altitude and decreased quickly to the initial baseline at the phase of descending altitude. Moreover, the change of cerebral impedance in the mild hypoxia group (3,000 m) was significantly smaller than those in the other two groups (5,000 m and 8,000 m, P < 0.05). The changes in cerebral impedance and Sp_O2 were significantly correlated based on the total of measurement data (r² = 0.628, P < 0.001). Furthermore, the agreement analysis performed with Bland-Altman and standardized residual plots exhibited high concordance between cerebral impedance and Sp_O2. Receiver operator characteristic analysis manifested that the sensitivity, specificity, and area under the curve using cerebral impedance for changes in Sp_O2 >10% were 0.735, 0.826, and 0.845, respectively. These findings demonstrated that EBI could sensitively and accurately monitor changes of cerebral impedance induced by hypoxia, which might provide a potential tool for the real-time and noninvasive monitoring of hypoxic condition of pilots in flight for early identification of hypoxia.NEW & NOTEWORTHY This study is the first to examine the efficacy of electrical bioimpedance (EBI) in detecting the onset of high-altitude hypoxia in real time. The novelty of this research includes three aspects. First, the cerebral impedance of rabbits increased immediately during the rising of altitude and decreased quickly to the initial baseline at the phase of descending altitude. Second, there was a significant correlation and high concordance between cerebral impedance and Sp_O2. Third, cerebral impedance could determine the change of Sp_O2 resulting from hypoxia.

Comparative metabolism study on chlorogenic acid, cryptochlorogenic acid and neochlorogenic acid using UHPLC-Q-TOF MS coupled with network pharmacology

Chlorogenic acid (5-CQA), neochlorogenic acid (3-CQA), and cryptochlorogenic acid (4-CQA), usually simultaneously exist in many traditional Chinese medicines (TCMs). However, insufficient attentions have been paid to the comparative metabolism study on these three isomeric constituents with similar effects on anti-inflammation until now. In this study, a novel strategy was established to perform comparative analysis of their metabolic fates in rats and elucidate the pharmacological mechanism of anti-inflammation. Firstly, diagnostic product ions (DPIs) deduced from the representative reference standards were adopted to rapidly screen and characterize the metabolites in rat plasma, urine and faeces using UHPLC-Q-TOF MS. Subsequently, Network pharmacology was utilized to elucidate their anti-inflammatory mechanism. Consequently, a total of 73 metabolites were detected and characterized, including 50, 47 and 43 metabolites for 5-CQA, 4-CQA and 3-CQA, orderly. Moreover, the network pharmacology study indicated that these three isomeric constituents and their major metabolites with similar in vivo metabolic pathways exerted anti-inflammatory effects through co-owned 20 biological processes, which involved 10 major signal pathways and 159 potential targets. Our study shed light on the similarities and differences of the metabolic profiling and anti-inflammatory activity among these three isomeric constituents and set an example for the further researches on the active mechanism of isomeric constituents existing in TCMs based on comparative metabolism study.

Investigation of Phenolic Composition and Anticancer Properties of Ethanolic Extracts of Japanese Quince Leaves

Glioblastoma multiforme is an aggressive and invasive disease with no efficient therapy available, and there is a great need for finding alternative treatment strategies. This study aimed to investigate anticancer activity of the extracts of the Japanese quince (JQ) cultivars ‘Darius’, ‘Rondo’, and ‘Rasa’ leaf extracts on glioblastoma C6 and HROG36 cells. As identified by ultra high performance liquid chromatography electrospray ionization tandem mass spectrometry, the extracts contained three prevailing groups of phenols: hydroxycinnamic acid derivatives; flavan-3-ols; and flavonols. Sixteen phenols were detected; the predominant compound was chlorogenic acid. The sum of detected phenols varied significantly between the cultivars ranging from 9322 µg/g (‘Rondo’) to 17,048 µg/g DW (‘Darius’). Incubation with the extracts decreased the viability of glioblastoma HROG36 cells with an efficiency similar to temozolomide, a drug used for glioblastoma treatment. In the case of C6 glioblastoma cells, the extracts were even more efficient than temozolomide. Interestingly, primary cerebellar neuronal-glial cells were significantly less sensitive to the extracts compared to the cancer cell lines. The results showed that JQ leaf ethanol extracts are rich in phenolic compounds, can efficiently reduce glioblastoma cell viability while preserving non-cancerous cells, and are worth further investigations as potential anticancer drugs.

Chlorogenic acid: A comprehensive review of the dietary sources, processing effects, bioavailability, beneficial properties, mechanisms of action, and future directions

Chlorogenic acids (CGAs), a group of hydroxycinnamates, are generally abundant in everyday foods and beverages, most prominently in certain coffee drinks. Among them, the chlorogenic acid (CGA), also termed as 5-O-caffeoylquinic acid (5-CQA), is one of the most abundant, highly functional polyphenolic compounds in the human diet. The evidence of its health benefits obtained from clinical studies, as well as basic research, indicates an inverse correlation between 5-CQA consumption and a lower risk of metabolic syndromes and chronic diseases. This review focuses on the beneficial properties for health and mechanisms of action of 5-CQA, starting with its history, isomers, dietary sources, processing effects, preparation methods, pharmacological safety evaluation, and bioavailability. It also provides the possible molecular mechanistic bases to explain the health beneficial effects of 5-CQA including neuroprotective, cardiovascular protective, gastrointestinal protective, renoprotective, hepatoprotective, glucose and lipid metabolism regulatory, and anticarcinogenic effects. The information summarized here could aid in the basic and clinical research on 5-CQA as a natural dietary additive, potential drug candidate, as well as a natural health promoter.

Natural Sources, Pharmacokinetics, Biological Activities and Health Benefits of Hydroxycinnamic Acids and Their Metabolites

Hydroxycinnamic acids (HCAs) are important natural phenolic compounds present in high concentrations in fruits, vegetables, cereals, coffee, tea and wine. Many health beneficial effects have been acknowledged in food products rich in HCAs; however, food processing, dietary intake, bioaccessibility and pharmacokinetics have a high impact on HCAs to reach the target tissue in order to exert their biological activities. In particular, metabolism is of high importance since HCAs' metabolites could either lose the activity or be even more potent compared to the parent compounds. In this review, natural sources and pharmacokinetic properties of HCAs and their esters are presented and discussed. The main focus is on their metabolism along with biological activities and health benefits. Special emphasis is given on specific effects of HCAs' metabolites in comparison with their parent compounds.

Erythronium japonicum Alleviates Inflammatory Pain by Inhibiting MAPK Activation and by Suppressing NF-κB Activation via ERK/Nrf2/HO-1 Signaling Pathway

Microglial activation-mediated neuroinflammation influences the development of inflammatory pain. The aim of this study was to investigate the anti-inflammatory effects and mechanisms of aqueous Erythronium japonicum extract (EJE) in microglia activation-mediated inflammatory pain. EJE was found to suppress lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), ionized calcium-binding adapter molecule 1 (IBA-1), and pro-inflammatory cytokines in BV2 microglial cells. In addition, LPS-induced c-Jun NH₂ terminal protein kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) phosphorylation were inhibited by EJE. Intriguingly, EJE also inhibited p65 phosphorylation by activating extracellular signal-regulated kinase-1/2 (ERK)/nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling. Furthermore, the effects of EJE treatment, such as HO-1 induction and the reduction of NF-ĸB activation, were reversed by ERK1/2 inhibition. In an inflammatory pain mouse model, Complete Freund’s Adjuvant (CFA)-induced mechanical allodynia and foot swelling were alleviated by the oral administration of EJE. Consistent with in vitro results, EJE increased HO-1, while decreasing CFA-induced COX-2, IBA-1, and pro-inflammatory cytokines in the spinal cord. Among the components of EJE, butanol most heavily suppressed LPS-induced microglial activation and increased HO-1 expression. These findings indicate that EJE can alleviate inflammatory pain by inhibiting p38 and JNK and by suppressing NF-ĸB via ERK/Nrf2/HO-1 signaling.

In vitro and in vivo evaluation of the neuroprotective activity of Uncaria hirsuta Haviland

The incidence of neurodegeneration leading to the conditions such as Alzheimer's and Parkinson's diseases are on the increase, they require the approaches that focus on protection prevention rather than treatment. Plants are rich sources of many compounds which possess medicinal properties. We sought to investigate the neuroprotective effects of Uncariahirsuta and its compounds on d-galactose-induced stress in BALB/c mice as well as 6-hydroxydopamine (6-OHDA)-induced stress in mouse nerve growth factor (mNGF)-differentiated PC12 cells. Our results demonstrate that the 95% ethanol extract of U. hirsuta reversed the d-galactose-induced learning and memory dysfunctions and decreased the malodialdehyde levels. Furthermore, the isolated compounds, 5β-carboxystrictosidine (1) and chlorogenic acid (2), protected mNGF-differentiated PC12 cells against toxicity induced by 6-OHDA by acting as antiapoptotic agents. The 50% inhibitory concentration (IC₅₀) for intracellular reactive oxygen species (ROS) scavenging was found to be 24.5 (for 1) and 19.7 μM (for 2), and both 1 and 2 reduced intracellular calcium levels with respective IC₅₀ values of 46.9 and 27 μM. Interestingly, both compounds inhibited caspase 3 and 9 activities with respective IC₅₀ values of 25.6 and 24.5 μM for 1 and 19.4 and 16.3 μM for 2. Our results identify U. hirsuta and its active compounds as potential neuroprotective agents and deserve further evaluation for drug development for neuroprotection in the future.

Attenuation of Palmitic Acid-Induced Lipotoxicity by Chlorogenic Acid through Activation of SIRT1 in Hepatocytes

SCOPE

Saturated free fatty acids (FFAs) induce hepatocyte lipotoxicity, wherein oxidative stress-associated mitochondrial dysfunction is mechanistically involved. Chlorogenic acid (CGA), a potent antioxidant and anti-inflammatory compound, protects against high-fat-diet-induced oxidative stress and mitochondrial dysfunction in liver. This study investigates whether CGA protects against FFA-induced hepatocyte lipotoxicity via the regulation of mitochondrial fission/fusion and elucidates its underlying mechanisms.

METHODS AND RESULTS

AML12 cell, a non-transformed hepatocyte cell line, is treated with palmitate. Here, it is shown that CGA prevents palmitate-induced lipotoxicity by activation of SIRT1 regulated mitochondrial morphology. CGA treatment mitigates oxidative stress and mitochondrial dysfunction, as evidenced by a decrease in reactive oxygen species (ROS) production, and an increase in mitochondrial mass and mitochondrial membrane potential. CGA also significantly decreases Bax expression and thereby reduces mitochondria-mediated caspase-dependent apoptosis. Mechanistically, CGA attenuates ROS-induced mitochondrial fragmentation by inhibiting dynamin-related protein 1 (Drp1) and enhancing Mfn2 expression. In contrast, the inhibitory effects of CGA on the generation of mitochondrial ROS and Drp1 are blocked by siRNA knockdown of SIRT1.

CONCLUSION

Collectively, these findings show that supplementation with CGA protects hepatocytes from FFA-induced lipotoxicity through activation of SIRT1, which reverses the oxidative stress and dysfunction of mitochondrial biogenesis directly.

Chlorogenic acid prevents paraquat-induced apoptosis via Sirt1-mediated regulation of redox and mitochondrial function

Paraquat (PQ) is a widely used agro-chemical in agriculture and highly toxic to humans. Although the mechanism of PQ poisoning is not clear, it has been well documented that reactive oxygen species (ROS) generation and apoptosis play pivotal roles. Alternatively, chlorogenic acid (CA) is a biologically active dietary polyphenol, playing several therapeutic roles. However, it is not known whether CA has protective effect on PQ-induced apoptosis. Here, we investigated the effect of CA in preventing PQ-induced apoptosis and explored the underlying mechanisms. A549 cells were pretreated with 100 µM CA for 24 h and then exposed to 160 µM PQ for 24 h. We found that CA was effective in preventing PQ-induced apoptotic features, including the release of cytochrome c from the mitochondria to cytoplasm, the cleavages of caspase 3 and caspase 9, and the increases in levels of Bcl-2-associated X protein (Bax) and intracellular calcium ions. CA alleviated ROS production and prevented the reduction of antioxidant capacity in cells exposed to PQ by increasing NF-E2-related factor 2 (Nrf2), superoxide dismutase 2 (SOD2) and glutathione levels. In addition, CA also attenuated PQ-induced alterations of mitochondrial structure and function (such as the decreases in membrane potential and adenosine triphosphate level), and the impaired autophagic flux was improved by CA. Down-regulation of sirtuin 1 (Sirt1) by short hairpin RNA reversed the protective effects of CA. Thus, CA may be viewed as a potential drug to treat PQ-induced lung epithelial cell apoptosis and other disorders with similar pathologic mechanisms.

Effect of Chlorogenic Acid Supplementation in MPTP-Intoxicated Mouse

Oxidative stress and neuroinflammation play a key role in dopaminergic (DA) neuronal degeneration, which results in the hindrance of normal ongoing biological processes in the case of Parkinson's disease. As shown in several studies, on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) administration, different behavioral parameters have suggested motor impairment and damage of antioxidant defence. Thus, some specific biological molecules found in medicinal plants can be used to inhibit the DA neuronal degeneration through their antioxidant and anti-inflammatory activities. With this objective, we studied chlorogenic acid (CGA), a naturally occurring polyphenolic compound, for its antioxidant and anti-inflammatory properties in MPTP-intoxicated mice. We observed significant reoccurrence of motor coordination and antioxidant defence on CGA supplementation, which has been in contrast with MPTP-injected mice. Moreover, in the case of CGA-treated mice, the enhanced expression of tyrosine hydroxylase (TH) within the nigrostriatal region has supported its beneficial effect. The activation of glial cells and oxidative stress levels were also estimated using inducible nitric oxide synthase (iNOS) and glial fibrillary acidic protein (GFAP) immunoreactivity within substantia nigra (SN) and striatum of MPTP-injected mice. Administration of CGA has prevented the neuroinflammation in SN by regulating the nuclear factor-κB expression in the MPTP-induced group. The significant release of certain pro-inflammatory mediators such as tumor necrosis factor-α and interleukin (IL)-1β has also been inhibited by CGA with the enhanced expression of anti-inflammatory cytokine IL-10. Moreover, reduced GFAP staining within the nigrostriatal region has supported the fact that CGA has significantly helped in the attenuation of astrocyte activation. Hence, our study has shown that CGA supplementation shows its therapeutic ability by reducing the oxidative stress and neuroinflammation in MPTP-intoxicated mice.

Indole-3-carbinol improves neurobehavioral symptoms in a cerebral ischemic stroke model

Stroke is one of the most common causes of death worldwide and also responsible for permanent disability. Ischemic stroke has been found to affect 80% of stroke patients. Recombinant tissue plasminogen activator (rtPA) is the widely used drug for the ischemic stroke with narrow therapeutic window. Indole-3-carbinol (I3C) is a natural compound obtained from brassica species having antithrombotic activity. Middle cerebral artery occlusion (MCAO) model was used followed by reperfusion after 2 h of ischemia for the evaluation of the I3C against ischemic stroke. After reperfusion, I3C (12.5, 25, and 50 mg/kg) was given by oral route once daily and continued up to the 14th day. Behavioral studies including postural reflex, forelimb placing, and cylinder tests showed I3C attenuated the MCAO-induced increase in average score and asymmetry score efficiently. Mean cerebral blood flow (CBF) was improved by treatment with I3C (12.5 mg/kg) by 60% of baseline at 6 h. I3C inhibited ADP-induced platelet aggregation and reduced ischemic volume significantly. It also inhibited in vitro the ADP-induced platelet aggregation in healthy human volunteers. I3C improves behavioral scores and mean CBF after focal cerebral ischemia in rats. Furthermore, I3C showed prophylactic anti-thrombotic activity against carrageenan induced tail thrombosis. Therefore, preclinical evidence points to I3C as a potential candidate for use in cerebral ischemic stroke.