Rosmarinic acid inhibits 6-OHDA-induced neurotoxicity by anti-oxidation in MES23.5 cells

Rosmarinic acid liposomes suppress ferroptosis in ischemic brain via inhibition of TfR1 in BMECs

BACKGROUND

Iron deposition and ferroptosis are involved in ischemic stroke injury, but the choice of drugs for treatment is limited.

PURPOSE

To investigate the potential neuroprotective effects of Rosmarinic acid (RosA) encapsulated within nanoliposomes (RosA-LIP) on ischemic stroke.

METHODS

Wild-type (WT) and TfR1EC cKO (specific knockout of the TfR1 gene in BMECs) mice used to establish a dMCAO model, with simultaneous administration of RosA-LIP (20 mg/kg/d, i.p.) or RosA (20 mg/kg/d, i.p.).

RESULTS

The successful synthesis of RosA-LIP resulted in enhanced stability and precise delivery in both the serum and brain. The administration of RosA-LIP effectively mitigated ischemia-induced behavioral abnormalities and pathological damage. RosA-LIP inhibited ferroptosis by ameliorating mitochondrial abnormalities, increasing GPX4 levels, and decreasing ACSL4/LPCAT3/Lox-dependent lipid peroxidation. RosA-LIP effectively improved blood‒brain barrier (BBB) permeability, increased tight junctions (TJs) protein expression and reduced iron levels in ischemic tissue and brain microvascular endothelial cells (BMECs) by modulating FPN1 and TfR1 levels. Furthermore, RosA-LIP suppressed TfR1 to attenuate ACSL4/LPCAT3/Lox-mediated ferroptosis in TfR1EC cKO mice subjected to dMCAO.

CONCLUSION

RosA-LIP effectively increased the brain level of RosA and protected against ferroptosis through the regulation of TfR1 in BMECs.

Rosmarinic acid mitigates acrylamide induced neurotoxicity via suppressing endoplasmic reticulum stress and inflammation in mouse hippocampus

BACKGROUND

Acrylamide (ACR) is a widely used compound that is known to be neurotoxic to both experimental animals and humans, causing nerve damage. The widespread presence of ACR in the environment and food means that the toxic risk to human health can no longer be ignored. Rosmarinic acid (RA), a natural polyphenolic compound extracted from the perilla plant, exhibits anti-inflammatory, antioxidant, and other properties. It has also been demon strated to possess promising potential in neuroprotection. However, its role and potential mechanism in treating ACR induced neurotoxicity are still elusive.

PURPOSE

This study explores whether RA can improve ACR induced neurotoxicity and its possible mechanism.

METHODS

The behavioral method was used to study RA effect on ACR exposed mice's neurological function. We studied its potential mechanism through metabolomics, Nissl staining, HE staining, immunohistochemical analysis, and Western blot.

RESULTS

RA pretreatment reversed the increase in mouse landing foot splay and decrease in spontaneous activity caused by 3 weeks of exposure to 50 mg/kg/d ACR. Further experiments demonstrated that RA could prevent ACR induced neuronal apoptosis, significantly downregulate nuclear factor-κB and tumor necrosis factor-α expression, and inhibit NOD-like receptor protein 3 inflammasome activation, thereby reducing inflammation as confirmed by metabolomics results. Additionally, RA treatment prevented endoplasmic reticulum stress (ERS) caused by ACR exposure, as evidenced by the reversal of significant P-IRE1α,TRAF2,CHOP expression increase.

CONCLUSION

RA alleviates ACR induced neurotoxicity by inhibiting ERS and inflammation. These results provide a deeper understanding of the mechanism of ACR induced neurotoxicity and propose a potential new treatment method.

Banxia-Houpu decoction inhibits iron overload and chronic intermittent hypoxia-induced neuroinflammation in mice

ETHNOPHARMACOLOGICAL RELEVANCE

The Banxia-Houpu decoction (BHD), a renowned prescription documented in the Chinese medical book "The Synopsis of the Golden Chamber," has been proven to effectively mitigate inflammation within the central nervous system. Previous studies have demonstrated the efficacy of BHD in ameliorating symptoms in patients with obstructive sleep apnea (OSA). Nevertheless, the precise mechanisms and comprehensive effects of BHD on central system injury in OSA models have not been fully investigated.

AIM OF THE STUDY

To investigate whether BHD could inhibit neuroinflammation to decrease iron-induced neurotoxic injury in CIH mice.

MATERIALS AND METHODS

C57BL/6N mice were divided into the Con, CIH, and BHD groups. Mice were exposed to CIH (21%-5% FiO2, 3 min/cycle, 8 h/d), and BHD was administered by gavage (3.51, 7.01, and 14.02 g/kg). The polarization of microglia, inflammatory factors, hepcidin, and brain iron levels were determined.

RESULTS

The administration of BHD at a dosage of 7.01 g/kg demonstrated a significant reduction in neurobehavioral abnormalities, neuronal damage, and degeneration caused by CIH. BHD exhibited the ability to inhibit the transition of microglial polarization from M2 to M1 by upregulating CD163 expression and downregulating iNOS levels. Furthermore, BHD decreased pro-inflammatory factor levels and increased anti-inflammatory factor levels. Additionally, BHD was found to decrease hepcidin expression in astrocytes through the TLR4/MyD88/NF-κB signaling pathway. BHD reduced the total and neuronal iron levels by elevating FPN1 and reducing TfR1 levels. BHD exhibited positive effects on synapse and synaptic spine abnormalities, as well as an increase in the Bcl-2/Bax ratio, thereby mitigating neuronal damage induced by CIH.

CONCLUSIONS

Based on these findings, BHD holds potential as a therapeutic intervention for neural damage injuries, which offers a theoretical foundation for the treatment of patients with OSA in clinical.

Rosmarinic Acid Liposomes Downregulate Hepcidin Expression via BMP6-SMAD1/5/8 Pathway in Mice with Iron Overload

The objective of this study is to examine the potential protective effect of rosmarinic acid (RosA) encapsulated within nanoliposomes (RosA-LIP) on hepatic damage induced by iron overload. The characteristics, stability, and release of RosA-LIP in vitro were identified. The mice were randomly assigned to five groups: Control, Model, Model+DFO (DFO), Model+RosA (RosA), and Model+RosA-LIP (RosA-LIP). The iron overload model was induced by administering iron dextran (i.p.). The DFO, RosA, and RosA-LIP groups received iron dextran and were subsequently treated with DFO, RosA, and RosA-LIP for 14 days. We developed a novel formulation of RosA-LIP that exhibited stability and controlled release properties. Firstly, RosA-LIP improved liver function and ameliorated pathological changes in a mouse model of iron overload. Secondly, RosA-LIP demonstrated the ability to enhance the activities of T-SOD, GSH-Px, and CAT, while reducing the levels of MDA and 4-HNE, thereby effectively mitigating oxidative stress damage induced by iron overload. Thirdly, RosA-LIP reduced hepatic iron levels by downregulating FTL, FTH, and TfR1 levels. Additionally, RosA-LIP exerted a suppressive effect on hepcidin expression through the BMP6-SMAD1/5/8 signaling pathway. Furthermore, RosA-LIP upregulated FPN1 expression in both the liver and duodenum, thereby alleviating iron accumulation in these organs in mice with iron overload. Notably, RosA exhibited a comparable iron chelation effect, and RosA-LIP demonstrated superior efficacy in mitigating liver damage induced by excessive iron overload. RosA-LIP exhibited favorable sustained release properties, targeted delivery, and efficient protection against iron overload-induced liver damage. A schematic representation of the proposed protective mechanism of rosmarinic acid liposome during iron overload. Once RosA-LIP is transported into cells, RosA is released. On the one hand, RosA attenuates the BMP6-SMAD1/5/8-SMAD4 signaling pathway activation, leading to inhibiting hepcidin transcription. Then, the declined hepcidin contacted the inhibitory effect of FPN1 in hepatocytes and duodenum, increasing iron mobilization. On the other hand, RosA inhibits TfR1 and ferritin expression, which decreases excessive iron and oxidative damage.

Biochemical and behavioral effects of rosmarinic acid treatment in an animal model of Parkinson's disease induced by MPTP

Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide. The main therapeutic approach available nowadays relieves motor symptoms but does not prevent or stop neurodegeneration. Rosmarinic acid (RA), an ester of caffeic and 3,4-dihydroxyphenylacetic acids, is obtained from numerous plant species such as Salvia officinalis L. (sage) and Rosmarinus officinalis (rosemary). This compound has a wide spectrum of biological activities, such as antioxidant and anti-inflammatory, and could be an additional therapy for neurodegenerative disorders. Here we evaluated the potential neuroprotective effects of RA treatment in a murine model of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Mice were separated into four groups: CN, Control/saline; RA, Rosmarinic acid/vehicle; MPTP, MPTP/saline; MPTP+RA, MPTP/RA. RA (20 mg/kg, or vehicle) was administered orally by intra-gastric gavage for 14 days, one hour before MPTP or saline injection. MPTP groups received the drug (30 mg/kg, intraperitoneally) once a day for five days (fourth to the eighth day of the experiment). MPTP-treated animals displayed hyperlocomotion behavior, which was significantly prevented by RA treatment. In addition, RA treatment increased dopaminergic signaling in the parkinsonian mice and improved the monoaminergic system in healthy animals. Analysis of alterations in the striatal mRNA expression of dopaminergic system components showed that MAO-A expression was increased in the MPTP+AR group. Overall, this study brings new evidence of the potential neuroprotective properties of RA not only in preventing behavioral features observed in PD, but also by improving neurotransmission in the healthy brain.

Effects of the Polyphenols Delphinidin and Rosmarinic Acid on the Inducible Intra-cellular Aggregation of Alpha-Synuclein in Model Neuron Cells

Intracellular aggregation of α-synuclein is a major pathological feature of Parkinson's disease. In this study, we show that the polyphenols delphinidin and rosmarinic acid suppress intracellular aggregation of α-synuclein in a mouse neuron cell model when added under oxidative stress conditions. To enhance the detection threshold of this preventive effect of the two polyphenols, we generated a new strain of "aggregation prone model cells" that tended to show prominent α-synuclein aggregation even under normal conditions. Using this new highly sensitive cell line, we demonstrate that addition of delphinidin to model cell cultures effectively suppresses the formation of intracellular α-synuclein aggregates. Flow cytometric analysis shows that adding delphinidin decreases the fraction of "dying cells," cells that were alive but in a damaged state. Our findings suggest the possibility of using polyphenols to prevent and treat the symptoms correlated with the onset of Parkinson's disease. Additionally, our aggregation-prone cell model may be used in future studies to probe numerous neurodegenerative diseases with high sensitivity.

Rosmarinic Acid Attenuates Rotenone-Induced Neurotoxicity in SH-SY5Y Parkinson’s Disease Cell Model through Abl Inhibition

Rosmarinic acid (RA) is a natural polyphenolic compound with antioxidative property. With the present study, we aimed to evaluate the neuroprotective role of RA on Parkinson’s disease using rotenone induced SH-SY5Y cell model of Parkinson’s disease, the underlying mechanism of action of RA was also investigated. Cell viability, cell morphology, apoptosis, signaling protein phosphorylation and expression, cellular reactive oxygen species (ROS) production, ATP content, and mitochondrial membrane potential were tested in SH-SY5Y cells. RA showed a neuroprotective effect in a rotenone-induced SH-SY5Y cell model of Parkinson’s disease with dose-dependent manner, it reduced cell apoptosis and restored normal cell morphology. RA not only decreased levels of α-synuclein and Tau phosphorylation but also elevated the contents of AMPK phosphorylation, Akt phosphorylation, and PGC-1α. RA restored the reduced mitochondrial membrane potential and ATP content as well as inhibited rotenone-induced ROS overproduction. Further findings demonstrated that the neuroprotective role of RA was partially due to the inhibition of Abl tyrosine kinase. RA treatment suppressed the hyperphosphorylation of Abl Y412 and CrkII Y221 induced by rotenone. Nilotinib, a specific inhibitor of Abl, elicited a similar neuroprotective effect as that of RA. The present study indicates that RA has a property of neuroprotection against rotenone, and the neuroprotective effect is partially attributed to the inhibition of Abl.

A Comprehensive Review of Rosmarinic Acid: From Phytochemistry to Pharmacology and Its New Insight

Polyphenolic acids are the widely occurring natural products in almost each herbal plant, among which rosmarinic acid (RA, C18H16O8) is well-known, and is present in over 160 species belonging to many families, especially the Lamiaceae. Aside from this herbal ingredient, dozens of its natural derivatives have also been isolated and characterized from many natural plants. In recent years, with the increasing focus on the natural products as alternative treatments, a large number of pharmacological studies have been carried out to demonstrate the various biological activities of RA such as anti-inflammation, anti-oxidation, anti-diabetes, anti-virus, anti-tumor, neuroprotection, hepatoprotection, etc. In addition, investigations concerning its biosynthesis, extraction, analysis, clinical applications, and pharmacokinetics have also been performed. Although many achievements have been made in various research aspects, there still exist some problems or issues to be answered, especially its toxicity and bioavailability. Thus, we hope that in the case of natural products, the present review can not only provide a comprehensive understanding on RA covering its miscellaneous research fields, but also highlight some of the present issues and future perspectives worth investigating later, in order to help us utilize this polyphenolic acid more efficiently, widely, and safely.

Rosmarinic Acid Inhibits Mitochondrial Damage by Alleviating Unfolded Protein Response

Mitochondria are essential organelles that perform important roles in cell biologies such as ATP synthesis, metabolic regulation, immunomodulatory, and apoptosis. Parkinson’s disease (PD) is connected with mitochondrial neuronal damage related to mitochondrial unfolded protein response (mtUPR). Rosmarinic acid (RA) is a naturally occurring hydroxylated polyphenolic chemical found in the Boraginaceae and the Labiatae subfamily Nepetoideae. This study looked into RA’s protective effect against mitochondrial loss in the substantia nigra (SN) caused by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), the underlying mechanism associated with the mtUPR. Pretreatment with RA reduced motor impairments and dopaminergic neuronal degeneration in the SN of a mouse model injected with MPTP. Pretreatment of SH-SY5Y cells from cell viability loss, morphological damage, and oxidative stress. Furthermore, RA pre-injection suppressed MPTP-induced mtUPR, lowered the expression of HSPA9, HSPE1, CLPP, LONP1, and SIRT 4, and protected the MPTP-mice and SH-SY5Y cells from mitochondrial failure. These findings imply that RA can prevent Parkinson’s disease by preventing mitochondrial damage in dopaminergic neurons in Parkinson’s disease via alleviating mitochondrial unfolded protein response.

Protective effects of Lavandula stoechas L. methanol extract against 6-OHDA-induced apoptosis in PC12 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Parkinson's disease (PD) is a neurodegenerative disorder associated with oxidative stress-induced neuronal damage and death. In European and Persian Traditional Medicine, aerial parts (leaves, stems, and flowers) of Lavandula stoechas L. have been widely used for treating neurodegenerative disorders including PD.

AIM OF THE STUDY

Herein, the protective effects of L. stoechas methanol extract were investigated on 6-hydroxydopamine (6-OHDA)-induced cytotoxicity and oxidative damage in PC12 cells.

MATERIALS AND METHODS

The cells were pretreated with a standardized L. stoechas methanol extract (2.5-20 μg/mL) for 24 h and exposed to 6-OHDA (200 μM) thereafter. The cell viability percentage was determined by AlamarBlue test. Intracellular reactive oxygen species (ROS) production was determined by a fluorimetric method using 2',7'-dichlorodihydrofluorescein diacetate and cellular apoptosis was assessed by the fluorescent probe propidium iodide test. Finally, the expression of proteins involved in apoptosis pathway (Phospho SAPK/JNK, SAPK/JNK, p44/42 MAPK (ERK1/2) and Poly ADP ribose polymerase (PARP)) was measured via Western blot analysis.

RESULTS

Treatment of PC12 cells with 6-OHDA could significantly increase cytotoxicity, ROS level, and cell apoptosis. Pretreatment of PC12 cells with the extract could significantly decrease 6-OHDA cytotoxicity, ROS production, (2.5 and 5 μg/mL) and cell apoptosis (5 μg/mL). Western blot analysis showed that 6-OHDA exposure could increase the expression of proteins involved in apoptosis signaling, while pretreatment with L. stoechas (5 μg/mL) reduced apoptotic proteins.

CONCLUSIONS

The present study demonstrated that L. stoechas, which has been traditionally used in Persian Medicine for treating CNS diseases, is a valuable source of active compounds with neuroprotective, anti-oxidant, and anti-apoptotic activity.

Herbal Resources to Combat a Progressive & Degenerative Nervous System Disorder- Parkinson's Disease

Parkinson's disease is one of the most common adult-onset, a chronic disorder involving neurodegeneration, which progressively leads to deprivation of dopaminergic neurons in substantia nigra, causing a subsequent reduction of dopamine levels in the striatum resulting in tremor, myotonia, and dyskinesia. Genetics and environmental factors are believed to be responsible for the onset of Parkinson's disease. The exact pathogenesis of Parkinson's disease is quite complicated and the present anti-Parkinson's disease treatments appear to be clinically insufficient. Comprehensive researches have demonstrated the use of natural products such as ginseng, curcumin, ashwagandha, baicalein, etc. for the symptomatic treatment of this disease. The neuroprotective effects exhibited by these natural products are mainly due to their ability to increase dopamine levels in the striatum, manage oxidative stress, mitochondrial dysfunction, glutathione levels, clear the aggregation of α- synuclein, induce autophagy and decrease the pro-inflammatory cytokines and lipid peroxidation. This paper reviews various natural product studies conducted by scientists to establish the role of natural products (both metabolite extracts as well as pure metabolites) as adjunctive neuroprotective agents.

Effects of rosmarinic acid on nervous system disorders: an updated review

Nowadays, the worldwide interest is growing to use medicinal plants and their active constituents to develop new potent medicines with fewer side effects. Precise dietary compounds have prospective beneficial applications for various neurodegenerative ailments. Rosmarinic acid is a polyphenol and is detectable most primarily in many Lamiaceae families, for instance, Rosmarinus officinalis also called rosemary. This review prepared a broad and updated literature review on rosmarinic acid elucidating its biological activities on some nervous system disorders. Rosmarinic acid has significant antinociceptive, neuroprotective, and neuroregenerative effects. In this regard, we classified and discussed our findings in different nervous system disorders including Alzheimer's disease, epilepsy, depression, Huntington's disease, familial amyotrophic lateral sclerosis, Parkinson's disease, cerebral ischemia/reperfusion injury, spinal cord injury, stress, anxiety, and pain.

The Role of Oxidative Stress in Parkinson's Disease

Parkinson’s disease (PD) is caused by progressive neurodegeneration of dopaminergic (DAergic) neurons with abnormal accumulation of α-synuclein in substantia nigra (SN). Studies have suggested the potential involvement of dopamine, iron, calcium, mitochondria and neuroinflammation in contributing to overwhelmed oxidative stress and neurodegeneration in PD. Function studies on PD-causative mutations of SNCA, PRKN, PINK1, DJ-1, LRRK2, FBXO7 and ATP13A2 further indicate the role of oxidative stress in the pathogenesis of PD. Therefore, it is reasonable that molecules involved in oxidative stress, such as DJ-1, coenzyme Q10, uric acid, 8-hydroxy-2’-deoxyguanosin, homocysteine, retinoic acid/carotenes, vitamin E, glutathione peroxidase, superoxide dismutase, xanthine oxidase and products of lipid peroxidation, could be candidate biomarkers for PD. Applications of antioxidants to modulate oxidative stress could be a strategy in treating PD. Although a number of antioxidants, such as creatine, vitamin E, coenzyme Q10, pioglitazone, melatonin and desferrioxamine, have been tested in clinical trials, none of them have demonstrated conclusive evidence to ameliorate the neurodegeneration in PD patients. Difficulties in clinical studies may be caused by the long-standing progression of neurodegeneration, lack of biomarkers for premotor stage of PD and inadequate drug delivery across blood–brain barrier. Solutions for these challenges will be warranted for future studies with novel antioxidative treatment in PD patients.

Glioprotective Effect of Chitosan-Coated Rosmarinic Acid Nanoemulsions Against Lipopolysaccharide-Induced Inflammation and Oxidative Stress in Rat Astrocyte Primary Cultures

Rosmarinic acid (RA) is a natural polyphenolic compound with a well-documented neuroprotective effect mainly associated with its anti-inflammatory and antioxidant activities. Recently, our research group developed and optimized chitosan-coated RA nanoemulsions (RA CNE) intended to be used for nasal delivery as a new potential neuroprotective therapy. In this sense, the present study aimed to evaluate the protective and/or therapeutic potential of RA CNE in inflammation/oxidative stress induced by LPS (1 μg mL-1) in rat astrocyte primary cultures. In summary, pre-treatment with RA CNE before exposure to LPS (protective protocol) reduced significantly the LPS-induced alterations in astrocyte cell viability, proliferation, and cell death by necrosis, which was not observed in therapeutic protocol. RA CNE protective protocol also enhanced anti-oxidative status by ~ 50% by decreasing oxygen reactive species production and nitric oxide levels and preventing total thiol content decrease. Finally, our results demonstrate the protective effect of RA CNE in migratory activation and GFAP expression of reactive astrocytes. Overall, our findings indicate for the first time the RA CNE glioprotective potential, associated with an increase in cell viability and proliferation, a preventive effect on cellular death by necrosis, migratory ability and hypertrophic reactive astrocytes, and the reparation of astrocyte redox state.

Therapeutic Potential of Rosmarinic Acid: A Comprehensive Review

Naturally occurring food-derived active ingredients have received huge attention for their chemopreventive and chemotherapy capabilities in several diseases. Rosmarinic acid (RA) is a caffeic acid ester and a naturally-occurring phenolic compound in a number of plants belonging to the Lamiaceae family, such as Rosmarinus officinalis (rosemary) from which it was formerly isolated. RA intervenes in carcinogenesis through different ways, including in tumor cell proliferation, apoptosis, metastasis, and inflammation. On the other hand, it also exerts powerful antimicrobial, anti-inflammatory, antioxidant and even antidepressant, anti-aging effects. The present review aims to provide an overview on anticancer activities of RA and to deliberate its therapeutic potential against a wide variety of diseases. Given the current evidence, RA may be considered as part of the daily diet in the treatment of several diseases, with pre-determined doses avoiding cytotoxicity.

A Review on Nutritional Value, Functional Properties and Pharmacological Application of Perilla (Perilla Frutescens L.)

Perilla frutescens is an annual herb belonging to the mint family (Lamiaceae). It is majorly produced in countries like China, Japan, India, Thailand and Korea. Recently, Perilla plant is gaining more attention because of its medicinal benefits and phytochemical contents. The major phytochemical compounds reported in this species are phenolic compounds (Rosmarinic acid, caffeic acid, ferulic acid), flavonoids (luteolin, apigenin), Phytosterols, Tocopherols, Policosanols and Fatty acid. Perilla seed oil is also a rich source of essential fatty acid such as α-linolenic acid (54-64%) and linoleic acid (14%). Perilla seeds and its oils have been widely used in traditional nutritional and medicinal formulations. Biological analysis of Perilla seeds revealed that it showed anticancer, ant-diabetic, antiasthma, antimicrobial, anti-inflammatory, antioxidant and cardioprotective effect. The aim of this review is to provide an update on the nutritional composition, phytochemical profile and pharmacological research of Perilla seed.

An overview of the neuroprotective potential of rosmarinic acid and its association with nanotechnology-based delivery systems: A novel approach to treating neurodegenerative disorders

Neurodegenerative disorders (ND) are characterized by slow and progressive neuronal dysfunction induced by the degeneration of neuronal cells in the central nervous system (CNS). Recently, the neuroprotective effects of natural compounds with anti-inflammatory and antioxidant activities has been clearly demonstrated. This appears to be an attractive therapeutic approach for ND, particularly regarding the use of polyphenols. In this review, we present an overview of the neuroprotective potential of rosmarinic acid (RA) and discuss the use of nanotechnology as a novel approach to treating ND. RA presents a variety of biological important activities, i.e. the modulation of pro-inflammatory cytokine expression, prevention of neurodegeneration and damage reduction. However, its poor bioavailability represents a limitation in terms of pharmacodynamics. In this sense, nanotechnology-based carriers could allow for the administration of higher but still safe amounts of RA, aiming for CNS delivery. Nasal administration could be a pleasant route for delivery to the CNS, as this represents a direct route to the CNS. With these advantages, RA-loaded nanotechnology-based therapy through the nasal route could be promising approach for the treatment of ND.

Rosmarinic acid protects against MPTP-induced toxicity and inhibits iron-induced α-synuclein aggregation

Rosmarinic acid (RA) is a naturally occurring polyphenolic compound. In this study, we demonstrated that RA could protect against the degeneration of the nigrostriatal dopaminergic system in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of Parkinson's disease (PD). In addition, RA could inhibit MPTP-induced decrease of superoxide dismutase (SOD) and tyrosine hydroxylase (TH) and increase in nigral iron content. Further studies elucidated the effects of RA on iron-induced neurotoxicity and the possible underlying mechanisms in the SK-N-SH cells. Results showed that iron could induce a decrease in the mitochondrial transmembrane potential and result in α-synuclein aggregation in the SK-N-SH cells, which could be restored by RA pretreatment. Further results showed RA pretreatment could inhibit iron-induced α-synuclein aggregation by up-regulating hemeoxygenase-1 (HO-1). In addition, iron could increase the mRNA levels of α-synuclein via iron responsive element/iron regulatory protein (IRE/IRP) system. RA pretreatment could decrease the mRNA levels of α-synuclein by decreasing the protein levels of IRP1. These results indicated that RA protected against iron-induced α-synuclein aggregation by up-regulating HO-1 and inhibiting α-synuclein expression.

Spica prunellae and its marker compound rosmarinic acid induced the expression of efflux transporters through activation of Nrf2-mediated signaling pathway in HepG2 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Spica prunellae (SP) is a well-known traditional Chinese medicinal herb with properties of antihypertensive, antihyperglycemic, antiviral, anti-inflammatory, and antitumor activities. This herb is also popularly consumed as a food additive in some drinks or other food forms for treating pyreticosis. Rosmarinic acid (RA) is the marker compound from SP, which possesses anti-oxidative and anti-inflammatory functions.

AIM OF THE STUDY

This study aims to investigate the regulatory effect of the water extract of SP (WESP) and RA on efflux transports (ETs), including P-glycoprotein (p-gp), multidrug resistance-associated protein 2 (MRP2), and breast cancer resistance protein (BCRP) in HepG2 cell line. Results would provide beneficial information for the proper application of SP in clinics.

MATERIALS AND METHODS

HepG2 cells were treated with different doses of the tested drugs for 24 or 96h. MTT assay was used to examine cell viability. The protein and mRNA levels of the ETs were measured by using Western blot and real-time PCR, respectively. Reporter assay was used to study the antioxidant response element (ARE)-luciferin activity by using HepG2-C8 cells, which were generated by transfecting plasmid containing ARE-luciferin gene into HepG2 cells. The transport activities of ETs were tested by using substrate probes.

RESULTS

WESP significantly (p<0.05) increased the expression of ETs in a dose-dependent manner. The increase caused by WESP was stronger than RA alone. Both WESP and RA promoted the translocation of nuclear factor E2-related factor-2 (Nrf2) from cytoplasm to the nucleus as well as significantly (p<0.05) enhanced the ARE-luciferin activity. WESP and RA also enhanced the efflux activity of P-gp and MRP2, accompanied by marked increase (p<0.05) in the intracellular ATP levels.

CONCLUSIONS

WESP could significantly induce the expression of ETs through the activation of Nrf2-mediated signaling pathway in HepG2 cells. RA could be one of the active compounds responsible for the induction. WESP and RA also enhanced the efflux activity of P-gp and MRP2, and the increased intracellular ATP levels were likely involved in this induction. Results of this study provide a better understanding of the regulation of SP on ETs and the underlying molecular mechanism. Results indicated that potential drug-drug interactions may exist when SP is co-administered with other substrate drugs that are transported via the ETs, especially P-gp and MRP2, thereby providing beneficial information for appropriate use of SP for clinical therapy.

Phytochemical and phytopharmacological review of Perilla frutescens L. (Labiatae), a traditional edible-medicinal herb in China

Perilla frutescens (L.) Britt., a worldwide distributed plant, is an important economic crop and with a long cultivation history in China as well as some other countries in Asia. Except for the edible applications, the plant of P. frutescens is also traditionally used as a medicinal herb in China for thousands years. The leaves, seeds and stems of P. frutescens are recommended by the Chinese Pharmacopeia as three medicinal materials for various therapeutic applications. In the past decades, amount investigations have been done about different aspects for P. frutescens. However, no literature review about these works has been compiled. This review aims to present the findings of research conducted up-to-date (2015) on the traditional use, phytochemicals, pharmacological activities and toxicities of P. frutescens to provide scientific evidence for well-understanding and future research of P. frutescens. It was found that more than 100 compounds have been reported for P. frutescens and most of them are contributed to its medical benefits such as anti-allergic, anti-inflammatory, anti-oxidant, anticancer, anti-microbial, anti-depressive and anti-cough effects. Toxicology studies have been conducted to evaluate the safety of P. frutescens to provide information on their dosages and usages.

Phytochemicals as future drugs for Parkinson’s disease: a comprehensive review

Parkinson’s disease (PD) is the second most common chronic neurodegenerative disease that affects motor skills and cognitive performance. The conventional therapeutic approaches for the management of PD are just able to alleviate symptoms. Exploring for achieving novel substances with therapeutic benefits in PD patients is the focus of a wide range of current investigations. The aim of the present study is to comprehensively review phytochemicals with protective or therapeutic activities in PD and focus on their neuropsychopharmacological mechanisms. Various subgroups of polyphenols (flavonoids, phenolic acids, stilbenes, and lignanes) and terpenes are the most abundant groups of phytochemicals with well-established antiparkinsonian effects. Other phytochemical categories, such as alkaloids, cinnamates, carbohydrates, amino acids, and fatty acid amides, also have some representatives with positive effects in PD. Phytochemicals perform their antiparkinsonian effect through several mechanisms of action, including suppressing apoptosis (via the reduction of Bax/Bcl-2, caspase-3, -8, and -9, and α-synuclein accumulation), decreasing dopaminergic neuronal loss and dopamine depletion, reducing the expression of proinflammatory cytokines (such as prostaglandin E2, interleukin-6, interleukin-1β, and nuclear factor-κB), and modulating nuclear and cellular inflammatory signaling, elevation of neurotrophic factors, and improvement of antioxidant status. Plant-derived natural products can be considered as future pharmaceutical drugs or adjuvant treatment with conventional therapeutic approaches to improve their efficacy and alleviate their psychological adverse effects in the management of PD. Well-designed clinical trials are mandatory to evaluate the protective and healing benefits of phytochemicals as promising future drugs in the management of neurodegenerative diseases.

Mitochondria-Targeted Protective Compounds in Parkinson's and Alzheimer's Diseases

Mitochondria are cytoplasmic organelles that regulate both metabolic and apoptotic signaling pathways; their most highlighted functions include cellular energy generation in the form of adenosine triphosphate (ATP), regulation of cellular calcium homeostasis, balance between ROS production and detoxification, mediation of apoptosis cell death, and synthesis and metabolism of various key molecules. Consistent evidence suggests that mitochondrial failure is associated with early events in the pathogenesis of ageing-related neurodegenerative disorders including Parkinson's disease and Alzheimer's disease. Mitochondria-targeted protective compounds that prevent or minimize mitochondrial dysfunction constitute potential therapeutic strategies in the prevention and treatment of these central nervous system diseases. This paper provides an overview of the involvement of mitochondrial dysfunction in Parkinson's and Alzheimer's diseases, with particular attention to in vitro and in vivo studies on promising endogenous and exogenous mitochondria-targeted protective compounds.

Development, characterization and nasal delivery of rosmarinic acid-loaded solid lipid nanoparticles for the effective management of Huntington's disease

OBJECTIVE

The objective of the present study was to investigate the potential use of solid lipid nanoparticles (SLNs) as a drug delivery system to enhance the brain-targeting efficiency of rosmarinic acid (RA) following intranasal (i.n.) administration.

MATERIALS AND METHODS

The RA-loaded SLNs was prepared by the hot homogenization technique, in which glycerol monostearate (GMS) as lipid, tween 80 and soya lecithin were used as surfactant along with hydrogenated soya phosphatidyl choline (HSPC) as a stabilizer, and were characterized for particle size, zeta potential (ZP), in vitro study. Nasal delivery of the developed formulation followed by the study of behavioral (locomotor, narrow beam, body weight) and biochemical parameters (glutathione, lipid peroxidation, catalase and nitrite) in wistar rat was carried out.

RESULTS

Optimized RA-loaded SLNs using tween 80 (SLNPRT) have the mean size of (149.2 ± 3.2 nm), ZP (-38.27 mV) entrapment efficiency (61.9 ± 2.2%). 3-NP-treated rat significantly increased behavioral alterations, oxidative damage as compared with the control group. SLNPRT treatment significantly improved behavioral abnormalities and attenuated the oxidative stress in 3NP-treated rats. However, the nasal delivery of SLNPRT produced significant therapeutic action as compared to intravenous application. In the organ distribution study, brain drug concentration was found to be 5.69 µg, in pharmacokinetic study Cmax, tmax, t1/2, AUC values were found to be 0.284 µg/ml, 1.5 h, 3.17 h, and 1.505 µg/ml/h, respectively.

CONCLUSION

The encouraging results confirmed the developed optimized RA-loaded SLNs formulation following the non-invasive nose-to-brain drug delivery that is a promising therapeutic approach for the effective management in Huntington disease.

Protection of MES23.5 dopaminergic cells by obestatin is mediated by proliferative rather than anti-apoptotic action

Obestatin is an endogenous peptide sharing a precursor with ghrelin. This study aims to investigate whether and how obestatin protects MES23.5 dopaminergic cells against 1-methyl-4-phenylpyridinium (MPP(+))-induced neurotoxicity. MES23.5 cells were pretreated with obestatin (10(-13)-10(-6) mol/L) for 20 min prior to incubation with 200 μmol/L MPP(+) for 12 or 24 h, or treated with obestatin alone (10(-13) to 10(-6) mol/L) for 0, 6, 12, and 24 h. The methyl thiazolyl tetrazolium (MTT) assay was used to measure cell viability. Flow cytometry was used to measure the caspase-3 activity and the mitochondrial transmembrane potential. Proliferating cell nuclear antigen (PCNA) protein levels were determined by Western blotting. Obestatin (10(-13) to 10(-7) mol/L) pretreatment blocked or even reversed the MPP(+)-induced reduction of viability in MES23.5 cells, but had no effect on MPP(+)-induced mitochondrial transmembrane potential collapse and caspase-3 activation. When applied alone, obestatin increased viability. Elevated PCNA levels occurred with 10(-7), 10(-9), 10(-11) and 10(-13) mol/L obestatin treatment for 12 h. The results suggest that the protective effects of obestatin against MPP(+) in MES23.5 cells are due to its proliferation-promoting rather than anti-apoptotic effects.

A review on bioactivities of perilla: progress in research on the functions of perilla as medicine and food

Perilla is a useful pharmaceutical and food product and is empirically consumed by humans. However, its properties have not been evaluated extensively. In this review, we summarize the progress made in research, focusing on the bioactivities of perilla. There are many in vitro and animal studies on the cytostatic activity and antiallergic effects, respectively, of perilla and its constituents. However, its influence on humans remains unclear. Hence, investigating and clarifying the physiological effects of perilla and its constituents on humans are imperative in the future to adhere to the ideals of evidence-based medicine.

Neurorescue effect of rosmarinic acid on 6-hydroxydopamine-lesioned nigral dopamine neurons in rat model of Parkinson's disease

Rosmarinic acid (RA) is a naturally occurring polyphenolic compound. It has been reported that RA possessed antioxidant and anti-inflammatory properties. Our previous study showed that RA could protect MES23.5 dopaminergic cells against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in vitro. The purpose of this study was to explore the neuroreparative (neurorescue) effect of RA on 6-OHDA-lesioned rat model of Parkinson's disease (PD) in vivo. In this study, the rats were given RA orally after intrastriatal 6-OHDA lesion. Results showed that the dopamine content in the striatum decreased and the numbers of tyrosine hydroxylase-immunoreactive neurons reduced after 6-OHDA treatment. RA treatment after 6-OHDA administration could restore these changes. Further studies demonstrated that 6-OHDA treatment increased the iron-staining positive cells, which were markedly decreased by RA treatment. Moreover, RA suppressed the increased ratio of Bax/Bcl-2 at gene level induced by 6-OHDA. This indicates that the neurorescue effects of RA against 6-ODHA-induced degeneration of the nigrostriatal dopaminergic system were achieved by decreasing nigral iron levels and regulating the ratio of Bcl-2/Bax gene expression.

Rosmarinic acid antagonized 1-methyl-4-phenylpyridinium (MPP+)-induced neurotoxicity in MES23.5 dopaminergic cells

Rosmarinic acid (RA) is a naturally occurring polyphenolic compound found in various plant families. We previously reported that RA exerted protective effects against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity through antioxidative properties. In this study, we investigated whether RA could prevent effects of 1-methyl-4-phenylpyridinium (MPP(+))-induced insult in MES23.5 dopamineric cells. 1-Methyl-4-phenylpyridinium treatment decreased cell viability and dopamine content, as well as caused apoptotic morphological changes. 1-Methyl-4-phenylpyridinium-induced mitochondrial dysfunction, indicated by inhibition of activity associated with mitochondrial respiratory chain complex I, suggested mitochondrial transmembrane potential collapse and generation of reactive oxygen species. Decreased Bcl-2/Bax ratio and caspase 3 activation were also observed. Rosmarinic acid pretreatment restored the complex I activity of the mitochondrial respiratory chain and partially reversed the other damaging effects of MPP(+). Our results indicate that RA plays a neuroprotective role by ameliorating mitochondrial dysfunction against MPP(+)-induced cell apoptosis and suggest that RA has the potential to be considered an aid for prevention of Parkinson's disease.