Protective effects of mangosteen extract on H2O2-induced cytotoxicity in SK-N-SH cells and scopolamine-induced memory impairment in mice

Chinese Artichoke (Stachys affinis Bunge): The Nutritional Profile, Bioactive Profile and Food Applications-A Review

Stachys affinis Bunge, known as Chinese artichoke, is a perennial plant originating from China, which has uprising scientific interest due to its complex and beneficial content. Chinese artichoke is rich in bioactive compounds useful for human health, including antioxidants, polyphenols, and prebiotics, and its edible tubers are high in essential nutrients and dietary fiber. Studies show its potential as a functional food ingredient in various products like rice bars, bread, and chocolate, enhancing their nutritional and sensory properties. Additionally, Chinese artichoke exhibits significant anti-inflammatory, neuroprotective, and antibacterial activities, warranting further research and utilization in the food industry. This review aims to summarize the existing knowledge of the S. affinis Bunge plant, focusing on its health-promoting aspects.

A Mechanistic Review on Protective Effects of Mangosteen and its Xanthones Against Hazardous Materials and Toxins

Due to its pharmacological properties, α-Mangostin, mainly found in Garcinia mangostana (G. mangostana) L. (Mangosteen, queen of fruits), treats wounds, skin infections, and many other disorders. In fact, α-Mangostin and other xanthonoid, including β-Mangostin and γ-Mangostin, are found in G. mangostana, which have various advantages, namely neuroprotective, anti-proliferative, antinociceptive, antioxidant, pro-apoptotic, anti-obesity, anti-inflammatory, and hypoglycemic through multiple signaling mechanisms, for instance, extracellular signal-regulated kinase1/2 (ERK 1/2), mitogenactivated Protein kinase (MAPK), nuclear factor-kappa B (NF-kB), transforming growth factor beta1 (TGF-β1) and AMP-activated protein kinase (AMPK). This review presents comprehensive information on Mangosteen's pharmacological and antitoxic aspects and its xanthones against various natural and chemical toxins. Because of the insufficient clinical study, we hope the current research can benefit from performing clinical and preclinical studies against different toxic agents.

Exploring the potential of Crotalaria juncea flower extracts as a source of antioxidants, antimicrobials, and cytoprotective agents for biomedical applications

Plants provide an unlimited source of bioactive compounds, possessing tremendous applications in the pharmaceutical industry. In the search for sources of antioxidants and antimicrobial agents against human pathogens, ethanol extracts of Crotalaria juncea flowers (CJ flower extract) were evaluated. The highest total phenolic (5.65 μg GAE/ml) and flavonoid (0.43 μg QE/ml) contents were observed in the 100 μg/ml CJ flower extract. To assess antioxidant activity, three in vitro antioxidant tests were employed: DPPH radical-scavenging, ABTS+ radical-scavenging, and hydroxyl radical-scavenging assay. The CJ flower extract demonstrated significant (P < 0.05) antioxidant activity, dependent on the percentage of solvent extraction and the specific assays utilized. The highest antioxidant activity was obtained with 100% ethanol extraction and using the hydroxyl radical-scavenging assay (56.63%). Antimicrobial activity was assessed against six human pathogens, including the fungi Microsporum gypseum and five Gram-positive bacteria (Propionibacterium acnes, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, and Streptococcus mutans), as well as one Gram-negative bacterium (Escherichia coli ). The CJ flower extract inhibited the growth of both fungal and bacterial pathogens. The cytotoxicity of the CJ flower extract was measured using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the highest concentration of the extract (100 μg/ml) did not affect L929 cell viability. Moreover, the CJ flower extract demonstrated the ability to suppress H2O2-induced toxicity in L929 cells. Overall, the CJ flower extract has potential as an alternative source for exploring new antioxidants, antimicrobial agents, and cytoprotectants that could prove valuable for biomedical applications.

A systematic review for the development of Alzheimer's disease in in vitro models: a focus on different inducing agents

Alzheimer's disease (AD) is the most common progressive neurodegenerative disease and is associated with dementia. Presently, various chemical and environmental agents are used to induce in-vitro models of Alzheimer disease to investigate the efficacy of different therapeutic drugs. We screened literature from databases such as PubMed, ScienceDirect, and Google scholar, emphasizing the diverse targeting mechanisms of neuro degeneration explored in in-vitro models. The results revealed studies in which different types of chemicals and environmental agents were used for in-vitro development of Alzheimer-targeting mechanisms of neurodegeneration. Studies using chemically induced in-vitro AD models included in this systematic review will contribute to a deeper understanding of AD. However, none of these models can reproduce all the characteristics of disease progression seen in the majority of Alzheimer's disease subtypes. Additional modifications would be required to replicate the complex conditions of human AD in an exact manner. In-vitro models of Alzheimer's disease developed using chemicals and environmental agents are instrumental in providing insights into the disease's pathophysiology; therefore, chemical-induced in-vitro AD models will continue to play vital role in future AD research. This systematic screening revealed the pivotal role of chemical-induced in-vitro AD models in advancing our understanding of AD pathophysiology and is therefore important to understand the potential of these chemicals in AD pathogenesis.

Antidotal and protective effects of mangosteen (Garcinia mangostana) against natural and chemical toxicities: A review

Chemical and natural toxic compounds can harm human health through a variety of mechanisms. Nowadays, herbal therapy is widely accepted as a safe method of treating toxicity. Garcinia mangostana (mangosteen) is a tree in the Clusiaceae family, and isoprenylated xanthones, its main constituents, are a class of secondary metabolites having a variety of biological properties, such as anti-inflammatory, anti-oxidant, pro-apoptotic, anti-proliferative, antinociceptive, neuroprotective, hypoglycemic, and anti-obesity. In this review, the protective activities of mangosteen and its major components against natural and chemical toxicities in both in vivo and in vitro experiments were evaluated. The protective effects of mangosteen and its components are mediated primarily through oxidative stress inhibition, a decrease in the number of inflammatory cells such as lymphocytes, neutrophils, and eosinophils, reduction of inflammatory mediators such as tumor necrosis factor-alpha (TNF-α), interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-8 (IL-8), cyclooxygenase-2 (COX-2), prostaglandin (PG) E2, inducible nitric oxide synthase, and nuclear factor-ĸB (NF-ĸB), modulation of apoptosis and mitogen-activated protein kinase (MAPK) signaling pathways, reducing p65 entrance into the nucleus, α-smooth muscle actin (α-SMA), transforming growth factor β1 (TGFβ1), improving histological conditions, and inhibition in acetylcholinesterase activity.

Effect of alpha-mangostin in the prevention of behavioural and neurochemical defects in methylmercury-induced neurotoxicity in experimental rats

Methylmercury (MeHg+) is a known neurotoxin that causes progressive motor neuron degeneration in the central nervous system. Axonal degeneration, oligodendrocyte degeneration, and myelin basic protein (MBP) deficits are among the neuropathological abnormalities caused by MeHg+ in amyotrophic lateral sclerosis (ALS). This results in demyelination and motor neuron death in both humans and animals. Previous experimental studies have confirmed that overexpression of the extracellular signalling regulated kinase (ERK1/2) signalling contributes to glutamate excitotoxicity, inflammatory response of microglial cells, and oligodendrocyte (OL) dysfunction that promotes myelin loss. Alpha-mangostin (AMG), an active ingredient obtained from the tree "Garcinia mangostana Linn," has been used in experimental animals to treat a variety of brain disorders, including Parkinson's and Huntington's disease memory impairment, Alzheimer's disease, and schizophrenia, including Parkinson's disease and Huntington's disease memory impairment, Alzheimer's disease, and schizophrenia. AMG has traditionally been used as an antioxidant, anti-inflammatory, and neuroprotective agent.Accordingly, we investigated the therapeutic potential of AMG (100 and 200 mg/kg) in experimental rats with methylmercury (MeHg+)-induced neurotoxicity. The neuroprotective effect of AMG on behavioural, cellular, molecular, and other gross pathological changes, such as histopathological alterations in MeHg+ -treated rat brains, is presented. The neurological behaviour of experimental rats was evaluated using a Morris water maze (MWM), open field test (OFT), grip strength test (GST), and force swim test (FST). In addition, we investigate AMG's neuroprotective effect by restoring MBP levels in cerebral spinal fluid and whole rat brain homogenate. The apoptotic, pro-inflammatory, and oxidative stress markers were measured in rat blood plasma samples and brain homogenate. According to the findings of this study, AMG decreases ERK-1/2 levels and modulates neurochemical alterations in rat brains, minimising MeHg+ -induced neurotoxicity.

Effects of water-soluble mangosteen extract on cognitive function and neuropsychiatric symptoms in patients with mild to moderate Alzheimer's disease (WECAN-AD): A randomized controlled trial

Introduction

The water-soluble mangosteen pericarp extract's (WME) effect was investigated in Alzheimer's disease (AD).

Methods

The participants received 4 mg/kg/day of WME for 24 weeks (low dose, n = 33), 4 mg/kg/day for 12 weeks and then 8 mg/kg/day for 12 weeks (high dose, n = 33); or a placebo (n = 42). The outcomes were neuropsychiatric test scores, safety, tolerability, and the blood 4-hydroxynonenal level.

Results

The proportion of participants who achieved the minimum clinically important difference for the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog; -2.6 points) at 24 weeks was significantly higher in the low-dose group (and a trend in the high-dose group) than in the placebo group. WME appeared safe and well tolerated. At 24 weeks, the 4-hydroxynonenal level declined in both intervention groups. The participants with a 5% reduction in this level showed greater ADAS-Cog improvements.

Conclusion

WME is a safe and well-tolerated cognitive enhancer in AD with varying benefits across individuals based on antioxidative response.

Effect of Water Extract of Mangosteen Pericarp on Donepezil Pharmacokinetics in Mice

The pharmacokinetic (PK) change in a drug by co-administered herbal products can alter the efficacy and toxicity. In the circumstances that herb-drug combinations have been increasingly attempted to alleviate Alzheimer's disease (AD), the PK evaluation of herb-drug interaction (HDI) is necessary. The change in systemic exposure as well as target tissue distribution of the drug have been issued in HDIs. Recently, the memory-enhancing effects of water extract of mangosteen pericarp (WMP) has been reported, suggesting a potential for the combination of WMP and donepezil (DNP) for AD treatment. Thus, it was evaluated how WMP affects the PK change of donepezil, including systemic exposure and tissue distribution in mice after simultaneous oral administration of DNP with WMP. Firstly, co-treatment of WMP and donepezil showed a stronger inhibitory effect (by 23.0%) on the neurotoxicity induced by Aβ(25-35) in SH-SY5Y neuroblastoma cells than donepezil alone, suggesting that the combination of WMP and donepezil may be more effective in moderating neurotoxicity than donepezil alone. In PK interaction, WMP increased donepezil concentration in the brain at 4 h (by 63.6%) after administration without affecting systemic exposure of donepezil. Taken together, our results suggest that WMP might be used in combination with DNP as a therapy for AD.

Acetylcholinesterase Inhibitors in the Treatment of Neurodegenerative Diseases and the Role of Acetylcholinesterase in their Pathogenesis

Acetylcholinesterase (AChE) plays an important role in the pathogenesis of neurodegenerative diseases by influencing the inflammatory response, apoptosis, oxidative stress and aggregation of pathological proteins. There is a search for new compounds that can prevent the occurrence of neurodegenerative diseases and slow down their course. The aim of this review is to present the role of AChE in the pathomechanism of neurodegenerative diseases. In addition, this review aims to reveal the benefits of using AChE inhibitors to treat these diseases. The selected new AChE inhibitors were also assessed in terms of their potential use in the described disease entities. Designing and searching for new drugs targeting AChE may in the future allow the discovery of therapies that will be effective in the treatment of neurodegenerative diseases.

The Effect of Adjunctive Mangosteen Pericarp on Cognition in People With Schizophrenia: Secondary Analysis of a Randomized Controlled Trial

Background: Cognitive impairment is prevalent and often highly burdensome in people with schizophrenia. The aim of this study was to investigate if mangosteen (Garcinia mangostana Linn.) pericarp extract may be an effective intervention to improve cognitive performance in this population. Methods: This was a secondary analysis of a larger randomized placebo-controlled trial that investigated a 24-weeks intervention of mangosteen pericarp extract supplementation in people diagnosed with schizophrenia. A subset of n = 114 participants with completed cognitive outcomes at follow up were included in this analysis. Using the Cogstate Brief Battery, the following cognitive outcomes were assessed: psychomotor function, attention, visual learning and memory (visual and working). Subgroup analyses investigated whether baseline clinical parameters (baseline cognitive functioning, illness severity and duration, depressive symptoms) moderated the relationship between mangosteen pericarp extract intervention and change in cognitive outcomes. Results: There were no significant between-group changes in any cognitive outcomes assessed. Subgroup analysis based on baseline cognition and clinical characteristics did not reveal any significant between-group difference in change. Conclusions: Mangosteen pericarp extract did not affect cognitive outcomes in people with schizophrenia. Further investigation regarding optimal dosing strategies for mangosteen interventions and the testing of additional cognitive domains may be warranted. Trial Registration: ANZCTR.org.au identifier: ACTRN12616000859482, registered 30 June 3 2016.

Effect of Garcinia mangostana pericarp extract on glial NF-κB levels and expression of serum inflammation markers in an obese-type 2 diabetes mellitus animal model

Type 2 diabetes mellitus (T2DM) is an age-related disease associated with cerebral inflammation and Alzheimer's disease. Garcinia mangostana pericarp (GMP) possesses antihyperglycemic, antidiabetic and anti-inflammatory effects. The aim of the present study was to evaluate the effect of GMP extract on cerebral inflammation in Wistar rats with T2DM by examining the expression levels of glial nuclear factor-κB (NF-κB), interleukin (IL)-6, tumor necrosis factor-α (TNF-α) and superoxide dismutase (SOD). A total of 36 8-10-week-old male Wistar rats were randomly divided into six groups and provided a standard diet (normal control; C1), high-fat diet (HFD) with 200 g/kg GMP extract BW/day (GMP control; C2), HFD with streptozotocin-nicotinamide (diabetic control; C3), and HFD with 100 (M1), 200 (M2) or 400 g/kg body weight (BW)/day (M3) GMP extract for Wistar rats with diabetes. GMP extract was administered for 8 weeks after induction of T2DM was confirmed. Glial NF-κB activity was assessed by immunohistochemical staining, and by measuring IL-6 levels, TNF-α levels and SOD activity in the serum using ELISA. BW significantly increased following HFD treatment. After 7 weeks, the BW remained significantly higher compared with the normal control and GMP extract-treated groups, but decreased continuously in the T2DM groups. Glial NF-κB immunoreaction in the hippocampal region was significantly higher in the diabetic Wistar rats compared with the normal control Wistar rats, and 200 g/kg BW/day GMP significantly reduced its activity. The T2DM Wistar rats showed significantly higher expression levels of serum IL-6 and TNF-α and lower activity of SOD compared with the normal control Wistar rats. Meanwhile, rats in GMP groups M1, M2 and M3 exhibited significant reductions in the levels of IL-6 and TNF-α expression, and increases in SOD activity. GMP extract treatment effectively reduced hippocampal NF-κB, IL-6 and TNF-α levels and increased antioxidant SOD activity. These results suggest that GMP extract prevents cerebral inflammation in T2DM Wistar rats.

α-mangostin preserves hepatic microvascular architecture in fibrotic rats as shown by scanning electron microscopy of vascular corrosion casts

Liver fibrosis is a dynamic condition caused by wound-healing in which scar tissue replaces the liver parenchyma following repetitive injuries. It is hypothesized that α-mangostin (AM), the major constituent of the xanthone fraction in extracts of Garcinia mangostana L., may protect the hepatic microvascular bed from thioacetamide (TAA)-induced fibrosis. In the present study, rats were divided into 4 groups: Control rats received no treatment; TAA-treated rats received 150 mg/kg TAA 3 times per week intraperitoneally; AM-treated rats received 75 mg/kg AM twice per week intraperitoneally; and TAA+AM-treated rats received both TAA and AM as described above. Rat livers were processed either for light microscopy or for vascular corrosion casting after 30 and 60 days of treatment. Vascular parameters were measured by 3D morphometry analysis of scanning electron micrographs. AM attenuated hepatocellular injuries and delayed both periportal and pericentral fibrosis in the TAA-treated rats. The comparison of findings at day 30 and 60 showed that TAA-induced fibrotic changes were progressive in time, and that the beneficial effects of AM only became apparent after prolonged treatment. The livers of rats treated with both TAA and AM had less space surrounding the portal vessels, improved preservation of the hepatic microvascular pattern, and minimally altered sinusoidal patterns with few signs of terminal portal venule remodeling. AM therefore partially protected the liver against hepatotoxin-induced fibrosis and the associated microvascular changes. The mechanism of the protective effect of AM on the liver remains to be investigated.

Isolation of a High Antioxidant Non-Toxic Polar Fraction from Garcinia mangostana Fruit Pericarp by Reverse Phase Column Chromatography

The crude polar extract of mangosteen fruit pericarp not only has a moderate antioxidant activity of (55±4 μg/mL) but also has high cytotoxicity (16±0.5 μg/mL). The high cytotoxicity presumably is caused by the presence of complex cytotoxic compounds from the mangosteen pericarp. To obtain a non-toxic extract preparation with high antioxidant activity, polar crude 50% ethanol extracts of mangosteen pericarp were partially purified using reverse-phase column chromatography with Silica C18 as the stationary phase and acetonitrile-water gradient elution. Six of the ten fractions collected had high antioxidant activities, with IC50 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging antioxidant levels <50 μg/mL. Three fractions (fractions 3, 5, and 7) with the highest antioxidant activities of (16.4 ± 0.6 µg/mL), (17.8 ± 2 µg/mL) and (17.4 ± 1.8 µg/mL) respectively, were chosen for further cytotoxicity, phenolic content and High-Performance Liquid Chromatography (HPLC) analysis. The cytotoxic tests were conducted with the Brine Shrimp Lethality Assay. Fraction 3 had low cytotoxicity (LC50 485 ± 96 µg/mL) and fraction 5 was non-toxic (LC50 ≥ 1000 µg/mL), while fraction 7 still had high cytotoxicity (LC50 2.8 ± 0.8 µg/mL). The chromatogram profiles of HPLC showed that fractions 3 and 5 contained more polar compounds than the compounds present in fraction 7. It can be concluded that the reverse phase method succeeded in the isolation of a non-toxic polar fraction, that is, fraction 5, with a significantly higher (p<0.05) antioxidant activity than in the original crude polar extracts. This fraction had a high total phenolic content of 43.3 ± 0.3 g GAE per 100 g extract.

Memory-Enhancing Effects of Mangosteen Pericarp Water Extract through Antioxidative Neuroprotection and Anti-Apoptotic Action

Mangosteen has long been utilized as a traditional medicine in Southeast Asia. Diverse extracts of mangosteen pericarp and its bioactive xanthones exhibit various bioactivities. However, the pharmacological potential of mangosteen pericarp water extract (MPW) has not been reported yet. This study used primary cultured rat cortical cells to investigate the effect of MPW on neurotoxicity. We found that MPW inhibited neurotoxicity and production of reactive oxygen species triggered by Aβ_(25–35) or excitatory amino acids. MPW inhibited caspase 3 activation and DNA fragmentation in Aβ_(25–35)- or N-methyl-D-aspartate-treated cells, suggesting an anti-apoptotic action. Additionally, MPW reduced lipid peroxidation and scavenged 1,1-diphenyl-2-picrylhydrazyl radicals, assuring its antioxidant property. Furthermore, MPW suppressed β-secretase and acetylcholinesterase activities. These findings prompted us to evaluate its effect on memory dysfunction in scopolamine-treated mice using Morris water maze test. Oral administration of MPW at the dosage of 50, 100, or 300 mg/kg for four days significantly decreased the latency time to find the platform and markedly increased the swimming time in the target quadrant. Taken together, our results suggest that MPW exerts memory-enhancing effect through antioxidative neuroprotection and anti-apoptotic action. Accordingly, MPW may have a potential to prevent or treat memory impairment associated with Alzheimer’s disease.

Mangosteen Pericarp and Its Bioactive Xanthones: Potential Therapeutic Value in Alzheimer's Disease, Parkinson's Disease, and Depression with Pharmacokinetic and Safety Profiles

Alzheimer's disease (AD), Parkinson's disease (PD), and depression are growing burdens for society globally, partly due to a lack of effective treatments. Mangosteen (Garcinia mangostana L.,) pericarp (MP) and its xanthones may provide therapeutic advantages for these disorders. In this review, we discuss potential therapeutic value of MP-derived agents in AD, PD, and depression with their pharmacokinetic and safety profiles. MP-derived agents have shown multifunctional effects including neuroprotective, antioxidant, and anti-neuroinflammatory actions. In addition, they target specific disease pathologies, such as amyloid beta production and deposition as well as cholinergic dysfunction in AD; α-synuclein aggregation in PD; and modulation of monoamine disturbance in depression. Particularly, the xanthone derivatives, including α-mangostin and γ-mangostin, exhibit potent pharmacological actions. However, low oral bioavailability and poor brain penetration may limit their therapeutic applications. These challenges can be overcome in part by administering as a form of MP extract (MPE) or using specific carrier systems. MPE and α-mangostin are generally safe and well-tolerated in animals. Furthermore, mangosteen-based products are safe for humans. Therefore, MPE and its bioactive xanthones are promising candidates for the treatment of AD, PD, and depression. Further studies including clinical trials are essential to decipher their efficacy, and pharmacokinetic and safety profiles in these disorders.

Xanthone-enriched fraction of Garcinia mangostana and α-mangostin improve the spatial learning and memory of chronic cerebral hypoperfusion rats

Objectives

Xanthones isolated from the pericarp of Garcinia mangostana has been reported to exhibit neuroprotective effect.

Methods

In this study, the effect of xanthone-enriched fraction of Garcinia mangostana (XEFGM) and α-mangostin (α-MG) were investigated on cognitive functions of the chronic cerebral hypoperfusion (CCH) rats.

Key findings

HPLC analysis revealed that XEFGM contained 55.84% of α-MG. Acute oral administration of XEFGM (25, 50 and 100 mg/kg) and α-MG (25 and 50 mg/kg) before locomotor activity and Morris water maze (MWM) tests showed no significant difference between the groups for locomotor activity.

Conclusions

However, α-MG (50 mg/kg) and XEFGM (100 mg/kg) reversed the cognitive impairment induced by CCH in MWM test. α-MG (50 mg/kg) was further tested upon sub-acute 14-day treatment in CCH rats. Cognitive improvement was shown in MWM test but not in long-term potentiation (LTP). BDNF but not CaMKII was found to be down-regulated in CCH rats; however, both parameters were not affected by α-MG. In conclusion, α-MG ameliorated learning and memory deficits in both acute and sub-acute treatments in CCH rats by improving the spatial learning but not hippocampal LTP. Hence, α-MG may be a promising lead compound for CCH-associated neurodegenerative diseases, including vascular dementia and Alzheimer's disease.

Effects of α-Mangostin Derivatives on the Alzheimer's Disease Model of Rats and Their Mechanism: A Combination of Experimental Study and Computational Systems Pharmacology Analysis

α-Mangostin (α-M) is a natural xanthone from the pericarp of fruit Garcinia mangostana and possesses versatile biological activities. α-M has a therapeutic potential to treat Alzheimer's disease (AD) because of its anti-inflammatory, antioxidative, and neuroprotective activities. However, the use of α-M for AD treatment is limited due to its cytotoxic activities and relatively low potency. Modifications of its chemical structure were needed to reduce its cytotoxicity and improve its therapeutic potential against AD. For this purpose, 16 α-M carbamate derivatives were synthesized. An animal model of AD was established, and the effects of AMG-1 on the spatial learning ability and memory ability were evaluated using behavioral tests. The effect on neuropathology was tested by histopathological evaluation, Nissl staining, and silver staining. Computational systems pharmacology analysis using the chemogenomics knowledgebase was applied for network studies. Compound-target, target-pathway, and target-disease networks were constructed, integrating both in silico analysis and reported experimental data. The results show that AMG-1 can demonstrate its therapeutic effects in a one-molecule, multiple-targets manner to remarkably ameliorate neurological changes and reverse behavioral deficits in AD model rats. The improved cognitive function and alleviated neuronal injury can be observed. The ability of AMG-1 to scavenge β-amyloid in the hippocampus was validated in AD model rats.

Nexus Between Immune Responses and Oxidative Stress: The Role of Dietary Hydrolyzed Lignin in ex vivo Bovine Peripheral Blood Mononuclear Cell Response

The control of immune responses is particularly critical when an increase of oxidative stress occurs, causing an impairment of immune cell response and a condition of systemic inflammation, named oxinflammation. Nutritional strategies based on the use in the diet of phytochemicals extracted from plants, rich in antioxidants, could help restore the antioxidant/oxidant balance and obtain a modulation of immune response. Lignin represents a valuable resource of phenolic compounds, which are characterized by a corroborated antioxidant effect. To date, there are no studies reporting the effects of lignin in the diet on immune responses and oxidative stress in ruminants. The objective of the present experiment was the evaluation of the dietary inclusion of Pinus taeda hydrolyzed lignin on the ex vivo immune responses and oxidative stress biomarkers by peripheral blood mononuclear cells (PBMCs) isolated from beef steers. In order to test the effect during oxidative stress exposition, cells were treated with hydrogen peroxide (H₂O₂). The proliferation test and the viability assay were carried out on cells, whereas, on supernatants, the cytokine profile and the oxidative stress biomarkers were evaluated. The dietary inclusion with P. taeda hydrolyzed lignin resulted in cytoprotection after H₂O₂ exposition, increasing the number of viable monocytes and decreasing the reactive oxygen/nitrogen species production in supernatants. The cytokine profile indicated the modulatory role of hydrolyzed lignin on immune response, with a concomitant decrease of TNF-α and increase of IL-8 production, which are strictly connected with monocyte activation and antioxidant response pathway. These results demonstrated that hydrolyzed lignin may provide a modulation of oxidative stress and inflammatory response in PBMCs; thus, the P. taeda hydrolyzed lignin could be suggested as an innovative phytochemical in ruminant feed.

Protective effects of diarylpropionitrile against hydrogen peroxide-induced damage in human neuroblastoma SH-SY5Y cells

Oxidative stress is implicated in pathogenesis of neurodegenerative disorders, such as Alzheimer's and Parkinson's diseases. The study demonstrates diarylpropionitrile (DPN), an antioxidant selective agonist of estrogen receptor β, protected human neuroblastoma SH-SY5Y cells against H₂O₂-induced toxicity by attenuating production of reactive oxygen species, apoptosis, autophagy, NF-κB activation, MAPK p38, JNK and ERK 1/2 signaling pathways, and β-site amyloid precursor protein cleaving enzyme level, but, interestingly, stimulating Akt pathway. These findings indicate the important potential of DPN to ameliorate oxidative stress-associated damage in neurodegenerative disorders.

Inhibition of Oxidative Neurotoxicity and Scopolamine-Induced Memory Impairment by γ-Mangostin: In Vitro and In Vivo Evidence

Among a series of xanthones identified from mangosteen, the fruit of Garcinia mangostana L. (Guttifereae), α- and γ-mangostins are known to be major constituents exhibiting diverse biological activities. However, the effects of γ-mangostin on oxidative neurotoxicity and impaired memory are yet to be elucidated. In the present study, the protective effect of γ-mangostin on oxidative stress-induced neuronal cell death and its underlying action mechanism(s) were investigated and compared to that of α-mangostin using primary cultured rat cortical cells. In addition, the effect of orally administered γ-mangostin on scopolamine-induced memory impairment was evaluated in mice. We found that γ-mangostin exhibited prominent protection against H₂O₂- or xanthine/xanthine oxidase-induced oxidative neuronal death and inhibited reactive oxygen species (ROS) generation triggered by these oxidative insults. In contrast, α-mangostin had no effects on the oxidative neuronal damage or associated ROS production. We also found that γ-mangostin, not α-mangostin, significantly inhibited H₂O₂-induced DNA fragmentation and activation of caspases 3 and 9, demonstrating its antiapoptotic action. In addition, only γ-mangostin was found to effectively inhibit lipid peroxidation and DPPH radical formation, while both mangostins inhibited β-secretase activity. Furthermore, we observed that the oral administration of γ-mangostin at dosages of 10 and 30 mg/kg markedly improved scopolamine-induced memory impairment in mice. Collectively, these results provide both in vitro and in vivo evidences for the neuroprotective and memory enhancing effects of γ-mangostin. Multiple mechanisms underlying this neuroprotective action were suggested in this study. Based on our findings, γ-mangostin could serve as a potentially preferable candidate over α-mangostin in combatting oxidative stress-associated neurodegenerative diseases including Alzheimer's disease.

The Therapeutic Potential of Mangosteen Pericarp as an Adjunctive Therapy for Bipolar Disorder and Schizophrenia

New treatments are urgently needed for serious mental illnesses including bipolar disorder and schizophrenia. This review proposes that Garcinia mangostana Linn. (mangosteen) pericarp is a possible adjunctive therapeutic agent for these disorders. Research to date demonstrates that neurobiological properties of the mangosteen pericarp are well aligned with the current understanding of the pathophysiology of bipolar disorder and schizophrenia. Mangosteen pericarp has antioxidant, putative neuroprotective, anti-inflammatory, and putative mitochondrial enhancing properties, with animal studies demonstrating favorable pharmacotherapeutic benefits with respect to these disorders. This review summarizes evidence of its properties and supports the case for future studies to assess the utility of mangosteen pericarp as an adjunctive treatment option for mood and psychotic disorders.

Low-molecular-weight chondroitin sulfate attenuated injury by inhibiting oxidative stress in amyloid β-treated SH-SY5Y cells

The neurotoxicity of aggregated amyloid β (Aβ) has been implicated as a critical cause in the pathogenesis of Alzheimer's disease. In a previous work, we have shown that low-molecular-weight chondroitin sulfate (LMWCS), a derivative of chondroitin sulfate, protected the SH-SY5Y neuroblastoma cells from Aβ25-35-induced neurotoxicity, decreased intracellular reactive oxygen species level and inhibited the cell apoptosis. However, the underlying mechanism of the antioxidative effect of LMWCS in the SH-SY5Y cells has not been well explored. In the present study, the SH-SY5Y cells were cultured and exposed to 30 μM Aβ25-35 in the absence or presence of LMWCS (50, 100 and 200 μg/ml). Results indicate that incubation of cells with LMWCS before Aβ25-35 exposure increased superoxide dismutase, glutathione peroxidase and Na/K-ATPase activities and decreased the malondialdehyde content. In addition, LMWCS inhibited the imbalance of Bcl-2 and Bax and decreased caspase-3 and caspase-9 expressions. LMWCS antagonizes Aβ25-35-induced neurotoxicity by attenuating oxidative stress, and our results suggest that LMWCS might be used as a potential compound for Alzheimer's disease prevention.

Hepatoprotective Effect of Steroidal Glycosides From Dioscorea villosa on Hydrogen Peroxide-Induced Hepatotoxicity in HepG2 Cells

Dioscorea villosa, commonly known as "Wild Yam" and native to North America, is well documented for its pharmacological properties due to the presence of steroidal glycosides. However, the hepatoprotective potential of these compounds has not been studied so far. The present investigation was aimed to study the hepatoprotective effect of the steroidal glycosides from D. villosa against H2O2, a known hepatotoxin, in human liver cell line (HepG2). Cytotoxicity assessment was carried out in cells exposed to various concentrations (10-50 μM) of compounds for 24 h using MTT assay and morphological changes. All tested compounds were known and among them, spirostans (zingiberensis saponin I, dioscin, deltonin and progenin III) were found to be cytotoxic whereas, furostans (huangjiangsu A, pseudoprotodioscin, methyl protobioside, protodioscin, and protodeltonin) were non-cytotoxic. Further, HepG2 cells were pretreated with biologically safe concentrations (10, 30, and 50 μM) of non-cytotoxic compounds and then cytotoxic (0.25 mM) concentration of H2O2. After 24 h, cell viability was assessed by MTT and NRU assays, while morphological changes were observed under the microscope. The results showed that treatment of HepG2 cells with compounds prior to H2O2 exposure effectively increased cell viability in a concentration-dependent manner. Furthermore, huangjiangsu A, pseudoprotodioscin, methyl protobioside, protodioscin, and protodeltonin at 50 μM increased GSH level and decreased intracellular ROS generation against H2O2-induced damages. The results from this study revealed that compounds isolated from D. villosa have hepatoprotective potential against H2O2-induced cytotoxicity and ROS generation and could be promising as potential therapeutic agents for liver diseases.

Stachys sieboldii Extract Supplementation Attenuates Memory Deficits by Modulating BDNF-CREB and Its Downstream Molecules, in Animal Models of Memory Impairment

Cholinergic dysfunction, impaired brain-derived neurotrophic factor and cAMP response element binding protein (BDNF-CREB) signaling are one of the major pathological hallmarks of cognitive impairment. Therefore, improving cholinergic neurotransmission, and regulating the BDNF-CREB pathway by downregulating apoptosis genes is one strategy for inhibiting the etiology of dementia. This study evaluates the potential effects of Stachys sieboldii MIQ (SS) extract against cognitive dysfunction and its underlying mechanisms. SS supplementation for 33 days improved scopolamine-induced memory impairment symptoms in Morris water maze test and Y-maze test. SS reduced the acetylcholineesterase activity and significantly increase acetylcholine and cholineacetyltransferase activity in the brain. In the subsequent mechanism study, SS regulated the mRNA expression level of neuronal plasticity molecules such as (nerve growth factor) NGF, BDNF, CREB, and its downstream molecules such as Bcl-2 and Egr-1 by downregulating the neuronal apoptosis targets in both hippocampus and frontal cortex. Additionally, inward currents caused by SS in hippocampal CA1 neurons was partially blocked by the GABA receptor antagonist picrotoxin (50 μM), suggesting that SS acts on synaptic/extrasynaptic GABA_A receptors. These findings indicate that SS may function in a way that is similar to nootropic drugs by inhibiting cholinergic abnormalities, and neuronal apoptosis targets and ultimately increasing the expression of BDNF-CREB.

Protective effects of γ-mangostin on 6-OHDA-induced toxicity in SH-SY5Y cells

γ-Mangostin is a xanthone with hydroxyl groups that confer the substance-free radical scavenging effects. As opposed to the other more extensively studied mangostins, scarce research has been conducted on neuroprotective effects of γ-mangostin on models of Parkinson's disease (PD). Therefore, this investigation aimed to elucidate its antioxidant and neuroprotective effects on 6-OHDA-induced toxicity in SH-SY5Y cells. 6-OHDA treatment, an inducer of PD pathology in vitro studies, decreased cell viability and increased the level of intracellular ROS production. Furthermore, the substance-induced the expression of phosphorylated p38 MAPK, negatively affected the Bax/Bcl-2 ratio and increased caspase-3 activity; all of which were factors that are associated with apoptosis. Pretreatment of cells with γ-mangostin at concentrations of 0.5, 1, and 2.5μM markedly increased cell survival and reduced the level of intracellular ROS formation as shown by DPPH radical scavenging activity of the compound. Furthermore, a significant suppression of p-p38, improved Bax/Bcl-2 ratio expression, and reduced caspase-3 activity was exhibited in the cells after γ-mangostin pretreatment. The reduction of apoptosis was further supported by the reduction of pyknotic nuclei indicated by Hoescht 33342 staining. These findings indicate that γ-mangostin could attenuate 6-OHDA-induced neuronal cell death and that the protective effect of γ-mangostin is associated with its antioxidative potential and through the modulation of the apoptotic signalling pathway. Therefore, γ-mangostin may be an effective xanthone among other mangostins for preventing neurodegeneration in PD caused by oxidative stress.

Antioxidant-Enhancing Property of the Polar Fraction of Mangosteen Pericarp Extract and Evaluation of Its Safety in Humans

Crude extract from the pericarp of the mangosteen (mangosteen extract [ME]) has exhibited several medicinal properties in both animal models and human cell lines. Interestingly, the cytotoxic activities were always observed in nonpolar fraction of the extract whereas the potent antioxidant was often found in polar fraction. Although it has been demonstrated that the polar fraction of ME exhibited the antioxidant activity, the safety of the polar fraction of ME has never been thoroughly investigated in humans. In this study, we investigated the safety of oral administration of the polar fraction of ME in 11 healthy Thai volunteers. During a 24-week period of the study, only minor and tolerable side effects were reported; no serious side effects were documented. Blood chemistry studies also showed no liver damage or kidney dysfunction in all subjects. We also demonstrated antioxidant property of the polar fraction of ME both in vitro and in vivo. Interestingly, oral administration of the polar fraction of ME enhanced the antioxidant capability of red blood cells and decreased oxidative damage to proteins within red blood cells and whole blood.

Protective Effects of Streblus asper Leaf Extract on H2O2-Induced ROS in SK-N-SH Cells and MPTP-Induced Parkinson's Disease-Like Symptoms in C57BL/6 Mouse

This study investigated the effects of Streblus asper leaf extract (SA) on reactive oxygen species (ROS) in SK-N-SH cell culture and on motor functions and behaviors in MPTP-treated C57BL/6 mice. SK-N-SH cell viability after incubation with SA for 24 h was measured by MTT assay. Intracellular ROS levels of SK-N-SH cells were quantified after pretreatment with SA (0, 200, 600, and 1000 µg/mL) in the presence of H₂O₂ (300 µM). Male C57BL/6 mice were force-fed with water or 200 mg/kg/day SA for 32 days. Intraperitoneal injection of MPTP was used to induce Parkinson's disease-like symptoms. Catalepsy, beam balance ability, olfactory discrimination, social recognition, and spontaneous locomotor activity were assessed on days 19, 21, 23, 26, and 32, respectively. In cell culture, SA at 200, 600, and 1000 µg/mL significantly decreased ROS levels in H₂O₂-treated SK-N-SH cells. MPTP-treated C57BL/6 mice showed a significant change in all parameters tested when compared to the control group. Pretreatment and concurrent treatment with 200 mg/kg/day SA could antagonize the motor and cognitive function deficits induced by MPTP. The results show that SA possesses anti-Parkinson effects in MPTP-treated C57BL/6 mice and that reduction in ROS levels might be one of the mechanisms.

Protective effect of Lepidium sativum seed extract against hydrogen peroxide-induced cytotoxicity and oxidative stress in human liver cells (HepG2)

CONTEXT

Garden cress [Lepidium sativum (Brassicaceae)] has been widely used to treat a number of ailments in traditional medicine. The pharmacological and preventive potential of Lepidium sativum, such as anti-inflammatory, antipyretic, antihypertensive, anti-ashthamatic, anticancer, and anti-oxidant, are well known.

OBJECTIVE

The present investigation was designed to study the protective effects of chloroform extract of Lepidium sativum seed (LSE) against oxidative stress and cytotoxicity induced by hydrogen peroxide (H2O2) in human liver cells (HepG2).

MATERIALS AND METHODS

Cytotoxicity of LSE and H2O2 was identified by (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), neutral red uptake (NRU) assays, and morphological changes in HepG2. The cells were pre-exposed to biologically safe concentrations (5-25 μg/ml) of LSE for 24 h, and then cytotoxic (0.25 mM) concentration of H2O2 was added. After 24 h of the exposures, cell viability by MTT, NRU assays, and morphological changes in HepG2 were evaluated. Further, protective effects of LSE on reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP), lipid peroxidation (LPO), and reduced glutathione (GSH) levels induced by H2O2 were studied.

RESULTS

Pre-exposure of LSE significantly attenuated the loss of cell viability up to 48% at 25 µg/ml concentration against H2O2 (LD50 value = 2.5 mM). Results also showed that LSE at 25 µg/ml concentration significantly inhibited the induction of ROS generation (45%) and LPO (56%), and increases the MMP (55%) and GSH levels (46%).

DISCUSSION AND CONCLUSION

The study suggests the cytoprotective effects of LSE against H2O2-induced toxicity in HepG2. The results also demonstrate the anti-oxidative nature of LSE.

Telomerase: a target for therapeutic effects of curcumin and a curcumin derivative in Aβ1-42 insult in vitro

This study was designed to investigate whether telomerase was involved in the neuroprotective effect of curcumin and Cur1. Alzheimer's disease is a consequence of an imbalance between the generation and clearance of amyloid-beta peptide in the brain. In this study, we used Aβ1-42 (10 µg/ml) to establish a damaged cell model, and curcumin and Cur1 were used in treatment groups. We measured cell survival and cell growth, intracellular oxidative stress and hTERT expression. After RNA interference, the effects of curcumin and Cur1 on cells were verified. Exposure to Aβ1–42 resulted in significant oxidative stress and cell toxicity, and the expression of hTERT was significantly decreased. Curcumin and Cur1 both protected SK-N-SH cells from Aβ1–42 and up-regulated the expression of hTERT. Furthermore, Cur1 demonstrated stronger protective effects than curcumin. However, when telomerase was inhibited by TERT siRNA, the neuroprotection by curcumin and Cur1 were ceased. Our study indicated that the neuroprotective effects of curcumin and Cur1 depend on telomerase, and thus telomerase may be a target for therapeutic effects of curcumin and Cur1.

Comparison of the biological activity of two different isolates from mangosteen

OBJECTIVE

Mangosteen has been used in traditional medicine for treatment of many diseases. Recent studies have reported the active constituents isolated from this plant. In this study, purified α-mangostin, a major component and partially purified water-soluble fraction found in fruit pericarps, was carefully isolated, and their biological activity was compared, i.e. antioxidative activity and cytotoxic effect in breast cancer cells: SKBR3.

METHODS

Antioxidative activity was determined using the 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH) assay and reactive oxygen species (ROS) assay, whereas the cytotoxic effect was evaluated by the MTT assay and morphological changes by fluorescence staining.

KEY FINDING

The DPPH scavenging capacities of α-mangostin and water-soluble extract were obtained, the IC50 at 183.95 and 54.57 μg/ml, respectively. Meanwhile, the intracellular ROS level was significantly decreased after treatment with α-mangostin and water-soluble extraction at 20 and 200 μg/ml, respectively. α-mangostin exhibited the cytotoxicity at ED50 8.21 μg/ml, while the water-soluble extract was non-toxic to cells at ED50 higher than 160 μg/ml. Both constituents showed antioxidative activity by chemical assay and in cells, but α-mangostin expressed strong cytotoxicity and showed apoptotic bodies.

CONCLUSION

The different isolated constituents would be further studied for future possible use as chemotherapy in cancer and chemoprevention in Alzheimer's disease.