Protective effects of catalpol against H2O2-induced oxidative stress in astrocytes primary cultures

Real-world Chinese herbal medicine for Parkinson's disease: a hospital-based retrospective analysis of electronic medical records

Background

Parkinson's disease (PD) is a progressive neurodegenerative condition. Chinese medicine therapies have demonstrated effectiveness for PD in controlled settings. However, the utilization of Chinese medicine therapies for PD in real-world clinical practice and the characteristics of patients seeking these therapies have not been thoroughly summarized.

Method

The study retrospectively analyzed initial patient encounters (PEs) with a first-listed diagnosis of PD, based on electronic medical records from Guangdong Provincial Hospital of Chinese Medicine between July 2018 and July 2023.

Results

A total of 3,206 PEs, each corresponding to an individual patient, were eligible for analyses. Approximately 60% of patients made initial visits to the Chinese medicine hospital after receiving a PD diagnosis, around 4.59 years after the onset of motor symptoms. Over 75% of the patients visited the Internal Medicine Outpatient Clinic at their initial visits, while a mere 13.85% visited PD Chronic Care Clinic. Rest tremor (61.98%) and bradykinesia (52.34%) are the most commonly reported motor symptoms, followed by rigidity (40.70%). The most commonly recorded non-motor symptoms included constipation (31.88%) and sleep disturbance (25.27%). Integration of Chinese medicine and conventional medicine therapies was the most common treatment method (39.15%), followed by single use of Chinese herbal medicine (27.14%). The most frequently prescribed herbs for PD included Glycyrrhiza uralensis Fisch. (gan cao), Astragalus mongholicus Bunge (huang qi), Atractylodes macrocephala Koidz. (bai zhu), Angelica sinensis (Oliv.) Diels (dang gui), Rehmannia glutinosa (Gaertn.) DC. (di huang), Paeonia lactiflora Pall. (bai shao), Bupleurum chinense DC. (chai hu), Citrus aurantium L. (zhi qiao/zhi shi/chen pi), Panax ginseng C. A. Mey. (ren shen), and Poria cocos (Schw.) Wolf (fu ling). These herbs contribute to formulation of Bu zhong yi qi tang (BZYQT).

Conclusion

Patients typically initiated Chinese medical care after the establishment of PD diagnosis, ~4.59 years post-onset of motor symptoms. The prevalent utilization of CHM decoctions and patented Chinese herbal medicine products, underscores its potential in addressing both motor and non-motor symptoms. Despite available evidence, rigorous clinical trials are needed to validate and optimize the integration of CHM, particularly BZYQT, into therapeutic strategies for PD.

Natural Products and Health

A natural product is an organic compound from a living organism that can be isolated from natural sources or synthesized [...].

Human coculture model of astrocytes and SH-SY5Y cells to test the neurotoxicity of chemicals

In this study, we established a coculture model comprising human neuroblastoma SH-SY5Y cells and induced pluripotent stem cell-derived astrocytes, faithfully replicating the human brain environment for in vitro neurotoxicity assessment. We optimized the cell differentiation duration and cell ratios to obtain images conducive to neurite outgrowth evaluation. Subsequently, the neurotoxic effects in the coculture and monoculture of SH-SY5Y cells were confirmed using neurotoxic agents such as acrylamide (ACR) and hydrogen peroxide (H2O2). Disparities in the neurotoxic impacts of ACR and H2O2 within the coculture were mirrored in the expression of genes associated with early neuronal injury. Notably, the reduction in neurite outgrowth induced by neurotoxic agents revealed the coculture's lower sensitivity compared to monocultures. Furthermore, the coculture system exhibited distinct effects of test agents on nerve damage and manifested protective influences on nerve cells. The proposed methodology holds promise for large-scale chemical neurotoxicity screening through neurite change measurements. This in vitro coculture model, accounting for cell interactions, emerges as a valuable tool in toxicity testing, offering insights into the potential effects of chemicals within the human body.

Catalpol ameliorates inflammation and oxidative stress via regulating Sirt1 and activating Nrf2/HO-1 signaling against acute kidney injury

BACKGROUND

Septic acute kidney injury (SAKI) is usually caused by sepsis. It has been shown that catalpol (Cat) impairs sepsis-evoked organ dysfunction to a certain degree. The current work aims to evaluate the protective effects of Cat on SAKI and potential mechanisms in vivo and in vitro.

METHODS

SAKI cellular and murine model were set up using lipopolysaccharide (LPS) in vitro and in vivo. Cell apoptosis in cells was determined by TUNEL assay. Levels of inflammatory cytokines were detected by enzyme-linked immunosorbent assay (ELISA). The levels of the markers of oxidative injury were evaluated by corresponding commercial kits. Protein levels were assayed via western blotting and immunohistochemistry (IHC) staining.

RESULTS

The results demonstrated that LPS upregulated TNF-α, IL-6, and malondialdehyde levels, and downregulated superoxide dismutase, whereas Cat treated cells have the opposite results. Functional assays displayed that Cat remarkably reversed the LPS-challenged damage as the impairment of TNF-α and IL-6 levels, oxidative stress, and the apoptosis in HK-2 cells. Moreover, knockdown of Sirtuin 1 (Sirt1) counteracted the suppressive impact of Cat on LPS-triggered inflammatory response, oxidative stress, and renal damage. Further, Cat elevated Sirt1 expression and activated the Nrf2/HO-1 signaling in LPS-engendered SAKI in vivo and in vitro.

CONCLUSION

Our study clearly proved that Cat protected against LPS-induced SAKI via synergic antioxidant and anti-inflammatory actions by regulating Sirt1 and Nrf2/HO-1 signaling pathways.

Water extract from Ligusticum chuanxiong delays the aging of Saccharomyces cerevisiae via improving antioxidant activity

Ligusticum chuanxiong is a common traditional edible-medicinal herb that has various pharmacological activities. However, its effects on Saccharomyces cerevisiae (S. cerevisiae) remains unknown. In this study, we found that water extract of Ligusticum chuanxiong (abbreviated as WEL) exhibited excellent free radical scavenging ability in-vitro. Moreover, WEL treatment could delay the aging of S. cerevisiae, an important food microorganism sensitive to reactive oxygen species (ROS) stress. Biochemical analyses revealed that WEL significantly increased the activity of antioxidant enzymes in S. cerevisiae, including superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR), as well as their gene expression. As a result, ROS level was significantly decreased and accompanied with the decline of malondialdehyde (MDA), which represented a state of low oxidative stress. The reduction of oxidative stress could elevate S. cerevisiae's ethanol fermentation efficiency. Taken together, WEL plays a protective role against S. cerevisiae aging via improving antioxidant activity.

The Role of Sirtuins in the Pathogenesis of Psoriasis

Psoriasis is the most common chronic inflammatory skin disease with a genetic basis. It is characterised by keratinocyte hyperproliferation, parakeratosis and inflammatory cell infiltration. Psoriasis negatively affects a patient's physical and emotional quality of life. Sirtuins (SIRTs; silent information regulators) are an evolutionarily conserved group of enzymes involved in the post-translational modification of proteins, including deacetylation, polyADP-ribosylation, demalonylation and lipoamidation. SIRTs are involved in a number of cellular pathways related to ageing, inflammation, oxidative stress, epigenetics, tumorigenesis, the cell cycle, DNA repair and cell proliferation, positioning them as an essential component in the pathogenesis of many diseases, including psoriasis. Activation of SIRT1 counteracts oxidative-stress-induced damage by inhibiting the mitogen-activated protein kinases (MAPK), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and signal transducer and activator of transcription 3 (STAT3) pathways and may mitigate pathological events in psoriasis. There is a significant reduction in the expression of SIRT1, SIRT2, SIRT3, SIRT4 and SIRT5 and an increase in the expression of SIRT6 and SIRT7 in psoriasis. The aim of the review is to draw the attention of physicians and scientists to the importance of SIRTs in dermatology and to provide a basis and impetus for future discussions, research and pharmacological discoveries to modulate SIRT activity. In light of the analysis of the mode of action of SIRTs in psoriasis, SIRT1-SIRT5 agonists and SIRT6 and SIRT7 inhibitors may represent new therapeutic options for the treatment of psoriasis.

Beneficial Effects of Catalpol Supplementation during In Vitro Maturation of Porcine Cumulus-Oocyte Complexes

Oxidative stress degrades oocytes during in vitro maturation (IVM). Catalpol, a well-known iridoid glycoside, exhibits antioxidant, anti-inflammatory, and antihyperglycemic effects. In this study, catalpol supplementation was tested on porcine oocyte IVM and its mechanisms. Corticalgranule (GC) distribution, mitochondrial function, antioxidant capacity, DNA damage degree, and real-time quantitative polymerase chain reaction were used to confirm the effects of 10 μmol/L catalpol in the maturation medium during IVM. Catalpol treatment significantly increased the first-pole rate and cytoplasmic maturation in mature oocytes. It also increased oocyte glutathione (GSH), mitochondrial membrane potential and blastocyst cell number. However, DNA damage as well as reactive oxygen species (ROS) and malondialdehyde (MDA) levels. Mitochondrial membrane potential and blastocyst cell number were also increased. Thus, the supplementation of 10 μmol/L catalpol in the IVM medium improves porcine oocyte maturation and embryonic development.

Catalpol Attenuates Oxidative Stress and Inflammation via Mechanisms Involving Sirtuin-1 Activation and NF-κB Inhibition in Experimentally-Induced Chronic Kidney Disease

Chronic kidney disease (CKD) is a stealthy disease, and its development is linked to mechanisms including inflammation and oxidative stress. Catalpol (CAT), an iridoid glucoside from the root of Rehmannia glutinosa, is reported to manifest anti-inflammatory, antioxidant, antiapoptotic and antifibrotic properties. Hence, we studied the possible nephroprotective effects of CAT and its mechanisms in an adenine-induced (0.2% w/w in feed for 4 weeks) murine model of CKD by administering 5 mg/kg CAT to BALB/c mice for the duration of 4 weeks except during weekends. Upon sacrifice, the kidney, plasma and urine were collected and various physiological, biochemical and histological endpoints were assessed. CAT significantly ameliorated the adenine-induced altered body and kidney weight, water intake, urine volume, and concentrations of urea and creatinine in plasma, as well as the creatinine clearance and the albumin and creatinine ratio. Moreover, CAT significantly ameliorated the effect of adenine-induced kidney injury by reducing the kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, cystatin C and adiponectin. Similarly, the augmented concentrations of markers of inflammation and oxidative stress in the adenine-treated group were markedly reduced with CAT pretreatment. Furthermore, CAT prevented adenine-induced deoxyribonucleic acid damage and apoptotic activity in the kidneys. Histologically, CAT significantly reduced the formation of tubular necrosis and dilation, as well as interstitial fibrosis in the kidney. In addition to that, CAT significantly decreased the adenine-induced increase in the phosphorylated NF-κB and reversed the reduced expression of sirtuin-1 in the kidney. In conclusion, CAT exhibits salutary effects against adenine-induced CKD in mice by mitigating inflammation, oxidative stress and fibrosis via mechanisms involving sirtuin-1 activation and NF-κB inhibition. Confirmatory studies are warranted in order to consider CAT as a potent nephroprotective agent against CKD.

The Role and Mechanisms of Traditional Chinese Medicine for Airway Inflammation and Remodeling in Asthma: Overview and Progress

Asthma as an individual disease has blighted human health for thousands of years and is still a vital global health challenge at present. Though getting much progress in the utilization of antibiotics, mucolytics, and especially the combination of inhaled corticosteroids (ICS) and long-acting β-agonists (LABA), we are confused about the management of asthmatic airway inflammation and remodeling, which directly threatens the quality of life for chronic patients. The blind addition of ICS will not benefit the remission of cough, wheeze, or sputum, but to increase the risk of side effects. Thus, it is necessary to explore an effective therapy to modulate asthmatic inflammation and airway remodeling. Traditional Chinese Medicine (TCM) has justified its anti-asthma effect in clinical practice but its underlying mechanism and specific role in asthma are still unknown. Some animal studies demonstrated that the classic formula, direct exacts, and natural compounds isolated from TCM could significantly alleviate airway structural alterations and exhibit the anti-inflammatory effects. By investigating these findings and data, we will discuss the possible pathomechanism underlined airway inflammation and remodeling in asthma and the unique role of TCM in the treatment of asthma through regulating different signaling pathways.

Effects of Catalpol on Alzheimer's Disease and Its Mechanisms

Alzheimer's disease (AD) is a degenerative disease of the central nervous system characterized by memory loss and cognitive dysfunction. With the increasing aging of the population, the incidence of AD and the number of patients are also increasing year by year, causing more and more heavy burdens to the family and society. Catalpol, an iridoid glycoside compound, is one of the main active components of Rehmannia glutinosa. At present, a large number of experimental studies in vivo and in vitro have confirmed that catalpol has antioxidant, anti-inflammatory, antiapoptotic, and other neuroprotective effects, and it plays a significant role in the prevention and treatment of AD, with very small side effects and high safety. Therefore, it may be an ideal drug for the treatment of AD. Based on this, the role and mechanism of catalpol in AD will be comprehensively reviewed in the following.

Catalpol Ameliorates Neurotoxicity in N2a/APP695swe Cells and APP/PS1 Transgenic Mice

Alzheimer's disease (AD) causes progressive decline of memory and cognitive deficits. Because of its complicated pathogenesis, the prevention and therapy of AD remain an enormous challenge. It has been reported that catalpol possessed neuroprotective effects against AD. However, the involved mechanism still needs to be intensively studied. Therefore, the effects of catalpol on N2a/APP695swe cells and APP/PS1 mice were identified in the current study. Catalpol could improve cytotoxicity according to CCK-8 assay and ameliorate cellular morphological changes in N2a/APP695swe cells. Neuronal structural damage in the hippocampal CA1 region of APP/PS1 AD mice was improved according to HE staining and immunohistochemistry of NeuN. Meanwhile, catalpol administration ameliorated cognitive deficits confirmed by behavior performance of APP/PS1 mice. Hoechst 33,342 staining and Annexin V-FITC/PI double staining demonstrated that catalpol could reduce apoptosis in N2a/APP695swe cells. Likewise, TUNEL staining also manifested that catalpol significantly reduced apoptosis in hippocampal CA1 region of APP/PS1 mice. Catalpol administration also could improve mitochondrial functions indicated by the ameliorative mitochondrial morphology, the decreased ROS generation, and the increased MMP in N2a/APP695swe cells. Subsequently, catalpol restrained oligomerization of Aβ_1-42, verified by a reduced ThT fluorescence dose- and time-dependently. Additionally, both Aβ_1-40 and Aβ_1-42 aggregation were decreased in N2a/APP695swe cells and APP/PS1 mice administrated with catalpol confirmed by ELISA and western blot. Western blot also showed that catalpol facilitated the phosphorylation of AKT and GSK3β, and impeded the expression of BACE1 both in vivo and in vitro. Finally, a slight alteration in lactylation, 2-hydroxyisobutyrylation, and phosphorylation were found in N2a/APP695swe cells treated with catalpol. Together, these findings manifested that catalpol served a neuroprotective effect in AD and might be a novel and expecting prophylactic or curative candidate for AD or neurodegenerative diseases therapy.

Exploring the Therapeutic Potential of Phytochemicals in Alzheimer’s Disease: Focus on Polyphenols and Monoterpenes

Alzheimer’s disease (AD) is a chronic, complex neurodegenerative disorder mainly characterized by the irreversible loss of memory and cognitive functions. Different hypotheses have been proposed thus far to explain the etiology of this devastating disorder, including those centered on the Amyloid-β (Aβ) peptide aggregation, Tau hyperphosphorylation, neuroinflammation and oxidative stress. Nonetheless, the therapeutic strategies conceived thus far to treat AD neurodegeneration have proven unsuccessful, probably due to the use of single-target drugs unable to arrest the progressive deterioration of brain functions. For this reason, the theoretical description of the AD etiology has recently switched from over-emphasizing a single deleterious process to considering AD neurodegeneration as the result of different pathogenic mechanisms and their interplay. Moreover, much relevance has recently been conferred to several comorbidities inducing insulin resistance and brain energy hypometabolism, including diabetes and obesity. As consequence, much interest is currently accorded in AD treatment to a multi-target approach interfering with different pathways at the same time, and to life-style interventions aimed at preventing the modifiable risk-factors strictly associated with aging. In this context, phytochemical compounds are emerging as an enormous source to draw on in the search for multi-target agents completing or assisting the traditional pharmacological medicine. Intriguingly, many plant-derived compounds have proven their efficacy in counteracting several pathogenic processes such as the Aβ aggregation, neuroinflammation, oxidative stress and insulin resistance. Many strategies have also been conceived to overcome the limitations of some promising phytochemicals related to their poor pharmacokinetic profiles, including nanotechnology and synthetic routes. Considering the emerging therapeutic potential of natural medicine, the aim of the present review is therefore to highlight the most promising phytochemical compounds belonging to two major classes, polyphenols and monoterpenes, and to report the main findings about their mechanisms of action relating to the AD pathogenesis.

Effects of Bushen-Tiaojing-Fang on the pregnancy outcomes of infertile patients with repeated controlled ovarian stimulation

Bushen-Tiaojing-Fang (BSTJF) is commonly used to treat infertility. This study investigated the effects of BSTJF on the pregnancy outcomes of patients with repeated controlled ovarian stimulation (COS), on mitochondrial function, and on oxidative stress in ovarian granulosa cells (GCs) and follicular fluid (FF). The samples and clinical data of 97 patients, including 35 in the control group, 29 in the placebo group and 33 in the BSTJF group, were collected for this study. The mitochondrial ultrastructure, ATP content, mitochondrial DNA (mtDNA) number, 8-hydroxy-2-deoxyguanosine (8-OHdG), Mn-superoxide dismutase (Mn-SOD), glutathione peroxidase (GSH-Px) activity levels, and mRNA expression levels of Mn-SOD, GSH-Px, and nuclear factor erythroid-derived factor 2-related factor 2 (Nrf2) were analyzed. The high-grade embryo (P < 0.001), implantation (P = 0.033), and clinical pregnancy (P = 0.031) rates, as well as the ATP content (P = 0.014), mtDNA number (P = 0.035), GSH-Px activity (P = 0.004 in GCs and P = 0.008 in FF) and mRNA expression levels (P = 0.019), were significantly lower in the placebo group than in the control group, whereas the 8-OHdG content was significantly (P = 0.006 in FF) higher in the placebo group than in the control group. Compared with those in the placebo group, the high-grade embryo rate (P = 0.007), antioxidant enzyme activity (P = 0.037 and 0.036 in Mn-SOD; P = 0.047 and 0.030 in GSH-Px) and mRNA level (P < 0.001 in Nrf2, P = 0.039 in Mn-SOD and P = 0.002 in GSH-Px) were significantly higher in the BSTJF group, as were changes in mitochondrial ultrastructure, ATP (P = 0.040) and mtDNA number (P = 0.013). In conclusion, BSTJF can improve oxidative stress in patients with repeated COS and pregnancy outcomes.

Therapeutic potential of catalpol and geniposide in Alzheimer's and Parkinson's diseases: A snapshot of their underlying mechanisms

Rehmannia glutinosa, the fresh or dried root of Rehmannia glutinosa (Gaertn.) Libosch. ex Fisch. & Mey., and Gardenia, the fruit of Gardenia jasminoides Ellis from Rubiaceae, both are famous traditional Chinese medicines that have been traditionally used in China. Catalpol and geniposide, as two kinds of iridoid glycosides with high activities, are the main bioactive components in Rehmannia glutinosa and Gardenia jasminoides Ellis, respectively. Over the past few decades, catalpol and geniposide have been widely studied for their therapeutic effects. The preclinical experiments demonstrated that they possessed significant neuroprotective activities against Alzheimer's disease, Parkinson's disease, stroke, and depression, etc. In this paper, the pharmacological effects and mechanisms of catalpol and geniposide on Alzheimer's disease and Parkinson's disease from 2005 to now were systematically summarized and comprehensively analyzed. At the same time, the pharmacokinetic characteristics of the analyzed compounds were also described, hoping to provide some enlightenment for the design, research, and development of iridoid glycosides.

Catalpol protects rat ovarian granulosa cells against oxidative stress and apoptosis through modulating the PI3K/Akt/mTOR signaling pathway

Disrupted follicular development may result in increased follicular atresia, which is a crucial mechanism of various ovarian pathologies. It has been demonstrated that oxidative stress is associated with disrupted follicular development. Catalpol is a natural compound that has been found to possess antioxidative stress. However, the effects of catalpol on oxidative stress-induced disrupted follicular development remain unclear. In the present study, we evaluated the protective effect of catalpol on hydrogen peroxide (H₂O₂)-induced oxidative damage in granulosa cells (GCs), which play crucial roles in the follicular development. Our results showed that catalpol significantly improved cell viability, reduced reactive oxygen species (ROS) and malondialdehyde (MDA) production, and elevated superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in H₂O₂-induced GCs. Catalpol treatment caused significant increase in bcl-2 expression, and decreases in bax and caspase-9 expressions. Compared with the H₂O₂-induced GCs, caspase-3 activity in catalpol-treated cells was markedly decreased. Furthermore, catalpol caused significant activation of PI3K/Akt/mTOR pathway in GCs in response to H₂O₂ stimulation. Additionally, inhibition of this pathway reversed the inhibitory effects of catalpol on H₂O₂-induced oxidative injury and apoptosis in GCs. In conclusion, these findings suggested that catalpol protected GCs from H₂O₂-induced oxidative injury and apoptosis via activating PI3K/Akt/mTOR signaling pathway. Thus, catalpol might serve as a therapeutic approach for regulating disrupted follicular development.

Natural products as pharmacological modulators of mitochondrial dysfunctions for the treatments of Alzheimer's disease: A comprehensive review

Alzheimer's disease (AD) is the most common progressive neurodegenerative disorder characterized by neuronal loss and cognitive impairment that harshly affect the elderly individuals. Currently, the available anti-AD pharmacological approaches are purely symptomatic to alleviate AD symptoms, and the curative effects of novel anti-AD drugs focused on Aβ target are disappointing. Hence, there is a tremendous need to adjust AD therapeutic targets and discover novel anti-AD agents. In AD, mitochondrial dysfunction gradually triggers neuronal death from different aspects and worsens the occurrence and progress of AD. Consequently, it has been proposed that the intervention of impaired mitochondria represents an attractive breakthrough point for AD treatments. Due to chemical diversity, poly-pharmacological activities, few adverse effects and multiple targeting, natural products (NPs) have been identified as a valuable treasure for drug discovery and development. Multiple lines of studies have scientifically proven that NPs display ameliorative benefits in AD treatment in relation to mitochondrial dysfunction. This review surveys the complicated implications for mitochondrial dysregulation and AD, and then summarizes the potentials of NPs and their underlying molecular mechanisms against AD via reducing or improving mitochondrial dysfunction. It is expected that this work may open the window to speed up the development of innovative anti-AD drugs originated from NPs and improve upcoming AD therapeutics.

Catalpol ameliorates psoriasis-like phenotypes via SIRT1 mediated suppression of NF-κB and MAPKs signaling pathways

Psoriasis is a chronic inflammatory skin disease that affects approximately 2% of worldwide population, and causing long-term troubles to the patients. Therefore, it is urgent to develop safe and effective therapeutic drugs. Catalpol is a natural iridoid glucoside, that has several remarkable pharmacological effects, however, whether catalpol can alleviated psoriasis has not been explored. The goal of the present work is to study the role of catalpol in psoriasis in vivo and in vitro. Imiquimod-induced psoriasis-like mice were applied with different concentrations of catalpol for 8 consecutive days. The severity degree of psoriasis was estimated and the skin pathological changes were detected by H&E staining. Also, TNF-α-stimulated keratinocytes were treated with different concentrations of catalpol, then the oxidative stress and inflammation factors, as well as the expression of SIRT1 and activation of NF-kB and MAPK pathways were measured. The results showed that catalpol reduced the erythema, scaling, ear thickness, and changed pathological phenotypes in the lesioned skin region in mice. Treatment with catalpol significantly suppressed the oxidative stress and inflammatory reactions in vivo and in vitro, as reflected by the decreased secretion or expression of oxidative stress indicators and proinflammatory factors. Furthermore, the SIRT1 was up-regulated and the NF-κB and MAPKs signaling pathways were suppressed by the treatment of catalpol in vivo and in vitro. In summary, our data suggested that catalpol may have a therapeutic property of psoriasis by ameliorating oxidative stress and inflammation partly through SIRT1 mediated suppression of NF-κB and MAPKs pathways.

Abbreviation: CAT: catalase; ELISA: enzyme-linked immunosorbent assay; GSH: glutathione; HRP: horseradish peroxidase; IMQ: imiquimod; JNK: c-Jun NH 2-terminal kinases; MAPKs: mitogen-activated protein kinases; MDA: malondialdehyde; NC: negative control group; NF-kB: nuclear factor kappa B; PASI: psoriasis area and severity index; PVDF: polyvinylidene difluoride membranes; qRT-PCR: quantitative real time polymerase chain reaction; ROS: reactive oxygen species; SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel; SIRT1: silent information regulator 1; SOD: Cu/Zn superoxide dismutase

Activation of the Keap1-Nrf2 pathway by specioside and the n-butanol extract from the inner bark of Tabebuia rosea (Bertol) DC

Background: A large number of chemical compounds exert their antioxidant effects by activation of key transcriptional regulatory mechanisms, such as the transcription factor Nrf2. The aim of this study was to evaluate the activation of the Keap1-Nrf2 pathway by both the n-butanol extract obtained from the inner bark of Tabebuia rosea (Bertol) DC and specioside isolated from this extract. Methods: The antioxidant activity of the extract and specioside isolated from the inner bark of T. rosea were evaluated using the oxygen radical absorbance capacity (ORAC) and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH) techniques, whereas their effects on the viability of HepG2 cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The effects of the compound and the extract on activating the Keap1-Nrf2 pathway were evaluated using a Nrf2 Transcription Factor Assay kit. Induction of the Nrf2-mediated antioxidant response genes HMOX-1 and NQO1 was evaluated by real-time PCR. The protective effects against H 2O 2-induced oxidative stress in HepG2 cells was determined as the percent protection using the MTT method. Results: Both the n-butanol extract and specioside exhibited activity at low concentrations without affecting cellular viability, since the cell viability was greater than 80% after 24 hours of exposure at each tested concentration. In addition, Nrf2 dissociated from Keap1 after treatment with the n-butanol extract at a concentration of 0.25 µg/mL after 4 hours of exposure. An increase in the Nrf2 level in the cytoplasm after 4 hours of exposure to 2 μM specioside was observed. Nrf2 levels stabilized in the nucleus 12 hours after stimulation with both specioside and the extract. After 6 hours of stimulation, both the extract and specioside induced the expression of HMOX-1 and NQO1. Conclusion: The n-butanol extract from the inner bark of T. rosea and specioside produced protective effects against H 2O 2-induced oxidative stress in HepG2 cells.

Activation of the Keap1-Nrf2 pathway by specioside and the n-butanol extract from the inner bark of Tabebuia rosea (Bertol) DC

Background: A large number of chemical compounds exert their antioxidant effects by activation of key transcriptional regulatory mechanisms, such as the transcription factor Nrf2. The aim of this study was to evaluate the activation of the Keap1-Nrf2 pathway by both the n-butanol extract obtained from the inner bark of Tabebuia rosea (Bertol) DC and specioside isolated from this extract. Methods: The antioxidant activity of the extract and specioside isolated from the inner bark of T. rosea were evaluated using the oxygen radical absorbance capacity (ORAC) and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH) techniques, whereas their effects on the viability of HepG2 cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The effects of the compound and the extract on activating the Keap1-Nrf2 pathway were evaluated using a Nrf2 Transcription Factor Assay kit. Induction of the Nrf2-mediated antioxidant response genes HMOX-1 and NQO1 was evaluated by real-time PCR. The protective effects against H 2O 2-induced oxidative stress in HepG2 cells was determined as the percent protection using the MTT method. Results: Both the n-butanol extract and specioside exhibited activity at low concentrations without affecting cellular viability, since the cell viability was greater than 80% after 24 hours of exposure at each tested concentration. In addition, Nrf2 dissociated from Keap1 after treatment with the n-butanol extract at a concentration of 0.25 µg/mL after 4 hours of exposure. An increase in the Nrf2 level in the cytoplasm after 4 hours of exposure to 2 μM specioside was observed. Nrf2 levels stabilized in the nucleus 12 hours after stimulation with both specioside and the extract. After 6 hours of stimulation, both the extract and specioside induced the expression of HMOX-1 and NQO1. Conclusion: The n-butanol extract from the inner bark of T. rosea and specioside produced protective effects against H 2O 2-induced oxidative stress in HepG2 cells.

Activation of the Keap1-Nrf2 pathway by specioside and the n-butanol extract from the inner bark of Tabebuia rosea (Bertol) DC

Background: A large number of chemical compounds exert their antioxidant effects by activation of key transcriptional regulatory mechanisms, such as the transcription factor Nrf2. The aim of this study was to evaluate the activation of the Keap1-Nrf2 pathway by both the n-butanol extract obtained from the inner bark of Tabebuia rosea (Bertol) DC and specioside isolated from this extract. Methods: The antioxidant activity of the extract and specioside isolated from the inner bark of T. rosea were evaluated using the oxygen radical absorbance capacity (ORAC) and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH) techniques, whereas their effects on the viability of HepG2 cells was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. The effects of the compound and the extract on activating the Keap1-Nrf2 pathway were evaluated using a Nrf2 Transcription Factor Assay kit. Induction of the Nrf2-mediated antioxidant response genes HMOX-1 and NQO1 was evaluated by real-time PCR. The protective effects against H 2O 2-induced oxidative stress in HepG2 cells was determined as the percent protection using the MTT method. Results: Both the n-butanol extract and specioside exhibited activity at low concentrations without affecting cellular viability, since the cell viability was greater than 80% after 24 hours of exposure at each tested concentration. In addition, Nrf2 dissociated from Keap1 after treatment with the n-butanol extract at a concentration of 0.25 µg/mL after 4 hours of exposure. An increase in the Nrf2 level in the cytoplasm after 4 hours of exposure to 2 μM specioside was observed. Nrf2 levels stabilized in the nucleus 12 hours after stimulation with both specioside and the extract. After 6 hours of stimulation, both the extract and specioside induced the expression of HMOX-1 and NQO1. Conclusion: The n-butanol extract from the inner bark of T. rosea and specioside produced protective effects against H 2O 2-induced oxidative stress in HepG2 cells.

Qi-Xian Decoction Upregulated E-cadherin Expression in Human Lung Epithelial Cells and Ovalbumin-Challenged Mice by Inhibiting Reactive Oxygen Species-Mediated Extracellular-Signal-Regulated Kinase (ERK) Activation

Background

Loss of the epithelial barrier is characterized by a reduction in E-cadherin expression and is a hallmark of asthma. Qi-xian decoction (QXT) is a Chinese medicinal formula that has been used to effectively treat asthma. This study aimed to investigate the effect of QXT on E-cadherin expression in human lung epithelial 16HBE cells and ovalbumin-challenged mice and to explore the underlying molecular mechanism.

Material/Methods

Ovalbumin (OVA)-induced mice were used as a model of asthma. Real-time PCR and Western blotting were utilized to examine mRNA and protein levels. Lung tissue reactive oxygen species (ROS) levels were evaluated using dichloro-dihydro-fluorescein diacetate (DCFH-DA). Serum superoxide dismutase (SOD) and the total antioxidant capacity (TAOC) were measured via enzyme-linked immunosorbent assay (ELISA)-based analyses. 16HBE cells were utilized to explore the effect of QXT or hydrogen peroxide (H₂O₂) on the expression of E-cadherin in vitro.

Results

We found that QXT treatment increased E-cadherin expression and decreased extracellular-signal-regulated kinase (ERK) phosphorylation levels in the lung tissues of OVA-challenged mice. QXT also downregulated ROS levels and increased serum SOD and TAOC levels in OVA-challenged mice. In vitro studies demonstrated that increased ROS generation induced by H₂O₂ resulted in decreased E-cadherin expression levels in 16HBE cells, which was attenuated by inhibition of ERK signaling. Moreover, the H₂O₂-induced downregulation of E-cadherin expression, increased ROS generation, and ERK activation in 16HBE cells were restored by treatment with QXT water or ethanol extract.

Conclusions

These data demonstrate that one mechanism by which QXT protects against asthma is to restore E-cadherin expression in vivo and in vitro by inhibiting ROS-mediated ERK activation.

Catalpol Exerts a Neuroprotective Effect in the MPTP Mouse Model of Parkinson's Disease

The degeneration of dopaminergic (DA) neurons in Parkinson’s disease (PD) is related to inflammation and oxidative stress. Anti-inflammatory agents could reduce the risk or slow the progression of PD. Catalpol, an iridoid glycoside extracted from the roots of Rehmannia radix, has been reported to reduce the release of inflammatory factors and exert neuroprotective effects. 1-methyl-4-phenyl-1,2,3, 6-tetrahydropyridine (MPTP)-treated mice were used as the PD model and the roles of catalpol on DA neurons and its potential mechanism were investigated in this study. We found that catalpol administration mitigated the loss of DA neurons induced by MPTP and increased exploratory behavior along with tyrosine hydroxylase (TH) expression, which was accompanied by astrocyte and microglia activation. Importantly, catalpol administration significantly inhibited MPTP-triggered oxidative stress, restored growth-associated protein 43 (GAP43) and vascular endothelial growth factor (VEGF) levels. Further, we found that catalpol suppressed the activation of MKK4/JNK/c-Jun signaling, and reduced the pro-inflammatory factors and inflammasome in the mouse model of PD. Our results suggest that catalpol relieves MPTP-triggered oxidative stress, which may benefit to avoid the occurrence of chronic inflammatory reaction. Catalpol alleviates MPTP-triggered oxidative stress and thereby prevents neurodegenerative diseases-related inflammatory reaction, highlighting its therapeutic potential for the management of PD symptoms.

Catalpol protects against 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced cytotoxicity in osteoblastic MC3T3-E1 cells

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is a well-known environmental contaminant that produces a wide variety of adverse effects in humans. Catalpol, a major bioactive compound enriched in the dried root of Rehmannia glutinosa, is a major iridoid glycoside that alleviates bone loss. However, the detailed mechanisms underlying the effects of catalpol remain unclear. The present study evaluated the effects of catalpol on TCDD-induced cytotoxicity in osteoblastic MC3T3-E1 cells. Catalpol inhibited TCDD-induced reduction in cell viability and increases in apoptosis and autophagic activity in osteoblastic MC3T3-E1 cells. Additionally, pretreatment with catalpol significantly decreased the nitric oxide and nitrite levels compared with a control in TCDD-treated cells and significantly inhibited TCDD-induced increases in the levels of cytochrome P450 1A1 and extracellular signal-regulated kinase. Pretreatment with catalpol also effectively restored the expression of superoxide dismutase and extracellular signal-regulated kinase 1 and significantly enhanced the expression of glutathione peroxidase 4 and osteoblast differentiation markers, including alkaline phosphatase and osterix. Taken together, these findings demonstrate that catalpol has preventive effects against TCDD-induced damage in MC3T3-E1 osteoblastic cells.

Protective effects of catalpol on diabetes mellitus-induced male reproductive damage via suppression of the AGEs/RAGE/Nox4 signaling pathway

AIMS

Diabetes mellitus (DM)-induced reproductive damage is an important cause of infertility for male DM patients, we herein evaluated the effects of catalpol on diabetic reproductive damage through the suppression of the AGEs/RAGE/Nox4 signaling pathway.

METHODS

KK-Ay diabetic reproductive damage mice were administered with catalpol for 8 weeks, the testis/body weight ratio, testicular histopathology, the levels of endogenous hormone and the activity of testicular marker enzymes were determined. In vitro, the GC-2 cell injury model was induced by advanced glycation end-products (AGEs) and pretreated with catalpol. Cell viability, apoptosis, and oxidative stress markers were detected and the mechanism based on the AGEs/RAGE/Nox4 pathway was explored.

KEY FINDINGS

Catalpol showed remarkable capacity on protecting diabetic reproductive damage by improving the histomorphology of the testes, increasing the testis/body weight ratio and activity of acid phosphatase (ACP), lactate dehydrogenase (LDH), gamma-glutamyl transferase (γ-GT). The reduced testosterone (T), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels in DM mice were also reversed with catalpol intervention. Moreover, catalpol showed markedly effects of anti-oxidative in vivo and in vitro, which significantly down-regulated reactive oxygen species (ROS) levels and restored superoxide dismutase (SOD) activity, meanwhile decreased GC-2 cell apoptosis and Bax/Bcl-2 ratio. Moreover, the over-expression of receptors for AGEs (RAGE), NADPH oxidase type 4 (Nox4) and phosphorylation of nuclear transcription factor-κB p65 (NF-κB p65) were suppressed by catalpol.

SIGNIFICANCE

Catalpol could alleviate DM-induced male reproductive damage by inhibiting oxidative stress-induced apoptosis and inflammation mediated by AGEs/RAGE/Nox4 signaling pathway.

Bu-Shen-Yi-Qi formula ameliorates airway remodeling in murine chronic asthma by modulating airway inflammation and oxidative stress in the lung

Bu-Shen-Yi-Qi formula (BSYQF) could suppress chronic airway inflammation according to previous studies. However, there is relatively little direct experimental evidence to evaluate the effects of BSYQF treatment on airway remodeling in chronic asthma. Recent evidence suggests that oxidative stress is involved in airway inflammation and airway remodeling in chronic asthma. BSYQF which includes various of chemical components having antioxidant effects, could be beneficial in attenuating airway remodeling in chronic asthma. The purpose of this study was to elucidate the effect of BSYQF treatment on airway remodeling and investigate its potential mechanisms in chronic asthma. To develop the murine models of chronic asthma, BALB/c mice were sensitized and challenged to ovalbumin for 8 weeks. BSYQF (5, 10, 20 g raw herbs/kg body weight) or tiotropium bromide (0.1 mM) were administered orally and intranasal instillation, respectively. The effect of BSYQF on pulmonary inflammation and remodeling was evaluated. The parameters of oxidative stress in the lung were analyzed. BSYQF treatment reduced airway hyperresponsiveness (AHR), Th2 response including IL-4, IL-13, and OVA-specific IgE and IgG1, transforming growth factor-β (TGF-β), vascular endothelium growth factor (VEGF), airway inflammation and airway remodeling including smooth muscle thickening and peribronchial collagen deposition. As for oxidative stress, BSYQF treatment reduced reactive oxygen species (ROS), Malondialdehyde (MDA), NO, and the expression of inducible nitric oxide synthase (iNOS), but increased significantly glutathione (GSH) /Oxidized glutathione(GSSH) ratios in the lung, restored mitochondrial ultrastructural changes of bronchial epithelia and ATP levels in the lung. In summary, this study suggested that BSYQF treatment ameliorated airway remodeling and alleviated asthmatic features in chronic asthma models. Anti-inflammatory and antioxidant effect of BSYQF may explain why BSYQF has effects on preventing airway remodeling.

Protective Effects of Myxobacterial Extracts on Hydrogen Peroxide-induced Toxicity on Human Primary Astrocytes

Astrocytes, the main non-neuronal cells in the brain, have significant roles in the maintenance and survival of neurons. Oxidative stress has been implicated in various neurodegenerative disorders such as Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). Myxobacteria produce a wide range of bioactive metabolites with notable structures and modes of action, which introduce them as potent natural product producers. In the present study, we evaluated the effects of myxobacterial extracts on hydrogen peroxide (H₂O₂)-mediated toxicity on primary human astrocytes. We showed that myxobacterial extracts could decrease the formation of reactive oxygen species (ROS), nitric oxide (NO) production, and cell death assessed by the release of lactate dehydrogenase (LDH). Myxobacterial extracts were also able to reduce the nitric oxide synthase (NOS) activity. The extracts reduced the oxidative effect of H₂O₂ on over-activation of poly (ADP-ribose) polymerase (PARP1), therefore preventing the cell death by restoring the NAD⁺ levels. In addition, myxobacterial extracts ameliorated the oxidative stress by increasing the glutathione level in cells. The overall results showed myxobacterial extracts, especially from the strains Archangium sp. UTMC 4070 and Cystobacter sp. UTMC 4073, were able to protect human primary astrocytes from oxidative stress.

Herbal Medicine Formulas for Parkinson's Disease: A Systematic Review and Meta-Analysis of Randomized Double-Blind Placebo-Controlled Clinical Trials

Background: Parkinson's disease (PD) is a debitlitating, chronic, progressive neurodegenerative disorder without modifying therapy. Here, we aimed to evaluate the available evidence of herbal medicine (HM) formulas for patients with PD according to randomized double-blind placebo-controlled clinical trials. Methods: HM formulas for PD were searched in eight main databases from their inception to February 2018. The methodological quality was assessed using Cochrane Collaboration risk of bias tool. Meta-analysis was performed using RevMan 5.3 software. Results: Fourteen trials with Seventeen comparisons comprising 1,311 patients were identified. Compared with placebo groups, HM paratherapy (n = 16 comparisons) showed significant better effects in the assessments of total Unified Parkinson's Disease Rating Scale (UPDRS) (WMD: -5.43, 95% CI:-8.01 to -2.86; P < 0.0001), UPDRS I (WMD: -0.30, 95% CI: -0.54 to -0.06; P = 0.02), UPDRS II (WMD: -2.21, 95% CI: -3.19 to -1.22; P < 0.0001), UPDRS III (WMD: -3.26, 95% CI:-4.36 to -2.16; P < 0.00001), Parkinson's Disease Quality of Life Questionnaire (p < 0.01) and Parkinson's Disease Questionnaire-39 (WMD: -7.65, 95% CI: -11.46 to -3.83; p < 0.0001), Non-motor Symptoms Questionnaire (p < 0.01) and Non-Motor Symptoms Scale (WMD: -9.19, 95% CI: -13.11 to -5.28; P < 0.00001), Parkinson's Disease Sleep Scale (WMD: 10.69, 95% CI: 8.86 to 12.53; P < 0.00001), and Hamilton depression rating scale (WMD: -5.87, 95% CI: -7.06 to -4.68; P < 0.00001). The efficiency of HM monotherapy (n = 1 comparison) was not superior to the placebo according to UPDRS II, UPDRS III and total UPDRS score in PD patients who never received levodopa treatment, all P > 0.05. HM formulas paratherapy were generally safe and well tolerated for PD patients (RR: 0.41, 95% CI: 0.21 to 0.80; P = 0.009). Conclusion: The findings of present study supported the complementary use of HM paratherapy for PD patients, whereas the question on the efficacy of HM monotherapy in alleviating PD symptoms is still open.

Herbal Prescriptions and Medicinal Herbs for Parkinson-Related Rigidity in Korean Medicine: Identification of Candidates Using Text Mining

BACKGROUND

Dongeuibogam (DongYiBaoGian), one of the most important books in Korean medicine, comprises a comprehensive summary of all traditional medicines of North-East Asia before the 17th century. This medicinal literature was mined to establish a list of candidate herbs to treat Parkinson-related rigidity.

METHODS

A systematic search for terms describing Parkinson-related rigidity and candidate prescriptions for the treatment of Parkinson-related rigidity in the Dongeuibogam was performed. A high-frequency medicinal herb combination group and candidates for the treatment of Parkinson-related rigidity were also selected through an analysis of medicinal herb combination frequencies. The existing literature pertaining to the potential effects of candidate herbs for Parkinson-related rigidity was reviewed.

RESULTS AND CONCLUSIONS

Ten medicinal herb candidates for the treatment of Parkinson-related rigidity were selected, and their respective precedent studies were analyzed.

Iridoids and Other Monoterpenes in the Alzheimer's Brain: Recent Development and Future Prospects

Iridoids are a class of monoterpenoid compounds constructed from 10-carbon skeleton of isoprene building units. These compounds in their aglycones and glycosylated forms exist in nature to contribute to mechanisms related to plant defenses and diverse plant-animal interactions. Recent studies have also shown that iridoids and other structurally related monoterpenes display a vast array of pharmacological effects that make them potential modulators of the Alzheimer’s disease (AD). This review critically evaluates the therapeutic potential of these natural products by assessing key in vitro and in vivo data published in the scientific literature. Mechanistic approach of scrutiny addressing their effects in the Alzheimer’s brain including the τ-protein phosphorylation signaling, amyloid beta (Aβ) formation, aggregation, toxicity and clearance along with various effects from antioxidant to antiinflammatory mechanisms are discussed. The drug likeness of these compounds and future prospects to consider in their development as potential leads are addressed.

New iridoids from Verbascum nobile and their effect on lectin-induced T cell activation and proliferation

The Verbascum species are widely used traditional herb remedies against respiratory, inflammatory conditions and disorders. In the present study methanol extract of the aerial parts of the endemic Verbascum nobile Velen, was investigated and two novel iridoid glycosides 1 and 2, together with nine known constituents: iridoids, phenylethanoids, and saponins characteristic of Verbascum genus were identified. Further, the biological activity of the extract and selected isolated compounds on concanavalin (Con A)-induced T cell proliferation and activation of human Jurkat T cell line and splenic murine CD3 T cells was evaluated. T cell growth was studied by colorimetric-based WST proliferation assay while DNA content, cell cycling, dynamic of cell proliferation, expression of activation markers, intracellular expression of cytokine IFN-γ, and phosphorylation of ERK were analyzed by flow cytometry. Caspase-mediated apoptosis resulting in a poly (ADP-ribose) polymerase (PARP) cleavage was assessed by colorimetric in-cell kit. It was found that the extract, and all tested compounds (1, 2, 3 and 9) inhibited lectin-induced cell growth of Jurkat T cell line. The novel compounds decreased the frequencies of cells in S phase without causing a significant cell cycle arrest at G1 phase, caspases-mediated apoptosis and/or a profound change in the dynamic of splenic murine CD3⁺ T cell proliferation. Both compounds showed stronger inhibitory effect on Con A-induced ERK phosphorylation than the known bioactive compounds 3 and 9, and suppressed the expression of early activation marker CD69, the intracellular level of IFN-γ, and the generation of CD3⁺IFN-γ⁺ effectors. Our data suggest that the novel iridoid glycosides might have a potential to modulate T cell-related pathologies.

Jia-Jian-Di-Huang-Yin-Zi decoction reduces apoptosis induced by both mitochondrial and endoplasmic reticulum caspase12 pathways in the mouse model of Parkinson's disease

ETHNOPHARMACOLOGICAL RELEVANCE

As a classical prescription of traditional Chinese medicine (TCM), Jia-Jian-Di-Huang-Yin-Zi decoction (JJDHYZ) has been used to treat the symptoms of neurological disorders with a long history.

AIM OF THE STUDY

To evaluate the effects and possible mechanisms of JJDHYZ on a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced subacute mouse model of Parkinson's disease.

MATERIALS AND METHODS

Adult male C57BL/6 mice were randomly divided into five groups: control, MPTP, JJDHYZ low dosage (JJDHYZ-L, 8.5g/kg/day), medium dosage (JJDHYZ-M, 17g/kg/day) and high dosage (JJDHYZ-H, 34g/kg/day). Behavioral tests, immunohistochemistry, immunofluorescence, and high-performance liquid chromatography (HPLC) were conducted to evaluate the neuroprotective effects of JJDHYZ. The mechanism was further explored using TdT-mediated dUTP nick end labeling staining and transmission electron microscopy. The protein expression of Bax, Bcl-2, cytochrome c, full-length caspase9, cleaved caspase9, cleaved caspase3, caspase12 and C/EBP homologous protein was assessed. The toxicity on hepatocytes and renal cells was detected using the enzyme-linked immunosorbent assay kits.

RESULTS

JJDHYZ-H restored the behavior performance impaired by MPTP, and reduced the loss of tyrosine hydroxylase. Additionally, it blocked the apoptosis, activated cleaved caspase3 and protected the ultrastructural integrity of mitochondria by regulating the expression of proteins in both mitochondrial and endoplasmic reticulum (ER) caspase12 pathways.

CONCLUSIONS

JJDHYZ-H showed behavior recovery and dopamine neuron protection by inhibiting the apoptotic activities associated with mitochondrial and ER caspase12 pathways.

Effect of catalpol on remyelination through experimental autoimmune encephalomyelitis acting to promote Olig1 and Olig2 expressions in mice

BACKGROUND

Multiple sclerosis (MS) as an autoimmune disorder is a common disease occurring in central nervous system (CNS) and the remyelination plays a pivotal role in the alleviating neurological impairment in the MS. Catalpol, an effective component extracted from the Chinese herb Radix Rehmanniae, which has been proved protective in cerebral diseases.

METHODS

To determine the protective effects and mechanisms of Catalpol on MS, the mice with experimental autoimmune encephalomyelitis (EAE) were induced by myelin oligodendrocyte glycoprotein (MOG) 35-55, as a model for human MS. Th17 cells were counted by flow cytometric (FCM). The expressions of nerve-glial antigen (NG) 2 and myelin basic protein (MBP) were measured by immunohistochemical staining. Olig1+ and Olig2+/BrdU+ cells were counted by immunofluorescence. Olig1 and Olig2 gene expressions were detected by real-time fluorescent quantitative reverse transcription (qRT) -PCR.

RESULTS

The results showed that Catalpol improved neurological function, reduced inflammatory cell infiltration and demyelination. It could decrease Th17 cells in the peripheral blood. It increased the protein expressions of NG2 and MBP in mice brains, up-regulated markedly protein and gene expressions of Olig1 and Olig2 in terms of timing, site and targets.

CONCLUSIONS

These data demonstrated that Catalpol had a strong neuroprotective effect on EAE mice. Catalpol also plays a role in remyelination by promoting the expressions of Olig1 and Olig2 transcription factors.

Catalpol alleviates ovalbumin-induced asthma in mice: Reduced eosinophil infiltration in the lung

BACKGROUND

Radix Rehmanniae Preparata is a traditional Chinese herbal medicine used to treat asthma, and catalpol is one of the main active ingredients in this herb. In the present study, the effects of catalpol on asthma and the underlying mechanism were explored.

METHODS

Mice with ovalbumin (OVA)-induced asthma were given 5 or 10mg/kg catalpol from Day 15 to Day 28 (intraperitoneal injection). Histopathologic changes were detected by Hematoxylin and Eosin staining and Periodic Acid Schiff staining. The levels of IgE, interleukin (IL)-4, IL-5 and eotaxin were measured by ELISA. The numbers of lymphocytes, monocytes, basophils and eosinophils in the bronchoalveolar lavage fluid were determined by Wright-Giemsa staining. The expression and distribution of eotaxin and C-C chemokine receptor 3 (CCR3) were detected by immunohistochemistry and immunofluorescence. The expression of interleukin-5 receptor α (IL-5Rα) was detected by Western blot assay.

RESULTS

Catalpol inhibited OVA-induced inflammation and IgE secretion in the lung. OVA-induced type 2 inflammation was suppressed by catalpol as evidenced by decreased levels of IL-4 and IL-5. Moreover, catalpol inhibited the aberrant eosinophil infiltration in the lungs, and also suppressed OVA-induced elevation of eosinophil chemokine eotaxin and its receptor CCR3. In addition, IL-5Rα expression in the bone marrow cells derived from catalpol-treated asthmatic mice was lower than that from the untreated asthmatic mice.

CONCLUSION

Our study demonstrated that catalpol attenuated OVA-induced asthma and inhibit the infiltration of inflammatory cells, especially eosinophils, into the lung. This study suggests that catalpol may become a promising drug for the treatment of asthma.

Loss-of-function mutations in the APX1 gene result in enhanced selenium tolerance in Arabidopsis thaliana

It is generally recognized that excess selenium (Se) has a negative effect on the growth and development of plants. Numerous studies have identified key genes involved in selenium tolerance in plants; however, our understanding of its molecular mechanisms is far from complete. In this study, we isolated an Arabidopsis selenium-resistant mutant from the mutant XVE pool lines because of its increased root growth and fresh weight in Se stress, and cloned the gene, which encodes the cytosolic ascorbate peroxidase (APX1). Two other APX1 gene knockout allelic lines were also selenium resistant, and the APX1-complementary COM1 restored the growth state of wild type under Se stress. In addition, these APX1 allelic lines accumulated more Se than did wild-type plants when subjected to Se stress. Further analysis revealed that the APX1-mediated Se tolerance was associated, at least in part, with the enhanced activities of antioxidant enzymes catalase, glutathione peroxidase and glutathione reductase. Moreover, enhanced Se resistance of the mutants was associated with glutathione (GSH), which had the higher expression level of GSH1 gene involved in GSH synthesis and consequently increased GSH content. Our results provide genetic evidence indicating that loss-of-function of APX1 results in tolerance to Se stress.

Catalpol inhibits apoptosis in hydrogen peroxide-induced cardiac myocytes through a mitochondrial-dependent caspase pathway

These findings indicated for the first time that pretreatment of H9c2 cells with catalpol can against H₂O₂-induced apoptosis, and the protective effect of catalpol via a mitochondrial-dependent caspase pathway and is associated with increased Bcl-2 and decreased Bax expression.

Catalpol, an iridoid glucoside, has been reported to inhibit apoptosis of neuron and endothelial cells. In the present study, we investigated the mechanism of catalpol-mediated cardioprotection. The rat embryonic ventricular myocardial cell line (H9c2) cells were first incubated with catalpol, and then exposed to hydrogen peroxide (H₂O₂). The concentration of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD) were all determined by using commercially available kits. Apoptotic cells were assessed by Hoechst 33258 and Annexin V-fluorescein isothiocyanate binding assay. Synthesis of Bcl-2, Bax, cytochrome c and caspase-3 were analysed by real-time semiquantitative reverse transcription-PCR and Western blotting. We observed that apoptosis in H9c2 was associated with increased Bax, cytochrome c, caspase-3, decreased Bcl-2 activity after 24 h of H₂O₂ exposure. Catalpol pretreatment afforded a marked protection against the above H₂O₂-mediated cytotoxicity and apoptosis in H9c2 cells. Moreover, the catalpol pretreatment led to a great reduction in H₂O₂-induced MDA release and increased SOD. These findings indicated for the first time that pretreatment of H9c2 cells with catalpol can be against H₂O₂-induced apoptosis, and the protective effect of catalpol involves the mitochondrial-dependent caspase pathway and is associated with increased Bcl-2 and decreased Bax expression.

Antidiabetic and antioxidant effects of catalpol extracted from Rehmannia glutinosa (Di Huang) on rat diabetes induced by streptozotocin and high-fat, high-sugar feed

Background

Diabetes, associated with hyperlipidemia and oxidative stress, would lead to an increased production of reactive oxygen species. Rehmannia glutinosa (Di Huang) is widely used to nourish yin, invigorate the kidney (shen), and treat xiao ke (a diabetes-like syndrome in Chinese medicine). This study aims to investigate the antidiabetic and antioxidant effects of catalpol from R. glutinosa on rat diabetes induced by streptozotocin (STZ) and high-fat, high-sugar feed.

Methods

Rats (eight rats in each group at least) were induced diabetes by an initial high-fat high-sugar feed for 3 weeks, followed by an intraperitoneal injection of STZ (30 mg/kg) for 3 days, and rats were fasted overnight before treatments. Catalpol at a dose of 0, 5, 10, 20 or 50 mg/kg was administrated through bolus intravenous injection to the experimental rats to find the most effective anti-hyperglycemic dose of catalpol to further study body weight loss, water intake, and food intake. The most effective catalpol dose was given to the diabetic model rats with hyperlipidemia, and the levels of blood sugar, plasma total cholesterol (TC), triglyceride (TG), and high-density lipoprotein cholesterol (HDL-C) were measured after catalpol administration once a day for 2 weeks. An oral glucose challenge test (OGCT) was performed after above experiments in which the most effective dose of catalpol has been determined. Levels of glutathione peroxidase (GSH-PX), catalase (CAT), superoxide dismutase (SOD), and malondialdehyde (MDA) were measured by corresponding reagent kits and morphological changes of the pancreas were observed with histopathological examination using H&E stain.

Results

Catalpol at a dose of 50 mg/kg ameliorated body weight loss and increased water and food intake. Catalpol also attenuated the increase of plasma TC (P = 0.0067) and TG (P = 0.0084) and increased HDL-C (P = 0.0336). The OGCT revealed that catalpol reduced the increase of plasma glucose. The activities of antioxidative enzymes (SOD, P = 0.0037; GSH-PX, P = 0.0066; CAT, P = 0.005) were enhanced and MDA was reduced (P = 0.003). Furthermore, catalpol reduced the morphological impairment of the pancreas.

Conclusion

Catalpol protected against STZ-induced diabetes with high-fat and high-sugar feed with ameliorated structural impairment of the pancreas and restored balance between oxidative enzymes and antioxidative enzymes.

Achillolide A Protects Astrocytes against Oxidative Stress by Reducing Intracellular Reactive Oxygen Species and Interfering with Cell Signaling

Achillolide A is a natural sesquiterpene lactone that we have previously shown can inhibit microglial activation. In this study we present evidence for its beneficial effects on astrocytes under oxidative stress, a situation relevant to neurodegenerative diseases and brain injuries. Viability of brain astrocytes (primary cultures) was determined by lactate dehydrogenase (LDH) activity, intracellular ROS levels were detected using 2',7'-dichlorofluorescein diacetate, in vitro antioxidant activity was measured by differential pulse voltammetry, and protein phosphorylation was determined using specific ELISA kits. We have found that achillolide A prevented the H₂O₂-induced death of astrocytes, and attenuated the induced intracellular accumulation of reactive oxygen species (ROS). These activities could be attributed to the inhibition of the H₂O₂-induced phosphorylation of MAP/ERK kinase 1 (MEK1) and p44/42 mitogen-activated protein kinases (MAPK), and to the antioxidant activity of achillolide A, but not to H₂O₂ scavenging. This is the first study that demonstrates its protective effects on brain astrocytes, and its ability to interfere with MAPK activation. We propose that achillolide A deserves further evaluation for its potential to be developed as a drug for the prevention/treatment of neurodegenerative diseases and brain injuries where oxidative stress is part of the pathophysiology.

Catalpol downregulates vascular endothelial‑cadherin expression and induces vascular hyperpermeability

Catalpol, an iridiod glucoside isolated from Rehmannia glutinosa, has been reported to possess anti‑inflammatory properties. However, the molecular mechanisms underlying this effect have not been fully elucidated. This study aimed to investigate the effects of catalpol on vascular permeability. Using Transwell permeability assays and measurements of trans‑endothelial electrical resistance (TEER), it was demonstrated that 1 mM catalpol induces a significant increase in the permeability of the monolayers of human umbilical vein endothelial cells (HUVECs). Western blotting and immunofluorescence demonstrated that catalpol inhibits the expression of vascular endothelial (VE)‑cadherin, the key component of adherens junctions, but not occludin, the major constituent of tight junctions. In addition, catalpol inhibits the ETS transcription factor ERG, a positive regulator of VE‑cadherin. Knockdown of ERG expression compromised the catalpol‑induced reduction of TEER in HUVECs. The present study revealed a novel effect of catalpol on vascular permeability and gave insight into the multifaceted roles of catalpol in inflammation.

Assessment of C-phycocyanin effect on astrocytes-mediated neuroprotection against oxidative brain injury using 2D and 3D astrocyte tissue model

Drugs are currently being developed to attenuate oxidative stress as a treatment for brain injuries. C-phycocyanin (C-Pc) is an antioxidant protein of green microalgae known to exert neuroprotective effects against oxidative brain injury. Astrocytes, which compose many portions of the brain, exert various functions to overcome oxidative stress; however, little is known about how C-Pc mediates the antioxidative effects of astrocytes. In this study, we revealed that C-Pc intranasal administration to the middle cerebral artery occlusion (MCAO) rats ensures neuroprotection of ischemic brain by reducing infarct size and improving behavioral deficits. C-Pc also enhanced viability and proliferation but attenuated apoptosis and reactive oxygen species (ROS) of oxidized astrocytes, without cytotoxicity to normal astrocytes and neurons. To elucidate how C-Pc leads astrocytes to enhance neuroprotection and repair of ischemia brain, we firstly developed 3D oxidized astrocyte model. C-Pc had astrocytes upregulate antioxidant enzymes such as SOD and catalase and neurotrophic factors BDNF and NGF, while alleviating inflammatory factors IL-6 and IL-1β and glial scar. Additionally, C-Pc improved viability of 3D oxidized neurons. In summary, C-Pc was concluded to activate oxidized astrocytes to protect and repair the ischemic brain with the combinatorial effects of improved antioxidative, neurotrophic, and anti-inflammatory mechanisms.

Mitochondrial fusion/fission process involved in the improvement of catalpol on high glucose-induced hepatic mitochondrial dysfunction

Catalpol, an iridoid glycoside, has been shown to exert hypoglycemic effect by rescuing mitochondrial function, but the detailed mechanism remains unclear yet. In this study, the effect and mechanism of catalpol on the hepatic mitochondria under diabetic conditions were further examined. Oral administration of catalpol significantly reduced the blood glucose, triglyceride, and cholesterol levels in high-fat diet- and streptozotocin-induced diabetic mice. Additionally, catalpol attenuated the decrease in liver mitochondrial ATP content resulting from diabetes. Furthermore, the number of mitochondria possessing a long size was increased in catalpol-treated mice. Interestingly, the catalpol-induced recovery of mitochondrial function was associated with decreased fission protein 1 and dynamin-related protein 1 expression as well as increased mitofusin 1 expression in the liver. In HepG2 cells, catalpol alleviated the decrease of ATP content and mitochondrial membrane potential, and the increase of reactive oxygen species formation induced by high glucose. MitoTracker Green stain shows that the tubular feature of mitochondria was maintained when cells were treated with catalpol. Catalpol also decreased fission protein 1 and dynamin-related protein 1 expression and increased mitofusin 1 expression in HepG2 cells. The present results suggest that catalpol can ameliorate hepatic mitochondrial dysfunction under a diabetic state, and this may be related to its regulation of mitochondrial fusion and fission events.

Glutamine Reduces the Apoptosis of H9C2 Cells Treated with High-Glucose and Reperfusion through an Oxidation-Related Mechanism

Mitochondrial overproduction of reactive oxygen species (ROS) in diabetic hearts during ischemia/reperfusion injury and the anti-oxidative role of glutamine have been demonstrated. However, in diabetes mellitus the role of glutamine in cardiomyocytes during ischemia/reperfusion injury has not been explored. To examine the effects of glutamine and potential mechanisms, in the present study, rat cardiomyoblast H9C2 cells were exposed to high glucose (33 mM) and hypoxia-reoxygenation. Cell viability, apoptosis, intracellular glutamine, and mitochondrial and intracellular glutathione were determined. Moreover, ROS formation, complex I activity, membrane potential and adenosine triphosphate (ATP) content were also investigated. The levels of S-glutathionylated complex I and mitochondrial apoptosis-related proteins, including cytochrome c and caspase-3, were analyzed by western blot. Data indicated that high glucose and hypoxia-reoxygenation were associated with a dramatic decline of intercellular glutamine and increase in apoptosis. Glutamine supplementation correlated with a reduction in apoptosis and increase of glutathione and glutathione reduced/oxidized ratio in both cytoplasm and mitochondria, but a reduction of intracellular ROS. Glutamine supplementation was also associated with less S-glutathionylation and increased the activity of complex I, leading to less mitochondrial ROS formation. Furthermore, glutamine supplementation prevented from mitochondrial dysfunction presented as mitochondrial membrane potential and ATP levels and attenuated cytochrome c release into the cytosol and caspase-3 activation. We conclude that apoptosis induced by high glucose and hypoxia-reoxygenation was reduced by glutamine supplementation, via decreased oxidative stress and inactivation of the intrinsic apoptotic pathway.

Effects of vitexin-2"-O-rhamnoside and vitexin-4"-O-glucoside on growth and oxidative stress-induced cell apoptosis of human adipose-derived stem cells

OBJECTIVES

Vitexin-2"-O-rhamnoside (VOR) and vitexin-4"-O-glucoside (VOG) are the two main flavonoid glycosides of the leaves of Cratagus pinnatifida Bge. var. major N. E. Br. that has been widely used for the treatment of cardiovascular system diseases. In this study, we simultaneously investigated the influence of VOR and VOG on human adipose-derived stem cells (hADSCs) injury induced by hydrogen peroxide (H2 O2 ) to further characterize their anti-oxidative and anti-apoptotic activity.

METHODS

hADSCs were isolated, cultured in vitro and pretreated with 62.5 μm VOR or 120 μm VOG for 24 h and then exposed to 500 μm H2 O2 for an additional 4 h.

KEY FINDINGS

Pretreatment of hADSCs with VOR and VOG was demonstrated to significantly ameliorate the toxicity and apoptosis effects, such as morphological distortion, nuclear condensation, decreased intracellular caspase-3 activity and percentage of cells in apoptosis/necrosis by using morphological assay, immunocytochemistry and flow cytometric evaluation. In addition, VOR and VOG caused no cytotoxic effect on hADSCs at concentrations up to 250 and 480 μm, respectively.

CONCLUSIONS

Our results indicated that both VOR and VOG contribute to the protection against H2 O2 -mediated oxidative stress damage and could be safely used for a wide range of concentrations.

Assessment of the genotoxic and mutagenic properties of Himatanthus articulatus bark extracts used as phytotherapeutic drug in the Amazon

ETHNOPHARMACOLOGICAL RELEVANCE

Himatanthus articulatus (Apocynaceae) is a plant native to the Amazon, popularly used to treat external ulcers, tumors, inflammations, cancer, syphilis and malaria.

AIM OF THE STUDY

To investigate the in vivo genotoxic and mutagenic potential of this plant, using the comet assay and the micronucleus test.

MATERIAL AND METHODS

Female and male adult mice were treated with 500 mg/kg, 1000 mg/kg or 2000 mg/kg of Himatanthus articulatus aqueous or ethanolic bark extracts by gavage for two consecutive days. In addition, blood slides were exposed to hydrogen peroxide (ex vivo) to evaluate the anticlastogenic effect using the comet assay. The HPLC analyses indicated plumieride as the main constituent of both extracts from Himatanthus articulatus barks.

RESULTS

No differences between genders were observed. Micronuclei were observed only in the group treated with the highest dose of both extracts. Conversely, lower doses of these extracts showed protective effects to DNA against damage induced by hydrogen peroxide, indicating an important antigenotoxic effect.

CONCLUSIONS

The toxicological evaluation indicated that the extracts are non-genotoxic and reduce the clastogenic damage induced by hydrogen peroxide. In part, this result can be atributted to the phytochemical profile of Himatanthus articulatus, which presents iridoids and phenolic compounds.

Rehmannia glutinosa suppresses inflammatory responses elicited by advanced glycation end products

Fresh rhizome of Rehmannia glutinosa Libosch. (Saeng-jihwang in Korean: SJH) has been prescribed for the treatment of diabetes-associated complications. The purpose of the present study is to investigate the underlying mechanisms of the efficacy of SJH in diabetes-related complications. Decoction was obtained after boiling SJH in water and subsequent lyophilization. The cellular toxicity of SJH was determined by MTT assay. The antioxidant activity of SJH was measured by DPPH and DCFH-DA assays. The effects of SJH on inflammatory responses elicited by AGEs were assessed by western blotting and semi-quantitative RT-PCR analyses. The water extract of SJH had a high free radical scavenging activity in vitro and decreased the level of intracellular ROS in THP-1 cells treated with AGEs. SJH suppressed the expression of pro-inflammatory genes, including TNF-α, MCP-1, IP-10, COX-2, and iNOS; the activation of NF-κB; and the expression of RAGE, a receptor for AGEs, where the expressions of which were induced by AGEs. These results suggest the possibility that SJH can be an alternative therapeutics for diabetes-associated diseases.

Radio-protective effect of catalpol in cultured cells and mice

Ionizing radiation can induce DNA damage and cell death by generating reactive oxygen species (ROS). The objective of this study was to investigate the radio-protective effect of catalpol (a main bioactive component in the traditional Chinese Rehmannia) on irradiated cells and mice. We found that treating cells with catalpol (25-100 μg/ml) before irradiation could significantly inhibit ionizing radiation (IR)-induced human lymphocyte AHH-1 cells apoptosis and increase cells viability in vitro. At the same time our study also showed that catalpol (25-100 mg/kg) reduced morphological damage of the gastrointestinal tract by 15.6%, 33.3% and 44.4%, respectively compared with the radiation-induced group, decreased plasma malondialdehyde (MDA) intestinal 8-hydroxydeoxyguanosine (8-OHdG) levels and increased plasma endogenous antioxidants and peripheral white blood cells and platelets in vivo. These results suggest that catalpol possesses notable radio-protective activity, which might be related to its effect of reducing ROS.

Catalpol inhibits LPS plus IFN-γ-induced inflammatory response in astrocytes primary cultures

A large body of evidence suggests that the inflammatory reaction plays an important role in the pathogenesis of neurodegenerative diseases. Our previous studies described the neuroprotective effects of catalpol in lipopolysaccharide (LPS)-induced inflammatory models, in which catalpol was shown to prevent mesencephalic neuron death and ameliorate cognitive ability animals. To further investigate the protective effect and underlying mechanism of catalpol, astrocytes were pretreated with low (0.1mM) and high dose (0.5mM) catalpol for 1h prior to LPS plus interferon-γ stimulation. Biochemical analyses showed that NO and ROS production and iNOS activity were significantly reduced by catalpol. Data at transcriptional level also demonstrated that catalpol potently attenuated gene expressions involved in inflammation, such as iNOS, COX-2 and TLR4. In addition, our exploration further revealed that the suppressive action of catalpol on inflammation was mediated via inhibiting nuclear factor-κB (NF-κB) activation. Collectively, these results suggest that catalpol can exert inhibitory effects on the inflammatory reaction in astrocytes and that inactivation of NF-κB could be the major determinant for its anti-inflammatory mechanism. Therefore, catalpol may potentially be a highly effective therapeutic agent in treating neurodegenerative diseases associated with inflammation.