Regulatory mechanisms of Gentiopicroside on human diseases: a brief review.

Gentiopicroside (GPS), a single compound isolated from Gentiana lutea L. and the crucial representative of secoiridoid constituent, has been permitted for centuries in traditional Chinese medicine. GPS and its metabolites have been increasingly used in the search for clinical management with therapeutic properties and fewer side effects. The objective of this review was to provide a comprehensive overview of the involvement of molecular pathways in the therapeutic effects of GPS on human diseases and chronic conditions. This study presents a meticulously conducted comprehensive search of the PubMed and Google Scholar databases (from 1983 to 2023), aimed at identifying articles relating to regulatory mechanisms of GPS on human diseases and the pharmacokinetics of GPS. The inclusion criteria were meticulously and precisely defined to encompass original research papers that explicitly focused on elucidating the regulatory mechanisms of GPS in various human diseases through in vitro and animal studies. Notably, these studies were mandated to integrate specific genetic markers or pathways as essential components of their research inquiries. The evaluated pharmacokinetic parameters included maximum plasma concentration (Cmax), time to reach maximum plasma concentration (Tmax), area under the curve (AUC), clearance, and plasma half-life (t1/2). Subsequently, through a rigorous screening process of titles and abstracts, studies conducted in vitro or on animals, as well as those reporting pharmacokinetic data related to drugs other than GPS or language barriers, were systematically excluded. Drawing from the data and studies pertaining to this review, we conducted a thorough and informative analysis of the pharmacological characteristics and biological functions of GPS. These encompassed a wide range of effects, including hepatoprotective, anti-inflammatory, antifibrotic, antioxidant, analgesic, antitumor, and immunomodulatory properties. The analysis provided a comprehensive and insightful understanding of GPS's pharmacological profile and its diverse activities. Enhancing theoretical and experimental methodologies could prove advantageous in expanding the clinical applications of GPS. This could involve optimizing the bioavailability and pharmacokinetics of GPS, uncovering additional biomarkers and potential biotransformation pathways, and investigating its combined effects with standard-of-care medications.

Anti-inflammatory effect and mechanism of catalpol in various inflammatory diseases.

Catalpol is a kind of iridoid glucoside, widely found in a variety of plants, mostly extracted from the rhizome of the traditional medicinal herb rehmanniae. It has various biological activities such as anti-inflammatory, antioxidant, and antitumor. The anti-inflammatory effects of catalpol have been demonstrated in a variety of diseases, such as neurological diseases, atherosclerosis, renal diseases, respiratory diseases, digestive diseases, bone and joint diseases, eye diseases, and periodontitis. The purpose of this review is to summarize the existing literature on the anti-inflammatory effects of catalpol in a variety of inflammatory diseases over the last decade and to focus on the anti-inflammatory mechanisms of catalpol.

Catalpol rescues cognitive deficits by attenuating amyloid ß plaques and neuroinflammation.

This study sought to investigate the anti-amyloid ß (Aß) and anti-neuroinflammatory effects of catalpol in an Alzheimer's disease (AD) mouse model. METHODS: The effects of catalpol on Aß formation were investigated by thioflavin T assay. The effect of catalpol on generating inflammatory cytokines from microglial cells and the cytotoxicity of microglial cells on HT22 hippocampal cells were assessed by real-time quantitative PCR, ELISA, redox reactions, and cell viability. APPswe/PS1ΔE9 mice were treated with catalpol, and their cognitive ability was investigated using the water maze and novel object recognition tests. Immunohistochemistry and immunofluorescence were used to probe for protein markers of microglia and astrocyte, Aß deposits, and NF-κB pathway activity. Aß peptides, neuroinflammation, and nitric oxide production were examined using ELISA and redox reactions. RESULTS: Catalpol potently inhibited Aß fibril and oligomer formation. In microglial cells stimulated by Aß, catalpol alleviated the expression of the proinflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and inducible nitric oxide synthase (iNOS) but promoted the expression of the anti-inflammatory cytokine IL-10. Catalpol alleviated the cytotoxic effects of Aß-exposed microglia on HT22 cells. Treatment with catalpol in APPswe/PS1ΔE9 mice downregulated neuroinflammation production, decreased Aß deposits in the brains and alleviated cognitive impairment. Catalpol treatment decreased the number of IBA-positive microglia and GFAP-positive astrocytes and their activities of the NF-κB pathway in the hippocampus of APPswe/PS1ΔE9 mice. CONCLUSION: The administration of catalpol protected neurons by preventing neuroinflammation and Aß deposits in an AD mouse model. Therefore, catalpol may be a promising strategy for treating AD.

Catalpol induces apoptosis in breast cancer in vitro and in vivo: Involvement of mitochondria apoptosis pathway and post-translational modifications.

Breast cancer is a fatal cancer with the highest mortality in female. New strategies for anti-breast cancer are still urgently needed. Catalpol, an iridoid glycoside extracted from the traditional Chinese medicinal plant Rehmannia glutinosa, has shown anticancer efficacy in various cancer cells. However, its effect on breast cancer remains unclear. In this study, we aim to investigate the anti-breast cancer activity of catalpol and elucidate its underlying mechanism. Cell counting kit-8 (CCK-8) and morphology change showed that catalpol could inhibit the proliferation and viability of MCF-7 cells. Catalpol administration reduced the tumor volume in xenograft model. Catalpol induced apoptosis in MCF-7 cells confirmed by Hoechst 33342 staining and Annexin V-FITC/PI double staining. In vivo, catalpol also induced apoptosis as seen from the increased level of terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) in tumor. According to JC-1 and Dichlorodi-hydrofluorescein Diacetate (DCFH-DA) staining, loss of mitochondrial membrane potential (MMP) and reactive oxygen species (ROS) generation was found in MCF-7 cells treated with catalpol. Furthermore, catalpol also increased the level of cytoplasmic cytochrome c and activity of caspase-3 in MCF-7 cells. Likewise, histopathological and immunohistochemical (IHC) assay also found that catalpol enhanced the levels of cytochrome c and caspase-3 in breast cancer tissues. Ultimately, acetylation, 2-hydroxyisobutyrylation and lactylation were dramatically increased, whereas succinylation, malonylation and phosphorylation were markedly decreased in the breast cancer tumor treated with catalpol. Taken together, catalpol inhibited breast cancer in vitro and in vivo through induction of apoptosis via mitochondria apoptosis pathway and regulation of protein post-translational modifications (PTMs). Thus, it can be considered as an excellent candidate compound for treatment of breast cancer.

Antidepressant mechanism of catalpol: Involvement of the PI3K/Akt/Nrf2/HO-1 signaling pathway in rat hippocampus.

Catalpol is a major compound in Rehmanniae Radix with outstanding medicinal and nutritional values. Our previous studies have demonstrated catalpol's antidepressant effect, but its mechanisms remain unclear. This study aimed to explore the antidepressant mechanisms of catalpol via the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/nuclear factor E2-related factor 2(Nrf2)/heme oxygenase-1 (HO-1) pathway. Results demonstrated that chronic unpredictable mild stress (CUMS) for 5 consecutive weeks caused significant decreases in the sucrose preference and the horizontal and vertical scores of open-field test, as well as a significant increase in the swimming-immobility time of rats; catalpol administration significantly reversed the abnormality of these indicators. Further real-time fluorescent quantitative polymerase chain reaction and Western blotting results together showed that CUMS significantly downregulated the expression levels of hippocampal genes and proteins, including PI3K, Akt, Nrf2, HO-1, tropomyosin-related kinase B (TrkB), and brain-derived neurotrophic factor; catalpol administration significantly reversed the abnormal expression of these genes and proteins. CUMS also caused a significant decrease in the hippocampal superoxide dismutase, catalase, glutathione peroxidase, glutathione-s transferase, and reduced glutathione levels, as well as a significant increase in thiobarbituric acid reactive substances level in rats; catalpol administration significantly reversed the abnormality of these indicators. Taken together, this study confirmed for the first time that the antidepressant effect of catalpol on CUMS-induced depression involved the upregulation of the PI3K/Akt/Nrf2/HO-1 signaling pathway, thereby improving the hippocampal neurotrophic, neuroprotective, and antioxidant levels. The PI3K/Akt/Nrf2/HO-1 pathway-related molecules may serve as potential new biomarkers and candidate molecular targets for catalpol's antidepressant effects.

Chloroquine enhances catalpol's ability to promote apoptosis by inhibiting catalpol's autophagy-promoting effect on gastric cancer.

PURPOSE: Gastric cancer, which is derived from gastric mucosal epithelial cells, is a representative solid tumour, and more than 1 million cases are diagnosed worldwide each year. However, treatment methods and therapeutics for gastric cancer are limited, and further research is needed to develop novel strategies. METHODS: In this experiment, we studied the effect of catalpol from the extract of Dihuang from traditional Chinese medicine on gastric cancer cells. RESULTS: The results showed that catalpol led to a dose-dependent reduction in gastric cancer cell proliferation. When the promotion of autophagy by catalpol was inhibited, the proapoptotic effects of catalpol on gastric cancer cells were enhanced. Bax, an apoptosis-related marker, was upregulated in catalpol-treated cells, and its expression was increased in the group treated with catalpol in combination with an inhibitor compared to the group treated with catalpol alone. Opposite results were obtained with BCL-2 inhibition. Flow cytometry showed that apoptosis rates were higher in cells treated with a combination of autophagy inhibitors. Accumulation of reactive oxygen species (ROS) in gastric cancer cells showed the group treated with the combination of catalpol and an inhibitor enhanced ROS production. Transwell assays showed that catalpol plus autophagy inhibitors exerted a stronger inhibitory effect on the migration ability of AGS cells than catalpol alone. CONCLUSIONS: In summary, the above results indicate that inhibition of catalpol-induced autophagy could better promote the apoptosis of gastric cancer cells.

Catalpol enhanced physical exercise-mediated brain functional improvement in post-traumatic stress disorder model via promoting adult hippocampal neurogenesis.

Post-traumatic stress disorder (PTSD) is a serious psychiatric disorder characterized by hyper-response to environmental cues as well as the associated depressive and cognitive dysfunctions. According to the key roles of hippocampus for cognitive and emotional regulation, improving hippocampal functions, particularly hippocampal neural plasticity, is the necessary pathway to attenuate the core symptoms of PTSD. The effects of the alternative therapies such as exercise and natural compounds to reduce PTSD symptoms and promote adult hippocampal neurogenesis have been widely demonstrated. However, what is the effect of combining the exercise with traditional Chinese medical compounds remains unknown. In current study, we evaluated the effects of catalpol, which showed the pro-neurogenic effects in previous report, in regulating exercise-mediated PTSD therapeutic effects. With behavioral tests, we found that catalpol treatment promoted the effects of exercise to reduce the response of mice to dangerous cues, and simultaneously enhanced the antidepressant and cognitive protection effects. Moreover, by immunofluorescence we identified that catalpol promoted exercise-mediated hippocampal neurogenesis by enhancing the neural differentiation and mature neuronal survive. We further found that the promote effects of catalpol to exercise-induced environmental hyper-response, antidepressant effects and cognitive protective effects were all compromised by blocking neurogenesis with temozolomide (TMZ). This result indicates that hippocampal neurogenesis is prerequisite for catalpol to promote exercise-mediated brain functional improvement in PTSD model. In conclusion, our research identified the new function of natural compounds catalpol to promote the exercise-mediated brain functional changes in PTSD model, which depend on its effect promoting adult hippocampal neurogenesis.

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.

Olive leaf extract prevents obesity, cognitive decline, and depression and improves exercise capacity in mice.

Obesity is a risk factor for development of metabolic diseases and cognitive decline; therefore, obesity prevention is of paramount importance. Neuronal mitochondrial dysfunction induced by oxidative stress is an important mechanism underlying cognitive decline. Olive leaf extract contains large amounts of oleanolic acid, a transmembrane G protein-coupled receptor 5 (TGR5) agonist, and oleuropein, an antioxidant. Activation of TGR5 results in enhanced mitochondrial biogenesis, which suggests that olive leaf extract may help prevent cognitive decline through its mitochondrial and antioxidant effects. Therefore, we investigated olive leaf extract's effects on obesity, cognitive decline, depression, and endurance exercise capacity in a mouse model. In physically inactive mice fed a high-fat diet, olive leaf extract administration suppressed increases in fat mass and body weight and prevented cognitive declines, specifically decreased working memory and depressive behaviors. Additionally, olive leaf extract increased endurance exercise capacity under atmospheric and hypoxic conditions. Our study suggests that these promising effects may be related to oleanolic acid's improvement of mitochondrial function and oleuropein's increase of antioxidant capacity.

Effects of oleuropein on rat's atria and thoracic aorta: a study of antihypertensive mechanisms.

Oleuropein (OLE) is the main bioactive ingredient in the leaves of the olive plant Olea europaea L. (Oleaceae), which has proven beneficial due to the antiinflammatory, antiatherogenic, anticancer, antimicrobial, and antiviral effects. This study aimed to investigate the antihypertensive and vasodilator potential of OLE by analyzing its acute effects on spontaneous atrial contractions and vasomotor responses of the isolated thoracic aorta in rats. We showed that the application of OLE induces negative chronotropic and inotropic effects on the heart. OLE also causes mild aortic vasodilation given that the maximal reduction in tension of intact aortic rings precontracted with phenylephrine was approximately 30%. This vasodilation is likely dependent on the nitric oxide released from the endothelium based on the effect obtained on denuded and phenylephrine precontracted aortic rings and responses reordered following vasoconstriction induced by high concentrations of K+ and heparin. Our findings provide a basis for further testing of OLE cardiovascular effects, which may lead to subsequent clinical research for its application in the treatment of hypertension and heart disease.

Swertiamarin and quercetin combination ameliorates hyperglycemia, hyperlipidemia and oxidative stress in streptozotocin-induced type 2 diabetes mellitus in wistar rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Swertiamarin (Sw) and quercetin (Qu) have been isolated from different plants and are reported for their antidiabetic activities. The plants from which swertiamarin and quercetin were isolated are also traditionally used in the treatment of diabetes mellitus. AIM OF THE STUDY: The present study is aimed to evaluate the synergistic effect of a combination of swertiamarin and quercetin (CSQ) on α-amylase in vitro and on streptozotocin (STZ) induced diabetes mellitus in vivo. METHODS: Swertiamarin was isolated from the plant Enicostemma axillare and quercetin was procured in its pure form. Sw, Qu and CSQ were evaluated for in vitro α-amylase inhibitory activity. Based on the in vitro study results, CSQ was assessed for in vivo streptozotocin induced diabetes mellitus in Wistar rats. The effect of CSQ on blood glucose levels, body weight, serum biochemical parameters and antioxidant enzymes such as glutathione (GSH), superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx) and lipid peroxide levels were estimated. The histopathological observations of pancreatic tissues were also made. RESULTS: The purity of swertiamarin was confirmed by HPLC. The results showed that CSQ was found to possess high percentage of inhibition in an in vitro α-amylase inhibitory study. In a STZ-induced type 2 diabetes mellitus (T2DM), body weight of rats in CSQ treated and control groups were unaltered. A marked reduction in the blood glucose levels was observed in the CSQ treated groups on 14th and 28th day. Decrease in the levels of low-density lipoprotein (LDL), triglycerides, total cholesterol and an increase in high-density lipoprotein (HDL) cholesterol level was observed in a dose dependant in CSQ treated groups. However, CSQ treated groups could significantly improve antioxidant protection by increasing the levels of serum GSH, SOD, Catalase and GPx and decreasing the levels of lipid peroxide (p < 0.05). In the histopathological study, the pancreatic islets of Langerhans and vacuolization have shown significant increase in both the treated groups. CONCLUSIONS: The combination of swertiamarin and quercetin (CSQ) has proven a preventive and therapeutic effect against T2DM and suggests that this is a potential combination of phytoconstituents for excellent hypoglycemic activity in T2DM.

Gentiopicroside, a Secoiridoid Glycoside from Gentiana rigescens Franch, Extends the Lifespan of Yeast via Inducing Mitophagy and Antioxidative Stress.

Gentiopicroside (GPS), an antiaging secoiridoid glycoside, was isolated from Gentiana rigescens Franch, a traditional Chinese medicine. It prolonged the replicative and chronological lifespans of yeast. Autophagy, especially mitophagy, and antioxidative stress were examined to clarify the mechanism of action of this compound. The free green fluorescent protein (GFP) signal from the cleavage of GFP-Atg8 and the colocation signal of MitoTracker Red CMXRos and GFP were increased upon the treatment of GPS. The free GFP in the cytoplasm and free GFP and ubiquitin of mitochondria were significantly increased at the protein levels in the GPS-treated group. GPS increased the expression of an essential autophagy gene, ATG32 gene, but failed to extend the replicative and chronological lifespans of ATG32 yeast mutants. GPS increased the survival rate of yeast under oxidative stress condition; enhanced the activities of catalase, superoxide dismutase, and glutathione peroxidase; and decreased the levels of reactive oxygen species and malondialdehyde. The replicative lifespans of Δsod1, Δsod2, Δuth1, and Δskn7 were not affected by GPS. These results indicated that autophagy, especially mitophagy, and antioxidative stress are involved in the antiaging effect of GPS.

Investigation of a Medical Plant for Hepatic Diseases with Secoiridoids Using HPLC and FT-IR Spectroscopy for a Case of Gentiana rigescens.

Secoiridoids could be used as a potential new drug for the treatment of hepatic disease. The content of secoiridoids of G. rigescens varied in different geographical origins and parts. In this study, a total of 783 samples collected from different parts of G. rigescens in Yunnan, Sichuan, and Guizhou Provinces. The content of secoiridoids including gentiopicroside, swertiamarin, and sweroside were determined by using HPLC and analyzed by one-way analysis of variance. Two selected variables including direct selected and variable importance in projection combined with partial least squares regression have been used to establish a method for the determination of secoiridoids using FT-IR spectroscopy. In addition, different pretreatments including multiplicative scatter correction (MSC), standard normal variate (SNV), first derivative and second derivative (SD), and orthogonal signal correction (OSC) were compared. The results indicated that the sample (root, stem, and leaf) with total secoiridoids, gentiopicroside, swertiamarin, and sweroside from west Yunnan had higher content than samples from the other regions. The sample from Baoshan had more total secoiridoids than other samples for the whole medicinal plant. The best performance using FT-IR for the total secoiridoid was with the direct selected variable method involving pretreatment of MSC+OSC+SD in the root and stem, while in leaf, of the best method involved using original data with MSC+OSC+SD. This method could be used to determine the bioactive compounds quickly for herbal medicines.

Sweroside ameliorated carbon tetrachloride (CCl4)-induced liver fibrosis through FXR-miR-29a signaling pathway.

To date, there are very few effective drugs for liver fibrosis treatment; therefore, it is urgent to develop novel therapeutic targets and approaches. In the present research, we sought to study the protective effect of sweroside contained in Lonicera japonica or blue honeysuckle berries in a mouse model of liver fibrosis and investigate the underlying mechanism. The mouse model of liver fibrosis in was induced by intraperitoneal injections of 10% CCl4 for 6 weeks (three times/week). At the beginning of the fourth week, sweroside was intragastrically administered once a day and at the end of the treatment, biochemical and histological studies were investigated. The expression of FXR, miR-29a and the downstream targets were analyzed as well. Moreover, the effect of sweroside on cell proliferation was observed in human hepatic stellate cells (HSCs) (LX-2), along with using the siRNA for FXR and miR-29a inhibitor to investigate the underpinning of the anti-fibrotic effect of sweroside. Sweroside successfully protected the liver fibrosis in CCl4-induced mouse model, accompanied by miR-29a induction. Furthermore, sweroside also induced miR-29a in HSCs, resulting in the inhibition of COL1 and TIMP1. Our data also showed that either silencing miR-29a or knockdown of FXR in LX-2 cell abolished the inhibition of COL1 and TIMP1 as well as the inhibition of cell proliferation by sweroside treatment. In conclusion, sweroside exerted its anti-fibrotic effect in vivo and in vitro by up-regulation of miR-29a and repression of COL1 and TIMP1, which was at least in part through FXR.

Aucubin, An Active Ingredient in Aucuba japonica, Prevents N-methyl-N-nitrosourea-induced Retinal Degeneration in Mice.

In the present study, we examined the potent retinoprotective effects of an ethanol-based extract of Aucuba japonica (AJE) and its active ingredient, aucubin, on N-methyl-N-nitrosourea (MNU)-induced retinal degeneration in mice. Retinal degeneration was induced by an intraperitoneal injection of MNU (60 mg/kg). AJE (250 mg/kg) and aucubin (15 mg/kg) were orally administered for 1 week after the MNU injection. Electroretinography (ERG) and histological examinations were performed. Retinal apoptosis and oxidative DNA damage were also quantified. The retinoprotective abilities of AJE and aucubin were also assessed in primary cultured retinal cells. Morphologically, MNU induced a remarkable decrease in the outer nuclear layer, which contains photoreceptor cells. However, this layer was well preserved in the AJE- and aucubin-administered mice. The ERG responses significantly decreased in both a- and b-wave amplitudes in the MNU-injected mice. In the AJE and aucubin-treated mice, ERG responses were significantly increased. In addition, a terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) assay and immunohistochemical staining for 8-hydroxydeoxyguanosine (8-OHdG) revealed that both AJE and aucubin attenuated MNU-induced photoreceptor cell apoptosis and oxidative DNA damage. Furthermore, the in vitro assay also showed that AJE and aucubin have potent anti-oxidative and anti-apoptotic activities in primary cultured retinal cells. These results indicate that AJE and aucubin have potent retinoprotective effects, and that this retinoprotective activity is as a result of the potency of the bioactive compound, aucubin. These pharmacological characteristics suggest the additional application of AJE or aucubin in the treatment of patients with retinal degenerative diseases.

Catalpol induces autophagy and attenuates liver steatosis in ob/ob and high-fat diet-induced obese mice.

Impaired autophagy has been implicated in the pathogenesis of nonalcoholic fatty liver disease. Catalpol (CAT), a bioactive compound from Rehmannia (Di Huang) glutinosa, is known to ameliorate insulin resistance and the histological NAFLD spectrum in obese mice. Here, we investigated the effects of CAT on hepatic steatosis and autophagy in ob/ob and high-fat diet-induced obese mice, as well as in hepatocytes. In ob/ob mice, CAT reduced liver weight, liver triglyceride and cholesterol content, and hepatic lipogenic enzyme levels and increased fatty acid oxidase levels. In addition, CAT administration increased LC3-II levels and decreased SQSTM1/P62 levels in ob/ob mice. Similar effects on hepatic steatosis and autophagy were observed in high-fat diet-induced mice after administration of CAT. Additionally, we found that CAT stimulated AMPK and increased nuclear translocation of transcription factor EB (TFEB) in obese mice and hepatocytes. Inhibition of AMPK completely blocked the effects of CAT on TFEB nuclear localization, hepatic autophagy, and liver steatosis. These findings revealed that diminished AMPK/TFEB-dependent autophagy is involved in the pathogenesis of liver steatosis in obesity, and that CAT might be a novel therapeutic candidate for treatment of this condition.

Effect of catalpol on behavior and neurodevelopment in an ADHD rat model.

Studies suggest that abnormal neurodevelopment of prefrontal striatal circuits is implicated in the pathogenesis of attention deficit hyperactivity disorder (ADHD). In the present study, we investigated the effect of catalpol, an active ingredient of Rehmanniae radix preparata, which is the most frequently used Chinese medicinal herb for the treatment of ADHD, on behavior and neurodevelopment in spontaneously hypertensive rats (SHR). SHR were divided into SHR group (vehicle, i.g.), methylphenidate (MPH) group (2 mg/kg/day, i.g.), and catalpol group (50 mg/kg/day i.g.), and Wistar-Kyoto (WKY) rats were used as control group (vehicle, i.g.). Open Field Test (OFT) and Morris water maze (MWM) test were performed to assess the effect of catalpol on behavior. Results revealed that both catalpol and MPH treatment decreased average speed, time spent in the central area, rearing times, and central area visits, increased the immobility time of SHR in OFT, and increased number of visits to the annulus, and time spent in target quadrant in the MWM test. Hematoxylin and eosin (H&E) staining showed that catalpol reduced irregular neuronal arrangement, ruptured nuclear membranes, and resulted in disappearance of the nucleolus in the prefrontal cortex (PFC) and striatum of SHR. Moreover, immuno-fluorescent staining of NeuN and myelin basic protein (MBP) indicated that catalpol ameliorated neuronal loss and contributed to myelination. Finally, western blot and immunostaining analysis suggested that several regulatory proteins involved in PFC development were up-regulated by catalpol treatment, such as brain-derived neurotrophic factor (BDNF), cyclin-dependent kinase 5 (Cdk5), p35, fibroblast growth factor (FGF) 21 and its receptor (FGFR)1. Taken together, catalpol can effectively ameliorate hyperactive and impulsive behavior, improve spatial learning and memory in SHR, likely through the neurodevelopmental pathways. Nonetheless, whether catalpol could attenuate inattention in SHR and the pathway by which catalpol reduces neuronal loss remain to be further studied.

Rhus verniciflua and Eucommia ulmoides Protects Against High-Fat Diet-Induced Hepatic Steatosis by Enhancing Anti-Oxidation and AMPK Activation.

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disorder associated with features of metabolic syndrome and oxidative stress. We examined the mechanism by which the combined extracts of Rhus verniciflua and Eucommia ulmoides extracts (ILF-RE) regulate hepatic dyslipidemia in an established NAFLD model, high-fat diet (HFD)-induced lipid dysmetabolism in rats. ILF-RE attenuated alanine aminotransferase (ALT) by 1.5% (p<0.05), aspartate aminotransferase (AST) by 1.5% (p<0.05), triglycerides by 1.5% (p<0.05), cholesterol by 2.0% (p<0.05), and lipid peroxidation by 1.5% (p<0.05) in the NAFLD model. ILF-RE, recently shown to have anti-oxidant properties, also inhibited hepatic ROS accumulation by 1.68% (p<0.05) and regulated ER-redox imbalance, a key phenomenon of ER stress. Due to nutrient overload stress-associated protein folding, ER stress and downstream SREBP-lipogenic transcription signaling were highly activated, and the mTORC1-AMPK axis was also disturbed, leading to hepatic steatosis. ILF-RE results in recovery from hepatic conditions induced by nutrient-based protein folding stress signaling and the ER stress-SREBP and AMPK-mTORC1-SREBP1 axes. Based on these results, ILF-RE is suggested to be a potential therapeutic strategy for hepatic steatosis and may represent a promising novel agent for the prevention and treatment of NAFLD.

Indigo Fruits Ingredient, Aucubin, Protects against LPS-Induced Cardiac Dysfunction in Mice.

Aucubin (AUB), which is extracted from Eucommia ulmoides Oliver seeds, has been found to possess anti-inflammatory and antiapoptotic properties. Recent studies have indicated that inflammation, oxidative stress, and apoptosis are involved in the pathophysiology of lipopolysaccharide (LPS)-induced cardiac dysfunction. Our study aimed to investigate the effect of AUB on LPS-induced acute cardiac injury. Male C57BL/6 mice were injected with LPS (one 6 mg/kg injection) to induce cardiac dysfunction without or with AUB pretreatment (20 or 80 mg/kg per day) for 1 week. We found that AUB ameliorated cardiac dysfunction, inflammation, oxidative stress, and apoptosis induced by LPS stimulation. Mechanistically, AUB inhibited LPS-induced oxidative stress by decreasing reactive oxygen species and thioredoxin interaction protein (TXNIP) levels. Moreover, AUB suppressed LPS-induced inflammation and apoptosis by reducing nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3)/apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC)/caspase-1 inflammasome formation. Overexpression of NLRP3 in cardiomyocytes attenuated the protective effects of AUB. Interestingly, NLRP3 deficiency ameliorated cardiac function and reduced the inflammatory response and oxidative stress after LPS insult in mice, whereas AUB could not further prevent LPS-induced cardiac dysfunction in NLRP3-deficient mice. In summary, AUB exerts a protective effect against LPS-induced inflammation, oxidative stress, and apoptosis in vivo and in vitro by regulating the TXNIP pathway and inactivating the NLRP3/ASC/caspase-1 inflammasome. Hence, AUB may be a promising agent against LPS-induced cardiac dysfunction. SIGNIFICANCE STATEMENT: Aucubin exerts a protective effect against lipopolysaccharide-induced cardiac dysfunction by regulating nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 inflammasome.

Gentiopicroside isolated from Gentiana scabra Bge. inhibits adipogenesis in 3T3-L1 cells and reduces body weight in diet-induced obese mice.

Gentiopicroside is a major active component of the Gentiana scabra Bge., which is commonly used as herbal medicine for the treatment of inflammation in Asia. Gentiopicroside significantly down-regulated expression of key adipogenic transcription factors (PPARγ, C/EBPα, SREBP-1c) and dose-dependently inhibited the lipid uptake-related gene (LPL), fatty acid transport-related gene (FABP4) and triglyceride (TG) synthesis-related gene (DGAT2), as well as fatty acid synthesis-related genes (FAS, SCD1), which resulted in reduced intracellular lipid droplet accumulation and TG content in 3T3-L1 cells. Gentiopicroside also down-regulated expression of inflammatory cytokine genes (NFκB1, TNFα, IL6) compared with vehicle. Oral administration of gentiopicroside (50 mg/kg) in mice fed with high-fat diet for 12 weeks resulted in reduced body weight and visceral fat mass compared with the control group. Overall, the results of this study showed that gentiopicroside had positive anti-obesity effects by regulating the expression of adipogenesis/lipogenesis-related genes and inflammatory genes in 3T3-L1, and that it effectively reduced body weight and visceral fat mass in vivo.