Therapeutic Potential of Genipin in Central Neurodegenerative Diseases

Genipin promotes the apoptosis and autophagy of neuroblastoma cells by suppressing the PI3K/AKT/mTOR pathway

This study investigated the underlying function and mechanism of genipin in neuroblastoma (NB). Using flow cytometry analysis and cytotoxicity tests, in vitro studies were conducted to assess the effects of genipin on the SK-N-SH cell line. The mechanism of action of genipin was explored through immunofluorescence staining, Western blotting, and caspase-3 activity assays. In addition, we also created a xenograft tumour model to investigate the effects of genipin in vivo. This research confirmed that genipin suppressed cell viability, induced apoptosis, and promoted autophagy, processes that are likely linked to the inhibition of the PI3K/AKT/mTOR signalling pathway. Autophagy inhibition increases the sensitivity of SK-N-SH cells to genipin. Furthermore, combination treatment with a PI3K inhibitor enhanced the therapeutic efficacy of genipin. These results highlight the potential of genipin as a candidate drug for the treatment of NB.

An increase in Wharton's jelly membrane osteocompatibility by a genipin-cross-link

Wharton's Jelly (WJ) has attracted significant interest in the field of tissue healing thanks to its biological properties, including antibacterial activity and immunomodulation. However, due to the fast degradation and poor mechanical behavior in biological environment, its application in bone regeneration is compromised. Here, we proposed to use genipin as an efficient cross-linking agent to significantly improve the elasticity and the enzymatical stability of the WJ matrix. The degree of cross-linking, linear elastic moduli, and collagenase resistance varied over a wide range depending on genipin concentration. Furthermore, our results highlighted that an increase in genipin concentration led to a decreased surface wettability, therefore impairing cell attachment and proliferation. The genipin cross-linking prevented rapid in vitro and in vivo degradation, but led to an adverse host reaction and calcification. When implanted in the parietal bone defect, a limited parietal bone regeneration to the dura was observed. We conclude that genipin-cross-linked WJ is a versatile medical device however, a careful selection is required with regards to the genipin concentration.

Endoplasmic reticulum stress in Alzheimer's disease: Molecular mechanisms and therapeutic prospects

Alzheimer's disease (AD) is a progressive neurodegenerative condition that leads to memory loss and cognitive impairment over time. It is characterized by protein misfolding as well as prolonged cellular stress, such as perturbing calcium homeostasis and redox management. Numerous investigations have proven that endoplasmic reticulum failure may exhibit exacerbation of AD pathogenesis in AD patients, in-vivo and in-vitro models. The endoplasmic reticulum (ER) participates in a variety of biological functions including folding of protein, quality control, cholesterol production, and maintenance of calcium balance. A diverse range of physiological, pathological and pharmacological substances can interfere with ER activity and thus lead to exaggeration of ER stress. The unfolded protein response (UPR), an intracellular signaling network is stimulated due to ER stress. Three stress sensors found in the endoplasmic reticulum, the PERK, ATF6, and IRE1 transducers detect protein misfolding in the ER and trigger UPR, a complex system to maintain homeostasis. ER stress is linked to many of the major pathological processes that are seen in AD, including presenilin1 and 2 (PS1 and PS2) gene mutation, tau phosphorylation and β-amyloid formation. The role of ER stress and UPR in the pathophysiology of AD implies that they can be employed as potent therapeutic target. This study shows the relationship between ER and AD and how the pathogenesis of AD is influenced by the impact of ER stress. An effective method for the prevention or treatment of AD may involve therapeutic strategies that modify ER stress pathways.

Synthesis of Methylgenipin and Evaluation of Its Anti-Hepatic Injury Activity

Genipin has been the focus of research as a multifunctional compound for the treatment of pathogenic diseases. However, hepatotoxicity caused by oral genipin raises concerns about its safety. To obtain novel derivatives with low toxicity and efficacy, we synthesized methylgenipin (MG), a new compound, using structural modification, and investigated the safety of MG administration. The results showed that the LD₅₀ of oral MG was higher than 1000 mg/kg, no mice died or were poisoned during the experiment in the treatment group, and there was no significant difference in biochemical parameters and liver pathological sections compared with the control. Importantly, MG (100 mg/kg/d) treatment for 7 days reduced alpha-naphthylisothiocyanate (ANIT)-induced increases in liver index, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP), and total bilirubin (TBIL) levels. Histopathology demonstrated that MG could treat ANIT-induced cholestasis. In addition, using proteomics to investigate the molecular mechanism of MG in the treatment of a liver injury may be related to enhancing antioxidant function. Kit validation showed that ANIT induced an increase in malondialdehyde (MDA) and a decrease in superoxide dismutase (SOD) and glutathione (GSH) levels, while the MG pretreatments, both of which were significantly reversed to some extent, suggested that MG may alleviate ANIT-induced hepatotoxicity by enhancing endogenous antioxidant enzymes and inhibiting oxidative stress injury. In this study, we demonstrate that the treatment of mice with MG does not cause impaired liver function and provide an investigation of the efficacy of MG against ANIT-induced hepatotoxicity, laying the foundation for the safety evaluation and clinical application of MG.

Stress stimulation maintaining by genipin crosslinked hydrogel promotes annulus fibrosus healing

Objective

To explore the repair effect of tissue engineering for annulus fibrosus (AF) injury in stress-stimulation environment.

Methods

Non-adhesive fibrinogen (Fib) representing the repair with non-stress stimulation and adhesive hydrogel of fibrinogen, thrombin and genipin mixture (Fib-T-G) representing the repair with stress stimulation were prepared to repair the AF lesion. The relationship between adhesion and stress stimulation was studied in rheological measurements, tension tests and atomic force microscopy (AFM) experiments. The repair effect of stress stimulation was studied in designed acellular AF scaffold models with fissures and defects. The models were repaired by the two different hydrogels, then implanted subcutaneously and cultured for 21 ​d in rats. Histology and qPCR of COL1A1, COL2A1, aggrecan, RhoA, and ROCK of the tissue engineering of the interface were evaluated afterward. Moreover, the repair effect was also studied in an AF fissure model in caudal disc of rats by the two different hydrogels. Discs were harvested after 21 ​d, and the disc degeneration score and AF healing quality were evaluated by histology.

Result

In interfacial stress experiment, Fib-T-G hydrogel showed greater viscosity than Fib hydrogel (24.67 ​± ​1.007 vs 459333 ​± ​169205 ​mPa ​s). Representative force-displacement and sample modulus for each group demonstrate that Fib-T-G group significantly increased the interfacial stress level and enhanced the modulus of samples, compared with Fib group (P ​< ​0.01). The Fib-T-G group could better bond the interface to resist the loading strain force with the broken point at 1.11 ​± ​0.10 ​N compared to the Fib group at 0.12 ​± ​0.08 ​N ​(P ​< ​0.01). Focusing on the interfacial healing in acellular AF scaffold model, compared with Fib ​+ ​MSCs group, the fissure and defect were connected closely in Fib-T-G ​+ ​MSCs group (P ​< ​0.01). Relative higher gene expression of COL2A1 and RhoA in Fib-T-G ​+ ​MSCs group than Fib ​+ ​MSCs group in AF fissure and AF defect model (P ​< ​0.05). The immunohistochemistry staining showed more positive staining of COL2A1 and RhoA in Fib-T-G ​+ ​MSCs group than in Fib ​+ ​MSCs group in both AF fissure and AF defect models. The degree of disc degeneration was more severe in Fib ​+ ​MSCs group than Fib-T-G ​+ ​MSCs group in vivo experiment (11.80 ​± ​1.11 vs 7.00 ​± ​1.76, P ​< ​0.01). The dorsal AF defect in Fib-T-G ​+ ​MSCs group (0.02 ​± ​0.01 ​mm²) was significantly smaller than that (0.13 ​± ​0.05 ​mm²) in Fib ​+ ​MSCs group (P ​< ​0.05). Immunohistochemical staining showed more positive staining of COL2A1 and Aggrecan in Fib-T-G ​+ ​MSCs group than in Fib ​+ ​MSCs group.

Conclusion

Genipin crosslinked hydrogel can bond the interface of AF lesions and transfer strain force. Stress stimulation maintained by adhesive hydrogel promotes AF healing.

The translational potential of this article

We believe the effect of stress stimulation could be concluded through this study and provides more ideals in mechanical effects for further research, which is a key technique for repairing intervertebral disc in clinic. The adhesive hydrogel of Fib-T-G+MSCs has low toxicity and helps bond the interface of AF lesion and transfer strain force, having great potential in the repair of AF lesion.

Genipin prevents alpha-synuclein aggregation and toxicity by affecting endocytosis, metabolism and lipid storage

Parkinson's Disease (PD) is a common neurodegenerative disorder affecting millions of people worldwide for which there are only symptomatic therapies. Small molecules able to target key pathological processes in PD have emerged as interesting options for modifying disease progression. We have previously shown that a (poly)phenol-enriched fraction (PEF) of Corema album L. leaf extract modulates central events in PD pathogenesis, namely α-synuclein (αSyn) toxicity, aggregation and clearance. PEF was now subjected to a bio-guided fractionation with the aim of identifying the critical bioactive compound. We identified genipin, an iridoid, which relieves αSyn toxicity and aggregation. Furthermore, genipin promotes metabolic alterations and modulates lipid storage and endocytosis. Importantly, genipin was able to prevent the motor deficits caused by the overexpression of αSyn in a Drosophila melanogaster model of PD. These findings widens the possibility for the exploitation of genipin for PD therapeutics.

Genipin Crosslinks the Extracellular Matrix to Rescue Developmental and Degenerative Defects, and Accelerates Regeneration of Peripheral Neurons

The peripheral nervous system (PNS) is essential for proper body function. A high percentage of the population suffer nerve degeneration or peripheral damage. For example, over 40% of patients with diabetes or undergoing chemotherapy develop peripheral neuropathies. Despite this, there are major gaps in the knowledge of human PNS development and therefore, there are no available treatments. Familial Dysautonomia (FD) is a devastating disorder that specifically affects the PNS making it an ideal model to study PNS dysfunction. FD is caused by a homozygous point mutation in ELP1 leading to developmental and degenerative defects in the sensory and autonomic lineages. We previously employed human pluripotent stem cells (hPSCs) to show that peripheral sensory neurons (SNs) are not generated efficiently and degenerate over time in FD. Here, we conducted a chemical screen to identify compounds able to rescue this SN differentiation inefficiency. We identified that genipin, a compound prescribed in Traditional Chinese Medicine for neurodegenerative disorders, restores neural crest and SN development in FD, both in the hPSC model and in a FD mouse model. Additionally, genipin prevented FD neuronal degeneration, suggesting that it could be offered to patients suffering from PNS neurodegenerative disorders. We found that genipin crosslinks the extracellular matrix, increases the stiffness of the ECM, reorganizes the actin cytoskeleton, and promotes transcription of YAP-dependent genes. Finally, we show that genipin enhances axon regeneration in an in vitro axotomy model in healthy sensory and sympathetic neurons (part of the PNS) and in prefrontal cortical neurons (part of the central nervous system, CNS). Our results suggest genipin can be used as a promising drug candidate for treatment of neurodevelopmental and neurodegenerative diseases, and as a enhancer of neuronal regeneration.

Research progress in traditional Chinese medicine in the treatment of Alzheimer's disease and related dementias

Alzheimer's disease (AD) is the world's leading cause of dementia and has become a huge economic burden on nations and families. However, the exact etiology of AD is still unknown, and there are no efficient medicines or methods to prevent the deterioration of cognition. Traditional Chinese medicine (TCM) has made important contributions in the battle against AD based on the characteristics of multiple targets of TCM. This study reviewed the treatment strategies and new discoveries of traditional Chinese medicine in current research, which may be beneficial to new drug researchers.

Involvement of Phytochemical-Encapsulated Nanoparticles' Interaction with Cellular Signalling in the Amelioration of Benign and Malignant Brain Tumours

Brain tumours have unresolved challenges that include delay prognosis and lower patient survival rate. The increased understanding of the molecular pathways underlying cancer progression has aided in developing various anticancer medications. Brain cancer is the most malignant and invasive type of cancer, with several subtypes. According to the WHO, they are classified as ependymal tumours, chordomas, gangliocytomas, medulloblastomas, oligodendroglial tumours, diffuse astrocytomas, and other astrocytic tumours on the basis of their heterogeneity and molecular mechanisms. The present study is based on the most recent research trends, emphasising glioblastoma cells classified as astrocytoma. Brain cancer treatment is hindered by the failure of drugs to cross the blood–brain barrier (BBB), which is highly impregnableto foreign molecule entry. Moreover, currently available medications frequently fail to cross the BBB, whereas chemotherapy and radiotherapy are too expensive to be afforded by an average incomeperson and have many associated side effects. When compared to our current understanding of molecularly targeted chemotherapeutic agents, it appears that investigating the efficacy of specific phytochemicals in cancer treatment may be beneficial. Plants and their derivatives are game changers because they are efficacious, affordable, environmentally friendly, faster, and less toxic for the treatment of benign and malignant tumours. Over the past few years, nanotechnology has made a steady progress in diagnosing and treating cancers, particularly brain tumours. This article discusses the effects of phytochemicals encapsulated in nanoparticles on molecular targets in brain tumours, along with their limitations and potential challenges.

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.

The Role of Natural Products in Treatment of Depressive Disorder

Depressive disorder is one of the most common psychiatric syndromes that, if left untreated, can cause many disturbances in a person's life. Numerous factors are involved in depression, including inflammation, brain-derived neurotrophic factor (BDNF), GABAergic system, hypothalamic- pituitary-adrenal (HPA) Axis, monoamine neurotransmitters (serotonin (5-HT), noradrenaline, and dopamine). Common treatments for depression are selective serotonin reuptake inhibitors, tricyclic antidepressants, and monoamine oxidase inhibitors, but these drugs have several side effects such as anxiety, diarrhea, constipation, weight loss, and sexual dysfunctions. These agents only reduce the symptoms and temporarily reduce the rate of cognitive impairment associated with depression. As a result, extensive research has recently been conducted on the potential use of antidepressant and sedative herbs. According to the available data, herbs used in traditional medicine can be significantly effective in reducing depression, depressive symptoms and improving patients' performance. The present study provides a summary of biomarkers and therapeutic goals of depression and shows that natural products such as saffron or genipin have antidepressant effects. Some of the useful natural products and their mechanisms were evaluated. Data on various herbs and natural isolated compounds reported to prevent and reduce depressive symptoms is also discussed.

Microemulsion Delivery System Improves Cellular Uptake of Genipin and Its Protective Effect against Aβ1-42-Induced PC12 Cell Cytotoxicity

Genipin has attracted much attention for its hepatoprotective, anti-inflammatory, and neuroprotection activities. However, poor water solubility and active chemical properties limit its application in food and pharmaceutical industries. This article aimed to develop a lipid-based microemulsion delivery system to improve the stability and bioavailability of genipin. The excipients for a genipin microemulsion (GME) preparation were screened and a pseudo-ternary phase diagram was established. The droplet size (DS), zeta potential (ZP), polydispersity index (PDI), physical and simulated gastrointestinal digestion stability, and in vitro drug release properties were characterized. Finally, the effect of the microemulsion on its cellular uptake by Caco-2 cells and the protective effect on PC12 cells were investigated. The prepared GME had a transparent appearance with a DS of 16.17 ± 0.27 nm, ZP of −8.11 ± 0.77 mV, and PDI of 0.183 ± 0.013. It exhibited good temperature, pH, ionic strength, and simulated gastrointestinal digestion stability. The in vitro release and cellular uptake data showed that the GME had a lower release rate and better bioavailability compared with that of free genipin. Interestingly, the GME showed a significantly better protective effect against amyloid-β (Aβ1-42)-induced PC12 cell cytotoxicity than that of the unencapsulated genipin. These findings suggest that the lipid-based microemulsion delivery system could serve as a promising approach to improve the application of genipin.

Novel Findings regarding the Bioactivity of the Natural Blue Pigment Genipin in Human Diseases

Genipin is an important monoterpene iridoid compound isolated from Gardenia jasminoides J.Ellis fruits and from Genipa americana fruits, or genipap. It is a precursor of a blue pigment which may be attractive alternative to existing food dyes and it possesses various potential therapeutic properties such as anti-cancer, anti-diabetic and hepatoprotective activity. Biomedical studies also show that genipin may act as a neuroprotective drug. This review describes new aspects of the bioactivity of genipin against various diseases, as well as its toxicity and industrial applications, and presents its potential mechanism of action.

Phenotype-Based HPLC-Q-TOF-MS/MS Coupled With Zebrafish Behavior Trajectory Analysis System for the Identification of the Antidepressant Components in Methanol Extract of Anshen Buxin Six Pills

Phenotype screening has become an important tool for the discovery of active components in traditional Chinese medicine. Anshen Buxin Six Pills (ASBX) are a traditional Mongolian medicine used for the treatment of neurosis in clinical settings. However, its antidepressant components have not been explicitly identified and studied. Here, the antidepressant effect of ASBX was evaluated in adult zebrafish. High performance liquid chromatography-mass spectrometry (HPLC-Q-TOF-MS/MS) was combined with zebrafish behavior trajectory analysis to screen and identify the antidepressant-active extract fraction and active components of ASBX. Finally, the antidepressant effect of the active ingredients were verified by the behavior, pathology, biochemical indices and protein level of adult fish. The novel tank driving test (NTDT) showed that ASBX can effectively improve the depressive effect of reserpine on zebrafish. Petroleum ether and dichloromethane extracts of ASBX were screened as antidepressant active extracts. Costunolide (COS) and dehydrocostus lactone (DHE) were screened as the active components of ASBX. COS had been shown to significantly improve the depressive behavior, nerve injury and neurotransmitter levels (5-hydroxytryptamine (5-HT) and norepinephrine (NE)) of zebrafish by inhibiting the high expression of serotonin transporter and norepinephrine transporter induced by reserpine suggesting the antidepressant effect of COS may be related to its effect on 5-HT and NE pathways. This study provided a phenotype based screening method for antidepressant components of traditional Chinese medicines, so as to realize the separation, identification and activity screening of components at the same time.

The Effects of Natural and Synthetic Blue Dyes on Human Health: A Review of Current Knowledge and Therapeutic Perspectives

Blue synthetic dyes are widely used in many industries. Although they are approved for use as food dyes and in cosmetics and some medicines, their impacts on consumer health remain unknown. Some studies indicate that 2 synthetic dyes, Blue No. 1 and Blue No. 2, may have toxic effects. It has therefore been suggested that these should be replaced with natural dyes; however, despite being nontoxic and arguably healthier than synthetic dyes, these compounds are often unsuitable for use in food or drugs due to their instability. Nevertheless, among the natural blue pigments, anthocyanins and genipin offer particular health benefits, as they are associated with the prevention of cardiovascular disease and have anticancer, neuroprotective, anti-inflammatory, and antidiabetic properties. This review summarizes the effects of blue food and drug colorings on health and proposes that synthetic colors should be replaced with natural ones.

Role of natural products for the treatment of Alzheimer's disease

Negative psychological and physiological consequences of neurodegenerative disorders represent a high social and health cost. Among the neurodegenerative disorders Alzheimer's disease (AD) is recognized as a leading neurodegenerative condition and a primary cause of dementia in the elderlys. AD is considered as neurodegenerative disorder that progressively impairs cognitive function and memory. According to current epidemiological data, about 50 milLion people worldwide are suffering from AD. The primary symptoms of AD are almost inappreciable and usually comprise forgetfulness of recent events. Numerous processes are involved in the development of AD, for example oxidative stress (OS) mainly due to mitochondrial dysfunction, intracellular the accumulation of hyperphosphorylated tau (τ) proteins in the form of neurofibrillary tangles, excessive the accumulation of extracellular plaques of beta-amyloid (Aβ), genetic and environmental factors. Running treatments only attenuate symptoms and temporarily reduce the rate of cognitive progression associated with AD. This means that most treatments focus only on controlLing symptoms, particularly in the initial stages of the disease. In the past, the first choice of treatment was based on natural ingredients. In this sense, diverse natural products (NPs) are capable to decrease the symptoms and alleviate the development of several diseases including AD attracting the attention of the scientific community and the pharmaceutical industry. Specifically, numerous NPs including flavonoids, gingerols, tannins, anthocyanins, triterpenes and alkaloids have been shown anti-inflammatory, antioxidant, anti-amyloidogenic, and anti-choLinesterase properties. This review provide a summary of the pathogenesis and the therapeutic goals of AD. It also discusses the available data on various plants and isolated natural compounds used to prevent and diminish the symptoms of AD.

Genipin improves reproductive health problems caused by circadian disruption in male mice

BACKGROUND

Circadian rhythm disruption impacts a wide range of physiological processes, including fertility. However, the effect of circadian disruption on male spermatogenesis and fertility, and treatments for these effects have been largely unexplored at the molecular level.

METHODS

In this study, we examined the effects of genipin on improving the reproductive health problems caused by circadian disruption. Three groups of animals were fed under different conditions: control group (normal T cycle with saline), group of shortened T cycles (Light/Dark = 4 hours/4 hours) with saline, and a group of shortened T cycles with genipin by oral gavage. The male fertility was evaluated by fertility study and pups parameters analysis after successful sexual behavior and mating with female mice. We sacrificed the treated animals after 5 or 10 weeks and collected the testis, sperm and serum for histological analysis, sperm motility assay, and serum hormone detection, respectively. Furthermore, the effect of genipin was assessed by detection of progesterone secretion and steroidogenic key proteins expression, including StAR and CYP11A1, in mouse Leydig tumor MLTC-1 cells.

RESULTS

Male mice exposed to shortened light-dark cycles, much shorter than 24 hours, had reduced fertility with decreased sperm concentrations and sperm motility. Male mice under circadian disruption have reduced testis size and abnormal morphology, leading to lower fertility rates, reduced litter size and pup body weight. Treatment with exogenous genipin, a natural plant-derived compound, alleviated circadian disruption-induced damage to fertility and spermatogenesis and normalized testosterone, dihydrotestosterone (DHT), and androstenedione (ASD) levels in the male mice. The levels of key proteins involved in steroidogenesis, StAR and CYP11A1, were reduced in mouse testes after the circadian disruption, but genipin treatment restored the reduction. The mRNA expression of SRD5A1, which encodes an androgen synthesis enzyme, was also upregulated by genipin treatment. Furthermore, genipin treatment showed a positive effect on steroidogenesis in MLTC-1 cells, resulting in an increase in hormone secretion and the upregulation of StAR and CYP11A1.

CONCLUSIONS

Our results showed an association between circadian disruption and reproductive health problems in male mice and indicated that treatments with genipin have positive effects on the reproductive health of male mice with circadian rhythm disorders.

Unraveling Targetable Systemic and Cell-Type-Specific Molecular Phenotypes of Alzheimer's and Parkinson's Brains With Digital Cytometry

Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common neurodegenerative disorders worldwide, with age being their major risk factor. The increasing worldwide life expectancy, together with the scarcity of available treatment choices, makes it thus pressing to find the molecular basis of AD and PD so that the causing mechanisms can be targeted. To study these mechanisms, gene expression profiles have been compared between diseased and control brain tissues. However, this approach is limited by mRNA expression profiles derived for brain tissues highly reflecting their degeneration in cellular composition but not necessarily disease-related molecular states. We therefore propose to account for cell type composition when comparing transcriptomes of healthy and diseased brain samples, so that the loss of neurons can be decoupled from pathology-associated molecular effects. This approach allowed us to identify genes and pathways putatively altered systemically and in a cell-type-dependent manner in AD and PD brains. Moreover, using chemical perturbagen data, we computationally identified candidate small molecules for specifically targeting the profiled AD/PD-associated molecular alterations. Our approach therefore not only brings new insights into the disease-specific and common molecular etiologies of AD and PD but also, in these realms, foster the discovery of more specific targets for functional and therapeutic exploration.

A Polymeric Delivery System Enables Controlled Release of Genipin for Spatially-Confined In Situ Crosslinking of Injured Connective Tissues

An emerging approach toward repair of connective tissues applies exogenous crosslinkers to mechanically augment injured structures in vivo. One crosslinker that has been explored for this purpose is the plant-derived small molecule genipin. However, genipin's high reactivity to primary amines in proteins, small size, and high diffusion coefficient necessitate localizing and controlling its delivery to avoid off-target or adverse effects. In this study, genipin-loaded polymers were evaluated for sustained local administration. Insoluble polymers comprising subunits of α-, β-, or γ-cyclodextrin, cyclic oligosaccharides possessing increasing cavity sizes, were compared to polymers comprising subunits of the non-cyclic polysaccharide dextran. Polymers made from β-cyclodextrin showed prolonged genipin release for over ten times longer than polymers made from α- or γ-cyclodextrins or dextran, indicating that genipin possesses molecular affinity for the β-cyclodextrin cavity. Modeling of complexation between genipin and cyclodextrin hosts supported this finding. Genipin released from all polymers was confirmed to be functional by exogenous collagen crosslinking through fluorometric and mechanical readouts. Co-incubation of genipin-loaded polymers with bovine tendon explants showed genipin crosslink-mediated coloration that was confined to the sites of exposure. Altogether, results indicate that host-guest interactions within a polymeric delivery vehicle can help to control and confine genipin release.

Therapeutic potential of genipin in various acute liver injury, fulminant hepatitis, NAFLD and other non-cancer liver diseases: More friend than foe

Genipin is an aglycone derived from the geniposide, the most abundant iridoid glucoside constituent of Gardenia jasminoides Ellis. For decades, genipin is the focus of studies as a versatile compound in the treatment of various pathogenic conditions. In particularly, Gardenia jasminoides Ellis has long been used in traditional Chinese medicine for the prevention and treatment of liver disease. Mounting experimental data has proved genipin possesses therapeutic potential for cholestatic, septic, ischemia/reperfusion-triggered acute liver injury, fulminant hepatitis and NAFLD. This critical review is a reflection on the valuable lessons from decades of research regarding pharmacological activities of genipin. Of note, genipin represents choleretic effect by potentiating bilirubin disposal and enhancement of genes in charge of the efflux of a number of organic anions. The anti-inflammatory capability of genipin is mediated by suppression of the production and function of pro-inflammatory cytokines and inflammasome. Moreover, genipin modulates various transcription factor and signal transduction pathway. Genipin appears to trigger the upregulation of several key genes encoding antioxidant and xenobiotic-metabolizing enzymes. Furthermore, the medicinal impact of genipin extends to modulation of regulated cell death, including autophagic cell death, apoptosis, necroptosis and pyroptosis, and modulation of quality of cellular organelle. Another crucial effect of genipin appears to be linked to dual role in targeting uncoupling protein 2 (UCP2). As a typical UCP2-inhibiting compound, genipin could inhibit AMP-activated protein kinase or NF-κB in circumstance. On the contrary, reactive oxygen species production and cellular lipid deposits mediated by genipin through the upregulation of UCP2 is observed in liver steatosis, suggesting the precise role of genipin is disease-specific. Collectively, we comprehensively summarize the mechanisms and pathways associated with the hepatoprotective activity of genipin and discuss potential toxic impact. Notably, our focus is the direct medicinal effect of genipin itself, whereas its utility as a crosslinking agent in tissue engineering is out of scope for the current review. Further studies are therefore required to disentangle these complicated pharmacological properties to confer this natural agent a far greater potency.

Molecular Mechanisms Responsible for Pharmacological Effects of Genipin on Mitochondrial Proteins

Genipin, a natural compound from Gardenia jasminoides, is a well-known compound in Chinese medicine that is used for the treatment of cancer, inflammation, and diabetes. The use of genipin in classical medicine is hindered because of its unknown molecular mechanisms of action apart from its strong cross-linking ability. Genipin is increasingly applied as a specific inhibitor of proton transport mediated by mitochondrial uncoupling protein 2 (UCP2). However, its specificity for UCP2 is questionable, and the underlying mechanism behind its action is unknown. Here, we investigated the effect of genipin in different systems, including neuroblastoma cells, isolated mitochondria, isolated mitochondrial proteins, and planar lipid bilayer membranes reconstituted with recombinant proteins. We revealed that genipin activated dicarboxylate carrier and decreased the activity of UCP1, UCP3, and complex III of the respiratory chain alongside with UCP2 inhibition. Based on competitive inhibition experiments, the use of amino acid blockers, and site-directed mutagenesis of UCP1, we propose a mechanism of genipin’s action on UCPs. At low concentrations, genipin binds to arginine residues located in the UCP funnel, which leads to a decrease in UCP’s proton transporting function in the presence of long chain fatty acids. At concentrations above 200 μM, the inhibitory action of genipin on UCPs is overlaid by increased nonspecific membrane conductance due to the formation of protein-genipin aggregates. Understanding the concentration-dependent mechanism of genipin action in cells will allow its targeted application as a drug in the above-mentioned diseases.

Genipin and EDC crosslinking of extracellular matrix hydrogel derived from human umbilical cord for neural tissue repair

Extracellular matrix (ECM) hydrogels, produced by tissue decellularization are natural injectable materials suitable for neural tissue repair. However, the rapid biodegradation of these materials may disrupt neural tissue reconstruction in vivo. The aim of this study was to improve the stability of the previously described ECM hydrogel derived from human umbilical cord using genipin and N-(3-Dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC), crosslinking at concentration of 0.5-10 mM. The hydrogels, crosslinked by genipin (ECM/G) or EDC (ECM/D), were evaluated in vitro in terms of their mechanical properties, degradation stability and biocompatibility. ECM/G, unlike ECM/D, crosslinked hydrogels revealed improved rheological properties when compared to uncrosslinked ECM. Both ECM/G and ECM/D slowed down the gelation time and increased the resistance against in vitro enzymatic degradation, while genipin crosslinking was more effective than EDC. Crosslinkers concentration of 1 mM enhanced the in vitro bio-stability of both ECM/G and ECM/D without affecting mesenchymal stem cell proliferation, axonal sprouting or neural stem cell growth and differentiation. Moreover, when injected into cortical photochemical lesion, genipin allowed in situ gelation and improved the retention of ECM for up to 2 weeks without any adverse tissue response or enhanced inflammatory reaction. In summary, we demonstrated that genipin, rather than EDC, improved the bio-stability of injectable ECM hydrogel in biocompatible concentration, and that ECM/G has potential as a scaffold for neural tissue application.

Identification of the absorbed components and their metabolites of Tianma-Gouteng granule in rat plasma and bile using ultra-high-performance liquid chromatography combined with quadrupole time-of-flight mass spectrometry

Tianma-Gouteng granule (TGG), a Chinese herbal formula preparation, is clinically used for the treatment of cardio-cerebrovascular diseases such as hypertension, cerebral ischaemia, acute ischaemic stroke and Parkinson's disease. Although few reports have been published concerning the absorbed prototype components of TGG, the possible metabolic pathways of TGG in vivo remain largely unclear. In this study, a method using UPLC-Q/TOF MS was established for the detection and identification of the absorbed prototype components and related metabolites in rat plasma and bile after oral administration of TGG at high and normal clinical dosages. A total of 68 components were identified or tentatively identified in plasma and bile samples, including absorbed prototypes and their metabolites. The major absorbed components were gastrodin, isorhynchophylline, rhynchophylline, isocorynoxeine, corynoxeine, geissoschizine methyl ether baicalin, baicalein, wogonoside, wogonin, geniposidic acid, leonurine, 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside and emodin. The main metabolic pathways of these components involved phase I (isomerization, hydrolysis and reduction) and phase II (glucuronidation and sulfation) reaction, and the phase II biotransformation pathway was predominant. The present study provides rich information on the in vivo absorption and metabolism of TGG, and the results will be helpful for further studies on the pharmacokinetics and pharmacodynamics of TGG.

Therapeutic Potential and Effective Components of the Chinese Herb Gardeniae Fructus in the Treatment of Senile Disease

Gardeniae fructus (GF), an evergreen Rubiaceae shrub, is one of the most commonly used Chinese herbs in traditional Chinese medicine (TCM) and has been used for over a thousand years. It is usually prescribed for the treatment of brain aging, vascular aging, bone and joint aging, and other age-related diseases. It has been demonstrated that several effective compounds of GF, such as geniposide, genipin and crocin, have neuroprotective or related activities which are involved in senile disease treatment. These bioactivities include the mitochondrion dysfunction, antioxidative activity, apoptosis regulation and an anti-inflammatory activity, which related to multiple signaling pathways such as the nuclear factor-κB pathway, AMP-activated protein kinase signaling pathway, and the mitogen-activated protein kinase pathway. To lay the ground for fully elucidating the potential mechanisms of GF in treating age-related pathologies, we summarized the available research conducted in the last fifteen years about GF and its effective components, which have been studied in vivo and in vitro