Therapeutic effects of diosgenin in experimental autoimmune encephalomyelitis

The neuroprotective effect of Diosgenin in the rat Valproic acid model of autism

BACKGROUND AND AIM

Autism spectrum disorder (ASD) is a neurodevelopmental disorder with two core behavioral symptoms restricted/repetitive behavior and social-communication deficit. The unknown etiology of ASD makes it difficult to identify potential treatments. Valproic acid (VPA) is an anticonvulsant drug with teratogenic effects during pregnancy in humans and rodents. Prenatal exposure to VPA induces autism-like behavior in both humans and rodents. This study aimed to investigate the protective effects of Diosgenin in prenatal Valproic acid-induced autism in rats.

METHOD

pregnant Wister female rats were given a single intraperitoneal injection of VPA (600 mg/kg, i.p.) on gestational day 12.5. The male offspring were given oral Dios (40 mg/kg, p.o.) or Carboxymethyl cellulose (5 mg/kg, p.o.) for 30 days starting from postnatal day 23. On postnatal day 52, behavioral tests were done. Additionally, biochemical assessments for oxidative stress markers were carried out on postnatal day 60. Further, histological evaluations were performed on the prefrontal tissue by Nissl staining and Immunohistofluorescence.

RESULTS

The VPA-exposed rats showed increased anxiety-like behavior in the elevated plus maze (EPM). They also demonstrated repetitive and grooming behaviors in the marble burying test (MBT) and self-grooming test. Social interaction was reduced, and they had difficulty detecting the novel object in the novel object recognition (NOR) test. Also, VPA-treated rats have shown higher levels of oxidative stress malondialdehyde (MDA) and lower GPX, TAC, and superoxide dismutase (SOD) levels. Furthermore, the number of neurons decreased and the ERK signaling pathway upregulated in the prefrontal cortex (PFC). On the other hand, treatment with Dios restored the behavioral consequences, lowered oxidative stress, and death of neurons, and rescued the overly activated ERK1/2 signaling in the prefrontal cortex.

CONCLUSION

Chronic treatment with Dios restored the behavioral, biochemical, and histological abnormalities caused by prenatal VPA exposure.

Saponins of Paris polyphylla for the Improvement of Acne: Anti-Inflammatory, Antibacterial, Antioxidant and Immunomodulatory Effects

Acne is a chronic inflammatory skin disease with a recurring nature that seriously impacts patients' quality of life. Currently, antibiotic resistance has made it less effective in treating acne. However, Paris polyphylla (P. polyphylla) is a valuable medicinal plant with a wide range of chemical components. Of these, P. polyphylla saponins modulate the effects in vivo and in vitro through antibacterial, anti-inflammatory, immunomodulatory, and antioxidant effects. Acne is primarily associated with inflammatory reactions, abnormal sebum function, micro-ecological disorders, hair follicle hyperkeratosis, and, in some patients, immune function. Therefore, the role of P. polyphylla saponins and their values in treating acne is worthy of investigation. Overall, this review first describes the distribution and characteristics of P. polyphylla and the pathogenesis of acne. Then, the potential mechanisms of P. polyphylla saponins in treating acne are listed in detail (reduction in the inflammatory response, antibacterial action, modulation of immune response and antioxidant effects, etc.). In addition, a brief description of the chemical composition of P. polyphylla saponins and its available extraction methods are described. We hope this review can serve as a quick and detailed reference for future studies on their potential acne treatment.

Gut microbiota modification by diosgenin mediates antiepileptic effects in a mouse model of epilepsy

Diosgenin, a natural steroid saponin, holds promise as a multitarget therapeutic for various diseases, including neurodegenerative conditions. Its efficacy in slowing Alzheimer's disease, Parkinson's disease, multiple sclerosis, and stroke progression has been demonstrated. However, the role of diosgenin in anti-epilepsy and its potential connection to the modulation of the intestinal microbiota remain poorly understood. In this study, exogenous diosgenin significantly mitigated pentylenetetrazole (PTZ)-induced seizures, learning and memory deficits, and hippocampal neuronal injury. 16S ribosomal RNA (16S rRNA) sequencing revealed a reversal in the decrease of Bacteroides and Parabacteroides genera in the PTZ-induced mouse epileptic model following diosgenin treatment. Fecal microbiota transplantation (FMT) experiments illustrated the involvement of diosgenin in modulating gut microbiota and providing neuroprotection against epilepsy. Our results further indicated the repression of enteric glial cells (EGCs) activation and the TLR4-MyD88 pathway, coupled with reduced production of inflammatory cytokines in the colonic lumen, and improved intestinal barrier function in epilepsy mice treated with diosgenin or FMT. This study suggests that diosgenin plays a role in modifying gut microbiota, contributing to the alleviation of intestinal inflammation and neuroinflammation, ultimately inhibiting epilepsy progression in a PTZ-induced mouse model. Diosgenin emerges as a potential therapeutic option for managing epilepsy and its associated comorbidities.

Identification of the Natural Steroid Sapogenin Diosgenin as a Direct Dual-Specific RORα/γ Inverse Agonist

The steroid sapogenin diosgenin is a well-known natural product with a plethora of described pharmacological activities including the amelioration of T helper 17 (Th17)-driven pathologies. However, the exact underlying mode of action of diosgenin leading to a dampened Th17 response is still largely unknown and specific molecular targets have yet to be identified. Here, we show that diosgenin acts as a direct ligand and inverse agonist of the nuclear receptor retinoic acid receptor (RAR)-related orphan receptor (ROR)α and RORγ, which are key transcription factors involved in Th17 cell differentiation and metabolism. IC₅₀ values determined by luciferase reporter gene assays, employing constructs for either RORγ-Gal4 fusion proteins or full length receptors, were in the low micromolar range at around 2 µM. To highlight the functional consequences of this RORα/γ inverse agonism, we determined gene expression levels of important ROR target genes, i.e., IL-17A and glucose-6-phosphatase, in relevant cellular in vitro models of Jurkat T and HepG2 cells, respectively, by RT-qPCR (reverse transcription quantitative PCR). Thereby, it was shown that diosgenin leads to a dose-dependent decrease in target gene expressions consistent with its potent cellular ROR inverse agonistic activity. Additionally, in silico dockings of diosgenin to the ROR ligand-binding domain were performed to determine the underlying binding mode. Taken together, our results establish diosgenin as a novel, direct and dual-selective RORα/γ inverse agonist. This finding establishes a direct molecular target for diosgenin for the first time, which can further explain reported amendments in Th17-driven diseases by this compound.

Diosgenin increases BBC3 expression in HepG2/C3A cells and alters cell communication in a 3D spheroid model

Preclinical studies have shown that diosgenin, a steroidal sapogenin, is a promising phytochemical for treating different pathological conditions, such as cancer, diabetes, and cardiovascular diseases. However, the toxicological safety of this molecule for therapeutic use in humans needs to be better understood. Thus, this study aimed to evaluate the mechanisms of action of diosgenin in HepG2/C3A human hepatocellular carcinoma cells. Cytotoxicity, genotoxicity, alterations in the cell cycle, and cell death (apoptosis) were investigated and associated with the gene expression profile of pathways involved in these processes. The effects of diosgenin on the growth of spheroids were also tested. Diosgenin induced a dose-dependent reduction in cell viability and cell cycle arrest in S and G₂/M phases and apoptosis in response to DNA damage. Apoptosis was associated with an increase in the expression of BBC3, a participant in the intrinsic apoptosis pathway. Diosgenin also promoted an increase in volume and greater cellular breakdown in spheroids. These results allowed a better understanding of the toxicity of diosgenin in human cells and contributed to the development of treatments based on this phytochemical.

Diosgenin: An Updated Pharmacological Review and Therapeutic Perspectives

Plants including Rhizoma polgonati, Smilax china, and Trigonella foenum-graecum contain a lot of diosgenin, a steroidal sapogenin. This bioactive phytochemical has shown high potential and interest in the treatment of various disorders such as cancer, diabetes, arthritis, asthma, and cardiovascular disease, in addition to being an important starting material for the preparation of several steroidal drugs in the pharmaceutical industry. This review aims to provide an overview of the in vitro, in vivo, and clinical studies reporting the diosgenin's pharmacological effects and to discuss the safety issues. Preclinical studies have shown promising effects on cancer, neuroprotection, atherosclerosis, asthma, bone health, and other pathologies. Clinical investigations have demonstrated diosgenin's nontoxic nature and promising benefits on cognitive function and menopause. However, further well-designed clinical trials are needed to address the other effects seen in preclinical studies, as well as a better knowledge of the diosgenin's safety profile.

Plant-microbial interaction: The mechanism and the application of microbial elicitor induced secondary metabolites biosynthesis in medicinal plants

Plants and microbes interact with each other via different chemical signaling pathways. At the risophere level, the microbes can secrete molecules, called elicitors, which act on their receptors located in plant cells. The so-called elicitor molecules as well as their actions differ according to the mcirobes and induce different bilogical responses in plants such as the synthesis of secondary metabolites. Microbial compounds induced phenotype changes in plants are known as elicitors and signaling pathways which integrate elicitor's signals in plants are called elicitation. In this review, the impact of microbial elicitors on the synthesis and the secretion of secondary metabolites in plants was highlighted. Moreover, biological properties of these bioactive compounds were also highlighted and discussed. Indeed, several bacteria, fungi, and viruses release elicitors which bind to plant cell receptors and mediate signaling pathways involved in secondary metabolites synthesis. Different phytochemical classes such as terpenoids, phenolic acids and flavonoids were synthesized and/or increased in medicinal plants via the action of microbial elicitors. Moreover, these compounds compounds exhibit numerous biological activities and can therefore be explored in drugs discovery.

Diosgenin suppresses COX-2 and mPGES-1 via GR and improves LPS-induced liver injury in mouse

Using a wild yam (Dioscorea japonica), we previously found novel anti-inflammatory and anti-carcinogenic effects via the downregulation of cyclooxygenase (COX)-2 and microsomal prostaglandin E synthase (mPGES)-1. One of the substances in wild yam is a steroidal saponin, diosgenin. We demonstrated that diosgenin suppressed COX-2 in human non-small-cell lung carcinoma A549 cells via nuclear factor-kappa B (NF-κB) translocation and the effects were reversed by a glucocorticoid receptor antagonist, RU486. In lipopolysaccharide (LPS)-induced mouse liver injury, COX-2 and mPGES-1 were induced and localized in sinusoidal macrophages and endothelial cells; however, diosgenin administration significantly suppressed Ptgs2 and Ptges expression and decreased COX-2 and mPGES-1 immunopositive cells in the sinusoids. Multiple immunohistochemical analyses showed that diosgenin had an effect on COX-2 and mPGES-1, particularly in the macrophages. Thus, we showed that diosgenin downregulated COX-2 and mPGES-1 via the glucocorticoid receptor and suppressed COX-2 and mPGES-1 in the macrophages of LPS-induced acute mouse liver injury.

Diosgenin and galactomannans, natural products in the pharmaceutical sciences

Background

Diosgenin is an isospirostane derivative, which is a steroidal sapogenin and the product of acids or enzymes hydrolysis process of dioscin and protodioscin. Galactomannans are heteropolysaccharides composed of D-mannose and D-galactose, which are major sources of locust bean, guar, tara and fenugreek.

Methods

Literature survey was accomplished using multiple databases including PubMed, Science Direct, ISI web of knowledge and Google Scholar.

Results

Four major sources of seed galactomannans are locust bean (Ceratonia siliqua), guar (Cyamopsis tetragonoloba), tara (Caesalpinia spinosa Kuntze), and fenugreek (T.foenum-graecum). Diosgenin has effect on immune system, lipid system, inflammatory and reproductive systems, caner, metabolic process, blood system, blood glucose and calcium regulation. The most important pharmacological benefits of galactomannan are antidiabetic, antioxidant, anticancer, anticholinesterase, antiviral activities, and appropriate for dengue virus and gastric diseases.

Conclusions

Considering the importance of diosgenin and galactomannans, the obtained findings suggest potential of diosgenin and galactomannans as natural products in pharmaceutical industries.

Diosgenin, a steroidal saponin, and its analogs: Effective therapies against different chronic diseases

BACKGROUND

Chronic diseases are a major cause of mortality worldwide, and despite the recent development in treatment modalities, synthetic drugs have continued to show toxic side effects and development of chemoresistance, thereby limiting their application. The use of phytochemicals has gained attention as they show minimal side effects. Diosgenin is one such phytochemical which has gained importance for its efficacy against the life-threatening diseases, such as cardiovascular diseases, cancer, nervous system disorders, asthma, arthritis, diabetes, and many more.

AIM

To evaluate the literature available on the potential of diosgenin and its analogs in modulating different molecular targets leading to the prevention and treatment of chronic diseases.

METHOD

A detailed literature search has been carried out on PubMed for gathering information related to the sources, biosynthesis, physicochemical properties, biological activities, pharmacokinetics, bioavailability and toxicity of diosgenin and its analogs.

KEY FINDINGS

The literature search resulted in many in vitro, in vivo and clinical trials that reported the efficacy of diosgenin and its analogs in modulating important molecular targets and signaling pathways such as PI3K/AKT/mTOR, JAK/STAT, NF-κB, MAPK, etc., which play a crucial role in the development of most of the diseases. Reports have also revealed the safety of the compound and the adaptation of nanotechnological approaches for enhancing its bioavailability and pharmacokinetic properties.

SIGNIFICANCE

Thus, the review summarizes the efficacy of diosgenin and its analogs for developing as a potent drug against several chronic diseases.

The Role of Th17/Treg Axis in the Traditional Chinese Medicine Intervention on Immune-Mediated Inflammatory Diseases: A Systematic Review

The Th17/Treg axis plays a crucial role in immune-mediated inflammatory diseases (IMID) and might represent an interesting drug target of treatment strategy for these diseases. Accumulating evidence suggests a role for traditional Chinese medicine (TCM) in the modulation of Th17/Treg axis, but a comprehensive overview which summarizes this field hitherto is lacked. This paper performs a systematic literature review of the regulatory effects of TCM on the imbalance of Th17/Treg axis and its potential mechanisms. In addition, the frequency analysis and network pharmacology for the collected TCM herbs from clinical trial data were performed. The studies reported the changes in the ratio of Th17 and/or Treg cells as well as their transcription factor and related cytokines were included. Frequency analysis of composition of the 39 assessed TCM prescriptions showed that Astragalus membranaceus var.mongholicus (5.20%), Glycyrrhiza uralensis (3.67%), Paeonia obovate (3.06%), Salvia digitaloides (3.06%), and Angelica sinensis (2.75%) were the top five herbal components, which were closely associated to the treatment of IMID. Network pharmacology showed that six target proteins (transforming growth factor (TGF)-beta receptor type-1, TGF-beta receptor type-2, retineic-acid-receptor-related orphan nuclear receptor gamma (ROR-gamma), TGFB2, IL-17 and IL-2, respectively) might be involved in the regulatory effects of TCM on Th17/Treg axis. Moreover, there were nine active ingredients (including Oxymatrine, Baicalin, Triptolide, Paeoniflorin, Sinomenine, Celastrol, Emodin, Diosgenin and Chlorogenic acid) originating from TCM reported to have an immunological regulation effect on the Th17/Treg axis. The highlight of this systematic review is to reveal the pharmacological basis of TCM treating IMID and is helpful for supporting future pharmacologic-driven studies. Further research elucidates the immune-modulating mechanisms on Th17/Treg axis by TCM might provide a broader insight for the treatment of IMID.

Therapeutic Potential of Diosgenin and Its Major Derivatives against Neurological Diseases: Recent Advances

Diosgenin (DG), a well-known steroidal sapogenin, is present abundantly in medicinal herbs such as Dioscorea rhizome, Dioscorea villosa, Trigonella foenum-graecum, Smilax China, and Rhizoma polgonati. DG is utilized as a major starting material for the production of steroidal drugs in the pharmaceutical industry. Due to its wide range of pharmacological activities and medicinal properties, it has been used in the treatment of cancers, hyperlipidemia, inflammation, and infections. Numerous studies have reported that DG is useful in the prevention and treatment of neurological diseases. Its therapeutic mechanisms are based on the mediation of different signaling pathways, and targeting these pathways might lead to the development of effective therapeutic agents for neurological diseases. The present review mainly summarizes recent progress using DG and its derivatives as therapeutic agents for multiple neurological disorders along with their various mechanisms in the central nervous system. In particular, those related to therapeutic efficacy for Parkinson's disease, Alzheimer's disease, brain injury, neuroinflammation, and ischemia are discussed. This review article also critically evaluates existing limitations associated with the solubility and bioavailability of DG and discusses imperatives for translational clinical research. It briefly recapitulates recent advances in structural modification and novel formulations to increase the therapeutic efficacy and brain levels of DG. In the present review, databases of PubMed, Web of Science, and Scopus were used for studies of DG and its derivatives in the treatment of central nervous system diseases published in English until December 10, 2019. Three independent researchers examined articles for eligibility. A total of 150 articles were screened from the above scientific literature databases. Finally, a total of 46 articles were extracted and included in this review. Keywords related to glioma, ischemia, memory, aging, cognitive impairment, Alzheimer, Parkinson, and neurodegenerative disorders were searched in the databases based on DG and its derivatives.