Molecular Chaperones as Mediators of Stress Protective Effect of Plant Adaptogens

Neuromodulatory Effects Induced by the Association of Moringa oleifera Lam., Tribulus terrestris L., Rhodiola rosea Lam., and Undaria pinnatidifida Extracts in the Hypothalamus

The present study investigated the role of a commercial formulation constituted by herbal extracts from Rhodiola rosea, Undaria pinnatifida, Tribulus terrestris, and Moringa oleifera. The formulation was analysed for determining the content in total phenols and flavonoids and scavenging/reducing properties. The formulation was also tested on isolated mouse hypothalamus in order to investigate effects on serotonin, dopamine, neuropeptide Y (NPY), and orexin A. The gene expression of gonadrotopin releasing hormone (GnRH) was also assayed. The formulation was able to reduce dopamine and serotonin turnover, and this could be related, albeit partially, to the capability of different phytochemicals, among which hyperoside and catechin to inhibit monoaminooxidases activity. In parallel, the formulation was effective in reducing the gene expression of NPY and orexin-A and to improve the gene expression of GnRH. In this context, the increased GnRH gene expression induced by the formulation may contribute not only to improve the resistance towards the stress related to ageing, but also to prevent the reduction of libido that could be related with a stimulation of the serotoninergic pathway. According to the in silico analysis, hyperoside could play a pivotal role in modulating the gene expression of GnRH. Regarding NPY and orexin A gene expression, no direct interactions between the formulation phytochemicals and these neuropeptides were anticipated; thus, suggesting that the pattern of gene expression observed following exposure of the hypothalamus to the formulation may be secondary to inhibitory effects of dopamine and serotonin turnover. Concluding, the present study demonstrated the efficacy of the formulation in exerting neuromodulatory effects at the hypothalamic level; thus, suggesting the potential to contrast stress and fatigue.

Ameliorating Effect of Morin Hydrate on Chronic Restraint Stress-induced Biochemical Disruption, Neuronal, and Behavioral Dysfunctions in BALB/c Mice

INTRODUCTION

Morin hydrate (MH) is a bioflavonoid component of many fruits and vegetables. Our previous research demonstrated that MH provides neuroprotection in mouse models of acute restraint stress and sleep deprivation by attenuating hippocampal neuronal damage and enhancing memory. Based on these findings, our study investigated the role of MH in chronic stress-induced neuronal and biochemical perturbations in BALB/c mice.

METHODS

Male BALB/c mice were divided into 6 groups (n=6). Groups 1 and 2 received vehicle (10 mL/kg normal saline), groups 3-5 received MH (5, 10, 20 mg/kg IP), while group 6 received ginseng (25 mg/kg) daily and 30 minutes afterward were restrained in a plastic cylindrical restrainer for 14 days.

RESULTS

Immobility time in the forced swim test increased in the MH-treated group, indicating an antidepressant-like effect. Also, a reduction in frequency and duration of open arms exploration was observed in the elevated plus-maze (EPM) test in stressed mice, and administration of MH (5, 10, 20 mg/kg, IP) reversed these effects. An increase in blood levels of glucose, triglycerides, total cholesterol, and brain malondialdehyde and nitrite levels was observed in the stressed groups, which was reversed by MH. Furthermore, MH reversed the stress-induced reduction in HDL cholesterol and glutathione (GSH) levels and attenuated stress-induced alterations in the prefrontal cortex and hippocampus.

CONCLUSION

Our findings suggest that MH attenuated chronic restraint stress-behavioral and biochemical perturbations, probably due to its capability to decrease oxidative stress and brain neuronal damage.

HIGHLIGHTS

Chronic stress perturbs physiological and psychological homeostasis;Morin hydrate normalized chronic stress-induced biochemical disruptions;Morin hydrate attenuated structural changes in prefrontal cortex and hippocampus.

PLAIN LANGUAGE SUMMARY

Stress is a state of being overwhelmed by demands exceeding the personal and social means of coping. Exposure to excessive stress has resulted in disruption of neurochemical and physiological processes, which sometimes manifest as behavioural abnormalities. Therefore to cope with the stressful life style, there is need to develop a therapeutic agent of plant origin. Morin hydrate is a flavonoid with known antioxidant and neuroprotective properties; however, its effect in a stressful condition has not been studies. The study thus evaluated ameliorating effect of Morin hydrate on chronic restraint stress-induced biochemical disruption, neuronal and behavioral dysfunctions in BALB/c mice. To achieve this, mice were exposed to chronic restraint stress protocol for fourteen days. Behavioural changes were examined using various techniques. The vital parameters like antioxidant, glucose and nitrite levels were also taken. Our findings show that Morin hydrate prevented behavioral abnormalities and damage to the brain cells. It also inhibited stress-induced biochemical disturbance.

Authenticity and quality evaluation of different Rhodiola species and commercial products based on NMR-spectroscopy and HPLC

INTRODUCTION

The main concern regarding the authenticity and quality of Rhodiola rosea L. (Sedum rosea (L.) Scop.) products is their adulteration with other Rhodiola species.

OBJECTIVE

The aim of the study was the development of a reliable and practical analytical platform for quality and quantity assessment of the characteristic molecules in three Rhodiola species (R. rosea, R. kirilowii (Regel) Maxim and R. crenulata (Hook. f. & Thomson) H. Ohba), commercial products and their possible application as markers for the authentication of R. rosea based products.

MATERIAL AND METHODS

The major molecules were identified by one-dimensional (1D) and two-dimensional (2D) nuclear magnetic resonance (NMR)-based metabolomics and quantitatively determined by high-performance liquid chromatography ultraviolet (HPLC-UV) analysis. The orthogonal projections to latent structures discriminant analysis (OPLS-DA) revealed the specific patterns in the metabolite profiles of R. rosea and R. crenulata.

RESULTS

The coumarin crenulatin was only identified in R. crenulata and can be used as a marker to detect potential adulteration of the commercial products. Crenulatin was identified in two of the four analysed products by NMR-spectroscopy. According to the HPLC data, in less than a quarter of all products, the labelled amounts of salidroside and total rosavins were confirmed.

CONCLUSIONS

The developed analytical platform was found to be useful in the investigations of the phytochemical diversity of different Rhodiola species, the recognition of the unique metabolites between them and the identification of adulterated products. Therefore, this approach could be applied from the earliest to the latest stages of the value chain in the manufacturing of R. rosea based products.

Novel molecular mechanisms for the adaptogenic effects of herbal extracts on isolated brain cells using systems biology

INTRODUCTION

Adaptogens are natural compounds or plant extracts that increase adaptability and survival of organisms under stress. Adaptogens stimulate cellular and organismal defense systems by activating intracellular and extracellular signaling pathways and expression of stress-activated proteins and neuropeptides. The effects adaptogens on mediators of adaptive stress response and longevity signaling pathways have been reported, but their stress-protective mechanisms are still not fully understood.

AIM OF THE STUDY

The aim of this study was to identify key molecular mechanisms of adaptogenic plants traditionally used to treat stress and aging-related disorders, i.e., Rhodiola rosea, Eleutherococcus senticosus, Withania somnifera, Rhaponticum carthamoides, and Bryonia alba.

MATERIALS AND METHODS

To investigate the underlying molecular mechanisms of adaptogens, we conducted RNA sequencing to profile gene expression alterations in T98G neuroglia cells upon treatment of adaptogens and analyzed the relevance of deregulated genes to adaptive stress-response signaling pathways using in silico pathway analysis software.

RESULTS AND DISCUSSION

At least 88 of the 3516 genes regulated by adaptogens were closely associated with adaptive stress response and adaptive stress-response signaling pathways (ASRSPs), including neuronal signaling related to corticotropin-releasing hormone, cAMP-mediated, protein kinase A, and CREB; pathways related to signaling involving CXCR4, melatonin, nitric oxide synthase, GP6, Gαs, MAPK, neuroinflammation, neuropathic pain, opioids, renin-angiotensin, AMPK, calcium, and synapses; and pathways associated with dendritic cell maturation and G-coupled protein receptor-mediated nutrient sensing in enteroendocrine cells. All samples tested showed significant effects on the expression of genes encoding neurohormones CRH, GNRH, UCN, G-protein-coupled and other transmembrane receptors TLR9, PRLR, CHRNE, GP1BA, PLXNA4, a ligand-dependent nuclear receptor RORA, transmembrane channels, transcription regulators FOS, FOXO6, SCX, STAT5A, ZFPM2, ZNF396, ZNF467, protein kinases MAPK10, MAPK13, MERTK, FLT1, PRKCH, ROS1, TTN), phosphatases PTPRD, PTPRR, peptidases, metabolic enzymes, a chaperone (HSPA6), and other proteins, all of which modulate numerous life processes, playing key roles in several canonical pathways involved in defense response and regulation of homeostasis in organisms. It is for the first time we report that the molecular mechanism of actions of melatonin and plant adaptogens are alike, all adaptogens tested activated the melatonin signaling pathway by acting through two G-protein-coupled membrane receptors MT1 and MT2 and upregulation of the ligand-specific nuclear receptor RORA, which plays a role in intellectual disability, neurological disorders, retinopathy, hypertension, dyslipidemia, and cancer, which are common in aging. Furthermore, melatonin activated adaptive signaling pathways and upregulated expression of UCN, GNRH1, TLR9, GP1BA, PLXNA4, CHRM4, GPR19, VIPR2, RORA, STAT5A, ZFPM2, ZNF396, FLT1, MAPK10, MERTK, PRKCH, and TTN, which were commonly regulated by all adaptogens tested. We conclude that melatonin is an adaptation hormone playing an important role in regulation of homeostasis. Adaptogens presumably worked as eustressors ("stress-vaccines") to activate the cellular adaptive system by inducing the expression of ASRSPs, which then reciprocally protected cells from damage caused by distress. Functional investigation by interactive pathways analysis demonstrated that adaptogens activated ASRSPs associated with stress-induced and aging-related disorders such as chronic inflammation, cardiovascular health, neurodegenerative cognitive impairment, metabolic disorders, and cancer.

CONCLUSION

This study has elucidated the genome-wide effects of several adaptogenic herbal extracts in brain cells culture. These data highlight the consistent activation of ASRSPs by adaptogens in T98G neuroglia cells. The extracts affected many genes playing key roles in modulation of adaptive homeostasis, indicating their ability to modify gene expression to prevent stress-induced and aging-related disorders. Overall, this study provides a comprehensive look at the molecular mechanisms by which adaptogens exerts stress-protective effects.