Antidepressant and anxiolytic like effects of Urtica dioica leaves in streptozotocin induced diabetic mice

The role of stinging nettle (Urtica dioica L.) in the management of rotenone-induced Parkinson's disease in rats

Parkinson's disease (PD) is one of the most common neurodegenerative conditions. Alpha-synuclein deposition, Lewy bodies (LBs) formation, disruption of the autophagic machinery, apoptosis of substantia nigra dopaminergic neurons, oxidative stress, and neuroinflammation are all pathologic hallmarks of PD. The leaves of the stinging Nettle (Urtica dioica L.) have a long history as an herbal cure with antioxidant, anti-inflammatory, anti-cancer, immunomodulatory, and neuroprotective properties. The current study aims for the first time to investigate the role of Nettle supplementation on Rotenone-induced PD. Rats were divided into five groups; a Saline control, Nettle control (100 mg/kg/day), Rotenone control (2 mg/kg/day), Rotenone + Nettle (50 mg /kg/day), and Rotenone + Nettle (100 mg/kg). After four weeks, the rats were examined for behavioral tests. The midbrains were investigated for histopathological alteration and immunohistochemical reaction for Tyrosine hydroxylase in the dopaminergic neurons, α-synuclein for Lewy bodies, caspase 3 for apoptotic neurons, LC3 and P62 for autophagic activity. Midbrain homogenates were examined for oxidative stress markers. mRNA expression of TNFα and Il6; inflammatory markers, Bcl-2, BAX and Caspase 3; apoptosis markers, were detected in midbrains. The results showed that Nettle caused recovery of midbrain dopaminergic neurons, by inhibiting apoptosis, inflammation, and oxidative stress and by restoring the autophagic machinery with clearance of α-synuclein deposits. We can conclude that Nettle is a potentially effective adjuvant in the treatment of Parkinson's disease.

Downregulation of BDNF-TrkB signaling may contribute to the colonic motility disorders in mice with streptozocin-induced diabetes

BACKGROUND

Brain-derived neurotrophic factor (BDNF) acts as a neuromodulator to regulate gut motility, but the role of BDNF in diabetes-related dysmotility is uncertain. The aim of this study was to investigate the possible involvement of BDNF and its receptor TrkB in the colonic hypomotility of mice with streptozotocin (STZ)-induced diabetes.

METHODS

A single intraperitoneal injection of STZ was used to establish a type 1 diabetes model. An organ bath system was applied to observe the contractile activities of colonic muscle strips. Immunofluorescence and western blotting were performed to evaluate the expression of BDNF and TrkB in the colon. ELISA was used to detect BDNF and SP levels in the serum and colon. The patch-clamp technique was applied to record the currents of L-type calcium channels and large conductance Ca2+ -activated K+ channels on smooth muscle cells.

KEY RESULTS

Compared with healthy controls, diabetic mice showed attenuated colonic muscle contraction (p < 0.001), which was partly reversed by BDNF supplementation. TrkB protein expression was significantly reduced in diabetic mice (p < 0.05). In addition, both BDNF and substance P (SP) levels were decreased, and exogenous administration of BDNF increased SP levels in diabetic mice (p < 0.05). Both the TrkB antagonist and the TrkB antibody inhibited the spontaneous contraction of colonic muscle strips (p < 0.01). Moreover, the BDNF-TrkB signaling system enhanced SP-induced muscle contraction.

CONCLUSIONS

Downregulation of BDNF/TrkB signaling and reduced SP release from the colon may contribute to the colonic hypomotility associated with type 1 diabetes. Brain-derived neurotrophic factor supplementation may have therapeutic potential for diabetes-related constipation.

Exploring Rosiglitazone's Potential to Treat Alzheimer's Disease through the Modulation of Brain-Derived Neurotrophic Factor

Alzheimer's disease (AD) is a progressive neurodegenerative disorder that debilitates over 55 million individuals worldwide. Currently, treatments manage and alleviate its symptoms; however, there is still a need to find a therapy that prevents or halts disease progression. Since AD has been labeled as "type 3 diabetes" due to its similarity in pathological hallmarks, molecular pathways, and comorbidity with type 2 diabetes mellitus (T2DM), there is growing interest in using anti-diabetic drugs for its treatment. Rosiglitazone (RSG) is a peroxisome proliferator-activated receptor-gamma agonist that reduces hyperglycemia and hyperinsulinemia and improves insulin signaling. In cellular and rodent models of T2DM-associated cognitive decline and AD, RSG has been reported to improve cognitive impairment and reverse AD-like pathology; however, results from human clinical trials remain consistently unsuccessful. RSG has also been reported to modulate the expression of brain-derived neurotrophic factor (BDNF), a protein that regulates neuroplasticity and energy homeostasis and is implicated in both AD and T2DM. The present review investigates RSG's limitations and potential therapeutic benefits in pre-clinical models of AD through its modulation of BDNF expression.

The medicinal chemistry of Urtica dioica L.: from preliminary evidence to clinical studies supporting its neuroprotective activity

Urtica dioica is a perennial herb from the family of Urticaceae that is commonly known as stinging nettle. This plant is widespread in Europe, Africa, America, and a part of Asia, as it adapts to different environments and climatic conditions. The leaves, stalk, and bark of U. dioica found applications in the field of nutrition, cosmetics, textile, pest control and pharmacology. In this connection, bioactive chemical constituents such as flavonoids, phenolic acids, amino acids, carotenoids, and fatty acids have been isolated from the plant. With this review, we aim at providing an updated and comprehensive overview of the contributions in literature reporting computational, in vitro, pre-clinical and clinical data supporting the therapeutic applications of U. dioica. Experimental evidence shows that U. dioica constituents and extracts can provide neuroprotective effects by acting through a combination of different molecular mechanisms, that are discussed in the review. These findings could lay the basis for the identification and design of more effective tools against neurodegenerative diseases.

Enriched Environment Attenuates Enhanced Trait Anxiety in Association with Normalization of Aberrant Neuro-Inflammatory Events

Neuroinflammation is discussed to play a role in specific subgroups of different psychiatric disorders, including anxiety disorders. We have previously shown that a mouse model of trait anxiety (HAB) displays enhanced microglial density and phagocytic activity in key regions of anxiety circuits compared to normal-anxiety controls (NAB). Using minocycline, we provided causal evidence that reducing microglial activation within the dentate gyrus (DG) attenuated enhanced anxiety in HABs. Besides pharmacological intervention, "positive environmental stimuli", which have the advantage of exerting no side-effects, have been shown to modulate inflammation-related markers in human beings. Therefore, we now investigated whether environmental enrichment (EE) would be sufficient to modulate upregulated neuroinflammation in high-anxiety HABs. We show for the first time that EE can indeed attenuate enhanced trait anxiety, even when presented as late as adulthood. We further found that EE-induced anxiolysis was associated with the attenuation of enhanced microglial density (using Iba-1 as the marker) in the DG and medial prefrontal cortex. Additionally, EE reduced Iba1 + CD68+ microglia density within the anterior DG. Hence, the successful attenuation of trait anxiety by EE was associated in part with the normalization of neuro-inflammatory imbalances. These results suggest that pharmacological and/or positive behavioral therapies triggering microglia-targeted anti-inflammatory effects could be promising as novel alternatives or complimentary anxiolytic therapeutic approaches in specific subgroups of individuals predisposed to trait anxiety.

Melatonin reverses depressive and anxiety like-behaviours induced by diabetes: involvement of oxidative stress, age, rage and S100B levels in the hippocampus and prefrontal cortex of rats

Diabetes is associated with depression and anxiety symptoms. The current investigation was designed to explore the effect of melatonin on depressive and anxiety like-behaviours, oxidative stress, levels of AGE, RAGE and S100B in streptozotocin-induced diabetic rats. The animals were divided into four groups: Normoglycemic; Normoglycemic + melatonin; diabetic; diabetic + melatonin (10 mg/kg, for 4 weeks). The malondialdehyde (MDA), reduced glutathione (GSH), AGE, RAGE and S100B were measured and the depressive and anxiety like-behaviours were assessed by forced swimming and elevated plus maze tests, respectively. Melatonin ameliorates depressive and anxiety like-behaviours. Concomitantly, melatonin reversed diabetes induced increase of MDA, AGE and decrease of GSH and S100B levels in the hippocampus and prefrontal cortex. In conclusion, our results showed that melatonin administration may exert antidepressant-like and anxiolytic effects in diabetic rats through normalising of AGE/RAGE, S100B and oxidative stress in the prefrontal cortex and hippocampus.

Role of medicinal plants in inhibiting SARS-CoV-2 and in the management of post-COVID-19 complications

BACKGROUND

The worldwide corona virus disease outbreak, generally known as COVID-19 pandemic outbreak resulted in a major health crisis globally. The morbidity and transmission modality of COVID-19 appear more severe and uncontrollable. The respiratory failure and following cardiovascular complications are the main pathophysiology of this deadly disease. Several therapeutic strategies are put forward for the development of safe and effective treatment against SARS-CoV-2 virus from the pharmacological view point but till date there are no specific treatment regimen developed for this viral infection.

PURPOSE

The present review emphasizes the role of herbs and herbs-derived secondary metabolites in inhibiting SARS-CoV-2 virus and also for the management of post-COVID-19 related complications. This approach will foster and ensure the safeguards of using medicinal plant resources to support the healthcare system. Plant-derived phytochemicals have already been reported to prevent the viral infection and to overcome the post-COVID complications like parkinsonism, kidney and heart failure, liver and lungs injury and mental problems. In this review, we explored mechanistic approaches of herbal medicines and their phytocomponenets as antiviral and post-COVID complications by modulating the immunological and inflammatory states.

STUDY DESIGN

Studies related to diagnosis and treatment guidelines issued for COVID-19 by different traditional system of medicine were included. The information was gathered from pharmacological or non-pharmacological interventions approaches. The gathered information sorted based on therapeutic application of herbs and their components against SARSCoV-2 and COVID-19 related complications.

METHODS

A systemic search of published literature was conducted from 2003 to 2021 using different literature database like Google Scholar, PubMed, Science Direct, Scopus and Web of Science to emphasize relevant articles on medicinal plants against SARS-CoV-2 viral infection and Post-COVID related complications.

RESULTS

Collected published literature from 2003 onwards yielded with total 625 articles, from more than 18 countries. Among these 625 articles, more than 95 medicinal plants and 25 active phytomolecules belong to 48 plant families. Reports on the therapeutic activity of the medicinal plants belong to the Lamiaceae family (11 reports), which was found to be maximum reported from 4 different countries including India, China, Australia, and Morocco. Other reports on the medicinal plant of Asteraceae (7 reports), Fabaceae (8 reports), Piperaceae (3 reports), Zingiberaceae (3 reports), Ranunculaceae (3 reports), Meliaceae (4 reports) were found, which can be explored for the development of safe and efficacious products targeting COVID-19.

CONCLUSION

Keeping in mind that the natural alternatives are in the priority for the management and prevention of the COVID-19, the present review may help to develop an alternative approach for the management of COVID-19 viral infection and post-COVID complications from a mechanistic point of view.

LC/ESI/TOF-MS Characterization, Anxiolytic and Antidepressant-like Effects of Mitragyna speciosa Korth Extract in Diabetic Rats

In this study, the attenuative effects of the hydro-alcoholic extract from Mitragyna speciosa (MSE) against diabetes-induced anxiety and depression-like behaviors were examined. In addition, UPLC/ESI/TOF-MS analysis was performed to identify the phytochemical nature of MSE. DM was induced using a combination of high fructose/streptozotocin, and the diabetic rats were treated with MSE (50 and 200 mg/kg) for 5 weeks. After treatment, the animals were subjected to a forced swim test, open field test and elevated plus-maze tests. Additionally, proinflammatory cytokines and oxidative stress parameters were evaluated in the brain tissues of the rats. UPLC/ESI/TOF-MS analysis revealed that MSE is abundantly rich in polyphenolic constituents, notably flavonoid and phenolic glycosides. Behavioral tests and biochemical analyses indicated that diabetic rats showed significantly increased anxiety and depressive-like behavioral deficits, brain oxidative stress and pro-inflammatory cytokines levels (IL-1β, IL-6 and TNF-α). Treatment with MSE (50 and 200 mg/kg) significantly attenuated increased blood glucose level, depressive and anxiety-like behaviors in diabetic rats. Additionally, the antioxidant enzymes activities were markedly increased in MSE-treated animals, while TNF-α, IL-1β and IL-6 cytokines were notably suppressed. Taken together, these results suggested that MSE has potentials as antidepressant and anxiolytic-like effects and improves the brain oxido-inflammatory status in diabetic rats.

Exercise and Urtica dioica extract ameliorate hippocampal insulin signaling, oxidative stress, neuroinflammation, and cognitive function in STZ-induced diabetic rats

INTRODUCTION

Diabetes mellitus is related to cognitive impairments and molecular abnormalities of the hippocampus. A growing body of evidence suggests that Urtica dioica (Ud) and exercise training (ET) have potential therapeutic effects on diabetes and its related complications. Therefore, we hypothesized that the combined effect of exercise training (ET) and Ud might play an important role in insulin signaling pathway, oxidative stress, neuroinflammation, and cognitive impairment in diabetic rats.

METHODS

Forty animals were divided into five groups (N = 8): healthy-sedentary (H-sed), diabetes-sedentary (D-sed), diabetes-exercise training (D-ET), diabetes-Urtica dioica (D-Ud), diabetes-exercise training-Urtica dioica (D-ET-Ud). Streptozotocin (STZ) (Single dosage; 45 mg/kg, i.p.) was used to induce diabetes. Then, ET (moderate intensity/5day/week) and Ud extract (50 mg/kg, oral/daily) were administered for six weeks. We also investigated the effects of ET and Ud on cognitive performance (assessed through Morris Water Maze tests), antioxidant capacity, and lipid peroxidation markers in hippocampus. Furthermore, we measured levels of insulin sensitivity and signaling factors (insulin-Ins, insulin receptor-IR and insulin-like growth factor-1 receptor-IGF-1R), and neuroinflammatory markers (IL-1 β, TNF-α). This was followed by TUNEL assessment of the apoptosis rate in all regions of the hippocampus.

RESULTS

D-sed rats compared to H-sed animals showed significant impairments (P < 0.001) in hippocampal insulin sensitivity and signaling, oxidative stress, neuroinflammation, and apoptosis, which resulted in cognitive dysfunction. Ud extract and ET treatment effectively improved these impairments in D-ET (P < 0.001), D-Ud (P < 0.05), and D-ET-Ud (P < 0.001) groups compared to D-sed rats. Moreover, diabetes mediated hippocampal oxidative stress, neuroinflammation, insulin signaling deficits, apoptosis, and cognitive dysfunction was further reversed by chronic Ud+ET administration in D-ET-Ud rats (P < 0.001) compared to D-sed animals.

CONCLUSIONS

Ud extract and ET ameliorate cognitive dysfunction via improvement in hippocampal oxidative stress, neuroinflammation, insulin signaling pathway, and apoptosis in STZ-induced diabetic rats. The results of this study provide new experimental evidence for using Ud+ET in the treatment of hippocampal complications and cognitive dysfunction caused by diabetes.

Global survey of medicinal plants during lactation and postpartum recovery: Evolutionary perspectives and contemporary health implications

ETHNOPHARMACOLOGICAL RELEVANCE

Cross-cultural comparison of plants used during lactation and the postpartum period offers insight into a largely overlooked area of ethnopharmacological research. Potential roles of phytochemicals in emerging models of interaction among immunity, inflammation, microbiome and nervous system effects on perinatal development have relevance for the life-long health of individuals and of populations in both traditional and contemporary contexts.

AIM OF THE STUDY

Delineate and interpret patterns of traditional and contemporary global use of medicinal plants ingested by mothers during the postpartum period relative to phytochemical activity on immune development and gastrointestinal microbiome of breastfed infants, and on maternal health.

MATERIALS AND METHODS

Published reviews and surveys on galactagogues and postpartum recovery practices plus ethnobotanical studies from around the world were used to identify and rank plants, and ascertain regional use patterns. Scientific literature for 20 most-cited plants based on frequency of publication was assessed for antimicrobial, antioxidant, anti-inflammatory, immunomodulatory, antidepressant, analgesic, galactagogic and safety properties.

RESULTS

From compilation of 4418 use reports related to 1948 species, 105 plant taxa were recorded ≥7 times, with the most frequently cited species, Foeniculum vulgare, Trigonella foenum-graecum, Pimpinella anisum, Euphorbia hirta and Asparagus racemosus, 81, 64, 42, 40 and 38 times, respectively. Species and use vary globally, illustrated by the pattern of aromatic plants of culinary importance versus latex-producing plants utilized in North Africa/Middle East and Sub-Saharan Africa with opposing predominance. For 18/20 of the plants a risk/benefit perspective supports assessment that positive immunomodulation and related potential exceed any safety concerns. Published evidence does not support a lactation-enhancing effect for nearly all the most-cited plants while antidepressant data for the majority of plants are predominately limited to animal studies.

CONCLUSIONS

Within a biocultural context traditional postpartum plant use serves adaptive functions for the mother-infant dyad and contributes phytochemicals absent in most contemporary diets and patterns of ingestion, with potential impacts on allergic, inflammatory and other conditions. Polyphenolics and other phytochemicals are widely immunologically active, present in breast milk and predominately non-toxic. Systematic analysis of phytochemicals in human milk, infant lumen and plasma, and immunomodulatory studies that differentiate maternal ingestion during lactation from pregnancy, are needed. Potential herb-drug interaction and other adverse effects should remain central to obstetric advising, but unless a plant is specifically shown as harmful, considering potential contributions to health of individuals and populations, blanket advisories against postpartum herbal use during lactation appear empirically unwarranted.

Depression with Comorbid Diabetes: What Evidence Exists for Treatments Using Traditional Chinese Medicine and Natural Products?

Comorbidity between diabetes mellitus (DM) and depression, two chronic and devastating diseases spreading worldwide, has been confirmed by a large body of epidemiological and clinical studies. Due to the bidirectional relationship between DM and depression, this comorbidity leads to poorer outcomes in both conditions. Given the adverse effects and limited effectiveness of the existing therapies for depression associated with diabetes, the development of novel therapeutic drugs with more potency and fewer side effects is still the most important goal. Hence, many researchers have made great efforts to investigate the potential usefulness of traditional Chinese medicine (TCM) and natural products, including natural extracts and purified compounds, in the treatment of comorbid depression in diabetes. Here, we reviewed the related literature on TCM and natural products that can remedy the comorbidity of diabetes and depression and presented them on the basis of their mechanism of action, focusing on shared risk factors, including insulin resistance, oxidative stress and inflammation, and nervous disturbances. In short, this review suggests that TCM and natural products could expand the therapeutic alternatives to ameliorate the association between DM and depressive disorders.

Review of the Effect of Natural Compounds and Extracts on Neurodegeneration in Animal Models of Diabetes Mellitus

Diabetes mellitus is a chronic metabolic disease with a high prevalence in the Western population. It is characterized by pancreas failure to produce insulin, which involves high blood glucose levels. The two main forms of diabetes are type 1 and type 2 diabetes, which correspond with >85% of the cases. Diabetes shows several associated alterations including vascular dysfunction, neuropathies as well as central complications. Brain alterations in diabetes are widely studied; however, the mechanisms implicated have not been completely elucidated. Diabetic brain shows a wide profile of micro and macrostructural changes, such as neurovascular deterioration or neuroinflammation leading to neurodegeneration and progressive cognition dysfunction. Natural compounds (single isolated compounds and/or natural extracts) have been widely assessed in metabolic disorders and many of them have also shown antioxidant, antiinflamatory and neuroprotective properties at central level. This work reviews natural compounds with brain neuroprotective activities, taking into account several therapeutic targets: Inflammation and oxidative stress, vascular damage, neuronal loss or cognitive impairment. Altogether, a wide range of natural extracts and compounds contribute to limit neurodegeneration and cognitive dysfunction under diabetic state. Therefore, they could broaden therapeutic alternatives to reduce or slow down complications associated with diabetes at central level.

The effect of silymarin supplementation on cognitive impairment induced by diabetes in rats

Background The objective of this investigation was to examine the impact of silymarin supplementation on locomotion, anxiety-related behavior, learning, and memory via several behavioral tests, such as open field, elevated plus maze, and Morris water maze tests in streptozotocin-induced diabetic rats. Methods The rats were divided into the control, diabetes, silymarin, and diabetes plus silymarin groups. On the 30th-35th days of the study, several behavioral tests were performed and blood and brain tissue samples were taken and brain-derived neurotrophic factor (BDNF) and histone deacetylase 3 (HDAC3) levels were analyzed. Results There was no significant difference in locomotor activity between the groups (p = 0.534). Spatial memory was lower (p = 0.000) but anxiety scores were higher (p = 0.005) in the diabetes group than in the control, silymarin, and diabetes plus silymarin groups. Plasma (p = 0.000) and brain tissue (p = 0.007) BDNF levels were lower in the diabetes group than in the control, silymarin, and diabetes plus silymarin groups; however, plasma (p = 0.432) and brain tissue (p = 0.321) HDAC3 levels did not significantly differ between the groups. Conclusions The findings obtained from this study suggest that silymarin supplementation could improve anxiety-related behavior, and learning and memory in diabetic rats by increasing the BDNF levels.