Echinacoside exhibits antidepressant-like effects through AMPAR–Akt/ERK–mTOR pathway stimulation and BDNF expression in mice

Background Several natural products have been demonstrated to be effective in the treatment of depressive disorders. Echinacoside, a naturally occurring phenol extracted from Cistanche tubulosa, Echinacea angustifolia, and Cistanche spp, has a wide range of physiological effects, such as antioxidation, neuroprotection, anti-inflammatory, and immunoregulation, which are closely related to depression. In addition, echinacoside can activate protein kinase B (Akt), extracellular signal–regulated kinase (ERK), and brain-derived neurotrophic factor (BDNF) in the brain. A key downstream event of the Akt, ERK, and BDNF signaling pathways, namely mechanistic target of rapamycin (mTOR) signaling, plays a crucial role in generating an rapid antidepressant effect. Thus, echinacoside is a promising therapeutic agent for depression. However, research regarding the role of echinacoside in antidepressant effect and brain mTOR activation remains lacking. Materials and methods The forced swimming test and Western blot analysis in C57BL/6 mice was used to investigate the antidepressant-like activities of echinacoside and the underlying mechanism involved inα-amino3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)–Akt/ERK–mTOR pathway. Results We confirmed the suggestions by previous reports that echinacoside activates Akt/ERK signaling and further demonstrated that echinacoside could provide antidepressant-like effects in mice via the activation of AMPAR–Akt/ERK–mTOR pathway in the hippocampus. Conclusions To the best of our knowledge, our study is the first to reveal that echinacoside is a potential treatment for depressive disorders. Moreover, the present study suggests a mechanism for the neuroprotective effect of echinacoside.

REVISÃO DA LITERATURA SOBRE PLANTAS MEDICINAIS NO CONTEXTO DA PANDEMIA DE SARS-COV-2

Introdução: COVID-19 é uma doença infecciosa causada pelo vírus SARS-CoV-2, que está causando crise sanitária e humanitária. Ainda não há medicamento e o modo de tratar tem sido principalmente de suporte. As comunidades científicas buscam encontrar agentes terapêuticos, como por exemplo, plantas tem sido alvo de estudos para o tratamento. Objetivo: Analisar os estudos recentes sobre plantas medicinais no contexto da pandemia de SARS-Cov-2. Materiais e Métodos: Revisão integrativa. Pergunta norteadora: quais os estudos recentes sobre as pesquisas envolvendo plantas medicinais no contexto da COVID-19? Critérios de inclusão: artigos, texto completo, recorte temporal de 2020 a junho de 2021. Idiomas: inglês, espanhol e português. Critérios de exclusão: fora da temática e não ser artigo científico. Bases de dados: BVS, SCIELO e LILACS. Descritores: Plantas Medicinais, COVID-19 e SARS-Cov-2. O instrumento para coleta de dados foi validado por Ursi (2005). Resultados: No BVS foram encontrados 526 estudos, Scielo 1 e LILACS 2. Critério de exclusão: 442 fora do tema, 15 fora do recorte temporal, 20 não eram artigo e 15 eram repetidos. Total de artigos estudados foram 36, sendo 72,2% de 2021. Foram estudos de 17 países, com 27,8% artigos da Índia e 8,34% do Brasil. As principais plantas estudadas foram: Allium sativum L.; Echinacea angustifolia D. C.; Echinacea pallida; Eucalyptus globulus Labill; Glycyrrhiza glabra L.; Mikania glomerata Spreng e Mauritia flexuosa L.. Os principais metabolitos estudados foram: Alicina, cistéina, Ácido chicórico, equinaceína, fitoesterois, Eucaliptol, hiperosídeo e Cumarinas, sesquiterpeno. Os estudos analisados demostram que essas espécies podem representar opções promissoras para o tratamento dos sintomas causados por agentes infecciosos. Um exemplo é a Mauritia flexuosa L. Ela possui 13-cis-β-caroteno, 9-cis -β-caroteno e α-caroteno e as análises da atividade anti-covid-19 se processaram utilizando métodos in silico de Docking Molecular, os resultados teóricos encorajam e permitem um direcionamento para estudos experimentais in vitro e in vivo. Conclusão: São pesquisas de revisão da literatura, estudos prospectivos, duplo cego, randomizado controlado por placebo. Auxiliam no combate a notícias falsas sobre profilaxia da COVID-19 utilizando plantas medicinais. É um campo de pesquisa importante, especialmente para o momento pandêmico, necessitando de investimento público e privado.

Enhanced Antibacterial Activity of Echinacea angustifolia Extract against Multidrug-Resistant Klebsiella pneumoniae through Niosome Encapsulation

With the increased occurrence of antibiotic-resistant bacteria, alternatives to classical antibiotics are urgently needed for treatment of various infectious diseases. Medicinal plant extracts are among the promising candidates due to their bioactive components. The aim of this study was to prepare niosome-encapsulated Echinacea angustifolia extract and study its efficacy against multidrug-resistant Klebsiella pneumoniae strains. Encapsulation was first optimized by Design of Experiments, followed by the empirical study. The obtained niosomes were further characterized for the size and morphology using dynamic light scattering (DLS), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Spherical niosomes had a diameter of 142.3 ± 5.1 nm, as measured by DLS. The entrapment efficiency (EE%) of E. angustifolia extract reached up to 77.1% ± 0.3%. The prepared niosomes showed a controlled drug release within the tested 72 h and a storage stability of at least 2 months at both 4 and 25 °C. The encapsulated E. angustifolia displayed up to 16-fold higher antibacterial activity against multidrug-resistant K.pneumoniae strains, compared to the free extract. Additionally, the niosome exhibited negligible cytotoxicity against human foreskin fibroblasts. We anticipate that the results presented herein could contribute to the preparation of other plant extracts with improved stability and antibacterial activity, and will help reduce the overuse of antibiotics by controlled release of natural-derived drugs.

A Review on Serenoa serrulata: A Potential Medicinal Plant for Prostatic Diseases

Background: Prostatic diseases which include prostatitis, benign prostatic hyperplasia (BPH) and prostate cancer are the benign or malignant disorders that affect the prostate. Phytotherapies have been adopted as the alternative treatment/ management option especially for BPH since the current modern methods of treatment presents a lot of adverse effects. Methodology: The literature was searched using different databases including Medline/PubMed, Cochrane library, Scopus, Proquest library, Embase, EBooks and Google Scholar for relevant records for a period from 1988 to 2018 to identify all the published articles of S. serrulata regarding treatment of prostatic diseases. The key search terms were Serenoa serrulata, S. repens, Saw palmetto, Prostate cancer treatment with Serenoa serrulata, treatment of Benign Prostatic Hyperplasia with Serenoa serrulata, phytochemicals of Serenoa serrulata, ethnobotanical uses of Serenoa serrulata, toxicity of Serenoa serrulata, pharmacological activities of Serenoa serrulata and also traditional management and treatment of prostatic diseases using Serenoa serrulata and also clinical trials on treatment of prostatic diseases with Serenoa serrulata. The retrieved articles were reviewed, synthesized and analyzed qualitatively. The reference list of the retrieved articles was also reviewed and synthesized. The original research articles which reported an investigation of S. serrulata of any study design, original published research articles, any time of publication and grey literature (conference papers, reported articles, academic thesis) were included. The articles whose full texts were not freely available by the time of search and those without clear information about methodology and study design were excluded. Results: This review reported that Serenoa serrulata belonging to the Arecaceae family commonly known as saw palmetto is used traditionally for treating prostatic disease conditions and other infertility conditions in both men and women. Phytochemical screening of hexanic and ethanolic extracts of S. serrulata comprised of free fatty acids and phytosterols which together contribute to their antiprostatic activities. These extracts of S. serrulata exhibited antiandrogenic, anti-inflammatory and anti-proliferative activities through inhibition of both isoenzymes 5α- reductase and inhibition of binding of dihydrotestosterone (DHT) to the cytosolic androgen receptors. This is a similar mechanism exhibited by finasteride and Tamsulosin both antiprostatic conventional drugs though the plant phytochemicals do not interfere with PSA secretion. S. serrulata has also been reported to be non-toxic in both non clinical and clinical trial studies. The medicinal plants reported by this review to be used in combination include; stinging nettle (Urtica dioca), Zingiber officinalis, Echinacea angustifolia and pumpkin (Cucurbita pepo). The antiprostatic conventional drugs reported include finasteride and Tamsulosin. Conclusion and Recommendation: The results showed that S. serrulata is effective in treating prostatic diseases. The potency and safety is improved when used in combination with Urtica dioca, Cucurbita pepo, Zingiber officinalis and Echinacea angustifolia as compared with anti-prostatic conventional drugs Finasteride and Tamsulosin alone. The plant combination has also been shown to have improvement in the quality of life and as well enhancing the synergy of Finasteride and Tamsulon and their adverse effects. Effective medicinal plant combinations should be formulated into products and integrated into the usual treatment for prostatic diseases.