Berberine: Botanical Occurrence, Traditional Uses, Extraction Methods, and Relevance in Cardiovascular, Metabolic, Hepatic, and Renal Disorders

Berberine-containing plants have been traditionally used in different parts of the world for the treatment of inflammatory disorders, skin diseases, wound healing, reducing fevers, affections of eyes, treatment of tumors, digestive and respiratory diseases, and microbial pathologies. The physico-chemical properties of berberine contribute to the high diversity of extraction and detection methods. Considering its particularities this review describes various methods mentioned in the literature so far with reference to the most important factors influencing berberine extraction. Further, the common separation and detection methods like thin layer chromatography, high performance liquid chromatography, and mass spectrometry are discussed in order to give a complex overview of the existing methods. Additionally, many clinical and experimental studies suggest that berberine has several pharmacological properties, such as immunomodulatory, antioxidative, cardioprotective, hepatoprotective, and renoprotective effects. This review summarizes the main information about botanical occurrence, traditional uses, extraction methods, and pharmacological effects of berberine and berberine-containing plants.

Hesperidin as a Neuroprotective Agent: A Review of Animal and Clinical Evidence

Neuroprotection is the preservation of function and networks of neural tissues from damages caused by various agents, as well as neurodegenerative diseases such as Parkinson's, Alzheimer's, Huntington's diseases, and multiple sclerosis. Hesperidin, a flavanone glycoside, is a natural phenolic compound with a wide range of biological effects. Mounting evidence has demonstrated that hesperidin possesses inhibitory effect against development of neurodegenerative diseases. Our review discusses neuropharmacological mechanisms for preventive and therapeutic effects of hesperidin in neurodegenerative diseases. In addition, the review examines clinical evidence confirming its neuroprotective function. Various cellular and animal models specific to neurodegenerative diseases have been conducted to evaluate the underlying neuropharmacological mechanisms of hesperidin. Neuroprotective potential of this flavonoid is mediated by improvement of neural growth factors and endogenous antioxidant defense functions, diminishing neuro-inflammatory and apoptotic pathways. Despite the various preclinical studies on the role of hesperidin in the neurodegenerative diseases, less is known about its definite effect on humans. A limited number of clinical trials showed that hesperidin-enriched dietary supplements can significantly improve cerebral blood flow, cognition, and memory performance. Further clinical trials are also required for confirming neuroprotective efficacy of this natural flavonoid and evaluating its safety profile.

The Signaling Pathways, and Therapeutic Targets of Antiviral Agents: Focusing on the Antiviral Approaches and Clinical Perspectives of Anthocyanins in the Management of Viral Diseases

As the leading cause of death worldwide, viruses significantly affect global health. Despite the rapid progress in human healthcare, there are few viricidal and antiviral therapies that are efficient enough. The rapid emergence of resistance, and high costs, as well as the related side effects of synthetic antiviral drugs, raise the need to identify novel, effective, and safe alternatives against viral diseases. Nature has been of the most exceptional help and source of inspiration for developing novel multi-target antiviral compounds, affecting several steps of the viral life cycle and host proteins. For that matter and due to safety and efficacy limitations, as well as high resistance rate of conventional therapies, hundreds of natural molecules are preferred over the synthetic drugs. Besides, natural antiviral agents have shown acceptable antiviral value in both preclinical and clinical trials.This is the first review regarding molecular and cellular pathways of the virus life cycle, treatment strategies, and therapeutic targets of several viral diseases with a particular focus on anthocyanins as promising natural compounds for significant antiviral enhancements. Clinical applications and the need to develop nano-formulation of anthocyanins in drug delivery systems are also considered.

Phytochemicals as potent modulators of autophagy for cancer therapy

The dysregulation of autophagy is involved in the pathogenesis of a broad range of diseases, and accordingly universal research efforts have focused on exploring novel compounds with autophagy-modulating properties. While a number of synthetic autophagy modulators have been identified as promising cancer therapy candidates, autophagy-modulating phytochemicals have also attracted attention as potential treatments with minimal side effects. In this review, we firstly highlight the importance of autophagy and its relevance in the pathogenesis and treatment of cancer. Subsequently, we present the data on common phytochemicals and their mechanism of action as autophagy modulators. Finally, we discuss the challenges associated with harnessing the autophagic potential of phytochemicals for cancer therapy.

Structure-Activity and Lipophilicity Relationships of Selected Antibacterial Natural Flavones and Flavanones of Chilean Flora

In this study, we tested eight naturally-occurring flavonoids-three flavanones and five flavones-for their possible antibacterial properties against four Gram-positive and four Gram-negative bacteria. Flavonoids are known for their antimicrobial properties, and due their structural diversity; these plant-derived compounds are a good model to study potential novel antibacterial mechanisms. The lipophilicity and the interaction of antibacterial compounds with the cell membrane define the success or failure to access its target. Therefore, through the determination of partition coefficients in a non-polar/aqueous phase, lipophilicity estimation and the quantification of the antibacterial activity of different flavonoids, flavanones, and flavones, a relationship between these parameters was assessed. Active flavonoids presented diffusion coefficients between 9.4 × 10^-10 and 12.3 × 10^-10 m²/s and lipophilicity range between 2.0 to 3.3. Active flavonoids against Gram-negative bacteria showed a narrower range of lipophilicity values, compared to active flavonoids against Gram-positive bacteria, which showed a wide range of lipophilicity and cell lysis. Galangin was the most active flavonoid, whose structural features are the presence of two hydroxyl groups located strategically on ring A and the absence of polar groups on ring B. Methylation of one hydroxyl group decreases the activity in 3-O-methylgalangin, and methylation of both hydroxyl groups caused inactivation, as shown for 3,7-O-dimethylgalangin. In conclusion, the amphipathic features of flavonoids play a crucial role in the antibacterial activity. In these compounds, hydrophilic and hydrophobic moieties must be present and could be predicted by lipophilicity analysis.

Natural products attenuate PI3K/Akt/mTOR signaling pathway: A promising strategy in regulating neurodegeneration

BACKGROUND

As common, progressive, and chronic causes of disability and death, neurodegenerative diseases (NDDs) significantly threaten human health, while no effective treatment is available. Given the engagement of multiple dysregulated pathways in neurodegeneration, there is an imperative need to target the axis and provide effective/multi-target agents to tackle neurodegeneration. Recent studies have revealed the role of phosphoinositide 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) in some diseases and natural products with therapeutic potentials.

PURPOSE

This is the first systematic and comprehensive review on the role of plant-derived secondary metabolites in managing and/or treating various neuronal disorders via the PI3K/Akt/mTOR signaling pathway.

STUDY DESIGN AND METHODS

A systematic and comprehensive review was done based on the PubMed, Scopus, Web of Science, and Cochrane electronic databases. Two independent investigators followed the PRISMA guidelines and included papers on PI3K/Akt/mTOR and interconnected pathways/mediators targeted by phytochemicals in NDDs.

RESULTS

Natural products are multi-target agents with diverse pharmacological and biological activities and rich sources for discovering and developing novel therapeutic agents. Accordingly, recent studies have shown increasing phytochemicals in combating Alzheimer's disease, aging, Parkinson's disease, brain/spinal cord damages, depression, and other neuronal-associated dysfunctions. Amongst the emerging targets in neurodegeneration, PI3K/Akt/mTOR is of great importance. Therefore, attenuation of these mediators would be a great step towards neuroprotection in such NDDs.

CONCLUSION

The application of plant-derived secondary metabolites in managing and/or treating various neuronal disorders through the PI3K/Akt/mTOR signaling pathway is a promising strategy towards neuroprotection.

Phytopharmacology and Clinical Updates of Berberis Species Against Diabetes and Other Metabolic Diseases

The incidences of diabetic mellitus and other metabolic diseases such as hypertension and hyperlipidemia are increasing worldwide; however, the current treatment is not able to control the rapidly increasing trend in diabetes mortality and morbidity. Studies related to the effectiveness of extracts and pure compounds obtained from plants have shown promising responses in preclinical and clinical studies related to these metabolic diseases. Plants belonging to the genus Berberis (Family: Berberidaceae) are widely distributed with nearly 550 species worldwide. Extracts and compounds obtained from Berberis species, especially Berberine alkaloid, showed effectiveness in the management of diabetes and other metabolic diseases. Various pharmacological experiments have been performed to evaluate the effects of Berberis extracts, berberine, and its natural and chemically synthesized derivatives against various cell and animal disease models with promising results. Various clinical trials conducted so far also showed preventive effects of Berberis extracts and berberine against metabolic diseases. The present review focuses on i) research updates on traditional uses, ii) phytopharmacology and clinical studies on Berberis species, and iii) active metabolites in the prevention and treatment of diabetes and other metabolic diseases with a detailed mechanism of action. Furthermore, the review critically analyzes current research gaps in the therapeutic use of Berberis species and berberine and provides future recommendations.

Bioprospecting for Antibacterial Drugs: a Multidisciplinary Perspective on Natural Product Source Material, Bioassay Selection and Avoidable Pitfalls

Bioprospecting is the exploration, extraction and screening of biological material and sometimes indigenous knowledge to discover and develop new drugs and other products. Most antibiotics in current clinical use (eg. β-lactams, aminoglycosides, tetracyclines, macrolides) were discovered using this approach, and there are strong arguments to reprioritize bioprospecting over other strategies in the search for new antibacterial drugs. Academic institutions should be well positioned to lead the early stages of these efforts given their many thousands of locations globally and because they are not constrained by the same commercial considerations as industry. University groups can lack the full complement of knowledge and skills needed though (eg. how to tailor screening strategy to biological source material). In this article, we review three key aspects of the bioprospecting literature (source material and in vitro antibacterial and toxicity testing) and present an integrated multidisciplinary perspective on (a) source material selection, (b) legal, taxonomic and other issues related to source material, (c) cultivation methods, (d) bioassay selection, (e) technical standards available, (f) extract/compound dissolution, (g) use of minimum inhibitory concentration and selectivity index values to identify progressible extracts and compounds, and (h) avoidable pitfalls. The review closes with recommendations for future study design and information on subsequent steps in the bioprospecting process.

Natural products in diabetes research: quantitative literature analysis

The current study aimed to identify which natural products and which research directions are related to the major contributors to academic journals for diabetes therapy. Bibliometric data were extracted from the Web of Science online database using the search string TOPIC = (''natural product*' OR ''natural compound*' OR ''natural molecule*' OR 'phytochemical*' OR ''secondary metabolite*') AND TS = ('diabet*') and analysed by a bibliometric software, VOSviewer. The search yielded 3694 publications, which were collectively cited 80,791 times, with an H-index of 117 and 21.9 citations per publication on average. The top-contributing countries were India, the USA, China, South Korea and Brazil. Curcumin, flavanone, resveratrol, carotenoid, polyphenols, flavonol, flavone and berberine were the most frequently cited natural products or compound classes. Our results provide a brief overview of the major directions of natural product research in diabetes up to now and hint on promising avenues for future research.

Antibacterial properties of 3 H-spiro[1-benzofuran-2,1'-cyclohexane] derivatives from Heliotropium filifolium

A re-examination of cuticular components of Heliotropium filifolium allowed the isolation of four new compounds: 3’-hydroxy-2’,2’,6’-trimethyl-3H-spiro[1-benzo-furan-2,1’-cyclohexane]-5-carboxylic acid (2), methyl 3’-acetyloxy-2’,2’,6’-trimethyl-3H-spiro[1-benzofuran-2,1’-cyclohexane]-5-carboxylate (3), methyl 3’-isopentanoyloxy-2’,2’,6’-trimethyl-3H-spiro[1-benzofuran-2,1’-cyclohexane]-5-carboxylate (4) and methyl 3’-benzoyloxy-2’,2’,6’-trimethyl-3H-spiro[1-benzofuran-2,1’-cyclohexane]-5-carboxylate (5). Compounds 2-5 were identified by their spectroscopic analogies with filifolinol (1), and their structures confirmed by chemical correlation with 1. The antimicrobial properties of the compounds were tested against Gram positive and Gram negative bacteria. Some of them proved to be active against Gram positive, but inactive against Gram negative bacteria. In searching for structure-activity relationships from the obtained MIC values, lipophilicity was shown to be an important variable.

Medicinal Plants and Natural Products Used in Cataract Management

Cataract is the leading reason of blindness worldwide and is defined by the presence of any lens opacities or loss of transparency. The most common symptoms of cataract are impaired vision, decreased contrast sensitivity, color disturbance, and glare. Oxidative stress is among the main mechanisms involved in the development of age-related cataract. Surgery through phacoemulsification and intraocular lens implantation is the most effective method for cataract treatment, however, there are chances of serious complications and irreversible loss of vision associated with the surgery. Natural compounds consisting of antioxidant or anti-inflammatory secondary metabolites can serve as potential leads for anticataract agents. In this review, we tried to document medicinal plants and plant-based natural products used for cataract treatment worldwide, which are gathered from available ethnopharmacological/ethnobotanical data. We have extensively explored a number of recognized databases like Scifinder, PubMed, Science Direct, Google Scholar, and Scopus by using keywords and phrases such as “cataract”, “blindness”, “traditional medicine”, “ethnopharmacology”, “ethnobotany”, “herbs”, “medicinal plants”, or other relevant terms, and summarized the plants/phytoconstituents that are evaluated in different models of cataract and also tabulated 44 plants that are traditionally used in cataract in various folklore medical practices. Moreover, we also categorized the plants according to scientific studies carried out in different cataract models with their mechanisms of action.

Phytochemicals: Potential Therapeutic Interventions Against Coronavirus-Associated Lung Injury

Since the outbreak of coronavirus disease 2019 (COVID-19) in December 2019, millions of people have been infected and died worldwide. However, no drug has been approved for the treatment of this disease and its complications, which urges the need for finding novel therapeutic agents to combat. Among the complications due to COVID-19, lung injury has attained special attention. Besides, phytochemicals have shown prominent anti-inflammatory effects and thus possess significant effects in reducing lung injury caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Also, the prevailing evidence reveales the antiviral effects of those phytochemicals, including anti-SARS-CoV activity, which could pave the road in providing suitable lead compounds in the treatment of COVID-19. In the present study, candidate phytochemicals and related mechanisms of action have been shown in the treatment/protection of lung injuries induced by various methods. In terms of pharmacological mechanism, phytochemicals have shown potential inhibitory effects on inflammatory and oxidative pathways/mediators, involved in the pathogenesis of lung injury during COVID-19 infection. Also, a brief overview of phytochemicals with anti-SARS-CoV-2 compounds has been presented.

Metabolomic Analysis, Fast Isolation of Phenolic Compounds, and Evaluation of Biological Activities of the Bark From Weinmannia trichosperma Cav. (Cunoniaceae)

Weinmannia trichosperma Cav. (Cunoniaceae) (local name, tineo; Mapuche names, madén, mëdehue) is an endemic species of Chile and Argentina used in Mapuche traditional medicine in the treatment of chronic diarrhea, inflammation, and wound healing. This study focused on the isolation, analysis, and characterization of the biological activity of compounds and bark extracts from this plant for the first time. The infusion and tincture of the bark were characterized regarding antioxidant and important enzyme inhibitory activities, phenolics, and flavonoids content and UHPLC-ESI-OT-MS metabolite profiling. Twenty-five metabolites were detected in the medicinal infusion of W. trichosperma, three flavonols were isolated: isoastilbin, neoisoastilbin, and neoastilbin ((2R,3S)-, (2S,3R)-, and (2S,3S)-dihydroquercetin 3-O-alpha-l-rhamnoside) by countercurrent chromatography, and the isomers were quantified in the bark using a validated analytical HPLC methodology. The antioxidant properties were measured by ABTS, DPPH, FRAP, ORAC, and TEAC methods. The infusion displayed a strong DPPH and ABTS scavenging activity (IC₅₀ = 20.58 and 3.070 µg ml⁻¹, respectively) while a moderated effect was observed in the FRAP, ORAC, and ABTS assays. The infusion showed a content of phenolic and flavonoid compounds of 442.1 mg GAE g⁻¹ and 15.54 mg QE g⁻¹, respectively. Furthermore, the infusion showed a good and promissory inhibitory activity (33.80%, 33.12%, and 82.86% for AChE, BuChE, and 5-hLOX, respectively) and isoastilbin (51.70%, 50.10%, and 34.29–80.71% for AChE, BuChE, and 5-hLOX, respectively). The biomolecules identified in this study support the traditional uses of this bark and the potential industrial interest from this Valdivian plant species.

Alkaloids as Potential Phytochemicals against SARS-CoV-2: Approaches to the Associated Pivotal Mechanisms

Since its inception, the coronavirus disease 2019 (COVID-19) pandemic has infected millions of people around the world. Therefore, it is necessary to find effective treatments against Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), as it is the viral source of COVID-19. Alkaloids are one of the most widespread plant-derived natural compounds with prominent antiviral effects. Accordingly, these phytochemicals have been promising candidates towards discovering effective treatments for COVID-19. Alkaloids have shown potential anti-SARS-CoV activities via inhibiting pathogenesis-associated targets of the Coronaviridae family that are required for the virus life cycle. In the current study, the chemistry, plant sources, and antiviral effects of alkaloids, as well as their anti-SARS-CoV-2 effect with related mechanisms, are reviewed towards discovering an effective treatment against COVID-19.

Involvement of TGF-β and Autophagy Pathways in Pathogenesis of Diabetes: A Comprehensive Review on Biological and Pharmacological Insights

Despite recent advancements in clinical drugs, diabetes treatment still needs further progress. As such, ongoing research has attempted to determine the precise molecular mechanisms of the disorder. Specifically, evidence supports that several signaling pathways play pivotal roles in the development of diabetes. However, the exact molecular mechanisms of diabetes still need to be explored. This study examines exciting new hallmarks for the strict involvement of autophagy and TGF-β signaling pathways in the pathogenesis of diabetes and the design of novel therapeutic strategies. Dysregulated autophagy in pancreatic β cells due to hyperglycemia, oxidative stress, and inflammation is associated with diabetes and accompanied by dysregulated autophagy in insulin target tissues and the progression of diabetic complications. Consequently, several therapeutic agents such as adiponectin, ezetimibe, GABA tea, geniposide, liraglutide, guava extract, and vitamin D were shown to inhibit diabetes and its complications through modulation of the autophagy pathway. Another pathway, TGF-β signaling pathway, appears to play a part in the progression of diabetes, insulin resistance, and autoimmunity in both type 1 and 2 diabetes and complications in diabetes. Subsequently, drugs that target TGF-β signaling, especially naturally derived ones such as resveratrol, puerarin, curcumin, hesperidin, and silymarin, as well as Propolis, Lycopus lucidus, and Momordica charantia extracts, may become promising alternatives to current drugs in diabetes treatment. This review provides keen insights into novel therapeutic strategies for the medical care of diabetes.

The International Natural Product Sciences Taskforce (INPST) and the power of Twitter networking exemplified through #INPST hashtag analysis

BACKGROUND

The development of digital technologies and the evolution of open innovation approaches have enabled the creation of diverse virtual organizations and enterprises coordinating their activities primarily online. The open innovation platform titled "International Natural Product Sciences Taskforce" (INPST) was established in 2018, to bring together in collaborative environment individuals and organizations interested in natural product scientific research, and to empower their interactions by using digital communication tools.

METHODS

In this work, we present a general overview of INPST activities and showcase the specific use of Twitter as a powerful networking tool that was used to host a one-week "2021 INPST Twitter Networking Event" (spanning from 31st May 2021 to 6th June 2021) based on the application of the Twitter hashtag #INPST.

RESULTS AND CONCLUSION

The use of this hashtag during the networking event period was analyzed with Symplur Signals (https://www.symplur.com/), revealing a total of 6,036 tweets, shared by 686 users, which generated a total of 65,004,773 impressions (views of the respective tweets). This networking event's achieved high visibility and participation rate showcases a convincing example of how this social media platform can be used as a highly effective tool to host virtual Twitter-based international biomedical research events.

Chemical Fingerprinting and Biological Evaluation of the Endemic Chilean Fruit Greigia sphacelata (Ruiz and Pav.) Regel (Bromeliaceae) by UHPLC-PDA-Orbitrap-Mass Spectrometry

Greigia sphacelata (Ruiz and Pav.) Regel (Bromeliaceae) is a Chilean endemic plant popularly known as "quiscal" and produces an edible fruit consumed by the local Mapuche communities named as "chupón". In this study, several metabolites including phenolic acids, organic acids, sugar derivatives, catechins, proanthocyanidins, fatty acids, iridoids, coumarins, benzophenone, flavonoids, and terpenes were identified in G. sphacelata fruits using ultrahigh performance liquid chromatography-photodiode array detection coupled with a Orbitrap mass spectrometry (UHPLC-PDA-Orbitrap-MS) analysis for the first time. The fruits showed moderate antioxidant capacities (i.e., 487.11 ± 26.22 μmol TE/g dry weight) in the stable radical DPPH assay, 169.08 ± 9.81 TE/g dry weight in the ferric reducing power assay, 190.32 ± 6.23 TE/g dry weight in the ABTS assay, and 76.46 ± 3.18% inhibition in the superoxide anion scavenging assay. The cholinesterase inhibitory potential was evaluated against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). From the findings, promising results were observed for pulp and seeds. Our findings suggest that G. sphacelata fruits are a rich source of diverse secondary metabolites with antioxidant capacities. In addition, the inhibitory effects against AChE and BChE suggest that natural products or food supplements derived from G. sphacelata fruits are of interest for their neuroprotective potential.

Targeting Neurological Manifestations of Coronaviruses by Candidate Phytochemicals: A Mechanistic Approach

The novel coronavirus 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made a wide range of manifestations. In this regard, growing evidence is focusing on COVID-19 neurological associations; however, there is a lack of established pathophysiological mechanisms and related treatments. Accordingly, a comprehensive review was conducted, using electronic databases, including PubMed, Scopus, Web of Science, and Cochrane, along with the author's expertize in COVID-19 associated neuronal signaling pathways. Besides, potential phytochemicals have been provided against neurological signs of COVID-19. Considering a high homology among SARS-CoV, Middle East Respiratory Syndrome and SARS-CoV-2, revealing their precise pathophysiological mechanisms seems to pave the road for the treatment of COVID-19 neural manifestations. There is a complex pathophysiological mechanism behind central manifestations of COVID-19, including pain, hypo/anosmia, delirium, impaired consciousness, pyramidal signs, and ischemic stroke. Among those dysregulated neuronal mechanisms, neuroinflammation, angiotensin-converting enzyme 2 (ACE2)/spike proteins, RNA-dependent RNA polymerase and protease are of special attention. So, employing multi-target therapeutic agents with considerable safety and efficacy seems to show a bright future in fighting COVID-19 neurological manifestations. Nowadays, natural secondary metabolites are highlighted as potential multi-target phytochemicals in combating several complications of COVID-19. In this review, central pathophysiological mechanisms and therapeutic targets of SARS-CoV-2 has been provided. Besides, in terms of pharmacological mechanisms, phytochemicals have been introduced as potential multi-target agents in combating COVID-19 central nervous system complications.

Targeting Multiple Signal Transduction Pathways of SARS-CoV-2: Approaches to COVID-19 Therapeutic Candidates

Due to the complicated pathogenic pathways of coronavirus disease 2019 (COVID-19), related medicinal therapies have remained a clinical challenge. COVID-19 highlights the urgent need to develop mechanistic pathogenic pathways and effective agents for preventing/treating future epidemics. As a result, the destructive pathways of COVID-19 are in the line with clinical symptoms induced by severe acute coronary syndrome (SARS), including lung failure and pneumonia. Accordingly, revealing the exact signaling pathways, including inflammation, oxidative stress, apoptosis, and autophagy, as well as relative representative mediators such as tumor necrosis factor-α (TNF-α), nuclear factor erythroid 2-related factor 2 (Nrf2), Bax/caspases, and Beclin/LC3, respectively, will pave the road for combating COVID-19. Prevailing host factors and multiple steps of SARS-CoV-2 attachment/entry, replication, and assembly/release would be hopeful strategies against COVID-19. This is a comprehensive review of the destructive signaling pathways and host-pathogen interaction of SARS-CoV-2, as well as related therapeutic targets and treatment strategies, including potential natural products-based candidates.

Estrogenic Plants: to Prevent Neurodegeneration and Memory Loss and Other Symptoms in Women After Menopause

In mammals, sexual hormones such as estrogens play an essential role in maintaining brain homeostasis and function. Estrogen deficit in the brain induces many undesirable symptoms such as learning and memory impairment, sleep and mood disorders, hot flushes, and fatigue. These symptoms are frequent in women who reached menopausal age or have had ovariectomy and in men and women subjected to anti-estrogen therapy. Hormone replacement therapy alleviates menopause symptoms; however, it can increase cardiovascular and cancer diseases. In the search for therapeutic alternatives, medicinal plants and specific synthetic and natural molecules with estrogenic effects have attracted widespread attention between the public and the scientific community. Various plants have been used for centuries to alleviate menstrual and menopause symptoms, such as Cranberry, Ginger, Hops, Milk Thistle, Red clover, Salvia officinalis, Soy, Black cohosh, Turnera diffusa, Ushuva, and Vitex. This review aims to highlight current evidence about estrogenic medicinal plants and their pharmacological effects on cognitive deficits induced by estrogen deficiency during menopause and aging.

The Potential Therapeutic Effect of RNA Interference and Natural Products on COVID-19: A Review of the Coronaviruses Infection

The SARS-CoV-2 virus was reported for the first time in Wuhan, Hubei Province, China, and causes respiratory infection. This pandemic pneumonia killed about 1,437,835 people out of 61,308,161cases up to November 27, 2020. The disease's main clinical complications include fever, recurrent coughing, shortness of breath, acute respiratory syndrome, and failure of vital organs that could lead to death. It has been shown that natural compounds with antioxidant, anticancer, and antiviral activities and RNA interference agents could play an essential role in preventing or treating coronavirus infection by inhibiting the expression of crucial virus genes. This study aims to introduce a summary of coronavirus's genetic and morphological structure and determine the role of miRNAs, siRNAs, chemical drugs, and natural compounds in stimulating the immune system or inhibiting the virus's structural and non-structural genes that are essential for replication and infection of SARS-CoV-2.

Determination of absolute configuration of salvic acid, an ent-labdane from Eupatorium salvia, by vibrational circular dichroism

The relative stereochemistry at C13 and the absolute configuration of salvic acid, a constituent of the leaves of Eupatorium salvia, were established as the 13-(R)-ent-labdane 1. The results follow from vibrational circular dichroism measurements of the derived O-methyl ether methyl ester 3 which were compared to DFT B3LYP/DGDZVP calculated spectra. The relative stereochemistry of salvic acid at C13 was independently verified by single crystal X-ray diffraction measurements of 1, and of its derived diol 4.