Effect of Ocimum basilicum, Ocimum selloi, and Rosmarinic Acid on Cerebral Vascular Damage in a Chronic Hypertension Model

Phytochemical analysis and investigation of analgesic, anti-inflammatory, and antispasmodic activities of hydroethanolic extracts of Alternanthera dentata, Ocimum carnosum, and Plectranthus barbatus, three species with vernacular names derived from analgesic drugs

ETHNOPHARMACOLOGICAL RELEVANCE

Plant vernacular names can provide clues about the popular use of a species in different regions and are valuable sources of information about the culture or vocabulary of a population. Several medicinal plants in Brazil have received names of medicines and brand-name products.

AIM OF THE STUDY

The present work aimed to evaluate the chemical composition and pharmacological activity in the central nervous system of three species known popularly by brand names of analgesic, anti-inflammatory, antispasmodic, and digestive drugs.

MATERIALS AND METHODS

Hydroethanolic extracts of Alternanthera dentata (AD), Ocimum carnosum (OC), and Plectranthus barbatus (PB) aerial parts were submitted to phytochemical analysis by HPLC-PAD-ESI-MS/MS and evaluated in animal models at doses of 500 and 1000 mg/kg. Mice were tested on hot plate, acetic acid-induced writing, formalin-induced licking, and intestinal transit tests. Aspirin and morphine were employed as standard drugs.

RESULTS

The three extracts did not change the mice's response on the hot plate. Hydroethanolic extracts of AD and PB reduced the number of writhes and licking time, while OC was only effective on the licking test at dose of 1000 mg/kg. In addition, AD and OC reduced intestinal transit, while PB increased gut motility.

CONCLUSIONS

Pharmacological tests supported some popular uses, suggesting peripheral antinociceptive and anti-inflammatory effects, while the phytochemical analysis showed the presence of several flavonoids in the three hydroethanolic extracts and steroids in PB, with some barbatusterol derivatives described for the first time in the species.

Rosmarinic acid alleviate CORT-induced depressive-like behavior by promoting neurogenesis and regulating BDNF/TrkB/PI3K signaling axis

Rosmarinic acid (RA), a natural phenolic acid compound with a variety of bioactive properties. However, the antidepressant activity and mechanism of RA remain unclear. The aim of this study is to investigate the effects and potential mechanisms of RA on chronic CORT injection induced depression-like behavior in mice. Male C57BL/6 J mice were intraperitoneally injected with CORT (10 mg/kg) and were orally given RA daily (10 or 20 mg/kg) for 21 consecutive days. In vitro, the HT22 cells were exposed to CORT (200 μM) with RA (12.5, 25 or 50 μM) and LY294002 (a PI3K inhibitor) or ANA-12 (a TrkB inhibitor) treatment. The depression-like behavior and various neurobiological changes in the mice and cell injury and levels of target proteins in vitro were subsequently assessed. Here, RA treatment decreased the expression of p-GR/GR, HSP90, FKBP51, SGK-1 in mice hippocampi. Besides, RA increased the average optical density of Nissl bodies and number of dendritic spines in CA3 region, and enhanced Brdu and DCX expression and synaptic transduction in DG region, as well as up-regulated both the BDNF/TrkB/CREB and PI3K/Akt/mTOR signaling. Moreover, RA reduced structural damage and apoptosis in HT22 cells, increased the differentiation and maturation of them. More importantly, LY294002, but not ANA-12, reversed the effect of RA on GR nuclear translocation. Taken together, RA exerted antidepressant activities by modulating the hippocampal glucocorticoid signaling and hippocampal neurogenesis, which related to the BDNF/TrkB/PI3K signaling axis regulating GR nuclear translocation, provide evidence for the application of RA as a candidate for depression.

Thymus atlanticus: A Source of Nutrients with Numerous Health Benefits and Important Therapeutic Potential for Age-Related Diseases

Thymus atlanticus (Lamiaceae) is a plant endemic to the Mediterranean basin that is found in significant quantities in the arid regions of Morocco. Thymus atlanticus is used in traditional medicine to treat infectious and non-infectious diseases. It is also used for the isolation of essential oils and for the seasoning of many dishes in the Mediterranean diet. The major constituents of Thymus atlanticus are saponins, flavonoids, tannins, alkaloids, various simple and hydroxycinnamic phenolic compounds, and terpene compounds. Several of these compounds act on signaling pathways of oxidative stress, inflammation, and blood sugar, which are parameters often dysregulated during aging. Due to its physiochemical characteristics and biological activities, Thymus atlanticus could be used for the prevention and/or treatment of age-related diseases. These different aspects are treated in the present review, and we focused on phytochemistry and major age-related diseases: dyslipidemia, cardiovascular diseases, and type 2 diabetes.

Vasorelaxant Mechanism of Herbal Extracts from Mentha suaveolens, Conyza canadensis, Teucrium polium and Salvia verbenaca in the Aorta of Wistar Rats

Mentha suaveolens (MS), Conyza canadensis (CC), Teucrium polium (TP) and Salvia verbenaca (SV) are used in Morocco to treat hypertension. Our aim was to characterize the composition and vasoreactivity of extracts of MS, CC, TP and SV. The chemical compositions of aqueous extracts of MS, SV and TP, and of a hydromethanolic extract of CC, were identified by HPLC-DAD. The vasoreactive effect was tested in rings of the thoracic aorta of female Wistar rats (8-14 weeks-old) pre-contracted with 10 µM noradrenaline, in the absence or presence of L-NAME 100 µM, indomethacin 10 µM or atropine 6 µM, to inhibit nitric oxide synthase, cyclooxygenase or muscarinic receptors, respectively. L-NAME and atropine decreased the vasorelaxant effect caused by low concentrations of MS. Atropine and indomethacin decreased the vasorelaxant effect of low concentrations of SV. High concentrations of MS or SV and the effect of SV and TP were not altered by any antagonist. The activation of muscarinic receptors and NO or the cyclooxygenase pathway underlie the vasorelaxant effect of MS and SV, respectively. Neither of those mechanisms underlines the vasorelaxant effect of CC and TP. These vasorelaxant effect might support the use of herbal teas from these plants as anti-hypertensives in folk medicine.

Anxiolytic and antidepressive potentials of rosmarinic acid: A review with a focus on antioxidant and anti-inflammatory effects

Depression and anxiety are the most prevalent neuropsychiatric disorders that have emerged as global health concerns. Anxiolytic and antidepressant drugs, such as benzodiazepines, selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, and tricyclics, are the first line used in treating anxiety and depression. Although these drugs lack efficacy and have a delayed response time and numerous side effects, their widespread abuse and market continue to grow. Over time, traditional practices using natural and phytochemicals as alternative therapies to chemical drugs have emerged to treat many pathological conditions, including anxiety and depression. Recent preclinical studies have demonstrated that the phenolic compound, rosmarinic acid, is effective against several neuropsychiatric disorders, including anxiety and depression. In addition, rosmarinic acid showed various pharmacological effects, such as cardioprotective, hepatoprotective, lung protective, antioxidant, anti-inflammatory, and neuroprotective effects. However, the potentialities of the use of rosmarinic acid in the treatment of nervous system-related disorders, such as anxiety and depression, are less or not yet reviewed. Therefore, the purpose of this review was to present several preclinical and clinical studies, when available, from different databases investigating the effects of rosmarinic acid on anxiety and depression. These studies showed that rosmarinic acid produces advantageous effects on anxiety and depression through its powerful antioxidant and anti-inflammatory properties. This review will examine and discuss the possibility that the anxiolytic and anti-depressive effects of rosmarinic acid could be associated with its potent antioxidant and anti-inflammatory activities.

Chronic knockdown of the tetraspanin gene CD81 in the mouse nucleus accumbens modulates anxiety and ethanol-related behaviors

CD81, a member of the tetraspanin family, plays important roles in many physiological processes, such as cell motility, attachment, and entry. Yet, CD81 functions in the brain remain unclear. In this study, we investigated the effects of CD81 knockdown, using lentiviral vectors (LV), on anxiety- and ethanol-related behaviors. For this purpose, mice were stereotaxically injected with CD81 shRNA-expressing LV into the nucleus accumbens (Nacc) and were assessed for anxiety-like behavior using the elevated plus maze (EPM) and open field (OF) tests. Alcohol's sedative effects were studied using loss-of-righting-reflex (LORR) and voluntary ethanol intake was assessed using a two-bottle choice (TBC) procedure. Results showed that mice depleted of CD81 exhibited an anxiolytic-like response in the EPM and OF tests with no effect on locomotor activity. In addition, genetic reduction of CD81 in the Nacc increased mice' sensitivity to alcohol's sedative effects in the LORR test, although plasma alcohol concentrations were unaffected. Interestingly, CD81 loss-of-function-induced anxiolysis was accompanied by a significant decrease in ethanol, but not saccharin nor quinine, intake in the TBC procedure. Finally, and following CD81 mRNA quantification, Pearson's correlations showed a significant positive relationship between accumbal CD81 mRNA with anxiety and ethanol-related behaviors. Our data indicate that CD81 is implicated in the pathogenesis of anxiety and alcoholism. Indeed the targeted disruption of CD81, with the resultant decrease in CD81 mRNA in the Nacc, converted ethanol-"preferring" mice into ethanol "non-preferring" mice. Collectively, these findings demonstrate that future CD81-targeted pharmacotherapies may be beneficial for the treatment of anxiety and alcoholism.

Biomedical features and therapeutic potential of rosmarinic acid

For decades, the use of secondary metabolites of various herbs has been an attractive strategy in combating human diseases. Rosmarinic acid (RA) is a bioactive phenolic compound commonly found in plants of Lamiaceae and Boraginaceae families. RA is biosynthesized using amino acids tyrosine and phenylalanine via enzyme-catalyzed reactions. However, the chemical synthesis of RA involves an esterification reaction between caffeic acid and 3,4-dihydroxy phenyl lactic acid contributing two phenolic rings to the structure of RA. Several studies have ascertained multiple therapeutic benefits of RA in various diseases, including cancer, diabetes, inflammatory disorders, neurodegenerative disorders, and liver diseases. Many previous scientific papers indicate that RA can be used as an anti-plasmodic, anti-viral and anti-bacterial drug. In addition, due to its high anti-oxidant capacity, this natural polyphenol has recently gained attention for its possible application as a nutraceutical compound in the food industry. Here we provide state-of-the-art, flexible therapeutic potential and biomedical features of RA, its implications and multiple uses. Along with various valuable applications in safeguarding human health, this review further summarizes the therapeutic advantages of RA in various human diseases, including cancer, diabetes, neurodegenerative diseases. Furthermore, the challenges associated with the clinical applicability of RA have also been discussed.

Ellagitannin, Phenols, and Flavonoids as Antibacterials from Acalypha arvensis (Euphorbiaceae)

There is a significant need to gain access to new and better antibacterial agents. Acalypha arvensis, a plant from the Euphorbiaceae family, has been used in traditional medicine for centuries to treat infectious diseases. This manuscript reports the isolation, characterization, and antibacterial screening of 8 natural products extracted from maceration of aerial parts of Acalypha arvensis. Specifically, three extracts were assessed (n-hexane, ethyl acetate, and ethanol), in which antibacterial activity was evaluated against diverse bacterial strains. The ethanolic extract showed the best activity against methicillin-sensitive and methicillin-resistant Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa strains, which supports the medicinal properties attributed to this plant. The chromatographic fractions AaR4 and AaR5 were the most bioactive, in which the ellagitannin natural product known as corilagin (1) was identified for the first time in this plant. Therefore, it can be said that this is the main chemical responsible for the observed antibacterial activity. However, we also identified chlorogenic acid (2), rutin (3), quercetin-3-O-glucoside (4), caffeic acid (5), among others (6–8). Hence, this plant can be considered to be a good alternative to treat health-related issues caused by various bacteria.

Hypothalamus-pituitary-adrenal Axis in Glucolipid metabolic disorders

With the change of life style, glucolipid metabolic disorders (GLMD) has become one of the major chronic disorders causing public health and clinical problems worldwide. Previous studies on GLMD pay more attention to peripheral tissues. In fact, the central nervous system (CNS) plays an important role in controlling the overall metabolic balance. With the development of technology and the in-depth understanding of the CNS, the relationship between neuro-endocrine-immunoregulatory (NEI) network and metabolism had been gradually illustrated. As the hub of NEI network, hypothalamus-pituitary-adrenal (HPA) axis is important for maintaining the balance of internal environment in the body. The relationship between HPA axis and GLMD needs to be further studied. This review focuses on the role of HPA axis in GLMD and reviews the research progress on drugs for GLMD, with the hope to provide the direction for exploring new drugs to treat GLMD by taking the HPA axis as the target and improve the level of prevention and control of GLMD.

Plants-Derived Biomolecules as Potent Antiviral Phytomedicines: New Insights on Ethnobotanical Evidences against Coronaviruses

SARS-CoV-2 infection (COVID-19) is in focus over all known human diseases, because it is destroying the world economy and social life, with increased mortality rate each day. To date, there is no specific medicine or vaccine available against this pandemic disease. However, the presence of medicinal plants and their bioactive molecules with antiviral properties might also be a successful strategy in order to develop therapeutic agents against SARS-CoV-2 infection. Thus, this review will summarize the available literature and other information/data sources related to antiviral medicinal plants, with possible ethnobotanical evidence in correlation with coronaviruses. The identification of novel antiviral compounds is of critical significance, and medicinal plant based natural compounds are a good source for such discoveries. In depth search and analysis revealed several medicinal plants with excellent efficacy against SARS-CoV-1 and MERS-CoV, which are well-known to act on ACE-2 receptor, 3CLpro and other viral protein targets. In this review, we have consolidated the data of several medicinal plants and their natural bioactive metabolites, which have promising antiviral activities against coronaviruses with detailed modes of action/mechanism. It is concluded that this review will be useful for researchers worldwide and highly recommended for the development of naturally safe and effective therapeutic drugs/agents against SARS-CoV-2 infection, which might be used in therapeutic protocols alone or in combination with chemically synthetized drugs.