A new dicoumarinyl ether and two rare furocoumarins from Ruta montana

Moroccan Antihypertensive Plants and their Mechanisms of Action

BACKGROUND

The use of herbal remedies, medicinal plants, and their derivatives for the treatment and control of hypertension is well-known and widespread throughout Morocco.

AIMS

The aim of the study was to review the antihypertensive and vasorelaxant medicinal plants of the Moroccan pharmacopeia.

OBJECTIVE

To date, no review on Moroccan medicinal plants exhibiting antihypertensive effects has been performed, and their mechanism of action has not been specified. The objective of this review was to collect, analyze, and critically assess published publications on experimental and clinical research that explored the blood pressure-reducing abilities of Moroccan medicinal plant extracts.

MATERIALS AND METHODS

This study collected, processed, and critically analyzed published studies related to experimental and clinical research that investigated Moroccan herbal derivatives' blood pressure-lowering abilities using a number of scientific databases, including ScienceDirect, Scopus, PubMed, Google Scholar, and others. Plantlist.org was used to validate the right plant names.

RESULTS

The results revealed 22 species of Moroccan medicinal plants belonging to 13 different groups with recognized antihypertensive properties. The species were abundant in a variety of chemical elements. Asteraceae (08 species), Lamiaceae (3 species), Apiaceae (2 species), and 1 species each from the following families: Parmeliaceae, Fabaceae, Cistaceae, Malvaceae, Polygonaceae, Brassicaceae, Myrtaceae, Rutaceae, Amaranthaceae, Rosaceae, and Lauraceae were the most frequently mentioned families for their antihypertensive properties. The most used parts were the leaves and the aerial parts. The two main methods of preparation among Moroccans were decoction and infusion. This study demonstrated the known antihypertensive and vasorelaxant properties of Moroccan medicinal plants in vivo and in vitro, as well as their mechanisms of action. Interestingly, phytochemicals can operate on blood vessels directly via a vasorelaxant impact involving a range of signaling cascades or indirectly by blocking or activating multiple systems, such as an angiotensin-converting enzyme (ACE), renin-angiotensin system (RAS), or diuretic activity.

CONCLUSION

The review of the available data reveals that more work needs to be done to examine all the Moroccan medicinal plants that have been suggested as antihypertensive in published ethnopharmacological surveys. A review of the literature in this area reveals that methodologies of the experimental study need to be standardized, and purified molecules need to be studied. In addition, mechanistic investigations, when they exist, are generally incomplete. In contrast, only a few advanced clinical investigations have been conducted. However, all studies fail to determine the efficacy/safety ratio.

Studies on the Accumulation of Secondary Metabolites and Evaluation of Biological Activity of In Vitro Cultures of Ruta montana L. in Temporary Immersion Bioreactors

The present work focuses on in vitro cultures of Ruta montana L. in temporary immersion Plantform^TM bioreactors. The main aim of the study was to evaluate the effects of cultivation time (5 and 6 weeks) and different concentrations (0.1-1.0 mg/L) of plant growth and development regulators (NAA and BAP) on the increase in biomass and the accumulation of secondary metabolites. Consequently, the antioxidant, antibacterial, and antibiofilm potentials of methanol extracts obtained from the in vitro-cultured biomass of R. montana were evaluated. High-performance liquid chromatography analysis was performed to characterize furanocoumarins, furoquinoline alkaloids, phenolic acids, and catechins. The major secondary metabolites in R. montana cultures were coumarins (maximum total content of 1824.3 mg/100 g DM), and the dominant compounds among them were xanthotoxin and bergapten. The maximum content of alkaloids was 561.7 mg/100 g DM. Concerning the antioxidant activity, the extract obtained from the biomass grown on the 0.1/0.1 LS medium variant, with an IC₅₀ 0.90 ± 0.03 mg/mL, showed the best chelating ability among the extracts, while the 0.1/0.1 and 0.5/1.0 LS media variants showed the best antibacterial (MIC range 125-500 µg/mL) and antibiofilm activity against resistant Staphylococcus aureus strains.

Ruta montana (L.) L.: An insight into its medicinal value, phytochemistry, biological properties, and toxicity

Ruta montana (RM) is a medicinal and aromatic plant (MAP) used in folk medicine, especially in North Africa, to treat digestive, infectious, respiratory, neurological, gynecological, and diabetic diseases. The current work aims to review the scientifically validated ethno-medicinal usage, bioactivities and phytochemistry of RM, in order to provide data support for further investigations. Data were procured from PubMed, Scopus, Google Scholar, Web of Science, ScienceDirect, and PubChem. The present study revealed that RM could be used to manage many diseases involved in public health problems, such as diabetes, hypertension, neurological disorders, infections, reproductive system disorders, and cancer. It might also replace chemical insecticides and fungicides since it exhibits antifungal, insecticidal, and larvicidal properties. RM extracts also contain mainly coumarins and alkaloids. The volatile oil of RM is characterized by an abundance of ketone compounds and 2-undecanone as major constituents. In the case of a high-dose administration, RM infusion can cause poisoning through the oral path. Thus, in-depth in vivo pharmacological studies and clinical trials are needed to transmute the traditional applications of RM into scientific-based information.

Phytochemical Analysis and Biological Activities of the Ethanolic Extract of Daphne sericea Vahl Flowering Aerial Parts Collected in Central Italy

In this paper, the first phytochemical analysis of the ethanolic extract of Daphne sericea Vahl flowering aerial parts collected in Italy and its biological activities were reported. Eleven compounds were identified i.e., α-linolenic acid (1), tri-linoleoyl-sn-glycerol (2), pheophorbide a ethyl ester (3), pilloin (4), sinensetin (5), yuanhuanin (6), rutamontine (7), syringin (8), p-coumaric acid (9), p-anisic acid (10) and caffeic acid (11). To the best of our knowledge, compounds (1-4, 7-8 and 10) were isolated from D. sericea for the first time during this work, whereas sinensetin (5) represents a newly identified component of the entire Thymelaeaceae family. The extract was found to possess radical scavenging against both DPPH^• and 2,2′-azino-bis(3-thylbenzothiazoline-6-sulfonic acid (ABTS^•+) radicals, with at least a 40-fold higher potency against the latter. Moreover, chelating abilities against both ferrous and ferric ions have been highlighted, thus suggesting a possible indirect antioxidant power of the extract. Although the precise bioactive compounds remain to be discovered, the polyphenolic constituents, including phenolic acids, tannins and flavonoids, seem to contribute to the antioxidant power of the phytocomplex. In addition, the extract produced cytotoxic effects in MDA-MB-231 and U87-MG cancer cell lines, especially at the concentration of 625 μg/mL and after 48–72 h. Further studies are required to clarify the contribution of the identified compounds in the bioactivities of the extract and to support possible future applications.

New Antiproliferative Triflavanone from Thymelaea hirsuta-Isolation, Structure Elucidation and Molecular Docking Studies

In this study isolates from Thymelaea hirsuta, a wild plant from the Sinai Peninsula of Egypt, were identified and their selective cytotoxicity levels were evaluated. Phytochemical examination of the ethyl acetate (EtOAc) fraction of the methanolic (MeOH) extract of the plant led to the isolation of a new triflavanone compound (1), in addition to the isolation of nine previously reported compounds. These included five dicoumarinyl ethers found in Thymelaea: daphnoretin methyl ether (2), rutamontine (3), neodaphnoretin (4), acetyldaphnoretin (5), and edgeworthin (6); two flavonoids: genkwanin (7) and trans-tiliroside (8); p-hydroxy benzoic acid (9) and β sitosterol glucoside (10). Eight of the isolated compounds were tested for in vitro cytotoxicity against Vero and HepG2 cell lines using a sulforhodamine-B (SRB) assay. Compounds 1, 2 and 5 exhibited remarkable cytotoxic activities against HepG2 cells, with IC₅₀ values of 8.6, 12.3 and 9.4 μM, respectively, yet these compounds exhibited non-toxic activities against the Vero cells. Additionally, compound 1 further exhibited promising cytotoxic activity against both MCF-7 and HCT-116 cells, with IC₅₀ values of 4.26 and 9.6 μM, respectively. Compound 1 significantly stimulated apoptotic breast cancer cell death, resulting in a 14.97-fold increase and arresting 40.57% of the cell population at the Pre-G1 stage of the cell cycle. Finally, its apoptosis-inducing activity was further validated through activation of BAX and caspase-9, and inhibition of BCL2 levels. In silico molecular docking experiments revealed a good binding mode profile of the isolates towards Ras activation/pathway mitogen-activated protein kinase (Ras/MAPK); a common molecular pathway in the development and progression of liver tumors.

Chemical Composition and Antimicrobial Activity of Selected Essential Oils against Staphylococcus spp. Isolated from Human Semen

Staphylococcus spp. is not only a commensal bacteria but also a major human pathogen that causes a wide range of clinical infections. Recent evidence suggests that Staphylococcus has the ability to colonize the reproductive system and to affect its structure and functions. The objective of this study was to determine the chemical properties and antibacterial effects of select essential oils (EOs): Amyris balsamifera L., Boswellia carterii Birdw., Canarium luzonicum (Blume) A. Gray, Cinnamomum camphora (L.) J. Presl., Cinnamomum camphora var. linaloolifera Y. Fuita, Citrus x aurantium L., Gaultheria procumbens L., Litsea cubeba (Lour.) Pers., Melaleuca ericifolia Smith., Melaleuca leucadendra L., Pogostemon cablin (Blanco) Benth., Citrus limon (L.) Osbeck, Santalum album L., and Vetiveria zizanoides (L.) Roberty against 50 Staphylococcus spp. cultures isolated from human semen, specifically Staphylococcus aureus, S. capiti, S. epidermidis, S. haemoliticus, and S. hominis. The disc diffusion and broth microdilution methods were used to assess the antimicrobial potential and to determine the minimum inhibitory concentration (MIC) of the selected EOs. The best anti-Staphylococcus activities were found with both methods for the essential oils of C. luzonicum (Blume) A. Gray, A. balsamifera, C. camphora, and P. cabli.

Genus Ruta: A natural source of high value products with biological and pharmacological properties

ETHNOPHARMACOLOGICAL RELEVANCE

Ruta genus is constituted by ten species, of which the most commonly described are R. chalepensis and R. graveolens. Ruta plants are perennial shrubs belonging to the family Rutaceae, which are traditionally used in folk medicine, since ancient times mostly for the treatment of various ailments of the womb.

AIM OF THE STUDY

To provide a review of the different uses of Ruta species in traditional medicine, as well as, on their multifactorial biological and pharmacological properties.

MATERIAL AND METHODS

A search of the literature on genus Ruta and Ruta species was performed using various scientific databases and search engines and the information of articles were reviewed and compiled.

RESULTS

Different parts of the plants belonging to Ruta genus are used in folk medicine to treat a wide range of different diseases. The principal use of these is in gynaecological field, but the treatment of pain, fever, nausea, inflammation, infections, nervous disorders, among others, are also described. These plants have been used to fertility regulation, as anti-fertility agent, to control menstrual flux and bleedings, as abortifacient and as contraceptive. The phytochemical composition of these plants consists mainly in essential oil (EO), but phenolic compounds were also reported, like coumarins and flavonoids, as well as alkaloids. Ruta species products like extracts and EOs have shown broad pharmacological activities, such as antimicrobial and antifungal activities, as well as, antiviral and antiparasitic. Moreover, Ruta plants products present antioxidant, neuroprotective, anti-inflammatory, anti-cancer and anti-diabetic activities and demonstrated contraceptive and abortifacient effects. These plants were also tested to be used for non-therapeutic approaches, as bio-insecticides in the control of different insect pests showing to be able to reduce infestation.

CONCLUSIONS

Ruta species could be a potential source of natural products with biological activities. Ruta extracts, essential oils and isolated compounds have shown a diverse potential for use in the treatment of different diseases, as well as, for pests control, contributing to the valorisation of these plants. Nonetheless, this review indicates that more studies are needed to demonstrate the full potential of Ruta species, and to further explore the toxicology and safety of these plants.

New Coumarinyl Ethers in Daphne oleoides Schreb. Collected from Sardinia Island

The phytochemical analysis of the ethanolic extract obtained from D. oleoides collected from Sardinia Island allowed the isolation of several new constituents for the species (3, 8, and 9) together with two new coumarinyl ethers (1 and 2) besides the chemotaxonomic markers of the Daphne genus (4 - 7 and 10) which are also known to possess interesting biological activities. The structure of the new compounds were elucidated by extensive spectroscopic and spectrometric analyses. The identification of these compounds gives an experimental evidence of the variability in the secondary metabolites pattern owned by populations growing in restricted area in respect to populations not confined by geographical barrier.

Chemical constituents from the aerial parts of Artemisia minor

Four new compounds including three bicoumarins, arteminorins A-C (1-3), and one neolignan, arteminorin D (4), together with 31 known ones were isolated from the aerial parts of Artemisia minor. Their structures were established on the basis of spectroscopic data and comparison with those of the related known compounds. Ethyl caffeate (27) showed in vitro cytotoxicity against the HepG2 cancer cell line. Arteminorin C (3) and luteolin (19) showed inhibitory activity on xanthine oxidase (XOD), and caffeic acid (28) exhibited inhibitory activity on protein tyrosine phosphatase 1B (PTP1B).