A Review of Rhazya stricta Decne Phytochemistry, Bioactivities, Pharmacological Activities, Toxicity, and Folkloric Medicinal Uses

The local medicinal plant Rhazya stricta Decne is reviewed for its folkloric medicinal, phytochemical, pharmacological, biological, and toxicological features. R. stricta has been used widely in different cultures for various medical disorders. The phytochemical studies performed on the R. stricta extract revealed many alkaloidal and fatty acid compounds. Moreover, several flavonoid and terpenoid compounds were also detected. Pharmacological activates of R. stricta extracts are approved to possess antimicrobial, antioxidant, anticancer, antidiabetic, and antihypertensive activities. Additionally, R. stricta extract was found to hold biological activates such as larvicidal and phytoremediation activates R. stricta extract was found to be toxic, genotoxic, and mutagenic. R. stricta contains novel phytochemical compounds that have not been investigated pharmacologically. Further research is needed through in vitro and in vivo experiments to pave the road for these compounds for medical, veterinary, and ecological uses.

Moisture and Salinity Drive the Vegetation Composition of Wadi Hargan, Riyadh, Saudi Arabia

Wetlands are represented in Saudi Arabia in the form of mangrove, sabkha, and wadi (valleys) systems, and these habitats are considered as a sanctuary for biodiversity. The present study aimed to identify different vegetation groups in a wetland site in Wadi Hargan near Alqurainah, Riyadh, Saudi Arabia, and to relate different plant communities and plant diversity to soil moisture, salinity, and other soil properties. Floristic analysis and vegetation structure were investigated within 15 stands along the wadi and were subjected to correlation analysis with soil factors via multivariate analysis. The floristic survey revealed the presence of 111 plant species belonging to 39 families. The most represented families were Asteraceae, Poaceae, Brassicaceae, Caryophyllaceae, and Papilionaceae, which accounted for the largest proportion (55.4%) of the total species. The therophytes were the dominant life form, where they were represented by 46.9% of the total number of species. The application of cluster analysis (TWINSPAN) to the importance value of each species based on the relative cover and density led to the recognition of four plant communities: (A) Phragmites australis—Tamarix nilotica community, (B) Zygophyllum coccineum—Acacia gerrardii community, (C) Lycium shawii—Zygophyllum coccineum community, and (D) Rhazya stricta community. The soil analysis and correlation test revealed significant variations in the content of salinity, moisture, CO3, Cl, SO4, Ca, Mg, and Na among the plant communities. It can be concluded that soil moisture and salinity factors were the fundamental driving forces for plant community structure in the studied wadi. The wadi was moderately grazed, mainly by camels; thereby, the invasive plant Rhazya stricta dominated the central region of the wadi. Also, human interference was observed at the end of the wadi, where some weeds sprouted such as Malva parviflora. The presence of those two rare wetland species, Adiantum capillus-veneris and Ficus salicifolia, in the study area, showed the unique properties of the studied wadi and necessitate an urgent biodiversity conservation action to protect its natural vegetation from overgrazing and human interference.

Effects of Different Solvents to Extract Phytochemical Materials of Rhazya stricta Against Salmonella typhimurium Activity

Background: The use of plant extracts prepared from medicinal plants is common in the developing countries. Meanwhile, due to the resistance of microorganisms to antibiotics, researchers are looking to discover new antimicrobials. Medicinal plants play an essential role in this regard. Objectives: This study was aimed at investigating the antimicrobial properties of various extracts of Rhazya stricta plant against Salmonella typhimurium. Methods: Methanolic, aqueous, ethanolic, hydroalcoholic, and ethyl acetate extracts of R. stricta were prepared. S. typhimurium strains were isolated from poultry feces. The microdilution method was used to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of this plant. The diameter of the growth inhibition zone using was determined using Whatman paper. Results: The lowest MIC against S. typhimurium was obtained from the hydroalcoholic solvent with 3.1 ppm. The most effective extraction solvent to inhibit the growth of S. typhimurium was the hydroalcoholic type with an average growth inhibition zone diameter of 12.25 mm, followed by the ethanolic extract with a growth inhibition zone diameter of 12.12 mm. Conclusions: According to the results of research and increasing resistance to synthetic antibacterial substances, it seems that R. stricta plant with the help of hydroalcoholic solvent, can be considered an effective plant in eliminating some bacteria, including S. typhimurium.

Anti-Proliferative, Cytotoxic and Antioxidant Properties of the Methanolic Extracts of Five Saudi Arabian Flora with Folkloric Medicinal Use: Aizoon canariense, Citrullus colocynthis, Maerua crassifolia, Rhazya stricta and Tribulus macropterus

Saudi Arabian flora have a history of use as folklore remedies, although such properties have yet to be explored rigorously, and the safety of such remedies should be assessed. This study determined the anti-proliferative, cytotoxic, and antioxidant properties of extracts of the following five plants indigenous to Saudi Arabia: Aizoon canariense, Citrullus colocynthis, Maerua crassifolia, Rhazya stricta, and Tribulus macropterus. The aerial parts of the five plants were collected from various locations of the western and northern regions of Saudi Arabia and used to prepare methanolic extracts. Three approaches were used to determine the proliferation and cytotoxicity effects using HaCaT cells: MTT, FACS, and confocal microscopy. Meanwhile, two approaches were used to study the antioxidant potential: DPPH (acellular) and RosGlo (cellular, using HaCaT cells). C. colocynthis possessed anti-proliferative activity against HaCaT cells, showing a significant decrease in cell proliferation from 24 h onwards, while R. stricta showed significant inhibition of cell growth at 120 and 168 h. The IC50 values were determined for both plant extracts for C. colocynthis, with 17.32 and 16.91 µg/mL after five and seven days of treatment, respectively, and for R. stricta, with 175 and 105.3 µg/mL after five and seven days of treatment. R. stricta and M. crassifolia exhibited the highest capacities for scavenging the DPPH radical with IC50 values of 335 and 448 µg/mL, respectively. The subsequent ROS-Glo H2O2 assay confirmed these findings. The R. stricta and M. crassifolia extracts showed potent antioxidant activity in both acellular and cellular models. The C. colocynthis extract also demonstrated significant anti-proliferation and cytotoxic activity, as did the R. stricta extract. These properties support their usage in folk medicine and also indicate a further potential for development for holistic medicinal use or as sources of new active compounds.

Effective Antiplasmodial and Cytotoxic Activities of Synthesized Zinc Oxide Nanoparticles Using Rhazya stricta Leaf Extract

In the present study, zinc oxide (ZnO) nanoparticles were prepared using ZnCl2.2H2O as a precursor, via green route using leaf extract of Rhazya stricta as capping and reducing agent. The prepared ZnO nanoparticles were examined using UV-visible spectrophotometer (UV-Vis), Fourier transform infrared spectrometer (FT-IR), X-ray diffraction spectrometer (XRD), and scanning electron microscope (SEM). The UV-Vis absorption spectrum at 355 nm showed an absorption peak, which indicates the formation of ZnO NPs. The FT-IR spectra analysis was performed to identify the potential biomolecule of the as-prepared ZnO NPs. The FT-IR spectra showed peaks at 3455, 1438, 883, and 671 cm−1 in the region of 4000–500 cm−1, which indicates –OH, NH, C-H, and M-O groups, respectively. The SEM images showed aggregation of ZnO nanoparticles with an average size of 70–90 nm. The XRD study indicated that the ZnO NPs were crystalline in nature with hexagonal wurtzite structure and broad peaks were observed at 2 theta positions 31.8°, 34.44°, 36.29°, 47.57°, 56.61°, 67.96°, and 69.07°. The synthesized ZnO NPs were found to be good antiplasmodial with a 50% inhibitory concentration (IC50) value of 3.41 μg/mL. It is concluded from the current study that the ZnO NPs exhibited noble antiplasmodial activity, and for the improvement of antiplasmodial medications, it might be used after further in vivo studies.

In silico Screening of Some Compounds Derived from the Desert Medicinal Plant Rhazya stricta for Potential Treatment of COVID -19

The recent emerging SARS-CoV-2 pandemic which was identified as COVID-19 disease has become a global health concern. It resulted in a major pneumonia outbreak worldwide. Currently, there are no approved drugs and several attempts have been made to use computational program approaches in drug repurposing for COVID-19 treatment. The SARS-CoV-2 spike glycoprotein receptor-binding domain (RBD) is vital for binding to the hACE2 receptor, which initiates entry into human cells, and thus is a key target for antiviral compound development. Many herbal natural products have been proved to exert virucidal activity against the vast majority of pathogenic viruses. Rhazya stricta, a folkloric medicinal desert plant of Saudi Arabia was shown to exhibit bactericidal activity against a verity of pathogens including Methicillin-resistant Staphylococcus aureus (MRSA) and some other Multidrug-Resistant Organisms (MDR’s). This study aims to test for antiviral activity of the folkloric medicinal desert plant Rhazya stricta against coronavirus SARS-CoV-2. We identified three non-alkaloid herbal natural compounds Lig230, Lig434, and Lig68 from Rhazya Stricta that bind and interact significantly with RBD (PDB: I.D. 6M0J) by using virtual screening and computer aiding program Autodock vina. Based on the results of docking scores, molecular docking simulations, RMSD, RMSF, and radius of gyration (Rg), the virtually screened antiviral compounds showed good binding interactions and high stability. Lig230 revealed the highest average of interaction energy during MD simulation (− 417.284 kJ/mol) followed by Lig434 (− 366.186 kJ/mol) and the lowest interaction energy was by Lig68 (− 352.5872 kJ/mol). To evaluate the oral bioavailability, a drug-likeness profile was performed by SwissADME and the results revealed that these compounds expected to confront permeability and solubility difficulties if they were introduced orally. In conclusion, the suggested three compounds can serve as potential anti- SARS-CoV-2 and should be furtherly tested in vitro and in vivo.

Global and Regional IUCN Red List Assessments: 11

In this contribution, the conservation status assessment of three vascular plants according to IUCN categories and criteria is presented. It includes the global assessment of Limonium parvifolium Tineo and Viscaria alpina (L.) G.Don, and the regional assessment of Rhazya stricta Decne. (Iraq).

Antioxidant and immune responses of broiler chickens supplemented with Rhazya stricta extract in drinking water

Background and Aim: Rhazya stricta is a herbal plant widely used in traditional medicine due to its proficiency and naturalness with few side effects. In this study, we investigated the impact of using an R. stricta extract supplement on broiler chickens' performance, especially the immune system. Materials and Methods: In addition to the control group, one group received the methanol extract of R. stricta in drinking water for the first 2 weeks before being challenged with sheep erythrocytes (SRBCs), while the other group was challenged with SRBCs without receiving the R. stricta treatment. We evaluated cellular immunity by determining the phagocytic activity and lymphocyte (L) proliferation and assessed humoral immunity by quantification of the serum total IgM and IgG. We measured the serum levels of antioxidant enzymes and performed a histological examination of the spleen and the bursa of Fabricius (BF). Results: Our results indicate a significant enhancement in cellular immunity in the group supplemented with R. stricta as demonstrated by a significant increase in the phagocytic activity, L proliferation, and percentages of circulating L (p<0.05). The chickens treated with R. stricta exhibit an enhanced humoral response shown by a significant elevation in the serum levels of the total antibodies of the IgM and IgG isotypes, along with a notable increase in BF activity. Furthermore, R. stricta supplementation is associated with a significant increase in the serum levels of catalase and superoxide dismutase (p<0.05), along with a significant improvement in broilers' general performance, body weight, and feed efficiency. Conclusion: Our results suggest an immunomodulatory effect for the methanol extract of R. stricta and highlight the potential use of this plant in preventive and therapeutic medicine.

Rhazya Stricta Assisted Green Synthesis of Multifunctional Carbon Coated Copper Oxide Nanosheets for Photocatalysis of Dyes and Antibacterial Candidate Against Solanaceous Pathogens

The studies of metal oxides in environmental remediation of chemical and biological pollutants are gaining huge importance. Herein, we report the facile synthesis of multi-functional copper oxide nanosheets (CuO NS) using an aqueous extract of Rhazya stricta. The phytochemical investigation of R. stricta indicated the presence of saponins, tannins, and reducing sugars responsible for the reduction and stabilization of CuO NS. The formation of CuO NS was confirmed by x-ray diffraction and UV-visible spectrophotometer with specific Surface Plasmon Resonance at 294 nm. Further characterization of the CuO NS was done by FE-SEM, FTIR, and XRD. The obtained CuO NS were poly-dispersed with an average size of 20 nm. Interestingly these particles were aligned together in the form of 3D cubical sheets layered above each other via self-assembly. The as-synthesized CuO NS shows enhanced antibacterial potential (17.63 mm, mean inhibition zone) as compared to the known antibiotics (11.51 mm, mean inhibition zone) against the wilt causing bacteria of Solanaceous crop, including Ralstonia solanacearum and Clavibacter michiganensis. Furthermore, the appreciable photocatalytic potential of CuO NS has been observed, causing 83% degradation of methylene blue (MB) upon solar irradiation. The synthesis methodology is devoid of any toxic waste and/or by-products and could be used to produce eco-friendly CuO nanomaterial for industrial uses.