Coronavirus Disease 2019 (COVID-19) has become a major health problem causing severe acute respiratory illness in humans. It has spread rapidly around the globe since its first identification in Wuhan, China, in December 2019. The causative virus is called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the World Health Organization (WHO) named the new epidemic disease Coronavirus Disease (COVID-19). The incidence of COVID-19 continues to increase with more than three million confirmed cases and over 244,000 deaths worldwide. There is currently no specific treatment or vaccine against COVID-19. Therefore, in the absence of pharmaceutical interventions, the implementation of precautions and hygienic measures will be essential to control and to minimize human transmission of the virus. In this review, we highlight the epidemiology, transmission, symptoms, and treatment of this disease, as well as future strategies to manage the spread of this fatal coronavirus.

Kidney disease is one of the most common health problems and kidney failure can be fatal. It is one of the health disorders associated with extreme pain and discomfort in patients. In developing countries, such as Morocco where socioeconomic and sanitary conditions are precarious, medicinal plants are considered the primary source of medication. In the present work an ethnobotanical survey was conducted in a remote area of North-Eastern Morocco and we focused on (1) establishing a record of medicinal plants used traditionally by local people to treat kidney diseases and (2) correlate the obtained ethnomedical use with well-studied pharmacological evidence. From February 2018 to January2020, information was gathered from 488 informants using semi-structured questionnaires. The data were analyzed using three quantitative indices: The use value (UV), family use value (FUV), and informant consensus factor (ICF). A total of 121 plant species belonging to 57 botanical families were identified to treat kidney diseases. The families most represented were Asteraceae (14 species), followed by Lamiaceae (12 species) and Apiaceae (10 species). The most commonly used plant parts were leaves, followed by the whole plant and they were most commonly prepared by decoction and infusion. The highest value of the (UV) index was attributed to Herniaria hirsuta L. (UV = 0.16), and the highest family use value (FUV) was assigned to Caryophyllaceae with (FUV = 0.163). Regarding the informant consensus factor (ICF), this index’s highest values were recorded for kidney stones (ICF = 0.72). The use of 45% of the selected plants were validated based on literature review. This study helped document and preserve crucial traditional plant knowledge of 121 plant species used to treat kidney problems that can be used in the search for new biologically active compounds through more upcoming pharmacological studies.

Nigella sativa L. (Ranunculaceae), commonly referred to as black seeds or black cumin, is used in popular medicine (herbal) all over the world for the treatment and prevention of several diseases, including diabetes. This study aims to investigate the inhibitory effect of N. sativa extracts and fractions against the activities of intestinal α-glucosidase and pancreatic α-amylase in vitro, and to explain the inhibitory effect of these fractions against these enzymes by identifying their active compounds responsible for this effect and determine their modes of inhibition. To do so, N. sativa hexane and acetone extracts were prepared and analyzed by GC–MS and HPLC–DAD, respectively. The hexane extract was further fractioned into eight different fractions, while the acetone extract generated eleven fractions. The extracts as well as the resulting fractions were characterized and evaluated for their potential in vitro antidiabetic activity using intestinal α-glucosidase and pancreatic α-amylase inhibitory assays in vitro. Hexane extract and fractions were less active than acetone extract and fractions. In the case of intestinal α-glucosidase activity, the acetone fraction SA3 had a high inhibitory effect on intestinal α-glucosidase activity with 72.26 ± 1.42%, comparable to the effect of acarbose (70.90 ± 1.12%). For the pancreatic α-amylase enzymatic inhibitory assay, the acetone fractions showed an inhibitory capacity close to that for acarbose. In particular, the SA2 fraction had an inhibitory effect of 67.70 ± 0.58% and was rich in apigenin and gallic acid. From these fractions, apigenin, (−)-catechin, and gallic acid were further characterized for their inhibitory actions. IC50 and inhibition mode were determined by analyzing enzyme kinetic parameters and by molecular modeling. Interestingly, (−)-catechin showed a possible synergistic effect with acarbose toward α-glucosidase enzyme inhibition, whereas apigenin showed an additive effect with acarbose toward α-amylase enzymatic inhibition. Furthermore, we studied the toxicity of N. sativa hexane and acetone extracts as well as that of acetone fractions. The result of acute toxicity evaluation demonstrated that N. sativa extracts were nontoxic up to a concentration of 10 g/kg, except for fraction SA3. Taken together, these results indicate that N. sativa extracts and/or derived compounds could constitute promising nutraceuticals for the prevention and treatment of type 2 diabetes mellitus.

Many medicinal plants around the world are used for therapeutic purposes against several diseases, including diabetes mellitus. Due to their composition of natural substances that are effective and do not represent side effects for users, unlike synthetic drugs, in this study, we investigated the inhibitory effect of Caralluma europaea (CE) on α-glucosidase activity in vitro; then the kinetics of the enzyme were studied with increasing concentrations of sucrose in order to determine the inhibition type of the enzyme. In addition, this effect of Caralluma europaea (CE) was confirmed in vivo using rats as an experimental animal model. Among the five fractions of CE, only the ethyl acetate fraction of C. europaea (EACe) induced a significant inhibition of α-glucosidase and its inhibition mode was competitive. The in vivo studies were conducted on mice and rats using glucose and sucrose as a substrate, respectively, to determine the oral glucose tolerance test (OGTT). The results obtained showed that the EACe and the aqueous extract of C. europaea (AECe) have significantly reduced the postprandial hyperglycemia after sucrose and glucose loading in normal and diabetic rats. AECe, also, significantly decreased intestinal glucose absorption, in situ. The results obtained showed that Caralluma europaea has a significant antihyperglycemic activity, which could be due to the inhibition of α-glucosidase activity and enteric absorption of glucose.

Opuntia dillenii (Ker-Gawl.) Haw. is a medicinal plant that is widely used by the Moroccan population to treat many diseases, thanks to its richness in bioactive molecules. This study aims to evaluate the total phenolic content and antioxidant, antihyperlipidemic, and antidiabetogenic activities of O. dillenii seeds oil (ODSO), in vivo. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay and the Folin–Ciocalteu method were applied in this study to determine antioxidant activity and total phenolic content of ODSO, respectively. The antihyperlipidemic effect of the ODSO (2 ml/kg) was evaluated in the high-fat diet-fed albino mice, relying on lipid profile, blood glucose, and growth performance variations. Moreover, the preventive effect of ODSO was evaluated against alloxan monohydrate-induced diabetes in albino mice. ODSO had the highest total phenolic content (518.18 ± 14.36 mg EAC/kg) and DPPH scavenging activity (IC50 = 0.38 ± 0.08 mg/mL). Furthermore, ODSO showed a significant antidiabetogenic effect by reducing bodyweight loss, blood sugar level rise, and mortality rate caused by alloxan in albino mice. Then, ODSO has exhibited a significant antihyperlipidemic effect by improving the lipid profile disorder and glucose level rise in the blood, produced by the high-fat diet-fed albino mice. Results suggest that antidiabetogenic and antihyperlipidemic activities of ODSO correlate to the phenolic content and antioxidant activity of this oil. Hence, this plant could be a significant source of medically important critical compounds.

Mental disorders are psychological symptoms that impact multiple areas of an individual’s life. Depression and anxiety are chronic illnesses described as the most prevalent stress-related mood disorders that cause injury and early death. In Morocco, Anise “Pimpinella anisum L.” is one of the most traditionally used condiment plants, which has long been used to cure various illnesses and in phytotherapy. The present study was designed to investigate the antidepressant, anxiolytic, and memory impact of the total extract of Pimpinella anisum (PATE) at the doses of 100 and 200 mg/kg, using the Forced Swimming Test (FST), Tail Suspension Test (TST), Open Field Test (OFT), and Light–Dark Box Test (LDBT) as an experimental paradigm of anxiety and depression, and Novel Object Recognition Test (NORT) and the Morris Water Maze Test (MWMT) as memory tests on Swiss albino mice. The tests were carried out on the 1st, 7th, 14th, and the 21st days of the study, and the extract groups were compared with normal controls and positive controls (receiving bromazepam and paroxetine at the doses of 1 mg/kg and 11.5 mg/kg for anxiety and depression, respectively). The daily oral gavage of the mice by the PATE induced a significant anxiolytic and antidepressant-like effect by shortening immobility time and decreasing downtime in the different tests. PATE at both doses was shown to have no impact on memory following the NORT and MWM tests. Different compounds, such as gallic acid, catechin, chlorogenic acid, caffeic acid, oleuropein, p-coumaric acid, trans-4-hydroxy-3-methoxycinnamic acid, myricetin, and quercetin, were identified during the phytochemical analysis carried out using HPLC analysis. This research supports and promotes the extract’s traditional use, suggesting its use as a phytomedicine against depression and anxiety, and calls for further research to clarify its mode of action.

Opuntia dillenii Ker Gawl. is one of the medicinal plants used for the prevention and treatment of diabetes mellitus (DM) in Morocco. This study aims to investigate the antihyperglycemic effect of Opuntia dillenii seed oil (ODSO), its mechanism of action, and any hypoglycemic risk and toxic effects. The antihyperglycemic effect was assessed using the OGTT test in normal and streptozotocin (STZ)-diabetic rats. The mechanisms of action were explored by studying the effect of ODSO on the intestinal absorption of d-glucose using the intestinal in situ single-pass perfusion technique. An Ussing chamber was used to explore the effects of ODSO on intestinal sodium-glucose cotransporter 1 (SGLT1). Additionally, ODSO’s effect on carbohydrate degrading enzymes, pancreatic α-amylase, and intestinal α-glucosidase was evaluated in vitro and in vivo using STZ-diabetic rats. The acute toxicity test on mice was performed, along with a single-dose hypoglycemic effect test. The results showed that ODSO significantly attenuated the postprandial hyperglycemia in normal and STZ-diabetic rats. Indeed, ODSO significantly decreased the intestinal d-glucose absorption in situ. The ex vivo test (Ussing chamber) showed that the ODSO significantly blocks the SGLT1 (IC50 = 60.24 µg/mL). Moreover, ODSO indu\ced a significant inhibition of intestinal α-glucosidase (IC50 = 278 ± 0.01 µg/mL) and pancreatic α-amylase (IC50 = 0.81 ± 0.09 mg/mL) in vitro. A significant decrease of postprandial hyperglycemia was observed in sucrose/starch-loaded normal and STZ-diabetic ODSO-treated rats. On the other hand, ODSO had no risk of hypoglycemia on the basal glucose levels in normal rats. Therefore, no toxic effect was observed in ODSO-treated mice up to 7 mL/kg. The results of this study suggest that ODSO could be suitable as an antidiabetic functional food.

Pollen is a male flower gametophyte located in the anthers of stamens in angiosperms and a considerable source of compounds with health protective potential. In the present work, phytochemical screening was carried out as well as analysis of the antioxidant and antibacterial properties of pollen extracts from Micromeria fruticosa, Achillea fragrantissima, and Phoenix dactylifera growing wild in Palestine. Phytochemical screening examined the total flavonol, flavone and phenolic content. The DPPH (1,2-Diphenyl-1-Picrylhydrazyl) and FRAP (ferric reducing antioxidant power) methods were used to assess antioxidant propriety, and disc diffusion, minimum inhibitory and bactericidal concentration tests were used to test the pollen extract’s antibacterial activity against multidrug-resistant (MDR) clinical isolates. The highest level of total phenolic was found in the extract of Micromeria fruticosa (56.78 ± 0.49 mg GAE (Gallic Acid Equivalent)/g). The flavone and flavonol content of samples ranged from 2.48 ± 0.05 to 8.03 ± 0.01 mg QE (Quercetin Equivalent)/g. Micromeria fruticosa pollen with IC50 values of 0.047 and 0.039 mg/mL in the DPPH and FRAP assays, respectively, showed the greatest radical scavenging action. In addition, this pollen showed a mild antibacterial action against the microorganisms studied, with MICs varying from 0.625 to 10 mg/mL and inhibition diameters ranging from 13.66 ± 1.5 to 16.33 ± 1.5 mm.