COVID-19: General Strategies for Herbal Therapies

The coronavirus disease-2019 (COVID-19) pandemic started in early 2020 with the outbreak of a highly pathogenic human coronavirus. The world is facing a challenge and there is a pressing need for efficient drugs. Plants and natural compounds are a proven rich resource for new drug discovery. Considering the potential of natural products to manage the pandemic, this article was designed to provide an inclusive map of the stages and pathogenetic mechanisms for effective natural products on COVID-19. New drug discovery for the COVID-19 pandemic can encompass both prevention and disease management strategies. Preventive mechanisms that may be considered include boosting the immune response and hand hygiene in the preexposure phase; and blocking of virus binding and entry in the postexposure phase. Potential therapeutic target mechanisms include virus-directed therapies and host-directed therapies. Several medicinal plants and natural products, such as Withania somnifera (L.) Dunal and propolis for prevention; Tanacetum parthenium (L.) for treatment; and Ammoides verticillata (Desf.) Briq and Nigella sativa L. for both prevention and treatment have been found effective and are good targets for future research. The examples of phytochemical compounds that may be effective include aloin and terpenes as anti-septics; isothymol, dithymoquinone, and glycyrrhizin as inhibitors of virus binding and entry; glycyrrhizin, and berberine as replication suppressants; ginsenoside Rg1 and parthenolide as immunomodulators; and eriocitrin, rhoifolin, hesperidin, naringin, rutin, and veronicastroside as anti-complements. Recognizing different mechanisms of fighting against this virus can lead to a more systematic approach in finding natural products and medicinal plants for COVID-19 prevention and treatment.

Ethnobotanical investigation on medicinal plants used by local populations in Tlemcen National Park (extreme North West Algeria)

Medicinal plants are currently used by local populations to treat different diseases around the world. In the present study, the local knowledge of medicinal plants used by indigenous populations living in the Park of Tlemcen (North-West Algeria) has been documented. A total of 254 informants with a strong ethnomedicinal knowledge living in the national park of Tlemcen were interviewed by using a questionnaire. Data collected was analyzed using quantitative indices such as the ethnobotanicity index (EI), use value (UV), and Informant Consensus Factor (FIC). 109 species belonging to 54 families were identified and used by indigenous populations to treat different diseases. The most frequent families were lamiaceae (15.5%), asteraceae (11.9%), and rosaceae (5.5%). Roots, rhizomes or tubers were the most used part for medical care (37.6%), followed by leaves (33.6%), other aerial parts (16%), fruits (8%), flowers (1.6%), and seeds (3.2%). Regarding modes of preparation, we noticed that decoction (40.4%) and infusion (28.5%) were the most predominant. Moreover, Thymus lanceolatus (UV=0.96), Origon glandulosum (UV=0.96) and Ammoides verticillata (UV=0.94) were the most frequently used species. FIC values ranged from 0.65 to 0.98. The highest FIC were recorded for reproductive and sexual disorders (0.98), respiratory tract diseases (0.98), cardiovascular system disease and blood disorders (0.94), digestive disorders (0.93), and general health (0.93). A variety of species are used to treat several ailments. Recorded species with high UV should be prioritized for conservation and subjected to further phytochemical and pharmacological studies.

Ammoides verticillata Essential Oil as Biocontrol Agent of Selected Fungi and Pest of Olive Tree

Background: Ammoides verticillata Briq is an aromatic and medicinal herb that has been widely used in folk medicine for treatment of several types of pathologies such as respiratory problems, colds, fever, headache, gastric disorders and renal infections. Objective: Essential oils have been subjected of numerous works for their antimicrobial and insecticidal properties which have been valued by hundreds of publications and patents. The main objective of this work was to evaluate the chemical composition, and the in vitro and in vivo antifungal, and insecticidal properties of essential oil of Ammoides verticillata. Methods: In this work, the air-dried aerial parts of Ammoides verticillata were hydrodistilled in a Clevenger-type apparatus. The essential oil isolated was analyzed using gas chromatography (GC) and mass spectrometry (GC/MS). The in vitro antifungal activity of the essential oil was investigated against four plant fungi using radial growth technique. The effect of the essential oil on disease development of olive caused by Penicillium crustosum and Aspergillus niger in the in vivo conditions. The fumigation test of the essential oil was evaluated against L3 stages, pupas and adults of Bactrocera oleae known as the olive fly. Results: The essential oil of A. verticillata was characterized mainly by carvacrol (44.3%), limonene (19.3%) and p-cymene (19.2%). The result of in vitro antifungal activity of essential oil showed an interesting antifungal inhibition against Alternaria alternata and Fusarium solani strains with percentage inhibition of 89%. Furthermore, oil of A. verticillata has demonstrated promising in vivo antifungal activity to control infections of olives caused by Aspergillus niger and Penicillium crustosum. In addition, the essential oil exhibited fumigation toxicity against Bactrocera oleae with mortality percentage of 100% at 2 μL/L air. Conclusion: The results showed that essential oil of A. verticillata has interesting biological activities, which suggests that oil have the potential to be used as biocide to protect olives of pathogenic fungi and pests.

Chemical variability and antioxidant activities of the essential oils of the aerial parts of Ammoides verticillata and the roots of Carthamus caeruleus and their synergistic effect in combination

Aim and Objective: Oxidative stress is implicated in the development and progression of many disease. Some of appropriate actions that could be initiated to taken to resolve the problem of these diseases are search for new antioxidant substances isolated from plants. The aims of this study were to study the intraspecies variations of A. verticillata and C. caeruleus essential oils from 8 locations using statistical analysis, the in vitro antioxidant properties of collective essential oils and in combinations. Materials and Methods: The essential oils were analyzed by GC and GC-MS. The intraspecies variations of the essential oil compositions were discussed using principal component analysis (PCA) and cluster analysis (CA). The antioxidant properties were evaluated DPPH-radical scavenging activity and β-carotene bleaching test. Results: The main components of Ammoides verticillata collective essential oil (Coll EO) were thymol (30.5%), carvacrol (23.2%), p-cymene (13.1%), limonene (12.5%) and terpinene-4-ol (12.3%). While roots of Carthamus caeruleus essential oil were dominated by carline oxide (86.2%). The chemical variability allowed the discrimination of two main Groups for both Coll EOs. A direct correlation between the altitudes, climate and the chemical compositions was evidenced. Ammoides verticulata and Carthamus caeruleus Coll Eos showed good antioxidant activity. In binary mixture, the interaction both Coll Eos and between oils rich of thymol and/or carvacrol with carlina oxide produced the best synergistic effects, compared to individual essential oils and the synthetic antioxidant (BHT). Conclusion: Ammoides verticillata and Carthamus caeruleus essential oil blends can be used as a natural food preservative and alternative to chemical antioxidants.

Chemical Composition and Combinatory Antifungal Activities of Ammoides verticillata, Allium sativum and Curcuma longa Essential Oils Against Four Fungi Responsible for Tomato Diseases

Background: Tomato is considered a model plant in genetics and is one of the most economically important crops of all those that exist in the world. Several species of fungi are reported on tomato fruit, causing damage both during cultivation and after harvest. Some of the appropriate actions that could be initiated to resolve the problem are to develop and search for new antimicrobial substances isolated from the bioactive natural products, such as essential oils. Aim and Objective: The aim of this work was to determine the chemical composition of essential oils of Ammoides verticillata, Allium sativum and Curcuma longa, to evaluate their in-vitro antifungal activities and in-vivo antifungal effect of essential oils to prevent the diseases caused by tomato. Materials and Methods: The essential oils obtained from aerial parts of plants were analyzed by GC/MS and tested for their antifungal activities against Penicillium expansum, Fusarium solani, Rhizopus stolonifer and Alternaria alternata using the radial growth technique method. The effectiveness in-vivo of the association between Allium sativum and Curcuma longa essential oils was also investigated on tomatoes inoculated by fungi. Results: The essential oil from A. verticilata was mainly composed of phenolic compounds (54.4%), the A. sativum oil was mainly composed of sulfur compounds (91.5%) and C. longa oil was dominated by oxygenated monoterpenes (82.0%). The obtained results in-vitro antifungal revealed that individual essential oils of A. verticillata and A. sativum were more active than the essential oil of C. longa against all screened microorganisms. An important antifungal effect of A. sativum and C. longa essential oils blend was obtained against P. expansum (100%), F. solani (95.2%), R. stolonifer (95.1%) and A. alternata (48.5%). Furthermore, A. sativum and C. longa essential oils blends have demonstrated promising in-vivo antifungal activity to control infection of tomato against P. expansum and R. stolonifer. Conclusion: A. sativum and C. longa essential oil blends can be used as a natural food preservative and alternative to chemical fungicides to protect stored tomato against many phytopathogens.

Synergistic Effects of Essential Oils of Ammoides verticillata and Satureja candidissima Against Many Pathogenic Microorganisms

Background: Antibiotic resistance is today one of the most serious threats to global health, food security and development. Due to the growing number of infections, treatment becomes more difficult, if not impossible, because of the loss of antibiotic efficacy. Objective: In the present investigation, the chemical composition of essential oils of Ammoides verticillata and Satureja candidissima and their synergistic effects on antimicrobial activities were investigated. Methods: The chemical composition of the essential oil was analyzed by Gas Chromatography (GC) and Gas Chromatography-Mass Spectroscopy (GC/MS). The antimicrobial activity of the essential oils was investigated using dilution-agar method against nine bacterial strains three Gram-negative Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853) and Salmonella typhi (ATCC 14028), and six Gram-positive: Staphylococcus aureus (ATCC 43300,) Clostridium sporogenes (ATCC 19404), Bacillus subtilis (ATCC 6633), Enterococcus faecalis (ATCC 7314), Lactobacillus rhamnosus (ATCC 53103) and Bacillus cereus (ATCC 14579). Results: The essential oil of A. verticillata was characterized principally by carvacrol (44,3%), Limonene (19,3%) and p-cymene (19,2%). The constituents identified of S. candidissima essential oil were principally oxygenated monoterpenes represented by pulegone (70,4%). The essential oil of A. verticillata had a good antimicrobial activity against four bacterial strains (Escherichia coli, Salmonella typhi, Lactobacillus rhamnosus and Bacillus cereus) with MIC and MBC values between 0.2-0.4 µl/ml and 0.2-6.2 µl/ml, respectively. While, S. candidissima essential oil had moderate antimicrobial activities against all strains with MIC and MBC values between 1.5-6.2 µl/ml and 6.2-12.5 µl/ml, respectively. The results of antimicrobial activity of essential oils blend presented higher antimicrobial activity against all tested bacteria with MIC and MBC values between 0.3-1.5 µl/ml and 0.4-6.2 µl/ml, respectively. Conclusion: The essential oils blend presented high antimicrobial activity compared to virgin oils. This activity can be due to the association of active compounds such as carvacrol and pulegone. These findings provide a new source of drugs that may help in therapy to lead to the development of a new treatment based on a combination of these essential oils against gram-negative and gram-positive bacteria that continue to pose a threat to public health.

Biological activities (antioxidant and antimicrobial activity) of the aqueous extracts and essential oil of Ammoides verticillata (Nounkha)

The phytochemical review conducted on the aerial part Ammoides verticillata has revealed the presence of six chemical families: flavonoids, tannins; gallic tannins, anthocyanins and the coumarins, cateichic tannins. The aqueous extract of the Ammoides verticillata could bring back the stable free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) to the yellow-colored diphenylpicrylhydrazine with an IC50 of 0.020 mg.mL-1. It is gifted with antioxidant activity, however it was less effective than vitamin C (0.001 mL-1). The essential oil of the Ammoides verticillata has presented a strong antimicrobial activity against Gram negatif germs targets of original clinical action: E. coli (ESBL) (37 mm), E. coli (39.5 mm), Klebsiella pneumoniae (36.5 mm) and especially with the yeast: Candida albicans ATCC 10231 (47 mm) and Saccharomyces cerevisie ATCC (42 mm), which are highly sensitive to the oil inhibitory action. However, the oil has presented a low activity against the bacteria P. aeruginosa (12.5 mm).