The taxonomic diversity and the richness of the region of Seraidi (North-East Algeria) in medicinal plants, as well as the appearance of diseases of viral origin, in particular, the current pandemic of SARS-CoV-2, led us to the realization of an ethnobotanical survey of plants with antiviral interests. The survey was conducted based on a pre-established quiz, with 120 people from different categories of the population of Seraidi, with the aim of listing the medicinal plants used in the treatment of viral diseases and collecting as much information as possible on this subject. After analyzing, the information provided by the people interviewed, we listed 32 species belonging to 20 families, of which the Lamiaceae family is the most represented. Older women are the most affected by the use of plants; people without a higher intellectual level have the most knowledge about the use of plants with antiviral interest. The leaf is the most widely used organ, in the form of a decoction or infusion, administered orally.

The plant world is an excellent source of active ingredients, which gives it significant antibacterial activity, often sought after in alternative medicine and the food industry for food preservation. Our work focuses on the study of essential oil extraction and study of the biological activities of a medicinal plant, Urtica dioica (Urticaceae). The phytochemical screening study of the aerial part of the plant confirmed the presence of alkaloids, tannins, saponosides, flavonoids. And the absence of coumarins and volatile oil. The results obtained show that the water content of the studied plants was observed with 13.74%. The extraction yield in methanol-water mixture is low compared to that of water which is 20.8%. The results obtained for total polyphenol contents (mg EAG/g RS) in the two extracts are of the order of: 26.02(EM); 19.26 (AQE). The flavonoid content is around 86.43 (EAq); 10.26 (EM). Condensed tannin content is around 22.29 (EAq); 26.17 (EM).The percentage inhibition of the DPPH radical only reached 05% inhibition with the aqueous extract and even for the methanolic extract the activity did not exceed 19% inhibition of the DPPH radical. The antimicrobial activity was determined on four bacterial strains, according to the disc diffusion method, the four strains studied show sensitivity towards plant extracts, the results indicate that the two extracts have a good antimicrobial activity against the strains tested (Escherichia coli, Staphylococcus aureus, Klebsiella pneumonia, Proteus mirabilis) and which act differently on the strains tested.

This work is based on an ethnobotanical inventory of plants used in traditional medicine in the El Oued region. The goal of this work was to enhance the medicinal plants in the region of El Oued through a survey directed to people who have information on medicinal plants and their use in the region as herbalists, traditional healers, nomads, and some of the city population. Therefore, we inventoried 73 plants belonging to 37 families, and the largest are the families Asteraceae and Lamiaceae, with 9 species each. According to the indigenous population, the spontaneous, local and perennial plants are the most used in the treatment because of their availability in a sustainable environment. Based on these plants and by oral administration with the decoction method of preparation, the population of El Oued uses the natural remedy to treat the majority of digestive and Broncho-pulmonary diseases, representing respectively the rates of (27,22%) and (13,29 %).