Background There is increasing interest in the pharmaceutical and food industries to substitute synthetic chemicals with naturally occurring compounds possessing bioactive properties. Plants are valuable sources of bioactive compounds. The present study investigates the chemical composition and antioxidant, antimicrobial, and anticancer activities of ethanolic extracts (EEs) and essential oils (EOs) from two species in the Lamiaceae family, Ocimum basilicum L. and Thymus algeriensis Boiss. & Reut., cultivated in the Algerian Saharan Atlas. Methods The total flavonoid contents of the plants’ ethanolic extracts were determined by the aluminium chloride method, while the total phenols were determined using the Folin-Ciocalteu method. Essential oils were obtained by hydrodistillation of the aerial parts of the plants and were analysed by GC-MS. The free radical-scavenging ability and antioxidant potential of the plants’ EEs and EOs were probed using the 2, 2-diphenyl-picrylhydrazyl radical-scavenging, ABTS radical-scavenging, ferric-reducing power and phosphomolybdenum assays. The antimicrobial activities were evaluated against several pathogens characteristic of gram-negative bacteria (three species), gram-positive bacteria (three species) and fungi (two species). The microdilution method was used to estimate the minimum inhibitory concentrations (MICs). The oils’ anticancer potential against several cancer types was also studied using the MTT assay and reported as the toxic doses that resulted in a 50% reduction in cancer cell growth (LD 50 ). Results Phenolic compounds in the EEs from both plants were analysed by HPLC and demonstrated a rich flavonoid content. Chemical analysis of the essential oil from Ocimum basilicum revealed 26 unique compounds, with linalool (52.1%) and linalyl acetate (19.1%) as the major compounds. A total of 29 compounds were identified in the essential oil from Thymus algeriensis , with α-terpinyl acetate (47.4%), neryl acetate (9.6%), and α-pinene (6.8%) as the major compounds. The ethanolic extracts and essential oils from both plants exhibited moderate antioxidant activities and moderate to weak antimicrobial activities. Furthermore, anticancer activities against the examined human cancer cell lines were associated with only the EOs from both plants, with LD 50 values ranging between 300 and 1000 μg/mL. Conclusion The results suggest that the bioactive compounds found in the ethanolic extracts and essential oils from Ocimum basilicum and Thymus algeriensis , with diverse antioxidant, antimicrobial and anticancer activities, may have beneficial applications in nutraceutical and pharmaceutical technologies.

BackgroundMentha spicata (M. spicata) is a member of Lamiaceae that spreads mainly in the temperate and sub-temperate zones of the world. It is considered as a rich source of essential oils, which is widely used in pharmaceutical industries and food production. The objectives of the current study were to evaluate chemical composition, antioxidant, antimicrobial and antiproliferative activities associated with the essential oil of M. spicata cultivated in Algerian Saharan Atlas.MethodsThe aerial parts of M. spicata were subjected to hydrodistillation to produce the oil. Chemical identification of the oil composition was conducted by GC and GC-MS analyses. The antioxidant activity of the hydrodistilled oil was studied using DPPH, ABTS radical scavenging and ferric-reducing power assay. Antimicrobial potential was characterized against two microorganisms, signifying Gram positive, and Gram negative bacteria, and one Candida species. The microdilution method was employed to determine the minimum inhibitory concentration (MIC). The oil’s antiproliferative effects against three human tumor cell lines were also investigated using the MTT assay, and the toxic doses that yielded 50% reduction of cell viability (LD50) were reported.ResultsChemical analysis of the essential oil composition revealed 44 unique compounds with oxygenated monoterpenes (67.2%), followed by monoterpene hydrocarbons (20.8%), as the most abundant chemical components. Essential oil of M. spicata demonstrated moderate antioxidant activities as well as moderate to weak antimicrobial activities with best susceptibility observed for Gram positive bacteria towards the oil. In addition, anticancer activities that are associated with the oil against three human cancer cell lines were observed with LD50 values of 324 μg/mL, 279 μg/mL, 975 μg/mL against T47D, HCT-116 and MCF-7 cell lines, respectively.ConclusionThe results suggest that M. spicata essential oil may have potential value as a bioactive oil, for nutraceutical and medical applications, with its antioxidant, antimicrobial and antiproliferative activities.

We compared the phytochemical constituents and antioxidant activities of three important species of Lamiaceae in Algeria (Mentha spicata, Ocimum basilicum and Thymus algeriensis). We noticed that the M. spicata species contains the largest fraction of phenolic and flavonoid products (231 and 22 mg / g) than the other two species studied. Other hand we founded that the two species M. spicata and T. algeriensis show excellent antioxidant activity in the ethanolic extract according to the two tests (DPPH and ABTS) compared to the ascorbic acid of reference. But the specie O. basilicum has good antioxidant activity in aqueous extraction. This Lamiaceae family takes an important place in the lives of Algerians citizens, so this species are very good source of natural antioxidant compounds in algerian traditional medicine. Keywords: Antioxidant activity, Lamiaceae, Mentha spicata, Ocimum basilicum and Thymus algeriensis, DPPH.

Lavandula officinalis is one of the important Algerian plants, it is traditionally used in the treatment of stomach ailments, headaches, infections, and aches. The aim of this study was to determine the chemical constituents of essential oils of aerial parts of L. officinalis growing wild in South Algerian (Laghouat region). The chemical composition of essential oil analyzed using a Gas Chromatography/ Mass Spectrometry (GC-MS) technique. The yield obtained of essential oil is 2.8%. The essential oil of L. officinalis characterized by the presence of linalool (35.8%), Linalyl acetate (21%), Camphor (7.2%) and α-Terpineol (5.2%) as major compounds.The quality of lavender oil produced in Laghouat region can be compared with other parts of the globe which indicates its international quantity.