Background: Several species of the genus Launaea are used in folk medicine such as in bitter stomachic, skin diseases, and reported to have antitumor, insecticide, and cytotoxic activities. The antimicrobial activities of coumarin constituents and the neuropharmacological properties have been investigated as well. In this study, the chemical composition of essential oils from Launaea resedifolia L. has been identified using the ordinary GC-MS technique to reveal the presence of 19 compounds dominated by dioctyl phthalate. Moreover, the antibacterial activity of the crude oil has been carried out using disk diffusion method against seven bacteria strains. Results: Nineteen compounds of essential oil of L. resedifolia L. were identified, representing 86.68% of the total oil. The compounds were identified by spectral comparison to be mainly esters, alcohols, ketones, and terpenes. The principal constituents are dioctyl phthalate (39.84%), Decanoic acid, decyl ester (12.09%), 11-Octadecenal (11.24%), and Eucalyptol (07.31%), while others were present in relatively small amounts. As far as antibacterial essays are concerned, it was found that the oils are active against most of the tested bacterial strains. Conclusion: A major constituent in visible parts was Dioctyl phthalate (39.84%) and the yield of essential oils was 0.9%. These extracts reveal in vitro antibacterial activity on the studied bacterial, confirmed by the inhibition zone diameter ranging from 11 to 37 mm and a MIC value between 0.09 and 0.69 depending on the microorganism being tested.

Arab Y, Sahin B, Ceylan O, Zellagui A, Olmez OT, Kucukaydin S, Tamfu AN, Ozturk M, Gherraf N. 2022. Assessment of in vitro activities and chemical profiling of Senecio hoggariensis growing in Algerian Sahara. Biodiversitas 23: 3498-3506. The in vitro antioxidant, anticholinesterase, tyrosinase inhibitory, antibiofilm, and anti-quorum sensing activities of the ethyl acetate extract of Senecio hoggariensis,growing in Algerian Sahara, were studied along with its chemical constituents using HPLC-DAD. The chromatographic analysisunveiled seven phenolic compounds, including p-coumaric acid as a major component. Additionally, the extract showed moderate DPPH radical scavenging activity, compared to known standards. At 200 ?g/mL, the extract disclosed equitable acetylcholinesterase (AChE), butyryl-cholinesterase (BChE) and tyrosinase inhibition rates with respective values of 37.01±1.48%, 18.87±4.18% and 45.99±1.81%. Likewise, the extract exhibited a good antibiofilm activity against Candida albicans ATCC 10239 biofilm production with an inhibition ratio of 59.56±0.40%, at 50µg/mL. The anti-quorum sensing by QS-regulated violacein pigment production inhibition test was determined using Chromobacterium violaceum CV026 and CV12472. The swarming motility inhibition assay was determined using Pseudomonas aeruginosa PA01. It is evident from the findings that Senecio hoggariensis could be considered potential antioxidant, anti-QS, and antibiofilm compounds. However, the origin of anti-biofilm and anti-quorum sensing activities of the ethyl acetate extract could be revealed by further studies on the mechanism of action of active compounds that can be isolated via activity-guided fractionation.

Background: These days, the desire for naturally occurring antioxidants has significantly increased, especially for use in foodstuffs, cosmetics, and pharmaceutical products, to replace synthetic antioxidants that are regularly constrained due to their carcinogenicity. Methods: The study in hand aimed to appraise the antioxidant effect of two Euphorbia dendroides extracts using reducing power, anti-peroxidation, and DPPH (1,1 Diphenyl 2 Pycril Hydrazil) scavenging essays, in addition to the anticancer activity against two tumor cell lines, namely C6 (rat brain tumor)cells, and Hela (human uterus carcinoma)cell lines. Results: The results indicated that the ethyl acetate extract exhibited antiradical activity of 29.49%, higher than that of n-butanol extract (18.06%) at 100 µg/mL but much lower than that of gallic acid (78.21%).The ethyl acetate extract exhibits better reducing capacity and lipid peroxidation inhibitory activity compared to n-butanol extract but less than all tested standards. Moreover, the ethyl acetate extract was found to have an antiproliferative activity of more than 5-FU (5-fluoro-Uracil) against C6 cells at 250 µg/mL with IC₅₀ and IC₇₅ of 113.97, 119.49 µg/mL, respectively, and good cytotoxic activity against the Hela cell lines at the same concentration. The HPLC-TOF-MS (high performance liquid chromatography-Time-of-flight-Mass Spectrometry) analyses exposed the presence of various compounds, among which Gallic and Chlorogenic acids functioned as major compounds. Conclusions: The two extracts exhibited moderate anticancer abilities and behaved somewhat as average antioxidant agents. Based on the total phenolics and flavonoids contents, as well as HPLC results, it could be concluded that antiproliferative and antioxidant activities depend upon the content of different phenolics and flavonoids.