Introduction: Synthetic colourants are subject to various allergies. As a result, the use of plant-based additives has proved promising. Objective: It is in this perspective that our objective was undertaken to investigate natural colourants from edible cactus. Opuntia species populations were singlesequence repeat (SSR) fingerprinted, the analysis of betalains and phenolic compounds and the evaluation of their biological potentials were also characterised. Results: Photometric quantification of betalains and phenols showed an interspecific variation across Opuntia species. Opuntia ficus indica fruits showed the highest betalain [betaxanthins; 843.67 and betacyanins; 1400 mg/100 g dry weight (DW)] and polyphenol contents. Reversed-phase high-performance liquid chromatography (RP-HPLC) analysis showed that the variation of individual phenols profile was influenced by interspecific and genetic factors. Isorhamnetin-O-(di-deoxyhexosylhexoside) was the major compound and its content varied according to Opuntia species, while catechol was the predominant phenolic compound in O. humifusa with 1.88 μg/g DW. Concerning cactus species, Opuntia colourants exhibited a potent antiradical activity [half maximal inhibitory concentration (IC 50) up to 1 μg/mL]. Opuntia species were effective against Gram-positive and Gram-negative bacterial strains [inhibition zone (IZ) up to 27 mm]. A high genetic diversity within Opuntia genotypes based on SSR markers was revealed. UPGMA (unweighted pair group method with arithmetic mean) dendrogram and PCoA (principal coordinate analysis) based on natural pigments and antimicrobial profiles indicated significant variation. The correlation approach proved the presence of a probably metabolic relationship between genetic markers, pigments and their biological activities. Conclusion: A possible association between molecular approach and metabolic profile analysis of Opuntia allows tracing the relationship among species for its genetic conservation.

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The present study investigated the antioxidant, antibacterial, antiviral and anti-inflammatory activities of different aerial parts (flowers, leaves and seeds) of Datura stramonium. The plant material was extracted with 80% methanol for about 24 h. The sensitivity to microorganisms analysis was performed by the microdilution technique. Antioxidant tests were performed by scavenging the DPPH and ABTS radicals, and by FRAP assay. Anti-inflammatory activity was evaluated through the inhibition of nitric oxide production in activated macrophage RAW 264.7 cells. Cell viability was assessed with an MTT assay. Results show that the flower extract revealed a powerful antimicrobial capacity against Gram-positive bacteria and strong antioxidant and anti-inflammatory activities. No significant cytotoxicity to activated macrophages was recorded. High resolution electrospray ionization mass spectrometry and nuclear magnetic resonance analysis identified two molecules with important anti-inflammatory effects: 12α-hydroxydaturametelin B and daturametelin B. Molecular docking analysis with both pro-inflammatory agents tumor necrosis factor alpha and interleukin-6 revealed that both compounds showed good binding features with the selected target proteins. Our results suggest that D. stramonium flower is a promising source of compounds with potential antioxidant, antibacterial, and anti-inflammatory activities. Isolated withanolide steroidal lactones from D. stramonium flower extract with promising anti-inflammatory activity have therapeutic potential against inflammatory disorders.