Phytochemical Content, Antioxidant and Antimicrobial Effects of Thapsia garganica L. Leaves and Roots Grown Wild in North-west Algeria

Background: Oxygen-centre free radicals and other reactive oxygen species (ROS) are continuously produced in vivo, resulting in cell death and tissues damage. Besides, the increasing resistance to existing antimicrobial agents has become a major problem. The present study aims to evaluate the antioxidant and antimicrobial activities of the Thapsia garganica L. leaves and roots. Methods: Broth dilution and single spore methods were developed and seven microorganisms were used. The evaluation was performed by measuring the diameter of the growth inhibition zones around the holes via the determination of the inhibition percentage of mycelium growth. Result: The determination of the polyphenol contents, total flavonoids and condensed tannins of the aqueous extract for both leaves and roots gave respectively (2.21 mg, 2.63 mg/100 mg gallic acide equivalents), (2.39 mg, 0.49 mg/100 mg catechin equivalent), (0.12 mg, 0.04 mg/100 mg catechin equivalent) in dry matter. The results of antioxidant activity showed that the methanolic, flavonoids and tannins extracts showed a potent scavenging activity with IC50 = 0.41; 0.81; 1.39; 1.80 and 1.90 mg/ml, respectively. As regards for antimicrobial activity, an important inhibition of the proposed extracts has been observed against the tested strains.

Exploring evolutionary theories of plant defence investment using field populations of the deadly carrot

Background and Aims There are a number of disparate models predicting variation in plant chemical defences between species, and within a single species over space and time. These can give conflicting predictions. Here we review a number of these theories, before assessing their power to predict the spatial–temporal variation of thapsigargins between and within populations of the deadly carrot (Thapsia garganica). By utilizing multiple models simultaneously (optimum defence theory, growth rate hypothesis, growth–differentiation balance hypothesis, intra–specific framework and resource exchange model of plant defence), we will highlight gaps in their predictions and evaluate the performance of each. Methods Thapsigargins are potent anti-herbivore compounds that occur in limited richness across the different plant tissues of T. garganica, and therefore represent an ideal system for exploring these models. Thapsia garganica plants were collected from six locations on the island of Ibiza, Spain, and the thapsigargins quantified within reproductive, vegetative and below-ground tissues. The effects of sampling time, location, mammalian herbivory, soil nutrition and changing root-associated fungal communities on the concentrations of thapsigargins within these in situ observations were analysed, and the results were compared with our model predictions. Key Results The models performed well in predicting the general defence strategy of T. garganica and the above-ground distribution of thapsigargins, but failed to predict the considerable proportion of defences found below ground. Models predicting variation over environmental gradients gave conflicting and less specific predictions, with intraspecific variation remaining less understood. Conclusion Here we found that multiple models predicting the general defence strategy of plant species could likely be integrated into a single model, while also finding a clear need to better incorporate below-ground defences into models of plant chemical defences. We found that constitutive and induced thapsigargins differed in their regulation, and suggest that models predicting intraspecific defences should consider them separately. Finally, we suggest that in situ studies be supplemented with experiments in controlled environments to identify specific environmental parameters that regulate variation in defences within species.

Seeds, Leaves and Roots of Thapsia garganica as a Source of New Potent Lipases Inhibitors: In vitro and In silico Studies

Background and Objective: Lipase inhibitors have gained great interest because they could help in the therapy of many diseases, however, unfortunately, only a few drugs are currently available on the market. Therefore, the aim of this work was to evaluate for the first time the lipase inhibition effect of Thapsia garganica extracts from seeds, leaves and roots. Methods: Polyphenols and flavonoids contents were determined using spectrophotometric method. Inhibitory activity of ethyl acetate extracts from seeds, leaves and roots of T. garganica against Candida rugosa lipase was determined. To uncover the active constituents responsible for this anti-lipase activity, further investigations were performed by employing theoretical docking simulations, using AutoDock Vina program to discuss the nature of interactions and the inhibition mechanism by major bioactive compounds synthesized by this plant. Results: Seeds, leaves and roots extracts of T. garganica showed appreciable contents of polyphenols and flavonoids which is most in seeds extract with 2.90±0.02mg GAE/gdw and 1.53±0.05mg QE/gdw, respectively. Hence, their inhibitory activities against Candida rugosa lipase were determined as IC50 of 1.19mg/ml, 1.96mg/ml and 1.87mg/ml, respectively. Docking simulations have shown that nortribolid and tribolid are best inhibitors for both lipases (Candida rugosa and human pancreatic lipases). Conclusion: Testing the anti-lipase activity of the ethyl acetate extracts of T. garganica revealed a potent lipase inhibition activity, which suggests the use of these molecules as anti-obesity drugs.