Abstract
In this study we investigated the phytoconstituents Calluna vulgaris, Ferula hermonis and Tribulus terrestris, and then assessed their possible biological activities by using standard methods. A preliminary phytochemical investigation of the three extracts revealed the presence of alkaloids, flavonoids, proteins, lipids, phenolic compounds, saponins, sterols and amino acids. Three extracts showed anti-oxidant effect as they inhibited the 1,1-diphenyl-2-picryl hydrazyl (DPPH) oxidation and production of thiobarbituric acid reactive substances (TBARS). Moreover, three extracts showed anti-acetylcholiesterase (AChE) and this effect was concentration dependent. C. vulgaris was the most potent inhibitor of AChE. Furthermore, the three plant extracts had an inhibitory effect toward α-glucosidase. The inhibitory effect was concentration dependent and the most potent inhibitor for α-glucosidase was the extract from T. terrestris. Calluna vulgaris showed anti-inflammatory effect at tested concentrations while the other two extracts exhibited this effect only at concentration of 25 μg/mL. Finally, C. vulgaris had a significant effect against pathogenic bacteria (Agrobacterium tumefaciens, Erwinia sp., Klebsiella pneumonia and Pseudomonas aeruginosa) in comparison to other extracts from Ferula sp., or Tribulus sp. In conclusion, all tested extracts could be promising sources for the treatment of diabetes, Alzheimer's disease, infectious diseases and oxidative stress related disorders because they are rich in phenols and flavonoids that give anti-oxidant molecules and produce an inhibitory effect against the tested enzymes.