Phytochemical Constituents, Antibacterial and Antioxidant Activities of some Medicinal Plants

Abstract

The present study provides a detailed description of the phytochemical analysis, physiological features and biological activities of four selected plant species, namely Calligomum polygnoides subsp. comosum and Nicotiana glauca collected from the coastal desert in the Delatic Mediterranean Sea, as well as Hyoscyamus muticus and pulicaria undulate subsp. Undulata collected from the inland desert in Wadi Hagul and Wadi El-Molaak in the North of Eastern Desert in Egypt. The obtained results showed that, the studied plant species are relatively rich in proximate constituents, elements and bioactive secondary metabolites. Hyscyamus muticus leaves appeared to accumulate ABA in highest magnitude if compared to Nicotiana glauca, Pulicaria undulata subsp. undulata and Calligonum Polygonoides subsp. comosum. Antioxidant enzymes as well as DPPH scavenging activities in leaves of Nicotiana glauca, found to be the highest activity in catalase, perioxidase and polyphenol oxidase as well as antioxidant activity and IC50 as compared to other selected plant species. On the other hand, Calligonum polygonoides subsp. comosum attained the highest activity of phenylalanine ammonia lyase and the weakest antioxidant activity with IC50 value (0.29 mg ml-1). The highest ratio of total saturated fatty acids to unsaturated fatty acids was recorded in Nicotiana glauca, while the lowest one was found in Calligonum polygonoides subsp. comosum. Concerning the biological activities, the methanolic extract of Nicotiana glauca showed the highest antioxidant activity, while the extract of Calligomum polygnoides subsp. comosum exhibited the weakest antioxidant activity. The methanolic extract of Pulicaria undulata subsp. undulata showed the highest antimicrobial activity, followed by the extracts of Hyoscyamus muticus, Nicotiana glauca and finally by Calligomum polygnoides subsp. comosum. On the other hand, the aqueous extract of Nicotiana glauca showed, the highest inhibition percentages of seed germination, radical growth and plumule growth of summer weed Portulaca oleracea, followed by the extracts of Pulicaria undulata subsp. undulata, Hyoscyamus muticus and finally by Calligomum polygnoides subsp. comosum. Therefore, it can be concluded that, the selected plant species in the present study are obviously considered as tolerant species against extreme drought and salinity. These species could be also used as natural renewable resources in numerous beneficial purposes such as medicine industry, natural antioxidants, antimicrobial agents and allopathic potential for biological control of weeds.