Preliminary investigation of Haloxylon persicum and Heliotropium bacciferum plants from the United Arab Emirates for possible development of new drugs

Natural antioxidants from plants have proved to be effective against various free radicals that contribute to human diseases. In this study, we aimed to explore the phytochemicals, mineral composition, antioxidant and free radical scavenging activities of methanolic extracts derived from Haloxylon and Heliotropium species, specifically Haloxylon persicum and Heliotropium bacciferum. These two plants are native to the arid regions. Phytochemical screening and macro-and micro-elemental analysis of the leaf extracts were done. Four different in vitro antioxidant assays (ABTS, DPPH, superoxide anions, hydroxyl radicals) were performed to investigate the scavenging properties of these plant extracts. Both H. persicum and H. bacciferum extracts contained flavonoids, tannins, phenols, and cardiac glycosides. H. persicum contained steroids while H. bacciferum contained alkaloids, saponins, and terpenoids. Results of the mineral analysis revealed significant levels of macro-and micro-elements in the studied Haloxylon and Helitropium species. While H. persicum exhibited high amounts of Mg (12.16 mg/kg), H. bacciferum had elevated levels of Ca (38.45 mg/kg) and S (6.73 mg/kg). Micronutrient content was particularly high in H. persicum, with varied composition of Cr (8.46 mg/kg), Ni (8.06 mg/kg), Pb (3.55 mg/kg), and Zn (60.73 mg/kg). Antioxidant activity analysis demonstrated that the methanolic extract of H. bacciferum displayed efficient scavenging activity against ABTS, DPPH, and hydroxyl radicals at a concentration of 160 µg/ml, inhibiting them by 81.23%, 83%, and 83.46%, respectively, with IC₅₀ values of 5.9 µg/ml, 26.16 µg/ml, and 25.82 µg/ml, respectively. Meanwhile, the methanolic extract of H. persicum exhibited the highest superoxide anion scavenging activity, at 160 µg/ml, with an inhibition of 80.06% and an IC50 value of 26.03 µg/ml. Methanolic extracts from the leaves of H. persicum and H. bacciferum are promising sources of natural antioxidants and has the potential to serve as effective free radical inhibitors in plant-based pharmaceutical products.