Hybrid solvothermal/sonochemical-mediated synthesis of ZnO NPs generative of (•)OH radicals: Photoluminescent approach to evaluate (•)OH scavenging activity of Egyptian and Yemeni Punica granatum arils extract

Zinc oxide NPs were synthesized solvothermally within sonochemical mediation and characterized by XRD, FTIR, SEM, EDX, elemental mapping, TEM and UV–vis. spectrophotometry. To evaluate the hydroxyl radicals ((•)OH) scavenging activity of arils extract of Egyptian (EGY-PAM) and Yemeni Punica granatum (YEM-PAM), the developed zinc oxide nano particles (ZnO NPs) as a highly productive source of hydroxyl radicals (under Solar-illumination) was used. The yield of (•)OH was trapped and probed via fluorimetric monitoring. This suits the first sensitive/selective photoluminescent avenue to evaluate the (•)OH scavenging activity. The high percentage of DPPH radical scavenging reflected higher contents of phenolics, flavonoids, and anthocyanins that were found in EGY-PAM and YEM-PAM. Although, some secondary metabolites contents were significantly different in EGY-PAM and YEM-PAM, the traditional DPPH radical scavenging methodology revealed insignificant IC(50). Unlike, the developed fluorimetric probing, sensitively discriminated the (•)OH scavenging activity with IC(50) (105.7 µg/mL) and lower rate of (•)OH productivity (k = 0.031 min(−1)) in case of EGY-PAM in comparison to IC(50) (153.4 µg/mL) and higher rate of (•)OH productivity (k = 0.053 min(−1)) for YEM-PAM. Our findings are interestingly superior to the TBHQ that is synthetic antioxidant. Moreover, our developed methodology for fluorimetric probing of (•)OH radicals scavenging, recommends EGY-PAM as (•)OH radicals scavenger for diabetic patients while YEM-PAM exhibited a better (•)OH radicals scavenging appropriate for high blood pressure patients. More interestingly, EGY-PAM and YEM-PAM exhibited high anticancer potentiality. The aforementioned (•)OH and DPPH scavenging activities as well as the anticancer potentiality present EGY-PAM and YEM-PAM as promising sources of natural antioxidants, that may have crucial roles in some chronic diseases such as diabetics and hypertension in addition to cancer therapeutic protocols.