Abstract
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)-O-center dot) 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)-O-center dot was trapped and probed via fluorimetric monitoring. This suits the first sensitive/selective photoluminescent avenue to evaluate the (OH)-O-center dot 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 IC50. Unlike, the developed fluorimetric probing, sensitively discriminated the (OH)-O-center dot scavenging activity with IC50 (105.7 mu g/mL) and lower rate of (OH)-O-center dot productivity (k = 0.031 min(-1)) in case of EGY-PAM in comparison to IC50 (153.4 mu g/mL) and higher rate of (OH)-O-center dot 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)-O-center dot radicals scavenging, recommends EGY-PAM as (OH)-O-center dot radicals scavenger for diabetic patients while YEM-PAM exhibited a better (OH)-O-center dot radicals scavenging appropriate for high blood pressure patients. More interestingly, EGY-PAM and YEM-PAM exhibited high anticancer potentiality. The aforementioned (OH)-O-center dot 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.