Antioxidant Properties of Volatile Oil of Indian Propolis
Dattatraya G Naikand Harshada S Vaidya
Antioxidant properties shown by volatile oil of propolis (VOP) from India were investigated by spectrophotometric methods (ABTS, DPPH and NO radical scavenging activity) and a photochemiluminescence (PCL) method (superoxide scavenging activity). It was seen that VOP exhibited superior TEAC activity to that of trolox at the concentration 0.2 mg/mL. It showed dose dependent DPPH radical scavenging activity and NO scavenging activity. It was observed that the overall NO scavenging activity shown by VOP was low which suggests that some of the compounds responsible for NO radical scavenging might be nonvolatile and might not be present in VOP. The superoxide scavenging activity of VOP was determined on nano scale by PCL method. These results indicate that superoxide scavenging activity was more efficient in dilute solutions of VOP. The polyphenol content in the VOP samples was also determined. It was seen that polyphenol content may not be the exclusive cause for the antioxidant activity. From IC50 values it could be concluded that the efficiency of scavenging ABTS radicals by the VOP was more pronounced as compared to scavenging other radicals. These findings indicate that VOP could be an easily accessible source of natural antioxidants.