The purpose of this study was to investigate whether
all-trans retinoic acid (ATRA) has
antioxidant property. The study was also focused on its inhibitory effect on the acute and chronic
inflammation and
tumor-associated capillary formation in terms of angiogenesis in C57BL/6 mice after incorporated in
liposome composed of
distearoylphosphatidylcholine (DSPC/
cholesterol). ATRA possesses a number of important
biologic activities including oncostatic,
antioxidant and immunostimulatory actions. Our study was designed to evaluate the
antioxidant activity of free ATRA by
nitric oxide scavenging,
superoxide radical scavenging,
hydroxyl radical scavenging and
lipid peroxide scavenging assays. The ATRA showed significant scavenging activities in all these
antioxidant assays comparable to the standard
antioxidant. We have also evaluated the activity of encapsulated ATRA against anti-inflammatory activity in C57BL/6 mice. The paw oedema inhibition was found in
carrageenan model as 55.56% and 66.67% for free ATRA and encapsulated ATRA treatment respectively and for
formaldehyde model it was found to be 60.87% and 69.57% respectively compared with saline treated control mice. Encapsulated ATRA inhibited the
tumor-associated capillary formation in mice induced by highly metastatic B16F10
melanoma cells significantly than the free ATRA did. In this study the inhibition of
tumor-directed capillary formation was found to be 56.25% and 62.50% for free ATRA and encapsulated ATRA treatment respectively. In conclusion, ATRA showed a significant
antioxidant property in vitro. Free ATRA has anti-inflammatory activity as proved by us in animal model of acute and chronic
inflammation and antiangiogenesis activity. Furthermore, its activity was boosted by encapsulation in
liposome.