Abstract
Natural substances have gained considerable attention for skin protection against UV light reactions. Artocarpus altilis plant's heartwood extract is comprised of artocarpin as a major substance, already known for its interesting biological attributes as an antimicrobial, an anti-inflammatory, an antioxidant, and a melanogenesis inhibitor. The present work clarified the mechanism of natural artocarpin (NAR) with a purity of approximately 99% against the effects of UVB-induced HaCaT keratinocyte apoptosis. The indicated results showed that NAR suppresses free radical production (ROS and nitrite) and apoptosis-related molecule activation (caspase-3, p-p53, p-p38, and NF-κB p65) and secretion (TNF-α). Additionally, NAR prevented structural damages (nuclei condensation and fragmentation, apoptotic body formation, impaired cell adherence and round cell shape, disruption of F-actin filament, and clustering of cell death receptor CD95/Fas) and biophysical changes (plasma membrane rigidification). Thus, NAR acts directly from scavenging free radicals generated by UV and indirectly by suppressing morphological and biochemical UV-induced cell damages. Its biological effects are mainly attributed to antioxidant and antiapoptotic properties. Taken together, NAR could be considered as an effective natural product for photoprotective formulations.