In vitro study of anti-oxidative effects of β-carotene and α-lipoic acid for nanocapsulated lipids

In this study we attempted to assess the efficacy of the in vitro activities of β-carotene and α-lipoic acid in conjugation with an encapsulated lipid. Nanoemulsion was prepared and freeze-dried to get nanocapsules. Highest encapsulation efficiency 84.32 ± 1.08% was achieved for α-lipoic acid nanocapsules, whereas for β-carotene nanocapsules it was 79.63 ± 1.41%. Morphology study showed that the dried capsules had an irregular, rough surface. Both anti-oxidants were equally effective in releasing core materials. Complete release of the total lipid occurred within 210 min from both β-carotene and α-lipoic acid bearing nanocapsules. Stability study revealed that β-carotene nanocapsules showed decrease in oil content from 79.63 g lipid to 72.8 g lipid for every 100 g lipid encapsulated, in 3 months, whereas α-lipoic acid nanocapsules retained oil much better, the oil retention being from 84.32 g lipid to 78.08 g lipid per 100 g lipid encapsulated. DPPH radical scavenging activity of β-carotene and α-lipoic acid ranged from 62.75% and 44.13% to 32.94% and 36.95% (after 90 days) respectively. Reducing activity of β-carotene was higher (absorbance 0.492 to 0.291 at 90 days) compared to α-lipoic acid (absorbance 0.243 to 0.109 after 90 days). Again β-carotene and α-lipoic acid metal-chelation activity ranged from 47.65% and 48.59% to 32.315% and 39.29% after 90 days.

► In vitro efficacy of β-carotene and α-lipoic acid has been compared. ► α-Lipoic acid nanocapsules show higher encapsulation efficiency. ► Both varieties facilitated lipid release from nanocapsules within 210 min. ► α-Lipoic acid nanocapsules show better shelf-life and metal-chelation properties. ► β-Carotene shows greater reducing activity than α-lipoic acid.