Comparative Analysis of the In Vitro and In Vivo Antioxidant and Anti-Inflammatory Capacities of Lycopene Extracts...

The sources of natural lycopene are diverse, and lycopene from different sources may have differences in functional characteristics and bioavailability. In this study, lycopene was extracted from tomatoes, cherry tomatoes, red guavas, carrots, and watermelons by ultrasonic-assisted extraction, and the structures were characterized. The differences in their in vitro and in vivo antioxidant capacities and anti-inflammatory capacity in vivo were compared. The results showed that under the extraction conditions of this experiment (sample: ethyl acetate: 1:5 m/v, 40 °C, 600 W, 40 kHz, 30 min), lycopene (primarily all-trans structure) from different sources could be effectively extracted from the above five raw materials. The concentration of lycopene extracted from the four samples except tomatoes (14.03 ± 1.08 mg/100 g fresh weight (FW)) was about 30 mg/100 g FW. The analysis of the in vitro antioxidant capacity of lycopene from five different sources showed that the 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), diphenyl-1-picrylhydrazyl (DPPH) scavenging rates and ferric reducing antioxidant power (FRAP) concentration of the red guava lycopene-rich sample were significantly higher than those of the other four sources of lycopene. Based on the in vitro performance of lycopene from five sources, further in vivo experiments (using only the tomato and red guava groups) also found that compared with lycopene from tomatoes, lycopene-rich extract from red guavas could significantly increase the antioxidant enzyme activities and total antioxidant capacity in the serum, liver and gastrocnemius muscle (GAS) of mice; reduce the malondialdehyde (MDA) concentration; and also increase the expression of antioxidant-related genes (GPx, CAT, SOD1, etc.) in the liver and GAS of mice by regulating the Nrf-2/keap1 signaling pathway. In addition, mice in the guava-derived lycopene-rich group had lower serum levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). In summary, these results indicated that the lycopene-rich extract derived from red guava demonstrated higher antioxidant activity both in vitro and in vivo as well as enhanced anti-inflammatory capabilities within the body, providing an important reference for its application in the food industry and functional foods.