ABSTRACT
Many biological activities have been reported for the Ilex genus. However, few studies in the literature have reported on guayusa. To address this gap in our knowledge, chemical analysis of guayusa leaves was made. Extracts were obtained by applying Soxhlet, maceration, supercritical CO2 and pressurised liquid extraction techniques, using water and ethanol as solvent/cosolvent. Extracts were evaluated for their phenolic content and antioxidant capacity. The chemical profile was obtained from HPLC. In raw guayusa leaves were identified caffeine (2.27 ± 0.05%), protein (15.31 ± 0.07%) and lipids (11.81 ± 0.14%). Extracts presented the highest phenolic content (156.56 ± 1.32 mg GAE g-1) and the best antioxidant activity (EC50= 61.85 ± 0.21 µg mL-1) when water was used as solvent/cosolvent. Through HPLC, three main substances were determined and quantified in the extracts: caffeine, theobromine and 5-caffeoylquinic acid. Based on these results, guayusa may be considered a natural source of compounds with potential application in the food and pharmaceutical industries.
ABSTRACT
Jackfruit seeds are an underestimate residue having important biological activity such as anti-inflammatory, cytotoxicity and antimicrobial effects. However few researches have been done for this material using alternative extraction technologies, so this study aimed to evaluate the extraction of triterpenes and sterols from jackfruit seed by applying high- and low-pressure techniques. Response surface methodology (RSM) was used to determine the best conditions of pressure, temperature and CO2 flow rate for extraction with supercritical CO2. The yield and profile of these compounds were compared with the low pressure technique, which was considered as a reference. In vitro biological tests of anti-inflammatory activity and cytotoxicity in L929 and RAW 264.7 cells were also performed. The best extraction conditions in SFE for sterols were 40 °C/20 MPa/4 mL min-1 (0.832 ± 0.007 mgSR g-1 sample) and 40 °C/20 MPa/3 mL min-1 (0.800 ± 0.009 mgSR g-1 sample), for triterpenes were 50 °C/12 MPa/4 mL min-1 (1.501 ± 0.004 mgTT g-1 sample) and 45 °C/9.3 MPa/3.5 mL min-1 (1.485 ± 0.004 mgTT g-1 sample). No cytotoxic activity was detected in L929 cells in the extracts obtained from ethanol up to concentration of 100 µg mL-1 of extract. The Pearson's coefficient indicated that the reduction in cell viability was related to the concentration of triterpenes. Anti-inflammatory assays showed that some extracts could inhibit the inflammatory action induced in RAW 264.7 cells at concentration of 30 µg mL-1 of extract. Our results justify the further exploration of these characteristics to obtain natural products for the pharmaceutical and food industries.
