Antioxidant characteristics and antibacterial activity of native woody species from Catamarca, Argentina.

Numerous reports describe the antioxidant and antimicrobial activity of polyphenols-rich plant extracts. The aim of this study was to determine the total polyphenols content (TPC), and the in vitro (DPPH, FRAP and TEAC) antioxidant and antibacterial activity of leaves and wood of six native woody species (Aspidosperma quebracho-blanct, Sarcomphalus mistol, Geoffroea decorticans, Prosopis chilensis, Larrea divaricata and Larrea cuneifolia) from Catamarca. Also, the phenolic profile was determined in the species with higher activity. L. cuneifolia leaf extracts showed the highest antioxidant activity followed by L. divaricata and S. mistol, while S. mistol wood extracts showed the highest. Furthermore, Larrea species showed antibacterial activity against S. aureus and E. faecalis strains showing cidal effects mainly against S. aureus. Fifty-nine polyphenols were identified in leaves and wood of Larrea and S. mistol species, which are likely to be responsible for the different activities observed.

First screening report of immune and protective effect of non-toxic Jatropha vernicosa stem bark against Vibrio parahaemolyticus in Longfin yellowtail Seriola rivoliana leukocytes.

In México, the infusion of Jatropha vernicosa stem bark has been used in folk medicine for many clinical situations, but no reports were available about this particular species of Jatropha in fish of mammals. In this first screening report, the phytochemical, antioxidant profile and antimicrobial properties of aqueous J. vernicosa stem bark extract were explored against Vibrio parahaemolyticus, an opportunist fish pathogen. To evaluate the cytotoxicity and immunological effect for the possible application of aqueous J. vernicosa stem bark in aquaculture, this study assessed it by using Longfin yellowtail Seriola rivoliana leukocytes. The results showed that phytochemical composition of the J. vernicosa extract was rich in phenol, flavonoid, saponin, and coumarin compounds. The antioxidant capacity of hydroxyl radical and superoxide anion scavenging activities, iron-chelation activity and ß-carotene bleaching coupled to linoleic acid showed that J. vernicosa extracts had a moderate antioxidant effect compared with synthetic antioxidants (BHT, BHA and EDTA). No adverse effects were observed on spleen leukocytes (viability > 98%). Interestingly, J. vernicosa stem bark extract has immunostimulant and antioxidant effects, increasing phagocytosis, respiratory burns activity, and nitric oxide production, as well as superoxide dismutase and catalase activities. Additionally, J. vernicosa extract increased pro-inflammatory cytokine IL-1ß and suppressed anti-inflammatory IL-10 gene expression upon stimuli and V. parahaemolyticus challenge. Finally, the data confirms that J. vernicosa stem bark extract is non-cytotoxic, rich in bioactive compounds with antioxidant effects, capable of enhancing the immune system in leukocytes and with great potential to fight against opportunistic diseases, such as vibriosis in fish.