Photodamage attenuating potential of Nectandra hihua against UVB-induced oxidative stress in L929 fibroblasts.

The total phenolic content (TP) and antioxidant activity of the ethanolic extract and fractions that were obtained from the leaves of Nectandra hihua were assessed using different methods. The ethanolic extract (EE) and ethyl acetate fraction (EAF) had the best antioxidant capacity, which was comparable to butylated hydroxytoluene and quercetin (ABTS+ 2.55 ±â€¯0.06, 3.54 ±â€¯0.03 mmol TE/g; DPPH IC50 10.27 ±â€¯0.05, 9.88 ±â€¯0.02 µg/mL; FRAP 2.17 ±â€¯0.08, 2.38 ±â€¯0.04 mmol TE/g; ORAC 5.16 ±â€¯0.08, 5.35 ±â€¯0.07 mmol TE/g; TP 568.05 ±â€¯18.15, 397.20 ±â€¯17.88 mg GAE/g, respectively). The cytoprotective effect, reactive oxygen species (ROS) and lipid peroxidation inhibitions on L929 fibroblasts irradiated with UVB (600 mJ/cm2) in pre- and post-treatments with EE and EAF were determined. These plant materials demonstrated high ROS scavenging activity and lipid peroxidation inhibition on L929 fibroblasts in both treatments, especially with pre-treatment (EE 38.47 ±â€¯1.95% and EAF 40.20 ±â€¯4.5% inhibition of ROS production, and EE 39.03 ±â€¯3.33% and EAF 41.67 ±â€¯7.6% of lipid peroxidation inhibition), indicating the best cytoprotection with pre-treatment (13.52 ±â€¯1.66% and 13.34 ±â€¯2.61% increases in cell viability). The antioxidant flavonoids quercitrin, avicularin, juglalin, afzelin and astragalin were isolated from EAF. The results obtained indicate that EE and EAF present photodamage attenuating potential against UVB-induced oxidative stress and can be useful as a starting point for developing dermatological products to prevent oxidative skin damage.

Antileishmanial and antioxidant potential of fractions and isolated compounds from Nectandra cuspidata.

The effects on the viability of promastigote and amastigote forms of Leishmania (Leishmania) amazonensis and citotoxicity in J774.A1 macrophages of ethanolic extract, fractions and isolated compounds that were obtained from the leaves of Nectandra cuspidata were determined. The total phenolics content (TP) and antioxidant activity were assessed using different assays. The ethyl acetate fraction (EAF) had the best antiproliferative activity (amastigote IC50: 4.42 ± 0.60 µg/mL, promastigote IC50: 33.33 ± 0.78) and presented no cytotoxicity at the highest concentration tested (1000 µg/mL). The EAF also had the greatest antioxidant capacity, which was comparable to butylated hydroxytoluene and quercetin (DPPH IC50 6.54 ± 0.10 µg/mL, ABTS 4.75 ± 0.11 mmol ET/g; FRAP 2.37 ± 0.03 mmol ET/g; ORAC = 33.52 ± 1.99 mmol ET/g; TP 387.11 ± 0.25 mg GAE/g). Vitexin, epicatechin and isovitexin isolated from EAF contribute to both activities.