Oxindole and Benzoxazinone Alkaloids from the Seeds of Persea americana (Avocado) and Their SIRT1 Stimulatory Activity.

Persea americana Mill. (Lauraceae), commonly known as avocado, is a well-known food because of its nutrition and health benefits. The seeds of avocado are major byproducts, and thus their phytochemicals and bioactivities have been of interest for study. The chemical components of avocado seeds were investigated by using UPLC-qTOF-MS/MS-based molecular networking, resulting in the isolation of seven new oxindole alkaloids (1-7) and two new benzoxazinone alkaloids (8 and 9). The chemical structures of the isolated compounds were identified by the analysis of NMR data in combination with computational approaches, including NMR and ECD calculations. Bioactivities of the isolated compounds toward silent information regulation 2 homologue-1 (SIRT1) in HEK293 cells were assessed. The results showed that compound 1 had the most potent effect on SIRT1 activation with an elevated NAD+/NADH ratio with potential for further investigation as an anti-aging agent.

Bioactivity of Acanthus mollis - Contribution of benzoxazinoids and phenylpropanoids.

ETHNOPHARMACOLOGICAL RELEVANCE: Acanthus mollis is a plant native to the Mediterranean region, traditionally used as diuretic, anti-inflammatory and soothing of the mucous membranes of the digestive and urinary tract and externally as healing of wounds and burns, also demonstrating analgesic and anti-inflammatory activities. However, studies focused on its phytochemical composition as well as scientific proof of Acanthus mollis efficacy are scarce. AIM OF THE STUDY: The proposed work aims to perform a phytochemical characterization and evaluation of the therapeutic potential of Acanthus mollis, based on biological properties that support its traditional uses. MATERIAL AND METHODS: In this study, an 96% ethanol extract from Acanthus mollis leaves was obtained and its phytochemical composition evaluated using High Performance Liquid Chromatography with Photodiode Array Detector coupled to Electrospray Ionization Mass Spectrometry (HPLC-PDA-ESI/MSn). The chemical structure of the compound isolated was elucidated using 1H and 13C Nuclear Magnetic Resonance (NMR), 1H-correlation spectroscopy (1H-COSY), heteronuclear single quantum correlation (HSQC) and heteronuclear multiple-bond correlation (HMBC). The quantification of the constituents was performed using two external standards (2,4-dihydroxy-1,4-benzoxazin-3-one and verbascoside). The antioxidant activity was determined by the 2,2-diphenyl-1-pycrylhydrazyl (DPPH) assay. Anti-inflammatory activity was determined measuring the inhibition of nitric oxide production by RAW 264.7 macrophages stimulated with the TLR4 agonist lipopolysaccharide (LPS) and through lipoxygenase (LOX) inhibition assay. The cytotoxicity was screened on two lines (RAW 264.7 and HaCaT) using the resazurin assay. RESULTS: Compounds such as verbascoside and its derivatives, as well as benzoxazinoids were found as the main constituents. A percentage of 5.58% was verified for the 2,4-dihydroxy-1,4-benzoxazin-3-one (DIBOA) derivatives. DIBOA was the main compound of the extract. Significant concentrations were also found for phenylpropanoids, which constitute about 4.39% of the total compounds identified. This extract showed antioxidant capacity against DPPH (IC50 = 40.00 ±â€¯1.59 µg/mL) and superoxide anion (IC50 = 29.42 ±â€¯1.99 µg/mL). It also evidenced anti-inflammatory potential in RAW 264.7 macrophages, presenting capacity for nitric oxide reduction (IC50 = 28.01 µg/mL). Moreover, in vitro studies have shown that this extract was able to inhibit the lipoxygenase, with an IC50 of 104.39 ±â€¯4.95 µg/mL. Importantly, all effective concentrations were devoid of cytotoxicity in keratinocytes, thus highlighting the safety of the extract for the treatment of skin inflammatory related diseases. Concerning macrophages it was also possible to disclose concentrations showing anti-inflammatory activity and without cytotoxicity (up to 30 µg/mL). The benzoxazinoid DIBOA demonstrated a considerable anti-inflammatory activity suggesting its important contribution to this activity. CONCLUSIONS: These results corroborate the anti-inflammatory properties traditionally attributed to this plant. Among the compounds identified in this study, benzoxazinoids exhibited a significant anti-inflammatory activity that was never previously described. Ethanol seems to be a good option for the extraction of these bioactive compounds, since relevant antioxidant/anti-radical and anti-inflammatory activities were found for this extract.

Bioactive benzoxazinoids in rye bread are absorbed and metabolized in pigs.

Recently, bioactive benzoxazinoids were discovered in cereal grains and bakery products. In this study, we studied the uptake, distribution, and metabolism of these secondary metabolites using a pig model. Twelve benzoxazinoid compounds and their 4 transformation products were quantified in the pigs' diets and biofluids using high-performance liquid chromatography coupled to electrospray ionization triple quadrupole mass spectrometry. The 2-ß-D-glucopyranosyloxy-4-hydroxy-1,4-benzoxazin-3-one (DIBOA-glc) was the most dominant benzoxazinoid (232 nmol/g DM) seconded by the double-hexose derivative of DIBOA (provisionally characterized here as DIBOA-glc-hex) in the rye-based diet. DIBOA-glc (derived from the diet and intestinal deglycosylation of DIBOA-glc-hex) was apparently reduced to 2-ß-D-glucopyranosyloxy-1,4-benzoxazin-3-one (HBOA-glc), the most dominant benzoxazinoid in the blood (829 nmol/L). The benzoxazinoid compounds were excreted in the urine, with HBOA-glc (18 µmol/L) as a major metabolite. In this study, we determined for the first time the bioavailability of dietary benzoxazinoids that have high digestibility, distribution, and metabolism in mammals. These findings could be a milestone for the exploitation of healthful and pharmacological properties of benzoxazinoids.

[Timing- and concentration effect of belowground treatment with jasmonic acid on maize seedlings chemical defense response].

Biochemical and gene expression analysis methods were adopted to investigate the defensive substances and the defense-related genes expression in the roots and leaves of maize (Zea mays L. ) cultivar Gaoyou 115 after underground treatment with 10, 50, 100 and 200 micromol x L(-1) of jasmonic acid (JA) for 3-48 h, aimed to explore the timing- and concentration effect of belowground treatment with JA on the chemical defense response of maize. The chemical defense response of both treated roots and non-treated leaves of Gaoyou 115 was related to the time span of JA treatment and the concentration of JA. After treated with JA for 3-12 h, the gene expression of Bx9, PAL, PR-2a, MPI and FPS in treated roots was directly induced, resulting in an increase of DIMBOA content and a decrease of total phenol content, with the strongest induction effect detected at 100 micromol x L(-1) of JA, followed by at 50 micromol x L(-1), and at 10 micromol x L(-1). The induction effect weakened with time. Underground treatment with JA indirectly affected the chemical defense response of non-treated leaves. After underground treatment with 50 micromol x L(-1) of JA for 3 h, the gene expression of Bx9 and FPS in non-treated leaves was induced, which caused a consequent increase of leaf DIMBOA content. Within 6-24 h of JA treatment, the gene expression of Bx9, PAL, PR-1, MPI and TPS in leaves was enhanced, while the leaf DIMBOA and total phenol contents were declined. For most of the parameters measured, the direct induction effect on roots was much more significant and started earlier than the indirect induction effect on leaves, and an increasing trend was observed in the induction effect with increasing JA concentration.