Seasonal effect on phenolic content and antioxidant activity of young, mature and senescent leaves from Anredera cordifolia (Ten.) Steenis (Basellaceae)

Abstract Anredera cordifolia (Ten.) Steenis is a vine species native to Brazil that is considered an unconventional food plant and a medicinal species whose phenolic compounds exert antioxidant activity. Since the production of metabolites is determined by environmental factors and leaf maturity, it is important to track these changes in order to determine the best time to harvest. This study aimed to verify whether leaf phenology and seasonality cause variations in the amount of phenolic compounds and in the antioxidant activity of this species. The leaves were collected in different seasons between September 2018 and April 2019, and separated according to maturity: young, mature, and senescent. Daily atmospheric temperature and rainfall data were used to characterize the collection period. The total phenolic content (TPC), determined by Folin-Ciocalteu method, was significantly higher in the young leaves collected in winter, a season of lower temperatures. These leaves showed 54.4 mg of gallic acid equivalents per 100 g of dry matter (mg GAE 100 g-1DM). Other results averaged 25.6 mg GAE 100 g-1DM. The highest antioxidant activity, assessed via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, regardless of leaf phenology, was observed in leaves harvested in autumn (73.7%) and winter (71.1%), seasons with lower rainfall. Leaves harvested in summer and spring had lower antioxidant action rates (54.3 e 37.5%, respectively). There was no significant correlation between the total phenolic content and antioxidant activity. Thus, the phenolic composition of A. cordifolia, and consequently its activity on free radicals, varies seasonally in response to temperature and rainfall, and may or may not interact with the age of the leaves.

Resumo Anredera cordifolia (Ten.) Steenis é uma trepadeira nativa do Brasil considerada uma planta alimentícia não convencional e uma espécie medicinal, cujos compostos fenólicos exercem ação antioxidante. Como a produção de metabólitos é determinada por fatores ambientais e pela maturidade das folhas, é importante acompanhar essas mudanças a fim de determinar a época de colheita. Neste estudo objetivou-se verificar se a fenologia foliar e a sazonalidade ocasionam variação na quantidade de compostos fenólicos e na ação antioxidante dessa espécie. As folhas foram coletadas em diferentes estações, entre setembro de 2018 e abril de 2019, e separadas conforme a maturidade: jovens, maduras e senescentes. Os dados diários de temperatura atmosférica e pluviosidade foram usados para caracterizar o período de coleta. O conteúdo de fenólicos totais (TPC), determinado pelo método Folin-Ciocalteu, foi significativamente maior nas folhas jovens coletadas no inverno, período caracterizado por temperaturas mais baixas. Estas folhas apresentaram 54,4 mg equivalentes de ácido gálico por 100 g de matéria seca (mg GAE 100 g-1DM) . A média dos outros resultados foi de 25,6 mg GAE 100 g-1DM. A maior ação antioxidante, avaliada pelo método do radical livre 2,2-difenil-1-picrilhidrazil (DPPH), foi observada em folhas colhidas no outono (73,7%) e inverno (71,1%), independentemente da fenologia foliar. Nestes períodos a pluviosidade foi menor. Folhas colhidas no verão e na primavera apresentaram menores percentuais de ação antioxidante (54,3 e 37,5%, respectivamente). Não houve correlação significativa entre o conteúdo de fenólicos totais e a atividade antioxidante. Conclui-se que a composição fenólica de A. cordifolia e, consequentemente, sua ação sobre radicais livres, varia sazonalmente em resposta à temperatura e pluviosidade, podendo ou não interagir com a idade das folhas.

Seasonal effect on phenolic content and antioxidant activity of young, mature and senescent leaves from Anredera cordifolia (Ten. ) Steenis (Basellaceae) / Efeito sazonal no conteúdo de fenólicos e ação antioxidante de folhas jovens, maduras e senescentes de Anredera cordifolia (Ten. ) Steenis (Basellaceae)

Anredera cordifolia (Ten.) Steenis is a vine species native to Brazil that is considered an unconventional food plant and a medicinal species whose phenolic compounds exert antioxidant activity. Since the production of metabolites is determined by environmental factors and leaf maturity, it is important to track these changes in order to determine the best time to harvest. This study aimed to verify whether leaf phenology and seasonality cause variations in the amount of phenolic compounds and in the antioxidant activity of this species. The leaves were collected in different seasons between September 2018 and April 2019, and separated according to maturity: young, mature, and senescent. Daily atmospheric temperature and rainfall data were used to characterize the collection period. The total phenolic content (TPC), determined by Folin-Ciocalteu method, was significantly higher in the young leaves collected in winter, a season of lower temperatures. These leaves showed 54.4 mg of gallic acid equivalents per 100 g of dry matter (mg GAE 100 g-1DM). Other results averaged 25.6 mg GAE 100 g-1DM. The highest antioxidant activity, assessed via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, regardless of leaf phenology, was observed in leaves harvested in autumn (73.7%) and winter (71.1%), seasons with lower rainfall. Leaves harvested in summer and spring had lower antioxidant action rates (54.3 e 37.5%, respectively). There was no significant correlation between the total phenolic content and antioxidant activity. Thus, the phenolic composition of A. cordifolia, and consequently its activity on free radicals, varies seasonally in response to temperature and rainfall, and may or may not interact with the age of the leaves.

Anredera cordifolia (Ten.) Steenis é uma trepadeira nativa do Brasil considerada uma planta alimentícia não convencional e uma espécie medicinal, cujos compostos fenólicos exercem ação antioxidante. Como a produção de metabólitos é determinada por fatores ambientais e pela maturidade das folhas, é importante acompanhar essas mudanças a fim de determinar a época de colheita. Neste estudo objetivou-se verificar se a fenologia foliar e a sazonalidade ocasionam variação na quantidade de compostos fenólicos e na ação antioxidante dessa espécie. As folhas foram coletadas em diferentes estações, entre setembro de 2018 e abril de 2019, e separadas conforme a maturidade: jovens, maduras e senescentes. Os dados diários de temperatura atmosférica e pluviosidade foram usados para caracterizar o período de coleta. O conteúdo de fenólicos totais (TPC), determinado pelo método Folin-Ciocalteu, foi significativamente maior nas folhas jovens coletadas no inverno, período caracterizado por temperaturas mais baixas. Estas folhas apresentaram 54,4 mg equivalentes de ácido gálico por 100 g de matéria seca (mg GAE 100 g-1DM) . A média dos outros resultados foi de 25,6 mg GAE 100 g-1DM. A maior ação antioxidante, avaliada pelo método do radical livre 2,2-difenil-1-picrilhidrazil (DPPH), foi observada em folhas colhidas no outono (73,7%) e inverno (71,1%), independentemente da fenologia foliar. Nestes períodos a pluviosidade foi menor. Folhas colhidas no verão e na primavera apresentaram menores percentuais de ação antioxidante (54,3 e 37,5%, respectivamente). Não houve correlação significativa entre o conteúdo de fenólicos totais e a atividade antioxidante. Conclui-se que a composição fenólica de A. cordifolia e, consequentemente, sua ação sobre radicais livres, varia sazonalmente em resposta à temperatura e pluviosidade, podendo ou não interagir com a idade das folhas.

Seasonal effect on phenolic content and antioxidant activity of young, mature and senescent leaves from Anredera cordifolia (Ten.) Steenis (Basellaceae).

Anredera cordifolia (Ten.) Steenis is a vine species native to Brazil that is considered an unconventional food plant and a medicinal species whose phenolic compounds exert antioxidant activity. Since the production of metabolites is determined by environmental factors and leaf maturity, it is important to track these changes in order to determine the best time to harvest. This study aimed to verify whether leaf phenology and seasonality cause variations in the amount of phenolic compounds and in the antioxidant activity of this species. The leaves were collected in different seasons between September 2018 and April 2019, and separated according to maturity: young, mature, and senescent. Daily atmospheric temperature and rainfall data were used to characterize the collection period. The total phenolic content (TPC), determined by Folin-Ciocalteu method, was significantly higher in the young leaves collected in winter, a season of lower temperatures. These leaves showed 54.4 mg of gallic acid equivalents per 100 g of dry matter (mg GAE 100 g-1DM). Other results averaged 25.6 mg GAE 100 g-1DM. The highest antioxidant activity, assessed via the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, regardless of leaf phenology, was observed in leaves harvested in autumn (73.7%) and winter (71.1%), seasons with lower rainfall. Leaves harvested in summer and spring had lower antioxidant action rates (54.3 e 37.5%, respectively). There was no significant correlation between the total phenolic content and antioxidant activity. Thus, the phenolic composition of A. cordifolia, and consequently its activity on free radicals, varies seasonally in response to temperature and rainfall, and may or may not interact with the age of the leaves.

Analysis of diterpenoid compounds from the latex of two Euphorbiaceae by liquid chromatography‒electrospray ionisation mass spectrometry.

The latex of Euphorbia papillosa A.St.-Hil. and Sapium glandulosum (L.) Morong was phytochemically investigated by liquid chromatography/mass spectrometry. The results reveal the presence of tigliane-type diterpenoid compounds, particularly 12-deoxyphorbol esters, in both species. In addition, ingenane-type diterpene esters were found in the latex of E. papillosa. The latex of S. glandulosum showed only tigliane-type diterpenes, confirming the literature data on this genus. According to mass data, we are proposing the presence of 10 compounds derived from 12-deoxyphorbol monoesters and diesters, from one 12-deoxyphorbaldehyde, from two ingenol derivatives and from one nitrogen-containing phorbol ester in the latex of the analysed species. Considering that 12-deoxy tigliane diterpenes are described as antitumour and antiviral agents, these results indicate a pharmacological potential for these two Euphorbiaceae species.

Effect of flavonol derivatives on the carrageenin-induced paw edema in the rat and inhibition of cyclooxygenase-1 and 5-lipoxygenase in vitro.

Alkoxyflavonols were synthesized by the Algar-Flynn-Oyamada (AFO) cyclization of chalcones. Hydroxyflavonols were prepared by dealkylation of methoxyflavonols by refluxing in hydroiodic acid. The alkoxyflavonols 3-hydroxy-2-(2,3,4-trimethoxyphenyl)-4H-chromen-4-one (6), 2-(4-ethoxyphenyl)-3-hydroxy-4H-chromen-4-one (7), 2-(4-butoxyphenyl)-3-hydroxy-4H-chromen-4-one (10), and 2-(3-n-butoxyphenyl)-3-hydroxy-4H-chromen-4-one (11) as well as the trihydroxy derivative 3-hydroxy-2-(3,4,5-trihydroxyphenyl)-4H-chromen-4-one (18) displayed high anti-inflammatory activity in carrageenin-induced rat paw edema. Additionally, the inhibition of enzymes of the arachidonic acid cascade by the derivatives was investigated in vitro. In contrast to the natural compound quercetin, the compounds were more potent inhibiting cyclooxygenase-1 than 5-lipoxygenase except for 3-hydroxy-7-methoxy-2-(4-methoxyphenyl)-4H-chromen-4-one (5). No correlation between the anti-inflammatory activity in the rat paw edema test and the inhibition of 5-lipoxygenase or cyclooxygenase-1 could be observed. In conclusion, the present results suggest that other effects than inhibition of these enzymes of the arachidonic acid cascade are important for the anti-inflammatory activity of the investigated alkoxyflavonols.