Hypericum sp.: essential oil composition and biological activities

Phytochemical composition of Hypericum genus has been investigated for many years. In the recent past, studies on the essential oils (EO) of this genus have been progressing and many of them have reported interesting biological activities. Variations in the EO composition of Hypericum species influenced by seasonal variation, geographic distribution, phenological cycle and type of the organ in which EO are produced and/or accumulated have also been reported. Although many reviews attributed to the characterization as well as biological activities of H. perforatum crude extracts have been published, no review has been published on the EO composition and biological activities of Hypericum species until recently (Crockett in Nat Prod Commun 5(9):1493–1506, 2010; Bertoli et al. in Global Sci Books 5:29–47, 2011). In this article, we summarize and update information regarding the composition and biological activities of Hypericum species EO. Based on experimental work carried out in our laboratory we also mention possible biotechnology approaches envisaging EO improvement of some species of the genus.Fundação para a Ciência e a Tecnologia (FCT) - project PTDC/AGR AAM/70418/2006, SFRH/BD/ 13283/2003

Calagem e adubação fosfatada promovem crescimento inicial e produção de hipericina em erva-de-São-João Liming and phosphate fertilization promote initial growth and hipericin production in St. John's wort

A erva-de-São-João é uma planta medicinal empregada no tratamento antidepressivo. A hipericina é considerada um dos compostos que contribui para o efeito medicinal da planta. Uma vez que a concentração e a quantidade do princípio ativo pode ser afetada pela nutrição das plantas, este trabalho teve por objetivo avaliar os efeitos do pH do solo e da adubação fosfatada sobre o crescimento inicial e a produção de hipericina em erva-de-São-João. O experimento foi realizado em Lages, SC, de julho a dezembro de 2003, em casa de vegetação. Utilizou-se delineamento experimental inteiramente casualizado (fatorial 4 x 3), correspondendo a quatro valores de pH (4,1; 5,5; 6,0 e 6,5) e três doses de P (0, 50 e 100 mg kg-1 de solo), com quatro repetições. Foram cultivadas duas plantas por vaso, em um Cambissolo Húmico Álico. Avaliou-se a produção de massa seca, a altura e o número de ramificações da parte aérea, o número de glândulas escuras nas folhas e a concentração e a quantidade total de hipericina na parte aérea. A produção de massa seca da parte aérea aumentou com a adição de P e, em maior magnitude, com a calagem. A altura das plantas somente foi influenciada pela calagem. O número de ramificações e de glândulas escuras e a concentração de hipericina aumentaram com a aplicação de P apenas na ausência de calagem, e com a calagem na ausência de P. Os maiores conteúdos de hipericina por vaso foram verificados nos tratamentos com pH 6,0 e 6,5 e doses de P de 50 e 100 mg kg-1 de solo.<br>St. Jonh's wort is a medicinal plant used for anti-depressive treatment. Hypericin is considered one of the compounds that contribute to the medicinal effect of the plant. Since the concentration and the total quantity of active ingredients may be affected by plant nutrition, this work was conducted to investigate the effects of soil pH and phosphorus (P) addition to the soil on initial growth and hypericin production of St. John's wort. The experiment was carried out in Lages, SC, from July until December of 2003, in a greenhouse. It followed a completely randomized factorial design (4 x 3), with four levels of pH (4.1, 5.5, 6.0, and 6.5) and three doses of P (0, 50, and 100 mg kg-1 of soil), and four replicates. Two plants were cultivated per pot, under a Humic Inceptisol. Plants were harvested and assessed for aerial dry matter production, height, number of lateral shoots, number of dark glands in the leaves, aerial hypericin content and aerial total hypericin production. The aerial dry matter production increased with P addition and, in a larger amount, with liming. The plant height was only affected by the liming. The number of lateral shoots and dark glands in the leaves as well as the hipericin concentration only increased with P application in the soil without liming, and with liming in the soil that did not receive P. The highest total hypericin production per pot was achieved in the treatments with pH values of 6.0 and 6.5 and P doses of 50 and 100 mg kg-1 of soil