Preclinical study of the topical anti-inflammatory activity of Cyperus rotundus L. extract (Cyperaceae) in models of skin inflammation.

ETHNOPHARMACOLOGICAL RELEVANCE: Cyperus rotundus L. (Cyperaceae) is considered one of the most widely distributed plant species in the world, especially in tropical and subtropical regions. In addition, it is commonly used in India, China and Japan in traditional medicine to treat different diseases, including dermatitis and other skin disorders. AIM OF THE STUDY: To investigate the topical anti-inflammatory activity of C. rotundus rhizome ethanolic extract in models of acute and chronic dermatitis. MATERIALS AND METHODS: Phytochemical analysis was carried out using High-performance liquid chromatography-ultraviolet detection (HPLC/UV) to determine the presence of quercetin and chlorogenic acid in C. rotundus extract. Topical anti-inflammmatory effects of C. rotundus extract were evaluated on arachidonic acid (AA) and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin inflammation in mice. Skin biopsies were collected and submitted to histological and enzymatic analysis to evaluate the C. rotundus effect in leukocyte migration into inflamed tissue. Antiproliferative activity of C. rotundus was confirmed by PCNA immunostained cell analysis. Systemic and possible adverse effects of topical treatment with C. rotundus were evaluated by the skin atrophy and same organ weights. In addition, the glucocorticoid receptor (GR) antagonist mifepristone was used to investigate possible GR-mediated mechanisms of action. RESULTS: The phytochemical analysis show that C. rotundus ethanol extract contains 45 µg/g of chlorogenic acid. Topical treatment with C. rotundus extract reduced ear edema and cellular infiltrate in acute and chronic skin inflammation models. Moreover, mice topically treated with C. rotundus exhibited decrease in TPA-induced keratinocyte hyperproliferation. Relevantly, topical treatment with C. rotundus did not caused skin atrophy or changes in lymphoid organ weight. The anti-inflammatory effect of C. rotundus was not influenced by the GR antagonist. CONCLUSION: The results here demonstrate for the first time the topical anti-inflammatory and antiproliferative efficacy of C. rotundus extract, suggesting that the extract could be a potential new therapeutic tool for the treatment of inflammatory skin disorders.

Peroxidase activity as an indicator of water deficit tolerance in soybean cultivars / Atividade de peroxidase como indicativo de tolerância à deficiência hídrica em cultivares de soja

This study had as purpose to test the hypothesis that peroxidase enzyme activity could be used as an indicator of tolerance to water deficit in soybean cultivars. The experiment was carried out in pots containing 20-L of a Rhodic Hapludox soil in greenhouse conditions. Treatments were arranged in a randomized block design in a 2 × 4 factorial: two water regimes (with and without water deficit) and four soybean cultivars (CD 204, CD 215, CD 225RR and CD 226RR), with four replications. Soybean plants were grown until the beginning of flowering (R1-R2) with soil moisture content near at the field capacity, and then, it started the differentiation of treatments under water deficit by the suspension of water supply. Changes in relative water content (RWC) in leaves, protoplasmic tolerance, peroxidase activity, and plant growth were measured after four days of drought stress and 4-d recovery. The soybean cultivars used in this study have different responses under water deficit conditions. The CD 215 cultivar was the most sensitive to water deficit in the beginning of flowering stage. Soybean cultivars presented variable responses to the peroxidase enzyme activity, and this variable can be used in the selection of soybean genotypes with greater tolerance to drought.

Este estudo teve como objetivo testar a hipótese de que a atividade das enzimas peroxidase poderia ser utilizada como um indicativo de tolerância à deficiência hídrica em cultivares de soja. O experimento foi realizado em vasos contendo 20L de um Latossolo vermelho argiloso em condições de casa-de-vegetação. Os tratamentos foram dispostos no delineamento de blocos casualizados em esquema fatorial 2 × 4, constituído de dois regimes hídricos (sem e com déficit hídrico) e quatro cultivares de soja (CD 204, CD 215, CD 225RR and CD 226RR), com quatro repetições. A soja foi cultivada até o início do florescimento com teor de água no solo próximo a capacidade de campo, e então, iniciouse a diferenciação dos tratamentos com déficit hídrico, mediante a suspensão do fornecimento de água. Alteração no conteúdo relativo de águas nas folhas, tolerância protoplasmática, atividade das enzimas peroxidade e crescimento das plantas foram avaliados após quatro dias de exposição ao déficit hídrico e após quatro dias de recuperação das plantas em condições controle. As cultivares de soja utilizadas neste estudo apresentam respostas distintas em condições de déficit hídrico. A cultivar CD 215 foi mais sensível ao déficit hídrico imposto no inicio do florescimento. As cultivares de soja apresentaram respostas variáveis à atividade das enzimas peroxidase, e esta variável pode ser utilizada na seleção de genótipos de soja com maior tolerância à seca.