Effects of NaCl on plant growth and antioxidant activities in fenugreek (Trigonella Foenum Graecum L. ) / Efeitos da NaCl no crescimento e capacidade antioxidante por feno-grego (Trigonella Foenum Graecum L. )

Fenugreek is used as a spice, vegetable and a important medicinal crops cultivated throughout the world. Since antioxidant properties have been linked to health benefits of natural products, such properties were studied salt concentrations (0, 50, 100,150 and 200 mM NaCl) effect on plant growth mineral contents composition, antioxidant responses and phenolilc contents. Results showed a reduction of dry weights of leaves stems and roots growth. These changes were associated with decreased in water content, K+ and Ca2+ concentrations and a highly increased in Na+ and Clcontents in different organs. Catalase, guaiacol peroxidase activities and total phenolic content significantly increased in fenugreek leaves. Data reported here revealed the variation of phenolic compound contents at different organs in the presence of salt, who suggested the use of Fenugreek in commercial and economic applications.

O feno-grego é usado como especiaria, vegetal e uma importante cultura medicinal cultivada em todo o mundo. Como as propriedades antioxidantes têm sido associadas aos benefícios à saúde dos produtos naturais, tais propriedades foram estudadas quanto ao efeito das concentrações de sal (0, 50, 100, 150 e 200 mM de NaCl) no crescimento das plantas, composição do conteúdo mineral, respostas antioxidantes e teores fenólicos. Os resultados mostraram uma redução do peso seco dos caules das folhas e crescimento das raízes. Essas alterações foram associadas à diminuição do conteúdo de água, concentrações de K+ e Ca2+ e um aumento nos teores de Na+ e Cl- em diferentes órgãos. As atividades de catalase e da peroxidase do guaiacol e o teor de fenólicos totais aumentaram significativamente em folhas de feno-grego. Os dados aqui relatados revelaram a variação do conteúdo de compostos fenólicos em diferentes órgãos na presença de sal, que sugeriu o uso do feno-grego em aplicações comerciais e econômicas.

Salt effect on phenolics and antioxidant activities of Tunisian and Canadian sweet marjoram (Origanum majorana L.) shoots.

BACKGROUND: Two varieties of Origanum majorana (Canadian and Tunisian) were evaluated for their phenolic, flavonoid and tannin contents, individual phenolic compounds and antioxidant activities under NaCl constraint. RESULTS: The results showed a significant variability in phenolic composition and antioxidant behavior between the two varieties under salt stress. The phenolic composition of methanolic extracts was determined by reversed-phase high-performance liquid chromatography. Amentoflavone was the predominant flavonoid compound; in addition, trans-2-hydrocinnamic acid became the major phenolic acid with salt treatment of the Tunisian variety. In the control, Canadian variety extract was characterized by high levels of gallic acid and amentoflavone. However, under 75 mmol L(-1) NaCl, gallic acid content doubled, whereas amentoflavone content was maintained in the Canadian variety. Stimulation of phenolic acid biosynthesis was observed in these two varieties under salt treatment despite the fact that shoots of the Tunisian variety showed higher antioxidant activities compared to those from the Canadian variety. Tunisian O. majorana might have developed tolerance to salinity and avoided tissue damage by activating enzymes involved in the galactosylation of quercetin into quercetin-3-galactoside and quercetin-3-rhamnoside. CONCLUSION: Our results confirmed the tolerance of Tunisian O. majorana plants.

Culture conditions and salt effects on essential oil composition of sweet marjoram (Origanum majorana) from Tunisia.

O. majorana shoots were investigated for their essential oil (EO) composition. Two experiments were carried out; the first on hydroponic medium in a culture chamber and the second on inert sand in a greenhouse for 20 days. Plants were cultivated for 17 days in hydroponic medium supplemented with NaCl 100 mmol L⁻¹. The results showed that the O. majorana hydroponic medium offered higher essential oil yield than that from the greenhouse. The latter increased significantly in yield (by 50 %) under saline constraint while it did not change in the culture chamber. Under greenhouse conditions and in the absence of salt treatment, the major constituents were terpinen-4-ol and trans-sabinene hydrate. However, in the culture chamber, the major volatile components were cis-sabinene hydrate and terpinen-4-ol. In the presence of NaCl, new compounds appeared, such as eicosane, spathulenol, eugenol, and phenol. In addition, in the greenhouse, with or without salt, a very important change of trans-sabinene hydrate concentration in EO occurred, whereas in the culture chamber change appeared in cis-sabinene hydrate content.

Salt effects on Origanum majorana fatty acid and essential oil composition.

BACKGROUND: The effects of salt on the essential oil yield and fatty acid composition of aerial parts of two marjoram varieties were investigated. Plants with 6 leaves were treated with NaCl (75mM). RESULTS: Salt treatment led to a reduction in aerial part growth. Salinity increased the fatty acid content more significantly in Tunisian variety (TV) than in Canadian variety (CV). CV showed an increase in double-bond index (DBI) and a decrease in malondialdehyde content under salt stress, while the opposite was observed in TV. The DBI was mainly affected by a strong reduction in oleic and linoleic acids in TV, whereas a strong stimulation of linoleic acid in CV was observed. Salt decreased and increased the essential oil yield in TV and CV respectively. The main constituents of the essential oil of TV were trans-hydrate sabinene and terpinen-4-ol, which showed a significant decrease under salt stress. In contrast, the main constituents of the essential oil of CV were sabinene and trans-hydrate sabinene, which showed a significant decrease and increase respectively under salt stress. CONCLUSION: Marjoram oil is a rich source of many compounds such as essential oils and fatty acids, but the distribution of these compounds differed significantly between the two varieties studied.