Insights on physiological, antioxidant and flowering response to salinity stress of two candidate ornamental species: the native coastal geophytes Pancratium maritimum L. and Eryngium maritimum L.

Increasing seawater influence in coastal areas is an ongoing environmental issue. Gardening is a widespread activity mainly in touristic areas such as the Mediterranean coasts. However, the use of exotic species well adapted to salinity encompasses the risk of invasive species introduction. This study aimed to evaluate salinity tolerance of native geophytes, Pancratium maritimum L. and Eryngium maritimum L., to assess their use as ornamental species in salt affected coastal areas. Experiments were conducted using cultivated plants for flowering response and physiological and enzymatic antioxidant response. Six treatments were applied for two months, exposing plants to seawater (SW) dilutions (Tap-Water, 6.25%SW, 12.5%SW, 25%SW, 50%SW and 100%SW). Taxa decreased inflorescence production being this effect more architectonical in E. maritimum and affecting all inflorescence integrity in P. maritimum. Flowering time was strongly delayed and reduced in P. maritimum, while E. maritimum showed smaller effects among treatments. Physiological and biochemical response showed at moderate salinity levels (1/4SW) variation concomitant with late stress response and senescence in P. maritimum, with decreased water use efficiency, NPQ values, and enzymatic activity, and increased malondialdehyde (MDA) levels. In contrast, E. maritimum showed early stress response with steady gas exchange response, increasing NPQ values and catalase (CAT) and superoxide dimutase (SOD) activity, and decreasing MDA levels with salinity. Glutathione enzymes showed limited participation in both species. The results of this study suggest that neither species can be classified as halophytes, but they exhibit tolerance to low and moderate salinity levels, making them suitable for ornamental use. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-024-01502-0.

Antioxidant and anti-inflammatory potential of rhizome aqueous extract of sea holly (Eryngium maritimum L.) on Jurkat cells.

ETHNOPHARMACOLOGICAL RELEVANCE: The genus Eryngium is known for producing a wide range of bioactive compounds with proved medicinal properties. In the last years, research has focused on E. maritimum, with previous studies reporting anticancer, antimicrobial, antioxidant, and anti-inflammatory activities. Ethnobotanical literature suggests that it has been traditionally used to treat a wide range of illnesses, having antitussive, diuretic and aphrodisiac properties. Being rhizome one of the most bioactive organs, much of the available references from traditional uses suggest that it has been specifically used to treat renal diseases. In this sense, inflammation and oxidative processes play a major role in kidney dysfunctions, which could be associated to the mechanism of action of the plant extracts. AIM OF THE STUDY: The main aim of the study was to investigate the effects of E. maritimum rhizome extract on the antioxidant and inflammatory response in human immune cells. MATERIAL AND METHODS: Rhizome extracts were obtained from plants growing in Mallorca (Balearic Islands), and its composition was determined using HPLC-DAD, highlighting simple phenolic compounds such as trans-ferulic acid, catechin, chlorogenic acid, epicatechin and rosmarinic acid as the major constituents. Total antioxidant capacity was determined using the FRAP assay. Jurkat cells were cultured to analyse cytotoxicity by cell viability assay. In parallel, cells were stimulated with phytohemagglutinin and treated with different extract concentrations. Gene and protein expression, as well as nitrite and cytokine levels were evaluated as indicators of metabolic responses. RESULTS: The plant extract showed a high diversity of pharmacologically bioactive compounds with potential therapeutic uses. The extract presented null cytotoxicity and exerted antioxidant and anti-inflammatory effects on Jurkat cells by inducing an antioxidant response and reducing cytokine and nitric oxide release and the expression of pro-inflammatory genes. CONCLUSION: The present findings suggest that E. maritimum is a promising phytotherapeutic species because of its strong antioxidant and anti-inflammatory potential, which could explain some of its traditional uses.

The role of E. maritimum (L.) in the dune pollination network of the Balearic Islands.

Eryngium maritimum L. (Apiaceae) is a geophyte that inhabits in the dunes of the Mediterranean and Atlantic. Although it is a highly entomophilous species, there is little literature on its pollinator assemblage. The aim of this study is to analyze the role played by E. maritimum in the dune pollination network of the Balearic Islands, where there is an intense anthropogenic impact in its habitat. For this purpose, two populations located in the North and South of Mallorca were chosen, in which diurnal transects were carried out to observe and capture pollinators on 15 plant species during the anthesis period of E. maritimum. The flowering period of 10 plant species flowering at the same period than E. maritimum was analyzed to identify periods of competition. A total of 71 pollinator species were found, belonging to 30 different families. Eryngium maritimum is a strongly generalist species, with a total of 45 pollinator species. Two new species, Odice blandula and Leucospis gigas, were found for the first time in Mallorca. In terms of pollinators, Teucrium dunense and Helichrysum stoechas are the most similar species to E. maritimum. However, analysis of phenology suggests that these three species have been able to decouple their blooms to avoid competition. The present study shows that E. maritimum plays an important role in the dune pollination network, being its anthesis located at the end of the dune flowering season, when there are no functionally similar species in flower.