Search

Functional traits have been defined as those that affect organismal performance, that is growth and development, reproduction and survival, so they have been generally associated with acclimation and adaptation. Here, we aimed to study the impact of an extreme drought event on clonal reproduction and hormonal mechanisms underlying acclimation of houseleek (Sempervivum tectorum L.), a plant adapted to survive harsh environments. We also explored the validity of growth- and stress-related phytohormones as functional traits to evaluate stress acclimation responses in the field. We compared the response of plants, considering both mother rosettes and newly produced clones, to a very extreme summer drought event occurring in small cliffs in Les Guilleries mountains (NE Spain). We measured various stress makers in the field together with hormonal profiling through a metabolomic approach using liquid chromatography coupled to tandem mass spectrometry. Results showed that clonal propagation was arrested during the study period and revealed a 100-fold increase in abscisic acid content from spring to summer both in mothers and new clones, concomitantly with reductions in relative water content, which decreased by 20% only. The stress-related bioactive jasmonate, jasmonoyl-isoleucine increased simultaneously with abscisic acid, while growth-related hormones, including bioactive cytokinins (2-isopentenyl adenine and trans -zeatin) decreased from spring to summer, which was consistent with growth arrest. It is concluded that S. tectorum adjusts recruitment of new clones during periods of low water availability and withstands extreme drought events during the summer (preventing severe cell turgor loss at soil water contents below 2% and temperatures above 43 ºC) by successfully activating a complex hormonal response that underlies the great capacity of this species to survive extreme climatic events. [ABSTRACT FROM AUTHOR]

Functional traits have been defined as those that affect organismal performance, that is growth and development, reproduction and survival, so they have been generally associated with acclimation and adaptation. Here, we aimed to study the impact of an extreme drought event on clonal reproduction and hormonal mechanisms underlying acclimation of houseleek (Sempervivum tectorum L.), a plant adapted to survive harsh environments. We also explored the validity of growth- and stress-related phytohormones as functional traits to evaluate stress acclimation responses in the field. We compared the response of plants, considering both mother rosettes and newly produced clones, to a very extreme summer drought event occurring in small cliffs in Les Guilleries mountains (NE Spain). We measured various stress makers in the field together with hormonal profiling through a metabolomic approach using liquid chromatography coupled to tandem mass spectrometry. Results showed that clonal propagation was arrested during the study period and revealed a 100-fold increase in abscisic acid content from spring to summer both in mothers and new clones, concomitantly with reductions in relative water content, which decreased by 20% only. The stress-related bioactive jasmonate, jasmonoyl-isoleucine increased simultaneously with abscisic acid, while growth-related hormones, including bioactive cytokinins (2-isopentenyl adenine and trans-zeatin) decreased from spring to summer, which was consistent with growth arrest. It is concluded that S. tectorum adjusts recruitment of new clones during periods of low water availability and withstands extreme drought events during the summer (preventing severe cell turgor loss at soil water contents below 2% and temperatures above 43 ºC) by successfully activating a complex hormonal response that underlies the great capacity of this species to survive extreme climatic events.

The aim of the study was to highlight the effect of Sempervivum tectorum and melatonin administration in rats exposed to aluminium sulphate through drinking water on the erythrocyte catalase activity The researches were carried out on Wistar albinos rats, grouped in 8 lots: a control lot (C) and 7 experimental lots (E1: 10% Sempervivum tectorum aqueous extract, 3 month; E2: melatonin, 10 mg/100 ml water, 3 month; E3: aluminium sulphate, 3 months; E4: aluminium sulphate with 10% Sempervivum tectorum aqueous extract, 3 months; E5: aluminium sulphate with melatonin 3 months; E6: aluminium sulphate 3 months followed by 10% Sempervivum tectorum aqueous extract for a month; E7: aluminium sulphate 3 months, followed by melatonin for a month). Al(3+) level in drinking water was 1000 ppb. It was registered decrease of catalase activity compared to C group in E3, E4 (p0.05) and an insignificant increase in E1, E2, E6, E7 groups. Sempervivum tectorum and melatonin administration led to the increase of catalase activity comparing to the group exposed only to aluminium. The catalase activity increase was significantly higher in case of consecutive administration to aluminium intake. Melatonin effect was more well-marked as the one induced by Sempervivum tectorum (p>0.05).

The present study was carried out to investigate the influence of Sempervivum tectorum aqueous extract and melatonin on reduced glutathione (GSH) protective effect in Wistar albino rat blood exposed to aluminium sulphate- Al2(SO4)3. The rats were divided in one control group (C) and 7 experimental groups (E). The control group received tap water. The experimental rats were feed the following way: E1 group – aluminum sulphate, daily, for 3 months; : E2 group – Sempervivum tectorum, daily, for 3 months; : E3 group – melatonin, daily, for 3 months; : E4 group – aluminum sulphate with Sempervivum tectorum, daily, for 3 months; : E5 group – aluminum sulphate with melatonin, daily, for 3 months; E6 group – aluminum sulphate, daily, for 3 months, and thereafter with Sempervivum tectorum for 1 month; E7 group – aluminum sulphate, daily, for 3 month, and thereafter with melatonin for 1 month. This study showed that Aluminum toxicity induced lower GSH. The oxidative stress caused by aluminum, given individual, is more pronounced than in the case in which aluminum is administered simultaneously with Sempervivum tectorum or melatonin. Decreasing GSH value is very small if Sempervivum tectorum or melatonin is given for one month, three months after the administration of aluminum. Effect induced by melatonin is more favorable than that of Sempervivum tectorum.

Activation of hormonal responses defines the drought acclimation ability of plants and may condition their survival. However, aside ABA, little is known about the possible contribution of other phytohormones, such as jasmonates and salicylates, in the response of CAM plants to water deficit. Here, we aimed to study the physiological mechanisms underlying the stress tolerance of house leek (Sempervivum tectorum L.), a CAM plant adapted to survive harsh environments, to a combination of water deficit and nutrient deprivation. We exposed plants to the combination of these two abiotic stresses by withholding nutrient solution for 10 weeks and monitored their physiological response every two weeks by measuring various stress makers together with the accumulation of stress-related phytohormones and photoprotective molecules, such as tocopherols (vitamin E). Results showed that ABA content increased by 4.2-fold after four weeks of water deficit to keep later constant up to 10 weeks of stress, variations that occurred concomitantly with reductions in the relative leaf water content, which decreased by up to 20% only. The bioactive jasmonate, jasmonoyl-isoleucine was the other stress-related phytohormone that simultaneously increased under stress together with ABA. While contents of salicylic acid and the jasmonoyl-isoleucine precursors, 12- oxo -phytodienoic acid and jasmonic acid decreased with water deficit, those of jasmonoyl-isoleucine increased 3.6-fold at four weeks of stress. The contents of ABA and jasmonoyl-isoleucine correlated positively between them and with the content of α-tocopherol per unit of chlorophyll, thus suggesting a photoprotective activation role. It is concluded that S. tectorum not only withstands a combination of water deficit and nutrient deprivation for 10 weeks without any symptom of damage but also activates effective defense strategies through the simultaneous accumulation of ABA and the bioactive jasmonate form, jasmonoyl-isoleucine. [ABSTRACT FROM AUTHOR]

The present study was carried out to investigate the influence of Sempervivum tectorum aqueous extract and melatonin on reduced glutathione (GSH) protective effect in Wistar albino rat blood exposed to aluminium sulphate- Al2(SO4)3. The rats were divided in one control group (C) and 7 experimental groups (E). The control group received tap water. The experimental rats were feed the following way: E1 group – aluminum sulphate, daily, for 3 months; : E2 group – Sempervivum tectorum, daily, for 3 months; : E3 group – melatonin, daily, for 3 months; : E4 group – aluminum sulphate with Sempervivum tectorum, daily, for 3 months; : E5 group – aluminum sulphate with melatonin, daily, for 3 months; E6 group – aluminum sulphate, daily, for 3 months, and thereafter with Sempervivum tectorum for 1 month; E7 group – aluminum sulphate, daily, for 3 month, and thereafter with melatonin for 1 month. This study showed that Aluminum toxicity induced lower GSH. The oxidative stress caused by aluminum, given individual, is more pronounced than in the case in which aluminum is administered simultaneously with Sempervivum tectorum or melatonin. Decreasing GSH value is very small if Sempervivum tectorum or melatonin is given for one month, three months after the administration of aluminum. Effect induced by melatonin is more favorable than that of Sempervivum tectorum. [ABSTRACT FROM AUTHOR]

Purpose: To examine the effect of Sempervivum tectorum aqueous extract, as infusion, on some biomarkers of oxidative stress induced by aluminium exposure in Wistar albino rat. Methods: The rats were randomly divided into five groups and treated daily for 3 months as follows: control received tap water; the 2nd group was given 1 mg/L aluminium as aluminium sulphate (AS) in drinking water daily; group 3, a combination of 1 mg/L AS and Sempervivum tectorum extract daily; the fourth group, Sempervivum tectorum extract daily; and fifth group 1 mg/L AS for three months and thereafter Sempervivum tectorum extract for one month. Results: Aluminium (Al) exposure increased, compared to control group, the level of blood Al (293.64 %, p < 0.0001), serum superoxide dismutase (SOD, 14.84 %, p > 0.05), glutathione peroxidase (G-Px, 31.25 %, p < 0.001) and thiobarbituric reactive substances (TBARS, 21.37 %, p < 0.001) but significantly decreased catalase (CAT, 49.59 %, p < 0.001), glutathione (GSH, 13.49 %, p < 0.001) and glutathione reductase (GSH-r, 23.08 %, p < 0.0001) levels. These results indicate that Al-induced oxidative stress in the rats. Following administration of Sempervivum tectorum extract, the levels of the oxidative stress biomarkers were restored to normal, indicating good antioxidant properties of the extract. Al blood level was also significantly reduced by 33.45 % (p < 0.001) in rats exposed to the extract. Rat body weight was not significantly (p > 0.05) affected by the extract. Conclusion: S. tectorum extract possesses antioxidant activity against free radicals produced in blood as a result of aluminium exposure. [ABSTRACT FROM AUTHOR]

The aim of the study was to highlight the effect of Sempervivum tectorum and melatonin administration in rats exposed to aluminium sulphate through drinking water on the erythrocyte catalase activity The researches were carried out on Wistar albinos rats, grouped in 8 lots: a control lot (C) and 7 experimental lots (E1: 10% Sempervivum tectorum aqueous extract, 3 month; E2: melatonin, 10 mg/100 ml water, 3 month; E3: aluminium sulphate, 3 months; E4: aluminium sulphate with 10% Sempervivum tectorum aqueous extract, 3 months; E5: aluminium sulphate with melatonin 3 months; E6: aluminium sulphate 3 months followed by 10% Sempervivum tectorum aqueous extract for a month; E7: aluminium sulphate 3 months, followed by melatonin for a month). Al(3+) level in drinking water was 1000 ppb. It was registered decrease of catalase activity compared to C group in E3, E4 (p<0.01), E5 group (p>0.05) and an insignificant increase in E1, E2, E6, E7 groups. Sempervivum tectorum and melatonin administration led to the increase of catalase activity comparing to the group exposed only to aluminium. The catalase activity increase was significantly higher in case of consecutive administration to aluminium intake. Melatonin effect was more wellmarked as the one induced by Sempervivum tectorum (p>0.05). [ABSTRACT FROM AUTHOR]

Oxygen free radicals play an important role in the development of different disorders like inflammatory-immune injury, carcinogenesis, hepatic toxicity and artherosclerosis. The antioxydant role of a wide spectrum of natural products has been established. Flavonoids and other phenolic compounds (proanthocyanidins, rosmarinic acid, hydroxicinnamic derivatives, catechines, etc.) of plant origin have been reported as scavengers and inhibitors of lipid peroxidation. We have studied the antioxidant activity as well as content and composition of natural phenolics in a series of medicinal plants with phytotherapeutical significance. Thus we determined the total phenol contents and studied the composition of flavonoids, polyphenols, phenolic acids of different vegetative and reproductive organs of medicinal plants: Anthriscus cerefolium (L.) Hoffm., Petroselinum crispum L., Cichorium intybus L., Helichrysum arenarium D.C.„cempervivum tectorum L., Taravacum officinale Web. Characteristic constituents in the various crude drugs were determined by chromatographic (TLC, HPLC) and spectroscopic (UV, UV-VIS) methods. The non specific scavenger activities of the medicinal plant extracts were studied by the chemiluminometric technique. The changes of chemiluminescence intensity of the H,G,•0H-luminol system at increasing concentrations of the H702/ -OH were measured. Inhibitory effects of selected standardized fractions from plants were tested on ascorbic acid induced lipid peroxidation in rat liver and homogenates. The best correlation were established with total phenolics in some medicinal plants (S. tectorum, T. officinale) while activities in other cases seem to be influenced by flavonoids (P. crispum, H. arenarium, A. cerefolium) and by hydroxicinnamic derivatives (C. intybus).

Human melanoma cells are known as one of the most aggressive cancer cells, and consequently, melanoma is one of the most incurable cancer diseases. There is intense activity in research and development of potential medicines for malignant diseases, including alternative forms of remedies. Therefore, the purpose of our work was testing extracts from the common houseleek (Sempervivum tectorum) grown in Slovenia to establish its impact on human melanoma cells. Namely, we wanted to verify if the extracts inhibit growth of malignant cells and their metabolic activity. Soxhlet, cold solvent, ultrasound, and supercritical extraction methods were applied to obtain S. tectorum extracts. Polyphenols and proanthocyanins content in acquired extracts was determined as well as their antioxidative potential. For a relevant comparison, Chinese (CHI) dried and Slovenian (SLO) lyophilized S. tectorum was used. Results showed that the highest contents of polyphenols and proanthocyanins were yielded from lyophilized material, which also had the highest antioxidative potential. The focus of our work was on analysis of possible inhibition effects of the extracts on human melanoma cells since no past studies were found regarding the possible effects of S. tectorum on metabolic activity of WM-266-4. We established that in a 24-h incubation period, the extracts inhibited metabolic activity of the cells at their concentrations of 20, 10, 4, 2, 1, 0.2, and 0.02 mg/mL. Extract obtained from SLO S. tectorum (ultrasound extraction with acetone as a solvent), which showed promising results of inhibitory effect on the mentioned cells, was further described since the local plant was the focus of our study. CHI S. tectorum extract (Soxhlet extraction with ehtanol:water mixture = 1:1 as a solvent) showed the highest inhibitory effect on human melanoma cells WM-266-4, although both obtained extracts are suitable for their growth inhibition of this specific cell line. Our results suggest inhibitory ability of S. tectorum extracts on the metabolic activity of WM-266-4 metastatic cell line, suggesting their potential use as an anticancer agent. [ABSTRACT FROM AUTHOR]

The reasons for CO2 release by some CAM plants during the light period were investigated by comparative gas‐exchange studies with three leaf‐succulent species, Kalanchoë tubiflora Hamet, Sedum morganianum E. Walth. and Sempervivum tectorum L. Sempervivum showed net CO2 output during the day at constant day‐night temperatures of both 15 and 25°C, whereas Kalanchoë and Sedum showed no CO2 release at this time at either temperature. Net nocturnal CO2 uptake was markedly reduced at 25°C compared with 15°C in Kalanchoë and Sempervivum, while CO2 was released at night at higher temperature by Sedum if leaf/air vapour pressure difference was also increased. Values for intercellular partial pressure of CO2 (piCO2) were calculated from leaf conductance and were characteristically lowest in the dark and highest in the light period. Maximum values of piCO2 ranged from 264 Pa in Sedum to 87 Pa in Kalanchoë, but were somewhat lower than those reported from direct measurements of the gas phase in other CAM plants. Leaf conductance declined with increasing piCO2 in all three species. Minimum values of approximately 0.2 mmol m−2 s−1 were observed at piCO2= 33 Pa in Kalanchoë and Sedum, with no further decrease at higher piCO2, implying that this largely represented the conductance of the cuticle. In Sempervivum, however, leaf conductance declined more gradually, and was as much as 0.8 mmol m−2 s−1 at the highest observed values of piCO2. The cause of net CO2 output in the light by Sempervivum thus appeared to be lower stomatal sensitivity to CO2, resulting in relatively high leaf conductance even at times when piCO2 greatly exceeded that of ambient air. [ABSTRACT FROM AUTHOR]