Nitrate modulates the physiological tolerance responses of the halophytic species Sarcocornia fruticosa to copper excess.

Coexistence impact of pollutants of different nature on halophytes tolerance to metal excess has not been thoroughly examined, and plant functional responses described so far do not follow a clear pattern. Using the Cu-tolerant halophyte Sarcocornia fruticosa as a model species, we conducted a greenhouse experiment to evaluate the impact of two concentration of copper (0 and 12 mM CuSO4) in combination with three nitrate levels (2, 14 and 50 mM KNO3) on plant growth, photosynthetic apparatus performance and ROS-scavenging enzymes system. The results revealed that S. fruticosa was able to grow adequately even when exposed to high concentrations of copper and nitrate. This response was linked to the plant capacity to uptake and retain a large amount of copper in its roots (up to 1500 mg kg-1 Cu), preventing its transport to aerial parts. This control of translocation was further magnified with nitrate concentration increment. Likewise, although Cu excess impaired S. fruticosa carbon assimilation capacity, the plant was able to downregulate its light-harvesting complexes function, as indicated its lowers ETR values, especially at 12 mM Cu + 50 mM NO3. This downregulation would contribute to avoid excess energy absorption and transformation. In addition, this strategy of avoiding excess energy was accompanied by the upregulation of all ROS-scavenging enzymes, a response that was further enhanced by the increase in nitrate concentration. Therefore, we conclude that the coexistence of nitrate would favor S. fruticosa tolerance to copper excess, and this effect is mediated by the combined activation of several tolerance mechanisms.

In vitro anti-HIV, cytotoxicity and nutritional analysis of Trianthema portulacastrum L. (Aizoaceae).

The development of antiretroviral therapy has brought a tremendous relief to the world as it minimizes mortality, reduces HIV transmission, and suppresses progression in infected patients. However, the orthodox antiretroviral therapy is faced with limitations which have necessitated a continuous search for more novel plant-based antiviral compounds, which can bypass the existing barriers created by drug resistance and target more viral proteins. Despite the edibility and enormous pharmacological benefits of T. portulacastrum, little is known about its nutrient profiles and potential use as a natural source of antiviral drug. This study focuses on the full feed analysis and anti-HIV potential of two biotypes of T. portulacastrum. Ethanolic extracts of both biotypes of T. portulacastrum (T01 and T02) had significant inhibitory effects on the level of replication of the HIV-1. Both extracts induced the inhibition of at least 50% of the HIV-1 viral load at considerably low IC50 values of 1.757 mg/mL (T01) and 1.205 mg/mL (T02) which is comparable to the AZT standard. The protein composition ranged between 8.63-22.69%; fat (1.84-4.33%); moisture (7.89-9.04%); fibre (23.84-49.98%); and carbohydrate content (38.54-70.14%). Mineral contents of tested T. portulacastrum varied considerably in different parts of the plant. Nitrogen N mineral ranged between 13.8-36.3 mg/g; sodium Na (2.0-14.0 mg/g); potassium K (14.0-82.0 mg/g); magnesium Mg (2.8-7.1 mg/g); calcium Ca (9.1-24.7 mg/g); phosphorus P (1.3-3.6 mg/g); iron Fe (193.5-984.0 ppm); zinc Zn (42.5-96.0 ppm); manganese Mn (28.5-167.5 ppm); and copper Cu (2.0-8.5 ppm). These mineral values are comparable or higher than values quoted for common vegetables, suggesting that T. portulacastrum is a nutrient-dense vegetable that could provide alternative sources of antiviral nutrients to HIV-infected individuals. Further studies are recommended to unravel key metabolites responsible for high nutrient profiles and antiretroviral effects in T. portulacastrum.

Early-responsive molecular signatures associated with halophytic adaptation in Sesuvium portulacastrum (L.).

Sesuvium portulacastrum (L.) is a halophyte, adapted to grow naturally under saline environments. The ability to use Na and K interchangeably indicated its facultative halophyte nature. No significant growth reduction occurs in seedlings up to 250 mM NaCl, except for curling of the youngest leaf. Within 8 h of salt treatment, seedlings accumulate proline, glycine betaine and other amino acids in both root and shoot. Despite a continued increase of tissue Na content, the number of differentially expressed genes (DEGs) decreases between 8 and 24 h of salt exposure, indicating transcriptional restoration after the initial osmotic challenge. At 8 h, upregulated genes mainly encode transporters and transcription factors, while genes in growth-related pathways such as photosynthesis and ribosome-associated biogenesis are suppressed. Overexpression of SpRAB18 (an ABA-responsive dehydrin), one of the most strongly induced DEGs, in soybean was found to increase biomass in control conditions and the growth benefit was maintained when plants were grown in 100 mM NaCl, indicating conservation of function in halophyte and glycophyte. An open-access transcriptome database "SesuviumKB" (https://cb.imsc.res.in/sesuviumkb/) was developed to involve the scientific community in wide-scale functional studies of S. portulacastrum genes, that could pave the way to engineer salt tolerance in crops.

Profiling of conserved orthologs and miRNAs for understanding their role in salt tolerance mechanism of Sesuvium portulacastrum L.

BACKGROUND: Sesuvium portulacastrum is a facultative halophyte capable of thriving in a saline environment. Despite molecular studies conducted to unravel its salt adaptation mechanism, there is a paucity of information on the role of salt-responsive orthologs and microRNAs (miRNAs) in this halophyte. Here, we searched the orthology to identify salt-responsive orthologs and miRNA targets of Sesuvium using the Arabidopsis genome. METHODS: The relative fold change of orthologs, conserved miRNAs, and miRNA targets of Sesuvium was analyzed under 100 mM (LS) and 250 mM NaCl (HS) treatment at 24 h using qRT-PCR. The comparison between the expression of Sesuvium orthologs and Arabidopsis orthologs (Arabidopsis eFP browser database) was used to identify differentially expressed genes. RESULTS: Upon salt treatment, we found that SpCIPK3 (1.95-fold in LS and 2.90-fold in HS) in Sesuvium roots, and SpNHX7 (1.61-fold in LS and 6.39-fold in HS) and, SpSTPK2 (2.54-fold in LS and 7.65-fold in HS) in Sesuvium leaves were upregulated in a salt concentration-specific manner. In Arabidopsis, these genes were either downregulated or did not show significant variation, implicating its significance in the halophytic nature of Sesuvium. Furthermore, miRNAs like miR394a, miR396a, and miR397a exhibited a negative correlation with their targets-Frigida interacting protein 1, Cysteine proteinases superfamily protein, and Putative laccase, respectively under different salt treatments. CONCLUSION: The study revealed that the high salt tolerance in Sesuvium is associated with distinct transcriptional reprogramming, hence, to gain holistic mechanistic insights, global-scale profiling is required.

Effects of Salinity Stress on Growth and Physiological Parameters and Related Gene Expression in Different Ecotypes of Sesuvium portulacastrum on Hainan Island.

We conducted a study to examine the growth and physiological changes in 12 different ecotypes of Sesuvium portulacastrum collected from Hainan Island in China. These ecotypes were subjected to different concentrations (0, 200, 400, and 600 mmol/L) of sodium chloride (NaCl) salt stress for 14 days. We also analyzed the expression of metabolic genes related to stress response. Under low salt stress, indicators such as plant height in region K (0 mmol/L: 45% and highest at 200 mmol/L: 80%), internode length (0 mmol/L: 0.38, 200 mmol/L: 0.87, 400 mmol/L: 0.25, and 600 mmol/L: 1.35), as well as leaf area, relative water content, fresh weight, and dry weight exhibited an overall increasing trend with the increase in salt concentration. However, as the salt concentration increased, these indicators showed a decreasing trend. Proline and malondialdehyde contents increased with higher salt concentrations. When the NaCl concentration was 400 mmol/L, MDA content in the leaves was highest in the regions E (196.23%), F (94.28%), J (170.10%), and K (136.08%) as compared to the control group, respectively. Most materials demonstrated a significant decrease in chlorophyll a, chlorophyll b, and total chlorophyll content compared to the control group. Furthermore, the ratio of chlorophyll a to chlorophyll b (Rab) varied among different materials. Using principal component analysis, we identified three ecotypes (L from Xinglong Village, Danzhou City; B from Shuigoupo Village, Lingshui County; and J from Haidongfang Park, Dongfang City) that represented high, medium, and low salt tolerance levels, respectively, based on the above growth and physiological indexes. To further investigate the expression changes of related genes at the transcriptional level, we employed qRT-PCR. The results showed that the relative expression of SpP5CS1, SpLOX1, and SpLOX1 genes increased with higher salt concentrations, which corresponded to the accumulation of proline and malondialdehyde content, respectively. However, the relative expression of SpCHL1a and SpCHL1b did not exhibit a consistent pattern. This study contributes to our understanding of the salt tolerance mechanism in the true halophyte S. portulacastrum, providing a solid theoretical foundation for further research in this field.

Effect of Tetragonia tetragonoides (Pall.) Kuntze Extract on Andropause Symptoms.

Testosterone and free testosterone levels decrease in men as they age, consequently inducing andropause symptoms, such as weight gain, fatigue, and depression. Therefore, this study aimed to evaluate the reducing effect of New Zealand spinach (NZS) on these androgenic symptoms by orally administering its extract to 26-week-old rats for four weeks. Biochemical blood testing was conducted, and the andropause symptoms-related indicators and muscular endurance levels were examined. In the NZS extract-treated rats, the decrease in muscle mass was suppressed, and immobility time was reduced in the forced swim test. In addition, the grip force and muscular endurance of the forelimbs were significantly increased compared to the control group; therefore, NZS extract exhibits a positive effect on the maintenance of muscle mass and improves muscular endurance. The representative male hormones, testosterone and progesterone, in the NZS extract-treated group were 1.84 times and 2.48 times higher than those in the control groups, respectively. Moreover, cholesterol and low-density lipoprotein, which affect lipid metabolism, were significantly reduced in the NZS extract-treated group. Overall, NZS extract shows potential for further development as a functional food material for improving muscle strength and relieving andropause symptoms.

Photodamage on Staphylococcus aureus by natural extract from Tetragonia tetragonoides (Pall.) Kuntze: Clean method of extraction, characterization and photophysical studies.

Photodynamic therapy (PDT) is a clinical modality that allows the destruction of tumor cells and microorganisms by reactive oxygen species, formed by the combination of photosensitizer (PS), molecular oxygen and adequate wavelength light. This research, through a clean methodology that involves pressurized liquids extraction (PLE), obtained a highly antimicrobial extract of Tetragonia tetragonoides, which rich in chlorophylls as photosensitizers. The Chlorophylls-based extract (Cbe-PLE) presented pharmacological safety, through the maintenance of cellular viability. In addition, Cbe-PLE showed great efficacy against Staphylococcus aureus, with severe dose-dependent damage to the cell wall of the pathogen. The obtained product has a high potential for the development of photostimulated phytotherapic formulations for clinical applications in localized infections, as a complementary therapeutic alternative to antibiotics.

The functional identification of glycine-rich TtASR from Tetragonia tetragonoides (Pall.) Kuntze involving in plant abiotic stress tolerance.

In this study, we reported on an ASR gene (TtASR) related to salt/drought tolerance from the edible halophyte Tetragonia tetragonoides (Pall.) Kuntze (Aizoaceae). A phylogenetic analysis revealed that TtASR was evolutionarily close to other two halophytic glycine-rich ASR members, SbASR-1 (from Salicornia brachiate) and SlASR (from Suaeda liaotungensis), with a typical abscisic acid (ABA)/water-deficit stress (WDS) domain at C-terminal. Quantitative RT-PCR analyses showed that TtASR was expressed in all tested different organs of the T. tetragonoides plant and that expression levels were apparently induced after salt, osmotic stress, and ABA treatments in T. tetragonoides seedlings. An induction of TtASR improved the growth performance of yeast and bacteria more than the control under high salinity, osmotic stress, and oxidative stress. TtASR was not a nuclear-specific protein in plant, and the transcriptional activation assay also demonstrated that TtASR could not activate reporter gene's expression in yeast. TtASR overexpressed Arabidopsis plants exhibited higher tolerance for salt/drought and oxidative stresses and lower ROS accumulation than wild type (WT) plants, accompanied by increased CAT, SOD activities, higher proline content, and lower MDA content in vivo. The results indicated that the TtASR was involved in plant responses to salt and drought, probably by mediating water homeostasis or by acting as ROS scavengers, and that it decreased the membrane damage and improved cellular osmotic adjustment that respond to abiotic stresses in microorganisms and plants.

Salinity decreases Cd translocation by altering Cd speciation in the halophytic Cd-accumulator Carpobrotus rossii.

Background and Aims: Salt has been shown to affect Cd translocation and accumulation in plants but the associated mechanisms are unclear. This study examined the effects of salt type and concentration on Cd uptake, translocation and accumulation in Carpobrotus rossii. Methods: Plants were grown in nutrient solution with the same Cd concentration or Cd2+ activity in the presence of 25 mm NaNO3, 12.5 mm Na2SO4 or 25 mm NaCl for ≤10 d. Plant growth and Cd uptake were measured and the accumulation of peptides and organic acids, and Cd speciation in plant tissues were analysed. Key Results: Salt addition decreased shoot Cd accumulation by >50 % due to decreased root-to-shoot translocation, irrespective of salt type. Synchrotron-based X-ray absorption spectroscopy revealed that, after 10 d, 61-94 % Cd was bound to S-containing ligands (Cd-S) in both roots and shoots, but its speciation was not affected by salt. In contrast, Cd in the xylem sap was present either as free Cd2+ or complexes with carboxyl groups (Cd-OH). When plants were exposed to Cd for ≤24 h, 70 % of the Cd in the roots was present as Cd-OH rather than Cd-S. However, NaCl addition decreased the proportion of Cd-OH in the roots within 24 h by forming Cd-Cl complexes and increasing the proportion of Cd-S. This increase in Cd-S complexes by salt was not due to changes in glutathione and phytochelatin synthesis. Conclusions: Salt addition decreased shoot Cd accumulation by decreasing Cd root-to-shoot translocation due to the rapid formation of Cd-S complexes (low mobility) within the root, without changing the concentrations of glutathione and phytochelatins.

Physiological response and mineral elements accumulation pattern in Sesuvium portulacastrum L. subjected in vitro to nickel.

Sesuvium portulacastrum, a halophyte with high tolerance to heavy metals like Cd, Pb and Ni is considered for phytoremediation of metal contaminated saline soils. The tolerance to a selected metal ion could, by hypothesis, be stimulated through in vitro adaptation and regeneration of the plant. Seedlings obtained by in vitro micro-propagation, were exposed to 0, 25 and 50 µM Ni, as NiCl2, in agar-based medium for 30 days. Growth parameters, plant water content, the concentration of photosynthetic pigments, proline and malondialdehyde (MDA) concentrations were determined. Nickel and nutrients distribution in leaves was studied by micro-Proton-Induced-X-ray-Emission (µ-PIXE). The results showed that Ni was mainly accumulated in vascular bundles, next in water storage tissues and chlorenchyma. Ni concentrations in chlorenchyma increased with increasing Ni in culturing medium, in direct relation to decrease of photosynthetic pigments and increase of oxidative stress. As compared to control plants, Ni induced substantial increase in MDA and proline accumulation. Plants exposed to 50 µM Ni accumulated up to 650 µg g-1 of Ni in the shoots, exhibiting chlorosis and necrosis and a drastically reduced plant growth. Perturbations in uptake and distribution of nutrients were observed, inducing mineral deficiency, probably through membrane leakage. The mineral nutrient disturbances induced by Ni could be highly implicated in the restriction of S. portulacastrum development under the acute 50 µM Ni level.

Metabolomic insights into the mechanisms underlying tolerance to salinity in different halophytes.

Salinity is among the most detrimental and diffuse environmental stresses. Halophytes are plants that developed the ability to complete their life cycle under high salinity. In this work, a mass spectrometric metabolomic approach was applied to comparatively investigate the secondary metabolism processes involved in tolerance to salinity in three halophytes, namely S. brachiata, S. maritima and S. portulacastrum. Regarding osmolytes, the level of proline was increased with NaCl concentration in S. portulacastrum and roots of S. maritima, whereas glycine betaine and polyols were accumulated in S. maritima and S. brachiata. Important differences between species were also found regarding oxidative stress balance. In S. brachiata, the amount of flavonoids and other phenolic compounds increased in presence of NaCl, whereas these metabolites were down regulated in S. portulacastrum, who accumulated carotenoids. Furthermore, distinct impairment of membrane lipids, hormones, alkaloids and terpenes was observed in our species under salinity. Finally, several other nitrogen containing compounds were involved in response to salinity, including amino acids, serotonin and polyamine conjugates. In conclusion, metabolomics highlighted that the specific mechanism each species adopted to achieve acclimation to salinity differed in the three halophytes considered, although response osmotic stress and oxidative imbalance have been confirmed as the key processes underlying NaCl tolerance.

Operating at the very low end of the crassulacean acid metabolism spectrum: Sesuvium portulacastrum (Aizoaceae).

Demonstration of crassulacean acid metabolism (CAM) in species with low usage of this system relative to C3-photosynthetic CO2 assimilation can be challenging experimentally but provides crucial information on the early steps of CAM evolution. Here, weakly expressed CAM was detected in the well-known pantropical coastal, leaf-succulent herb Sesuvium portulacastrum, demonstrating that CAM is present in the Sesuvioideae, the only sub-family of the Aizoaceae in which it had not yet been shown conclusively. In outdoor plots in Panama, leaves and stems of S. portulacastrum consistently exhibited a small degree of nocturnal acidification which, in leaves, increased during the dry season. In potted plants, nocturnal acidification was mainly facultative, as levels of acidification increased in a reversible manner following the imposition of short-term water-stress. In drought-stressed plants, nocturnal net CO2 exchange approached the CO2-compensation point, consistent with low rates of CO2 dark fixation sufficient to eliminate respiratory carbon loss. Detection of low-level CAM in S. portulacastrum adds to the growing number of species that cannot be considered C3 plants sensu stricto, although they obtain CO2 principally via the C3 pathway. Knowledge about the presence/absence of low-level CAM is critical when assessing trajectories of CAM evolution in lineages. The genus Sesuvium is of particular interest because it also contains C4 species.

Comparative physiological and proteomic analyses of the chloroplasts in halophyte Sesuvium portulacastrum under differential salt conditions.

Sesuvium portulacastrum, an important mangrove-associated true halophyte belongs to the family Aizoaceae, has excellent salt tolerance. Chloroplasts are the most sensitive organelles involved in the response to salinity. However, the regulation mechanism of chloroplasts of S. portulacastrum under salinity stress has not been reported. In this study, morphological and physiological analyses of leaves and comparative proteomics of chloroplasts isolated from the leaves of S. portulacastrum under different NaCl treatments were performed. Our results showed that the thickness of the palisade tissue, the leaf area, the maximum photochemical efficiency of photosystem II, and the electron transport rate increased remarkably after the plants were subjected to differential saline environments, indicating that salinity can increase photosynthetic efficiency and improve the growth of S. portulacastrum. Subsequently, 55 differentially expressed protein species (DEPs) from the chloroplasts of S. portulacastrum under differential salt conditions were positively identified by mass spectrometry. These DEPs were involved in multiple metabolic pathways, such as photosynthesis, carbon metabolism, ATP synthesis and the cell structure. Among these DEPs, the abundance of most proteins was induced by salt stress. Based on a combination of the morphological and physiological data, as well as the chloroplast proteome results, we speculated that S. portulacastrum can maintain photosynthetic efficiency and growth by maintaining the stability of the photosystem II complex, promoting the photochemical reaction rate, enhancing carbon fixation, developing plastoglobules, and preserving the biomembrane system of chloroplasts under salt stress.

Plasticity in the hormonal response to cold stress in the invasive plant Carpobrotus edulis.

Cold stress response is mediated by multiple signaling pathways with complex interactions, among which phytohormones may play a role. We explored changes in the contents of phytohormones, including abscisic acid, jasmonic acid, salicylic acid, auxin, cytokinins, gibberellins and melatonin, along with stress tolerance markers in an invasive halophyte, Carpobrotus edulis in response to chilling. In a first experiment, plants were exposed to mean daily temperatures from 10 °C to 5 °C during a cold wave in an experimental garden. In a second experiment, plants were subject to slowly decreasing temperatures, from 20 to 5 °C, in a climatic chamber. Although the cold response in both experiments was associated with a similar extent of leaf desiccation, hormonal variations differed. Cold stress reduced melatonin contents, while it increased salicylic acid contents in the experimental garden. Rather, transient increases in the contents of melatonin occurred in parallel with sustained increases in the contents of abscisic acid and cytokinins in the climatic chamber. In both experiments, plants were able to prevent cold-induced increases in lipid peroxidation and any eventual damage to the photosynthetic apparatus. We conclude that (i) the hormonal response to chilling in C. edulis is strongly dependent on time exposure to low temperatures, severity of stress, as well as other environmental conditions, (ii) the hormonal response of this plant species to low temperatures is very plastic, thus underlining its great capacity for cold acclimation.

Finite element modelling of complex movements during self-sealing of ring incisions in leaves of Delosperma cooperi.

A numerical computer model was developed in order to describe the complex self-sealing mechanism of injured Delosperma cooperi leaves. For this purpose, the leaf anatomy was simplified to a model consisting of five concentric tissue layers. Specific parameters (modulus of elasticity, permeability, porosity, etc.) were assigned to each tissue type for modelling its physical properties. These parameters were either determined experimentally from living plant material or taken from literature. The developed computer model considers the leaf as a liquid-filled porous body within a continuum approach in order to determine the governing equations. The modelling of the wound accounts for both the injury of peripheral tissues and the free surfaces caused by the incision. The loss of water through these free surfaces initiates the self-sealing process. It is further shown that the tissue permeability and the reflection coefficient (relative permeability of a cell membrane for solutes) are the determining parameters of the self-sealing process, whereas the modulus of elasticity has a negligible influence. Thus, the self-sealing mechanism is a hydraulically driven process which leads to a local (incision region) and global (total leaf) contraction of the leaf. The accuracy of the modelled self-sealing process was validated by comparing simulation results with experiments conducted on natural plant leaves. The results will serve as valuable input for developing novel, bio-inspired technical products with self-sealing function.

Tolerance and bioaccumulation of combined copper, zinc, and cadmium in Sesuvium portulacastrum.

Sesuvium portulacastrum was treated with mixture of copper, zinc, and cadmium for 60 days, with the concentration of each metal ranging from 0 to 20 mg/L. The tolerance of plants and bioaccumulation of heavy metals were then investigated. The height of S. portulacastrum decreased significantly with increasing heavy metal concentrations from 1 to 20 mg/L. The biomass was adversely impacted when the concentration exceeded 5 mg/L. There were no significant differences in malondialdehyde (MDA) concentration among different treatment groups, while the soluble protein content and superoxide dismutase (SOD) activity decreased with increasing heavy metal concentration. However, the BCF values of the three metals were all higher than 10 and the tolerance in root was up to 1000 mg/kg without causing significant growth inhibition, suggesting that S. portulacastrum should be a potential candidate for phytostabilization for the phytoremediation of polymetallic contaminations in coastal environments.

Revealing mechanisms of salinity tissue tolerance in succulent halophytes: A case study for Carpobrotus rossi.

Efforts to breed salt tolerant crops could benefit from investigating previously unexplored traits. One of them is a tissue succulency. In this work, we have undertaken an electrophysiological and biochemical comparison of properties of mesophyll and storage parenchyma leaf tissues of a succulent halophyte species Carpobrotus rosii ("pigface"). We show that storage parenchyma cells of C. rossii act as Na+ sink and possessed both higher Na+ sequestration (298 vs. 215 mM NaCl in mesophyll) and better K+ retention ability. The latter traits was determined by the higher rate of H+ -ATPase operation and higher nonenzymatic antioxidant activity in this tissue. Na+ uptake in both tissues was insensitive to either Gd3+ or elevated Ca2+ ruling out involvement of nonselective cation channels as a major path for Na+ entry. Patch-clamp experiments have revealed that Caprobrotus plants were capable to downregulate activity of fast vacuolar channels when exposed to saline environment; this ability was higher in the storage parenchyma cells compared with mesophyll. Also, storage parenchyma cells have constitutively lower number of open slow vacuolar channels, whereas in mesophyll, this suppression was inducible by salt. Taken together, these results provide a mechanistic basis for efficient Na+ sequestration in the succulent leaf tissues.

Anti-inflammatory activity of dimethyl octenol and oleanene tetrol isolated from Trianthema decandra L.

Dimethyl octenol from chloroform extract and oleanene tetrol from water extract of Trianthema decandra (TD) were isolated and characterized by using HPLC, UV, FT-IR, NMR, LC-MS and CHNS, their structure were elucidated from their respective spectral data. The anti-inflammatory activity of chloroform extract, water extract, dimethyl octenol and oleanene tetrol of T. decandra were studied and underlying cellular and molecular mechanisms of action were investigated in vitro and in vivo using macrophage-like cell line (RAW264.7 cells) and type II collagen induced arthritis mice models. Nitric oxide production was inhibited and TNF-α secretion was supressed in stimulated RAW cells treated with the chloroform extract and dimethyl octenol of T. decandra. Further, the chloroform and water extract, dimethyl octenol and oleanene tetrol inhibited protein denaturation and stabilized HRBC membranes in vitro. Reduction in inflammation as a measure of paw diameter was recorded in all the treated animals when compared to control animals. Catalase, peroxidase and glutathione peroxidase levels significantly increased in the joint tissue of treated groups. The possible mechanism of action of these compounds was studied using in silico molecular docking methods with phospholipase A2 (PLA2), cycloxygenase-1 (COX-1) and cycloxygenase-2 (COX-2) as targets. Among the three target proteins, the inhibition of the inflammatory protein PLA2 and COX-2 towards dimethyl octenol and oleanene tetrol respectively. Our results contribute towards confirmation of the traditional use of TD and its compounds for the therapy of rheumatoid arthritis and other inflammatory joint disorders.

1H-NMR and UPLC-MS metabolomics: Functional tools for exploring chemotypic variation in Sceletium tortuosum from two provinces in South Africa.

Sceletium tortuosum (Aizoaceae) is widely recognised for the treatment of stress, anxiety and depression, as well as for obsessive compulsive disorders. A comprehensive intraspecies chemotypic variation study, using samples harvested from two distinct regions of South Africa, was done using both proton nuclear magnetic resonance (1H-NMR) spectroscopy of methanol extracts (N = 145) and ultra performance liquid chromatography-mass spectrometry (UPLC-MS) of acid/base extracts (N = 289). Chemometric analysis of the 1H-NMR data indicated two main clusters that were region-specific (Northern Cape and Western Cape provinces). Two dimensional (2D) NMR was used to identify analytes that contributed to the clustering as revealed by the S-plot. The sceletium alkaloids, pinitol and two alkylamines, herein reported for the first time from S. tortuosum, were identified as markers that distinguished the two groups. Relative quantification of the marker analytes conducted by qNMR indicated that samples from the Northern Cape generally contained higher concentrations of all the markers than samples from the Western Cape. Quantitative analysis of the four mesembrine alkaloids using a validated UPLC-photo diode array (PDA) detection method confirmed the results of qNMR with regard to the total alkaloid concentrations. Samples from the Northern Cape Province were found to contain, on average, very high total alkaloids, ranging from 4938.0 to 9376.8 mg/kg dry w. Regarding the Western Cape samples, the total yields of the four mesembrine alkaloids were substantially lower (averages 16.4-4143.2 mg/kg). Hierarchical cluster analysis of the UPLC-MS data, based on the alkaloid chemistry, revealed three branches, with one branch comprising samples primarily from the Northern Cape that seemed somewhat chemically conserved, while the other two branches represented mainly samples from the Western Cape. The construction of an orthogonal projections to latent structures-discriminant analysis model and subsequent loadings plot, allowed alkaloid markers to be identified for each cluster. The diverse sceletium alkaloid chemistry of samples from the three clusters may facilitate the recognition of alkaloid profiles, rather than individual compounds, that exert targeted effects on various brain receptors involved in stress, anxiety or depression.

Temporal and spatial changes in ion homeostasis, antioxidant defense and accumulation of flavonoids and glycolipid in a halophyte Sesuvium portulacastrum (L.) L.

Salinity is an important environmental constraint limiting plant productivity. Understanding adaptive responses of halophytes to high saline environments may offer clues to manage and improve salt stress in crop plants. We have studied physiological, biochemical and metabolic changes in a perennial, fast growing halophyte, Sesuvium portulacastrum under 0 mM (control), 150 mM (low salt, LS) and 500 mM (high salt, HS) NaCl treatments. The changes in growth, relative water content, cation, osmolyte accumulation, H2O2 and antioxidant enzyme activity (SOD, CAT and APX) were observed under different treatment conditions. A positive correlation was revealed for sodium ion accumulation with malondialdehyde (r2 = 0.77), proline (r2 = 0.88) and chlorophyll content (r2 = 0.82) under salt treatment while a negative correlation was observed with relative tissue water content (r2 = -0.73). The roots and leaves showed contrasting accumulation of potassium and sodium ions under LS treatment. Temporal and spatial study of sodium and potassium ion content indicated differential accumulation pattern in roots and leaves, and, high potassium levels in root. Higher H2O2 content was recorded in roots than leaves and the antioxidant enzyme activities also showed significant induction under salt treatment conditions. Gene expression profiling of sodium transporters, Sodium proton exchanger (NHX3), Vacuolar ATPase (vATPase) and Salt overly sensitive1 (SOS1) showed up regulation under salt stress after 6-24 hr of NaCl treatment. Metabolite changes in the salt stressed leaves showed increased accumulation of flavonoids (3,5-dihydroxy-6,4'-dimethoxy-flavone-7-O-[α-L-rhamnopyranosyl-(1→6)-ß-D-glucopyranoside], and3,5-dihydroxy-6,3',4'-trimethoxy-flavone-7-O-[α-L-rhamnopyranosyl-(1→6)-ß-D-glucopyranoside] in both LS and HS treatments, while a glycolipid, 1-O-linolenyl-2-O-(palmitoyl)-3-O-galactopyranosyl glycerol, accumulated more in LS over HS treatments and control. The results suggest that differential spatial and temporal cation levels in roots and leaves, and accumulation of flavanoid and glycolipid could be responsible for salt adaptation of S. portulacastrum.