Antioxidant, Antihypertensive, Hypoglycaemic and Nootropic Activity of a Polyphenolic Extract from the Halophyte Ice Plant (Mesembryanthemum crystallinum)

Nutrients and phytochemical density in Mesembryanthemum crystallinum L. cultivated in growing media supplemented with dosages of nitrogen fertilizer

Mesembryanthemum crystallinum L. is an annual halophyte that originated from southern Africa. However, little has been reported about factors that modulate the quantity of secondary metabolites in the plant. In this study, the twin effect of different nitrogen concentrations (0.36, 0.6, 0.8 g/L) and growing media (LECA clay, peat, vermiculite and silica sand) on plant growth, chlorophyll contents, minerals, proximate and antioxidant metabolites in hydroponically cultivated M. crystallinum was investigated. This is important to determine the dosage of N fertilizer that will optimize the bio-productivity and biosynthesis of secondary metabolites and antioxidants in M. crystallinum grown in a hydroponic system. The untreated plant (0 g/L N) was taken as the control. At the end of the experiment, optimum yields in leaf number (9.2), fresh weight (50.40 g), Ca, N, and Protein (34.04 %) were recorded in M. crystallinum grown with peat enhanced with different dosages of N-fertilizer. Likewise, chlorophyll level, dry weight, ABTS/TEAC, FRAP, ADF and NDF contents were optimized in LECA clay treated with N-fertilizer. Silica sand with 0.36 g/L dosage of nitrogen fertilizer optimized P, Mn and Zn levels, so also the moisture (9.83 % at 0.8 g/L N), fat (2.38 %, 0 g/L N) and carbohydrates (44.98 and 44.95 %). The highest ash content, Mg and Fe were recorded in the untreated vermiculite as well as polyphenols and K, at 0.6 g/L; Cu and root length (14.60 cm), at 0.8 g/L. In conclusion, different dosages of nitrogen fertilizer and growing media could enhance the growth potential, chlorophyll, phytochemicals, and nutritional properties of M. crystallinum.

Identification of Polyphenols in Sea Fennel (Crithmum maritimum) and Seaside Arrowgrass (Triglochin maritima) Extracts with Antioxidant, ACE-I, DPP-IV and PEP-Inhibitory Capacity

Sea fennel and seaside arrowgrass are two abundant but underutilized halophytes along the Atlantic and Mediterranean coasts. This study investigated the antioxidant capacity and the potential antihypertensive (Angiotensin Converting Enzyme I, ACE-I inhibition), hypoglycaemic (Dipeptidyl Peptidase IV, DPP-IV inhibition), and nootropic (Prolyl Endopeptidase, PEP inhibition) activity of their polyphenol extracts. They had a high phenol content (21-24 mEq GA/g), antioxidant capacity evaluated using the ABTS (17-2 mg ascorbic acid/g) and FRAP (170-270 mM Mohr's salt/g) assays, and effective ACE-inhibiting properties (80-90% inhibiting activity at final concentration of 0.5 mg/mL). Additionally, the sea fennel extract displayed high DPP-IV inhibitory capacity (73% at 1 mg/mL), while the seaside arrowgrass extract exhibited potent Prolyl endopeptidase inhibitory capacity (75% at 1 mg/mL). Fractionation by HPLC concentrated the bioactive molecules in two fractions, for which the composition was analyzed by LC-MS/MS. Different chlorogenic acids seemed to play an important role in the bioactivity of sea fennel extract, and different flavonoids, mainly apigenin, luteolin and chrysoeriol, in the bioactivity of the seaside arrowgrass extract. Given their potential health benefits, these extracts could serve as valuable bioactive ingredients and could potentially encourage the cultivation of these species in regions where traditional crops face challenges in growth.

Bioactivity-Guided Isolation and Antihypertensive Activity of Citrullus colocynthis Polyphenols in Rats with Genetic Model of Hypertension

Background and Objectives: Citrullus colocynthis belongs to the Cucurbitaceae family and is a wild medicinal plant used in folk literature to treat various diseases. The purpose of the current study was to explore the antihypertensive and antioxidant potentials of Citrullus colocynthis (CC) polyphenol-rich fractions using a spontaneous hypertensive rat (SHR) model. Materials and Methods: The concentrated aqueous ethanol extract of CC fruit was successively fractioned using solvents of increasing polarity, i.e., hexane, chloroform, ethyl acetate and n-butanol. The obtained extracts were analyzed for total phenolic content (TPC), total flavonoid content (TFC) and total flavonol content (TOF). Moreover, the CC extracts were further evaluated for radical scavenging capacity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays and antioxidant activity using inhibition of linoleic acid peroxidation and determination of reducing potential protocols. The phytochemical components were characterized by HPLC-MWD-ESI-MS in positive ionization mode. Results: The results showed that ethyl acetate fraction (EAF) exhibited a higher content of phenolic compounds in term of TPC (289 mg/g), TFC (7.6 mg/g) and TOF (35.7 mg/g). EAF showed higher antioxidant and DPPH and ABTS scavenging activities with SC50 values of 6.2 and 79.5 µg/mL, respectively. LCMS analysis revealed that twenty polyphenol compounds were identified in the EAF, including phenolic acids and flavonoids, mainly myricetin and quercetin derivatives. The in vivo antihypertensive activity of EAF of CC on SHR revealed that it significantly decreased the mean arterial pressure (MAP), systolic blood pressure (SBP), diastolic blood pressures (DBP) and pulse pressure (PP) as compared to normal and hypertensive control groups. Moreover, EAF of CC significantly reduced the oxidative stress in the animals in a dose-dependent manner by normalizing the levels of superoxide dismutase (SOD), malondialdehyde (MDA), reduced glutathione (GSH), nitric oxide (NOx) and total antioxidant capacity (TAC). Furthermore, the treatment groups, especially the 500 mg of EAF per kg body weight (EA-500) group, significantly (p ≤ 0.05) improved the electrocardiogram (ECG) pattern and pulse wave velocity (PWV). Conclusion: It was concluded that the EAF of CC is a rich source of polyphenols and showed the best antioxidant activity and antihypertensive potential in SHR.

Effects of Platycladus orientalis Leaf Extract on the Growth Performance, Fur-Production, Serum Parameters, and Intestinal Microbiota of Raccoon Dogs

Platycladus orientalis leaves are rich in flavonoids and polysaccharides, which offer high medicinal and nutritional benefits. This study aimed to investigate the impact of P. orientalis leaf extract (PLE) on the growth performance, fur quality, serum parameters, and intestinal microbiota of raccoon dogs. Sixty healthy male black raccoon dogs, aged 85 (±5) days, were randomly assigned to four groups and fed a basal diet supplemented with 0, 0.25, 0.50, and 1.00 g/kg PLE for 125 days (designated as groups P0, P1, P2, and P3, respectively). The results revealed that the raccoon dogs in group P1 exhibited increased average daily gain and underfur length while showing a decreased feed/gain ratio compared to group P0 (p < 0.05). However, the heart index in group P2 was significantly lower than in group P0 (p < 0.05), and the kidney index and serum alanine aminotransferase activities in group P3 were higher than in groups P2 and P0 (p < 0.05), suggesting potential adverse effects at higher PLE dosages. Notably, dietary PLE supplementation led to a reduction in serum glucose concentrations (p < 0.05), which may have implications for glucose regulation. Furthermore, the study explored the impact of dietary supplementation with 0.25 g/kg PLE on the raccoon dogs' intestinal microbiota using high-throughput sequencing. The results showed significant alterations in the microbial community structure, with a notable decrease in the abundance of Prevotella copri in response to 0.25 g/kg PLE supplementation (p < 0.05). In conclusion, supplementing raccoon dogs' diet with 0.25 g/kg PLE can lead to improved growth performance and a positive influence on the intestinal microbiota. However, caution should be exercised regarding higher dosages, as they may have adverse effects on certain parameters. As a result, PLE holds promise as a potential feed additive for fur animal production.

Optimization of Nutrient-Rich Ice Plant (Mesembryanthemum crystallinum L.) Paste Fresh Noodle Pasta Using Response Surface Methodology

The ice plant is a species that is grown mainly in the dry regions of the American West and contains various minerals and ingredients beneficial for human health, such as inositol and beta-carotene. With the growing trend towards healthy foods, pasta consumption has also increased. Pasta is a convenient and low-glycemic-index food that is composed mainly of carbohydrates, proteins, lipids, dietary fiber, and trace amounts of minerals. The optimal mixing ratio was evaluated to produce pasta of the highest quality in terms of blood sugar elevation and antioxidant efficacy. The components and minerals of the ice plant, including D-pinitol and inositol, were analyzed, and 20 essential amino acids were identified. In this study, we also investigated the quality and characteristics of ice plant paste and eggs, as well as the quality, antioxidant activity, and formulation of raw materials mixed with ice plant at different ratios. Optimal conditions were found to be 46.73 g of ice plant paste in 100 g of durum wheat flour, 20.23 g of egg, and 2 g of salt, providing a way to develop fresh pasta that enhances the health benefits of ice plant paste without excessive moisture and other ingredients.

Soilless Cultivated Halophyte Plants: Volatile, Nutritional, Phytochemical, and Biological Differences

The use of halophyte plants appears as a potential solution for degraded soil, food safety, freshwater scarcity, and coastal area utilization. These plants have been considered an alternative crop soilless agriculture for sustainable use of natural resources. There are few studies carried out with cultivated halophytes using a soilless cultivation system (SCS) that report their nutraceutical value, as well as their benefits on human health. The objective of this study was to evaluate and correlate the nutritional composition, volatile profile, phytochemical content, and biological activities of seven halophyte species cultivated using a SCS (Disphyma crassifolium L., Crithmum maritimum L., Inula crithmoides L., Mesembryanthemum crystallinum L., Mesembryanthemum nodiflorum L., Salicornia ramosissima J. Woods, and Sarcocornia fruticosa (Mill.) A. J. Scott.). Among these species, results showed that S. fruticosa had a higher content in protein (4.44 g/100 g FW), ash (5.70 g/100 g FW), salt (2.80 g/100 g FW), chloride (4.84 g/100 g FW), minerals (Na, K, Fe, Mg, Mn, Zn, Cu), total phenolics (0.33 mg GAE/g FW), and antioxidant activity (8.17 µmol TEAC/g FW). Regarding the phenolic classes, S. fruticosa and M. nodiflorum were predominant in the flavonoids, while M. crystallinum, C. maritimum, and S. ramosissima were in the phenolic acids. Moreover, S. fruticosa, S. ramosissima, M. nodiflorum, M. crystallinum, and I. crithmoides showed ACE-inhibitory activity, an important target control for hypertension. Concerning the volatile profile, C. maritimum, I. crithmoides, and D. crassifolium were abundant in terpenes and esters, while M. nodiflorum, S. fruticosa, and M. crystallinum were richer in alcohols and aldehydes, and S. ramosissima was richer in aldehydes. Considering the environmental and sustainable roles of cultivated halophytes using a SCS, these results indicate that these species could be considered an alternative to conventional table salt, due to their added nutritional and phytochemical composition, with potential contribution for the antioxidant and anti-hypertensive effects.

A Culturomics-Based Bacterial Synthetic Community for Improving Resilience towards Arsenic and Heavy Metals in the Nutraceutical Plant Mesembryanthemum crystallinum

Plant-growth-promoting bacteria (PGPB) help plants thrive in polluted environments and increase crops yield using fewer inputs. Therefore, the design of tailored biofertilizers is of the utmost importance. The purpose of this work was to test two different bacterial synthetic communities (SynComs) from the microbiome of Mesembryanthemum crystallinum, a moderate halophyte with cosmetic, pharmaceutical, and nutraceutical applications. The SynComs were composed of specific metal-resistant plant-growth-promoting rhizobacteria and endophytes. In addition, the possibility of modulating the accumulation of nutraceutical substances by the synergetic effect of metal stress and inoculation with selected bacteria was tested. One of the SynComs was isolated on standard tryptone soy agar (TSA), whereas the other was isolated following a culturomics approach. For that, a culture medium based on M. crystallinum biomass, called Mesem Agar (MA), was elaborated. Bacteria of three compartments (rhizosphere soil, root endophytes, and shoot endophytes) were isolated on standard TSA and MA media, stablishing two independent collections. All bacteria were tested for PGP properties, secreted enzymatic activities, and resistance towards As, Cd, Cu, and Zn. The three best bacteria from each collection were selected in order to produce two different consortiums (denominated TSA- and MA-SynComs, respectively), whose effect on plant growth and physiology, metal accumulation, and metabolomics was evaluated. Both SynComs, particularly MA, improved plant growth and physiological parameters under stress by a mixture of As, Cd, Cu, and Zn. Regarding metal accumulation, the concentrations of all metals/metalloids in plant tissues were below the threshold for plant metal toxicity, indicating that this plant is able to thrive in polluted soils when assisted by metal/metalloid-resistant SynComs and could be safely used for pharmaceutical purposes. Initial metabolomics analyses depict changes in plant metabolome upon exposure to metal stress and inoculation, suggesting the possibility of modulating the concentration of high-value metabolites. In addition, the usefulness of both SynComs was tested in a crop plant, namely Medicago sativa (alfalfa). The results demonstrate the effectiveness of these biofertilizers in alfalfa, improving plant growth, physiology, and metal accumulation.