Polysaccharides from Trifolium repens L. extracted by different methods and extraction condition optimization

Review of isolation, purification, structural characteristics and bioactivities of polysaccharides from Portulaca oleracea L

Portulaca oleracea L., also known as purslane, affiliates to the Portulacaceae family. It is an herbaceous succulent annual plant distributed worldwide. P. oleracea L. is renowned for its nutritional value and medicinal value, which has been utilized for thousands of years as Traditional Chinese Medicine (TCM). The extract derived from P. oleracea L. has shown efficacy in treating various diseases, including intestinal dysfunction and inflammation. Polysaccharides from P. oleracea L. (POP) are the primary constituents of the crude extract which have been found to have various biological activities, including antioxidant, antitumor, immune-stimulating, and intestinal protective effects. While many publications have highlighted on the structural identification and bioactivity evaluation of POP, the underlying structure-activity relationship of POP still remains unclear. In view of this, this review aims to focus on the extraction, purification, structural features and bioactivities of POP. In addition, the potential structure-activity relationship and the developmental perspective for future research of POP were also explored and discussed. The current review would provide a valuable research foundation and the up-to-date information for the future development and application of POP in the field of the functional foods and medicine.

Rumen Lachnospiraceae isolate NK3A20 exhibits metabolic flexibility in response to substrate and coculture with a methanogen

Hydrogen (H2) is the primary electron donor for methane formation in ruminants, but the H2-producing organisms involved are largely uncharacterized. This work integrated studies of microbial physiology and genomics to characterize rumen bacterial isolate NK3A20 of the family Lachnospiraceae. Isolate NK3A20 was the first recognized isolate of the NK3A20 group, which is among the ten most abundant bacterial genera in 16S rRNA gene surveys of rumen microbiota. NK3A20 produced acetate, butyrate, H2, and formate from glucose. The end product ratios varied when grown with different substrates and at different H2 partial pressures. NK3A20 produced butyrate as a major product using glucose or under high H2 partial pressures and switched to mainly acetate in the presence of galacturonic acid (an oxidized sugar) or in coculture with a methanogen. Growth with galacturonic acid was faster at elevated H2 concentrations, while elevated H2 slowed growth with glucose. Genome analyses revealed the presence of multiple hydrogenases including a membrane-bound Ech hydrogenase, an electron bifurcating butyryl-CoA dehydrogenase (Bcd-Etf), and an Rnf complex that may be involved in modulating the observed metabolic pathway changes, providing insight into H2 formation in the rumen. IMPORTANCE The genus-level NK3A20 group is one of the ten most abundant genera of rumen bacteria. Like most of the rumen bacteria that produce the hydrogen that is converted to methane in the rumen, it is understudied, without any previously characterized isolates. We investigated isolate NK3A20, a cultured member of this genus, and showed that it modulates hydrogen production in response to its growth substrates and the hydrogen concentration in its environment. Low-hydrogen concentrations stimulated hydrogen formation, while high concentrations inhibited its formation and shifted the fermentation to more reduced organic acid products. We found that growth on uronic acids, components of certain plant polymers, resulted in low hydrogen yields compared to glucose, which could aid in the selection of low-methane feeds. A better understanding of the major genera that produce hydrogen in the rumen is part of developing strategies to mitigate biogenic methane emitted by livestock agriculture.

Astragalus polysaccharides alleviate type 1 diabetes via modulating gut microbiota in mice

Type 1 diabetes (T1D) is a serious health problem that needs to be addressed worldwide. Astragalus polysaccharides (APS), the main chemical components of Astragali Radix, have anti-diabetic activity. As most plant polysaccharides are difficult to digest and absorb, we hypothesised that APS exert hypoglycaemic effects through the gut. This study intends to investigate the modulation of T1D associated with gut microbiota by neutral fraction of Astragalus polysaccharides (APS-1). T1D mice were induced with streptozotocin and then treated with APS-1 for 8 weeks. Fasting blood glucose levels were decreased and the insulin levels were increased in T1D mice. The results demonstrated that APS-1 improved gut barrier function by regulating ZO-1, Occludin and Claudin-1 expression, and reconstructed gut microbiota by increasing the relative abundance of Muribaculum, Lactobacillus and Faecalibaculum. In addition, APS-1 significantly increased the levels of acetic acid, propionic acid, butyric acid and inhibited the expression of pro-inflammatory factors IL-6 and TNF-α in T1D mice. Further exploration revealed that APS-1 alleviation of T1D may be associated with short-chain fatty acids (SCFAs)-producing bacteria, and that SCFAs binds to GPRs and HDACs proteins and modulate the inflammatory responses. In conclusion, the study supports the potential of APS-1 as a therapeutic agent for T1D.

Tinospora cordifolia (Willd.) Hook.f. & Thomson polysaccharides: A review on extraction, characterization, and bioactivities

Human awareness of the need for health and wellness practices that enhance disease resilience has increased as a result of recent health risks. Plant-derived polysaccharides with biological activity are good candidates to fight diseases because of their low toxicity. Tinospora cordifolia (Willd.) Hook.f. & Thomson polysaccharides extract from different plant parts have been reported to possess significant biological activity such as anti-oxidant, anti-cancer, immunomodulatory, anti-diabetic, radioprotective and hepatoprotective. Several extraction and purification techniques have been used to isolate and characterize T. cordifolia polysaccharides. Along with hot-water extraction (HWE), other novel techniques like microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), pulsed electric field (PEF), supercritical-fluid extraction (SFE), and enzyme-assisted extraction (EAE) are used to extract T cordifolia polysaccharides. SFE is a revolutionary technology that gives the best yield and purity of low-molecular-weight polysaccharides. According to the findings, polysaccharides extracted and purified from T. cordifolia have a significant impact on their structure and biological activity. As a result, the methods of extraction, structural characterization, and biological activity of T. cordifolia polysaccharides are covered in this review. Research on T. cordifolia polysaccharides and their potential applications will benefit greatly from the findings presented in this review.

Red Clover and the Importance of Extraction Processes—Ways in Which Extraction Techniques and Parameters Affect Trifolium pratense L. Extracts’ Phytochemical Profile and Biological Activities

The purpose of this study was to gain an insight into the manner in which several extraction processes (both classical as well as innovative) affected bioactive compound yield, and subsequently to assess several of their biological activities. Red clover extracts were obtained using maceration, Soxhlet extraction, turbo-extraction, ultrasound-assisted extraction, and a combination of the last two. The resulting extracts were analyzed for total phenolic and flavonoid content. The extracts presenting the best results were subjected to a phytochemical assessment by way of HPLC-MS analysis. After a final sorting based on the phytochemical profiles of the extracts, the samples were assessed for their antimicrobial activity, anti-inflammatory activity, and oxidative stress reduction potential, using animal inflammation models. The Soxhlet extraction yielded the most satisfactory results both qualitatively and quantitatively. The ultrasound-assisted extraction offered comparable yields. The extracts showed a high potential against gram-negative bacteria and induced a modest antioxidant effect on the experimental inflammation model in Wistar rats.

Antimicrobial polysaccharides obtained from natural sources

With the increase in resistance to conventional antibiotics among bacterial pathogens, the search for new antimicrobials becomes more and more necessary. Although most studies focus on the discovery of antimicrobial peptides for the development of new antibiotics, several others in the literature have described polysaccharides with the same biological activity with the potential for use as therapeutic alternatives. Here we review the currently available literature on antimicrobial polysaccharides isolated from different sources to demonstrate that there are several possible unconventional carbohydrate polymers that could act as therapeutic alternatives in the battle against drug-resistant pathogens.

Perspectives on the Combined Effects of Ocimum basilicum and Trifolium pratense Extracts in Terms of Phytochemical Profile and Pharmacological Effects

Nowadays, the tendency in pharmaceutical and food industries is to replace synthetic antioxidants with the natural ones. For this reason, there is a growing interest in analyzing natural, healthy and non-toxic additives as potential antioxidants. Some plants, which contain high levels of phenolic compounds, present an increasing interest for medicine due to their ability to scavenge free radicals, along with other pharmacological activities, such as antibacterial activity, wound healing and anti-inflammatory effect, to mention only a few. The aim of this review is to explore the therapeutic potential of Ocimum basilicum and Trifolium pratense in relation with their phytochemical profile and to highlight the pharmacological activity of aqueous or ethanol extracts. Special attention was devoted to the dermal pathology and wound healing effects, in the context of multiple skin conditions such as acne, eczema boils, psoriasis and rashes. Additionally, both extracts (Trifolium sp. and Ocimum sp.) are characterized by high content of antioxidant compounds, which are responsible for the radiance and resistance of the skin and slowing down of the aging process by maintaining estrogen levels. Moreover, the potential combined effect of the mixed extract is pointed out in terms of future applications for wound healing, based on some preliminary results obtained from a “scratch tests” assay performed with respect to human dermal fibroblasts.

Extracting Conditions Optimization and Bioactivity of Polysaccharides from the Pods of Haricot Vert

Polysaccharides from the pods of haricot vert (Phaseolus vulgaris L.) were extracted using a simple heating method, by varying extracting temperature, heating time, solid-to-liquid ratio, and solvent compositions. The obtained results were processed using statistical analysis that helped to identify the optimal conditions for the polysaccharides’ extraction process. This study represents a promising production method of bioactive polysaccharides extract in the food and pharmaceutical industry.

Phytochemical profile and pharmacological properties of Trifolium repens

Trifolium repens belongs to the family Leguminosae and has been used for therapeutic purposes as traditional medicine. The plant is widely used as fodder and leafy vegetables for human uses. However, there is a lack of a detailed review of its phytochemical profile and pharmacological properties. This review presents a comprehensive overview of the phytochemical profile and biological properties of T. repens. The plant is used as antioxidants and cholinesterase inhibitors and for anti-inflammatory, antiseptic, analgesic, antirheumatic ache, and antimicrobial purposes. This review has summarized the available updated useful information about the different bioactive compounds such as simple phenols, phenolic acids, flavones, flavonols, isoflavones, pterocarpans, cyanogenic glucosides, saponins, and condensed tannins present in T. repens. The pharmacological roles of these secondary metabolites present in T. repens have been presented. It has been revealed that T. repens contain important phytochemicals, which is the potential source of health-beneficial bioactive components for food and nutraceuticals industries.

Optimization of ultrasonic-assisted extraction of polysaccharides from purple glutinous rice bran (Oryza sativa L.) and their antioxidant activities

Purple glutinous rice bran (Kum Doi Saket rice (KUM)) contains high content of edible polysaccharides and anthocyanins and has an excellent antioxidant activity. This research aimed to optimize the extraction of crude polysaccharides from defatted purple glutinous rice bran using an ultrasonic-assisted extraction (UAE) and compared with a hot water extraction (HWE). Results showed that optimal extraction condition was as follows: a defatted rice bran to water ratio of 1:20 w/v, extraction temperature and time of 70 °C for 20 min. Under the optimal extraction condition, the yield of polysaccharide of UAE (4%) was significantly higher than that obtained from the HWE (0.8%). Additionally, antioxidant activities of extracted polysaccharide including IC₅₀ value DPPH, IC₅₀ value ABTS, and FRAP value were 1.09 mg/mL, 2.80 mg/mL and 197 µM Fe²⁺/g, respectively. It is suggested that the UAE process is promising method to decrease the processing time and to enhance extracted polysaccharide yields by 4 times.

Extraction Optimization of Galla Turcica Polysaccharides and Determination of Its Antioxidant Activities In Vitro

Though natural polysaccharides commonly show antioxidant activities, the current research on the isolation of polysaccharides from Galla Turcica and their antioxidant activities still remain as an ongoing challenge. In this work, response surface analysis was employed to optimize an ultrasonic-assisted extraction method for polysaccharides of Galla Turcica. Their antioxidant and free radical scavenging activities were then evaluated using 2,2-diphenyl-1-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), total antioxidant activity, and iron ion reduction assays. Moreover, the protective effects of polysaccharides of Galla Turcica were determined on human embryonic kidney fibroblast 293 and hepatoma 7721 cells by cell proliferation assay. Overall, the key parameters of Galla Turcica polysaccharides extraction were optimized as crushing degree 100 mesh, ultrasonic time 50 min, and materials–liquid ratio 1:50. The isolated polysaccharides presented dose-dependent antioxidant and free radical scavenging effects in vitro. It also demonstrated an effective protective effect for human cells under oxidative damage. The results firstly determined the antioxidant activities of polysaccharides from Galla Turcica, thus providing a new natural resource for future investigation and development of the polysaccharides-based antioxidant drugs, health products, or additives.

Purification, Characterization of Two Polysaccharides from Pinelliae Rhizoma Praeparatum Cum Alumine and Their Anti-Inflammatory Effects on Mucus Secretion of Airway Epithelium

Pinelliae Rhizoma Praeparatum cum Alumine (PRPCA) is an important traditional processed herbal medicine mainly used for treating phlegm in China for more than 2000 years. In our previous studies, extraction optimization, characterization, and bioactivities of total polysaccharides from PRPCA were investigated. In this study, further purification of these polysaccharides was performed. Two polysaccharides named neutral fraction of total polysaccharides-II (TPN-II) and acidic fraction of total polysaccharides-II (TPA-II) were obtained by gradient ion-exchange chromatography followed by gel-permeation chromatography. Results of scanning electron microscopy (SEM) analysis in the present study showed that TPN-II had a tight structure with a rough and uneven surface, while TPA-II had a relative homogeneous surface and a loose structure. Further studies indicated that TPN-II was a homosaccharide mainly composed by glucose with a molecular weight of 8.0 kDa. TPA-II was mainly composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose and arabinose in a molar ratio of 2.1, 2.3, 1.7, 10.6, 2.6, 14.2, and 2.5, with a molecular weight of 1250 kDa. The nuclear magnetic resonance (NMR) results indicated that α and β form glycoside bonds existed in TPN-II and TPA-II, and TPN-II was composed of α-glucopyranose. In addition, both purified polysaccharides have significant anti-inflammatory effects on mucus secretion of human airway epithelial NCI-H292 cells without cytotoxicity. Compared with TPN-II, TPA-II exhibited more significant anti-inflammatory effects on lipopolysaccharide (LPS)-induced airway inflammation by regulating levels of interleukin-4 (IL-4) and interferon-γ (IFN-γ) and inhibiting mucus secretion. The results suggest that polysaccharides from PRPCA could be explored as therapeutic agents in treating inflammation and over secretion of mucus in asthma.