Innovative utilization of herbal residues: Exploring the diversity of mechanisms beneficial to regulate anaerobic fermentation of alfalfa.

In order to increase the utilization of herbal residues, realize efficient utilization of resources, the bacterial community and anaerobic fermentation characteristics of alfalfa ensiling treated with 36 kinds of herbal residues were studied. All the herbal residues improved the anaerobic fermentation quality in different degrees, indicated by lower pH, NH3-N and butyric acid concentrations. However, the contents of lactic and acetic acids varied widely in silage with different herbal residues. Pearson's correlation analysis showed that the improved fermentation quality was closely associated with the variation of lactic acid bacteria community. Consequently, the herbal residues could improve anaerobic fermentation quality by stimulating desirable Lactobacillus species and inhibiting undesirable microbes. This study provides new insights for efficient utilization of herbal residues.

Effect of incremental proportions of Desmanthus spp. in isonitrogenous forage diets on growth performance, rumen fermentation and plasma metabolites of pen-fed growing Brahman, Charbray and Droughtmaster crossbred beef steers.

Desmanthus (Desmanthus spp.), a tropically adapted pasture legume, is highly productive and has the potential to reduce methane emissions in beef cattle. However, liveweight gain response to desmanthus supplementation has been inconclusive in ruminants. This study aimed to evaluate weight gain, rumen fermentation and plasma metabolites of Australian tropical beef cattle in response to supplementation with incremental levels of desmanthus forage legume in isonitrogenous diets. Forty-eight Brahman, Charbray and Droughtmaster crossbred beef steers were pen-housed and fed a basal diet of Rhodes grass (Chloris gayana) hay supplemented with 0, 15, 30 or 45% freshly chopped desmanthus forage on dry matter basis, for 140 days. Varying levels of lucerne (Medicago sativa) hay were added in the 0, 15 and 30% diets to ensure that all diets were isonitrogenous with the 45% desmanthus diet. Data were analyzed using the Mixed Model procedures of SAS software. Results showed that the proportion of desmanthus in the diet had no significant effect on steer liveweight, rumen volatile fatty acids molar proportions and plasma metabolites (P ≥ 0.067). Total bilirubin ranged between 3.0 and 3.6 µmol/L for all the diet treatments (P = 0.67). All plasma metabolites measured were within the expected normal range reported for beef cattle. Rumen ammonia nitrogen content was above the 10 mg/dl threshold required to maintain effective rumen microbial activity and maximize voluntary feed intake in cattle fed low-quality tropical forages. The average daily weight gains averaged 0.5 to 0.6 kg/day (P = 0.13) and were within the range required to meet the target slaughter weight for prime beef markets within 2.5 years of age. These results indicate that desmanthus alone or mixed with other high-quality legume forages can be used to supplement grass-based diets to improve tropical beef cattle production in northern Australia with no adverse effect on cattle health.

Comparative Studies of Selected Criteria Enabling Optimization of the Extraction of Polar Biologically Active Compounds from Alfalfa with Supercritical Carbon Dioxide.

The aim of this research was to provide crucial and useful data about the selection of the optimization criteria of supercritical carbon dioxide extraction of alfalfa at a quarter-technical plant. The correlation between more general output, including total phenolics and flavonoids content, and a more specified composition of polar constituents was extensively studied. In all alfalfa extracts, polar bioactive constituents were analyzed by both spectrometric (general output) and chromatographic (detailed output) analyses. Eight specific phenolic acids and nine flavonoids were determined. The most dominant were salicylic acid (221.41 µg g-1), ferulic acid (119.73 µg g-1), quercetin (2.23 µg g-1), and apigenin (2.60 µg g-1). For all seventeen analyzed compounds, response surface methodology and analysis of variance were used to provide the optimal conditions of supercritical fluid extraction for each individual constituent. The obtained data have shown that eight of those compounds have a similar range of optimal process parameters, being significantly analogous for optimization based on total flavonoid content.

Effect of alfalfa (Medicago sativa L.) saponins on meat color and myoglobin reduction status in the longissimus thoracis muscle of growing lambs.

The effect of alfalfa saponins (AS) supplementation on the meat quality especially the color for growing lamb was investigated. Fifty Hu male lambs with body weights (BW, 19.21 ± 0.45 kg) were divided into five groups and supplemented AS with 0, 500, 1,000, 2,000, and 4,000 mg/kg of dietary dry matter intake. After 90 days, all lambs were slaughtered. The longissimus thoracis muscle in lamb displayed significant changes in the content of intramuscular fat, especially n-3 polyunsaturated fatty acids, and drip loss within AS treatment (p < .05) between control and treatments groups. Redness (a*) significantly improved in both 0-day and 7-day storage with the AS supplementation coupled with the percentage of met-myoglobin reduction (p < .05). The redness (a*) change may result from improved met-myoglobin reducing activity, antioxidant enzymes, lactate dehydrogenase, and succinate dehydrogenase (p < .05) by AS supplementation in muscle. These enzymes may help to protect mitochondria function and reduce met-myoglobin, which bring a bright and red meat color.

Effects of estrogen deficiency on liver function and uterine development: assessments of Medicago sativa's activities as estrogenic, anti-lipidemic, and antioxidant agents using an ovariectomized mouse model.

We investigated the effects of Medicago sativa supplementation on the lipid profiles and antioxidant capacities of ovariectomized mice.The study was performed on white Swiss female mice that were divided into five groups: control, treated with Medicago sativa (0.75 g/kg/day), ovariectomized, ovariectomized treated with ß-estradiol (1 µg/day) or with Medicago sativa. The mice were sacrificed after 3 and 8 weeks of treatment.Ovariectomy induced a decrease in overall growth, uterine atrophy, and hyperlipidemia demonstrated by increased cholesterol, triglycerides, and decreased HDL. We have shown the involvement of oxidative stress in this hepatic lesion proven by increased levels of TBARS, GPX, and GSH, and decreased levels of SOD and catalase.Treatment with Medicago sativa restores lipid balance, the activity of antioxidant enzymes and improves lipid peroxidation. This is probably due to the richness of this plant in polyphenols and flavonoids considered as an antioxidant and phytoestrogenic elements.

Feeding selenium-biofortified alfalfa hay during the preconditioning period improves growth, carcass weight, and nasal microbial diversity of beef calves.

We previously reported that feeding Se-biofortified alfalfa hay to weaned beef calves in a preconditioning program decreases morbidity and mortality during the feedlot period. To understand the mode of action by which supranutritional Se supplementation supports calf health, we examined the effect of agronomic Se-biofortification on nasal microbiome and fecal parasites. Recently weaned Angus-cross beef calves (n = 30) were randomly assigned to two groups and fed an alfalfa hay-based diet for 9 weeks in a preconditioning program. Alfalfa hay was harvested from fields fertilized with sodium selenate at a rate of 0 or 90 g Se/ha. Calculated Se intake from dietary sources was 1.09 and 27.45 mg Se/calf per day for calves consuming alfalfa hay with Se concentrations of 0.06 and 3.47 mg Se/kg dry matter, respectively. Feeding Se-biofortified alfalfa hay for 9 weeks was effective at increasing whole-blood Se concentrations (556 ± 11 vs 140 ± 11 ng/mL; P < 0.001) and increasing body weight (PTreatment, = 0.03) in weaned beef calves. Slaughter yield grades were higher for calves that had been fed Se-enriched alfalfa hay during the preconditioning period (PTreatment = 0.008). No significant differences were observed in fecal parasite load, which remained low. The nasal microbiome and microbiota diversity within calves and across calves expanded from weaning (week 0) to the feedlot period (week 12), which was promoted by feeding Se-biofortified alfalfa hay. Especially concerning was the expansion of nasal Mycoplasmataceae in the feedlot, which reached over 50% of the total microbiota in some calves. In conclusion, we identified dietary Se-biofortified alfalfa hay as a potential promoter of nasal microbiome genome and microbiota diversity, which may explain in part high-Se benefits for prevention of bovine respiratory disease complex in beef calves.

Quebracho tannins aid in the control of Eimeria spp. and gastrointestinal nematodes in lambs and goat kids.

The objective was to examine the effects of supplementary quebracho on control of coccidiosis and gastrointestinal nematodes in lambs and kids. In Exp. 1, naturally infected lambs weaned (87.8 ± 0.4 days of age; day 0) in January (winter) were blocked by sex and randomly assigned (n = 10/treatment) to receive supplement with or without 100 g/lamb of quebracho for 28 days. In Exp. 2, single or twin rearing ewes were randomly assigned into two groups, and naturally infected lambs were fed control (n = 28) or quebracho (100 g/lamb of quebracho tannins in feed; n = 27) between -28 and 21 days (weaning = day 0; 70.8 ± 0.1 days of age). In Exp. 3, weaned doe kids (57.6 ± 2.0 days of age) were randomly assigned to receive alfalfa (Medicago sativa) supplement with (n = 9) or without (n = 8) 50 g/kid quebracho or sericea lespedeza (Lespedeza cuneata) with quebracho (n = 8) for 21 days. Fecal oocyst count (FOC), nematode egg counts (FEC), fecal score, dag score (soiling around rear quarters), and blood packed cell volume (PCV) were determined every 7 days. Data were analyzed as repeated measures using mixed models. In Exp. 1, FOC decreased in quebracho-fed lambs (diet × time, P < 0.001) but FEC was similar between treatments during the feeding period (P = 0.19). Packed cell volume (P = 0.19) and fecal score (P = 0.42) were similar between groups. Quebracho-fed lambs had a greater dag score initially (diet × time, P = 0.02), but were similar by day 42 (P = 0.72). In Exp. 2, FOC remained low (P = 0.02), PCV tended to decrease (P = 0.06), but FEC increased on days 14 and 21 (diet × time; P < 0.001) in quebracho compared with control-fed lambs. Quebracho-fed lambs had lower fecal score (diet × time; P = 0.005) but higher dag score (diet × time; P < 0.001). In Exp. 3, FOC of kids fed quebracho (alfalfa or sericea lespedeza supplement) was lower than control (P < 0.001). Fecal score of kids fed sericea lespedeza compared with alfalfa were lower regardless of quebracho (P = 0.01). There were no differences among treatments for dag, FEC, PCV, or body weight (P> 0.10). Quebracho was effective in reducing FOC but not clinical signs of coccidiosis in both lambs and kids, and may not be highly digestible in lambs as it caused loose stools.

A polysaccharide extracted from alfalfa activates splenic B cells by TLR4 and acts primarily via the MAPK/p38 pathway.

Alfalfa polysaccharide (APS) has been proposed to exhibit growth-promoting and immune-enhancing bodily functions in vivo. However, little is known about its downstream immunomodulatory and intrinsic molecular mechanisms. Herein, mouse splenic lymphocytes were isolated to characterize the immunomodulatory effects and molecular mechanisms of APS in vitro. The results demonstrated that APS selectively improved the cell viability and IgM production of B cells, but no effects on T cell viability or secretion of IL-2, IL-4 and IFN-γ were observed in vitro. The receptor blocking assay showed that TLR4 was the primary receptor involved in APS-mediated B cell activation, which was confirmed by the results obtained using C57BL/10ScNJ (TLR4 gene-deficient) mice. Moreover, APS activated the TLR4-MyD88 signaling pathway at the translational level by significantly increasing the protein expression of TLR4 and MyD88. Downstream pathway blocking assay demonstrated that both the MAPK and NF-κB pathways were involved in APS-induced B cell activation. Additionally, APS significantly enhanced the phosphorylation of p38, ERK, and JNK and activated the nuclear translocation of the NF-κB p65 subunit. Therefore, we concluded that APS specifically activates the immune functions of splenic B cells by TLR4, acting through the MAPK and NF-κB signaling pathways, and potently activates the p38 pathway.

Protective effects of alfalfa saponins on oxidative stress-induced apoptotic cells.

As is known, alfalfa saponins can be used as a feed additive in a pig's diet and the addition of alfalfa saponins to a pig's diet could improve its antioxidant capacity. However, the mechanism by which alfalfa saponins exert their antioxidant effects has not been studied. To address this issue, H2O2-induced rat intestinal epithelial cells were used to establish an oxidative stress model to explore the protective mechanism of alfalfa saponins in this study. The results demonstrated that alfalfa saponins could rescue the cell proliferation activity, elevate the amount of antioxidant enzymes and downregulate the release of MDA and LDH in H2O2-induced cells. The antioxidant activity of alfalfa saponins was achieved by restoring GSH homeostasis. Further results demonstrated that alfalfa saponins could inhibit cell apoptosis through activating the MAPK signaling pathway. These results elucidated the mechanism by which alfalfa saponins exert their antioxidant effects and provided a potential strategy for alleviating oxidative stress in monogastric animals.

Comparison of Accelerated Solvent Extraction (ASE) and Energized Dispersive Guided Extraction (EDGE) for the analysis of pesticides in leaves.

Various techniques have been evaluated for the extraction and cleanup of pesticides from environmental samples. In this work, a Selective Pressurized Liquid Extraction (SPLE) method for pesticides was developed using a Thermo Fisher Scientific Accelerated Solvent Extraction (ASE) system. This instrument was compared to the newly introduced (2017) extraction instrument, the Energized Dispersive Guided Extraction (EDGE) system, which combines Pressurized Liquid Extraction (PLE) and dispersive Solid Phase Extraction (dSPE). We first optimized the SPLE method using the ASE instrument for pesticide extraction from alfalfa leaves using layers of Florisil and graphitized carbon black (GCB) downstream of the leaf homogenate in the extraction cell (Layered ASE method). We then compared results obtained for alfalfa and citrus leaves with the Layered ASE method to those from a method in which the leaf homogenate and sorbents were mixed (Mixed ASE method) and to similar methods modified for use with EDGE (Layered EDGE and Mixed EDGE methods). The ASE and EDGE methods led to clear, colorless extracts with low residual lipid weight. No significant differences in residual lipid masses were observed between the methods. The UV-Vis spectra showed that Florisil removed a significant quantity of the light-absorbing chemicals, but that GCB was required to produce colorless extracts. Recoveries of spiked analytes into leaf homogenates were generally similar among methods, but in several cases, significantly higher recoveries were observed in ASE extracts. Nonetheless, no significant differences were observed among pesticide concentrations in field samples when calculated with the isotope dilution method in which labelled surrogates were added to samples before extraction. The extraction time with the ASE methods was ~45 minutes, which was ~4.5 times longer than with the EDGE methods. The EDGE methods used ~10 mL more solvent than the ASE methods. Based on these results, the EDGE is an acceptable extraction instrument and, for most compounds, the EDGE had a similar extraction efficiency to the ASE methods.

Host immunity and the colon microbiota of mice infected with Citrobacter rodentium are beneficially modulated by lipid-soluble extract from late-cutting alfalfa in the early stages of infection.

Alfalfa is a forage legume commonly associated with ruminant livestock production that may be a potential source of health-promoting phytochemicals. Anecdotal evidence from producers suggests that later cuttings of alfalfa may be more beneficial to non-ruminants; however, published literature varies greatly in measured outcomes, supplement form, and cutting. The objective of this study was to measure body weight, average daily feed intake, host immunity, and the colon microbiota composition in mice fed hay, aqueous, and chloroform extracts of early (1st) and late (5th) cutting alfalfa before and after challenge with Citrobacter rodentium. Prior to inoculation, alfalfa supplementation did not have a significant impact on body weight or feed intake, but 5th cutting alfalfa was shown to improve body weight at 5- and 6-days post-infection compared to 1st cutting alfalfa (P = 0.02 and 0.01). Combined with the observation that both chloroform extracts improved mouse body weight compared to control diets in later stages of C. rodentium infection led to detailed analyses of the immune system and colon microbiota in mice fed 1st and 5th cutting chloroform extracts. Immediately following inoculation, 5th cutting chloroform extracts significantly reduced the relative abundance of C. rodentium (P = 0.02) and did not display the early lymphocyte recruitment observed in 1st cutting extract. In later timepoints, both chloroform extracts maintained lower splenic B-cell and macrophage populations while increasing the relative abundance of potentially beneficially genera such as Turicibacter (P = 0.02). At 21dpi, only 5th cutting chloroform extracts increased the relative abundance of beneficial Akkermansia compared to the control diet (P = 0.02). These results suggest that lipid soluble compounds enriched in late-cutting alfalfa modulate pathogen colonization and early immune responses to Citrobacter rodentium, contributing to protective effects on body weight.

Transcriptional analysis reveals sodium nitroprusside affects alfalfa in response to PEG-induced osmotic stress at germination stage.

Drought is one of the most common environmental factors that affect alfalfa germination and development. Nitric oxide (NO) could mediate stress tolerance in plants. The goal of this study was to determine exogenous NO donor-mediated drought adaption molecular mechanisms during the alfalfa germination stage. In this study, physiological and transcriptome analyses were performed on 7 days of the growth period seedlings by sodium nitroprusside (SNP) and polyethylene glycol (PEG) treatment. The results showed that SNP supplementation alleviated malondialdehyde accumulation, increased levels of proline and soluble sugars, and enhanced antioxidant enzyme activity under osmotic stress conditions. RNA-Seq experiments identified 5828 genes exhibiting differential expression in seedlings treated with PEG, SNP, or SNP+PEG relative to seedlings treated with distilled water. Of these DEGs, 3235 were upregulated, and 2593 were downregulated relative to the controls. Fifteen DEGs were amplified by qRT-PCR to verify the changes in expression determined by RNA-Seq, revealing that PIF3, glnA, PLCG1, and RP-S11e exhibited enhanced expression under the SNP+PEG treatment. SNP was found to modulate redox homeostasis-related genes such as GSTs, SOD2, GPX, and RBOH, and triggered calcium signaling transduction. It also induced some key genes relating to the abscisic acid, ethylene, and auxin signaling transduction in response to PEG stress. Conversely, genes associated with secondary metabolite biosynthesis and the metabolism of starch and sucrose during osmotic stress were downregulated by SNP. These results provide new insights into SNP-mediated drought adaption mechanisms at transcriptome-wide in alfalfa and reveal key drought tolerance pathways in this species.

Comparison of the Polyphenolic Profile of Medicago sativa L. and Trifolium pratense L. Sprouts in Different Germination Stages Using the UHPLC-Q Exactive Hybrid Quadrupole Orbitrap High-Resolution Mass Spectrometry.

Identification and quantification of polyphenols in plant material are of great interest since they make a significant contribution to its total bioactivity. In the present study, an UPLC-Orbitrap-MS/MS approach using the variable data acquisition mode (vDIA) was developed and applied for rapid separation, identification, and quantification of the main polyphenolic compounds in Medicago sativa L. and Trifolium pratense L. sprouts in different germination stages. Based on accurate MS data and fragment ions identification strategy, a total of 29 compounds were identified by comparing their accurate masses, fragment ions, retention times, and literatures. Additionally, a number of 30 compounds were quantified by comparing to the reference standards. Data were statistically analysed. For both plant species, the sprouts of the third germination day are valuable sources of bioactive compounds and could be used in phytotherapy and nutrition. Although Trifolium pratense L. (Red Clover) is considered to be a reference for natural remedies in relieving menopause disorders, alfalfa also showed a high level of biological active compounds with estrogenic activity.

Selenium biofortified alfalfa hay fed in low quantities improves selenium status and glutathione peroxidase activity in transition dairy cows and their calves.

The hypothesis of the study was that feeding a relatively low amount of Se biofortified alfalfa hay during the dry period and early lactation would improve selenium status and glutathione peroxidase activity in dairy cows and their calves. Ten Jersey and 8 Holstein primiparous dairy cows were supplemented with Se biofortified (TRT; n = 9) or non-biofortified (CTR; n = 9) alfalfa hay at a rate of 1 kg/100 kg of BW mixed with the TMR from 40 d prior parturition to 2 weeks post-partum. Se concentration in whole blood, liver, milk, and colostrum, the transfer of Se to calves, and the glutathione peroxidase (GPx) activity were assessed. TRT had 2-fold larger (P < 0.05) Se in blood v. CTR that resulted in larger Se in liver and colostrum but not milk and larger GPx activity in plasma and erythrocytes but not in milk. Compared to CTR, calves from TRT had larger Se in blood but only a numerical (P = 0.09) larger GPx activity in plasma. A positive correlation was detected between Se in the blood and GPx activity in erythrocytes and plasma in cows. Our results demonstrated that feeding pregnant primiparous dairy cows with a relatively low amount of Se-biofortified alfalfa hay is an effective way to increase Se in the blood and liver, leading to greater antioxidant activity via GPx. The same treatment was effective in improving Se concentration in calves but had a modest effect on their GPx activity. Feeding Se biofortified hay increased Se concentration in colostrum but not in milk.

Effects of dietary alfalfa protein concentrate supplementation on performance, egg quality, and fatty acid composition of raw, freeze-dried, and hard-boiled eggs from Polbar laying hens.

The aim of this study was to determine the effect of addition of alfalfa protein concentrate (APC) at the dose of 15 g or 30 g per 1 kg of complete feed ration for the native Polbar breed on selected production traits and the fatty acid profile in the yolk of raw, hard-boiled or freeze-dried eggs. Laying hens were assigned randomly to 3 experimental groups, each comprising 30 birds. The control group received a standard diet without the APC addition and the experimental groups received APC, which partially replaced postextraction soybean meal. Egg laying performance, feed intake, and feed conversion ratio were controlled throughout the experiment. At 33 wk of age, 45 eggs were randomly selected for assessment of the quality of the egg content and eggshell, and 30 eggs were taken for each of the cooking and freeze-drying treatments. The fatty acid composition was determined in the yolks of hard-boiled, freeze-dried, and raw eggs. There was no effect of the APC addition on the laying performance, feed intake and feed conversion ratio, and a majority of egg quality traits. Hens fed with the APC laid eggs with a darker colored eggshell and yolk and a slightly lower breaking strength. The yolks in the eggs from hens receiving the APC addition were characterized by distinctly higher content of polyunsaturated fatty acids (PUFA). The group fed with a higher dose of APC produced eggs with a substantially lower level of saturated fatty acids (SFA). Boiling resulted in an increase in the SFA content and a decline in the level of PUFAs and carotenoids. Freeze-drying led to an increase in the total SFA content and a decrease in the level of n-3 PUFA. The APC addition to feed can replace the genetically modified soybean meal without reducing the values of production traits and egg quality and with a beneficial effect on the yolk color and fatty acid profile.

Comparison of Protein Precipitation Ability of Structurally Diverse Procyanidin-Rich Condensed Tannins in Two Buffer Systems.

The protein precipitation (PP) of bovine serum albumin (BSA), lysozyme (LYS), and alfalfa leaf protein (ALF) by four procyanidin-rich condensed tannin (CT) samples in both 2-[N-morpholino]ethanesulfonic acid (MES) and a modified Goering-Van Soest (GVS) buffer is described. Purified CT samples examined included Vitis vinifera seed (mean degree of polymerization [mDP] 4.1, 16.5% galloylated), Tilia sp. flowers (B-type linkages, mDP 5.9), Vaccinium macrocarpon berries (mDP 8.7, 31.7% A-type linkages). and Trifolium pratense flowers (B-type linkages, mDP 12.3) and were characterized by 2D NMR (>90% purity). In general, CTs precipitated ALF > LYS ≥ BSA. PP in GVS buffer was 1 to 2.25 times greater than that in MES buffer (25 °C). The GVS buffer system better reflects the results/conclusions from the literature on the impacts mDP, galloylation, and A-type linkages have on PP. Determinations of PP using the MES buffer at 37 °C indicated that some of these differences may be attributed to the temperature at which GVS buffer determinations are conducted. In vitro PP studies using the GVS buffer may offer better guidance when selecting CT-containing forages and amendments for ruminant feeding studies.

Structural features, selenization modification, antioxidant and anti-tumor effects of polysaccharides from alfalfa roots.

Hot water extraction and chromatographic purification methods were used to extract and purify two polysaccharides (RAPS-1 and RAPS-2) from the roots of alfalfa. Subsequently, RAPS-2 was modified using the HNO3/Na2SeO3 method to obtain Se-RAPS-2. The structural features, antioxidant and in vitro anti-tumor activities of the three polysaccharides were evaluated. The structural analysis revealed that RAPS-1 (Mw = 10.0 kDa) was composed of rhamnose, xylose, arabinose, galacturonic acid, mannose and glucose, whereas RAPS-2 (Mw = 15.8 kDa) consisted of rhamnose, xylose, galacturonic acid, mannose, glucose and galactose. RAPS-1 contained 1 â†’ 2, 1 â†’ 4, 1 â†’ 3, and 1 â†’ 6 or 1 â†’ glycosidic bonds; however, while RAPS-2 lacked 1 â†’ 4 glycosidic linkages. The molecular weight of Se-RAPS-2 was 11.0 kDa less than that of RAPS-2. The results of activities demonstrated that Se-RAPS-2 displayed superior antioxidant activity and inhibitory effect in HepG2 cells than RAPS-1 and RAPS-2.

Distribution of sapogenins in morphological Medicago sativa L. parts: Comparison of various extraction techniques.

Saponins in plant extracts were indirectly determined by estimation of the content of sapogenins. The first step of determination is extraction with high efficiency. One conventional extraction technique (maceration) and two modern ones (accelerated solvent extraction and supercritical fluid extraction) were compared. Methanol and ethanol were used as solvents or co-solvents. The results were supported by statistical analysis. Saponins were extracted from leaves, roots, and sprouts of Medicago sativa. Acid hydrolysis, purification, and determination by high-performance liquid chromatography with evaporative light scattering detector were used. The content of sapogenins was the highest in the roots. Smaller amounts of sapogenins were found in sprouts and the smallest ones in leaves. The main ingredient was medicagenic acid with mean concentration of 621.8 µg/g in roots, 456.7 µg/g in sprouts, and 471.3 µg/g in leaf extract. The highest content of sapogenins in extract was obtained after maceration with methanol; however, this method is nonselective in relation to biologically active compounds. Due to the possibility of using the obtained extracts with sapogenins in the cosmetic or pharmaceutical industry, the selection of extraction techniques and solvents is a very important aspect. Additionally, the chosen technique should be considered eco-friendly and consistent with the assumptions of "green chemistry."

Structural characteristics of Medicago Sativa L. Polysaccharides and Se-modified polysaccharides as well as their antioxidant and neuroprotective activities.

Medicago Sativa L., a nutrient-rich plant used as feed for cattle and sheep, is widely planted globally. This study investigated the structural characteristics and activities of three kinds of novel polysaccharides (APS1, APS2 and APS3) isolated from the stems of M. sativa as well as its two selenium modified products (Se-APS2 and Se-APS3). APS1 (Mw = 13.4 KDa) and APS2 (Mw = 11.2 KDa) were composed of rhamnose, arabinose, mannose and galactose with different molar ratio, APS3 (Mw = 18.6 KDa) was composed of rhamnose, arabinose, fructose, mannose and galactose. All APS1-3 contained 1 â†’ 3 : 1 â†’ 6 : 1 â†’ 4 : 1 â†’ 2 glycosidic bonds in a ratio of 0.74:0.09:0.05:0.12, 0.34:0.20:0.36:0.10 and 0.63:0.17:0.06:0.14, respectively. The selenium content of Se-APS2 (Mw = 9.0 KDa) and Se-APS3 (Mw = 10.2 KDa) were 1.05 and 2.57 µg/mg, respectively. Their surface morphology and thermal stability were determined by scanning electron microscope (SEM) and thermal analysis (TGA), respectively. Further, the antioxidant and neuroprotective activities of the three natural polysaccharides and two Se-polysaccharides were studied. Interestingly, Se-polysaccharides not only exhibited higher antioxidant activity, but also higher neuroprotective activity compared to natural polysaccharides.

Optimisation and kinetic study of the ultrasonic-assisted extraction of total saponins from alfalfa (Medicago sativa) and its bioaccessibility using the response surface methodology.

The ultrasonic-assisted extraction of total saponins from alfalfa leaves was optimised by the simultaneous maximization of the yield and bioaccessibility as a factor with increasingly great relevance in the biological activity by Response Surface Methodology. The kinetics of total saponins and bioaccessibility were investigated for the optimum ultrasound-assisted method compared to conventional method by the pseudo-first order model. The optimum extraction conditions were of solvent/raw material ratio of 11.4 mL/g, extraction time of 2.84 h, extraction temperature of 76.8 °C, ultrasound power of 112.0 w and ethanol concentration of 78.2%. The yield of total saponins and bioaccessibility was 1.61 and 18.6%, respectively. The yield rate constant for the ultrasound extraction was almost two times more than that of the heat-reflux method. Ultrasonic-assisted extraction, comparing to conventional method, had greater efficiency for the extraction yield and bioaccessibility of total saponins.