The impact of saponins or saponin-containing plant materials on ruminant production--a review

Saponins and microbial biosurfactants: Potential raw materials for the formulation of cosmetics

The cosmetic industry is currently one of the fasting growing sections of the economy in many countries. The recent tendency toward the use of cosmetics of a natural origin has driven the industry to seek alternatives to synthetic components in the formulation of products. Biosurfactants are natural compounds that have considerable potential for application in the formulation of safe, effective cosmetics as a replacement for commonly used chemical tensioactive agents. The present review provides essential information on the physicochemical and biological properties of saponins and microbial biosurfactants employed in cosmetic products, with a focus on the use of these natural compounds in shampoos, addressing the current state of research and patents involving biosurfactants for this purpose. The challenges and prospects of this cosmetic application are also discussed. © 2018 American Institute of Chemical Engineers Biotechnol. Prog., 34:1482-1493, 2018.

Impact of potent bioremediation enhancing plant extracts on Raoultella ornithinolytica properties

Long-term contact of microorganisms with different compounds in the environment can cause significant changes in cell metabolism. Surfactants adsorption on cell surface or incorporation in the cell membrane, lead to their modification, which helps microorganisms adopt to the conditions of metabolic stress. The main objective of this study was to investigate the effects of three saponin-reach plant extracts from Hedera helix, Saponaria officinalis and Sapindus mucorossi on growth and adaptation of Raoultella ornithinolytica to high concentrations of these substances. For this purpose we investigated cell surface properties, membrane fatty acids and genetic changes of the microorganisms. The results revealed that prolonged exposure of the microorganisms to high concentrations of these surfactants can induce genetic changes of their genes. Moreover, the adaptation to contact with high concentrations of saponins was also associated with changes in composition of fatty acids responsible for the stabilisation of membrane structure and the increase in membrane permeability. The changes affected also the outer layer of cells. A significant increase (p < 0.05) in the cell surface hydrophobicity of tested strain was also observed. The cells after long-term contact with S. officinalis and S. mucorossi acquire properties that may be favourable in hydrophobic substances bioremediation.

Improving the antiprotozoal effect of saponins in the rumen by combination with glycosidase inhibiting iminosugars or by modification of their chemical structure

The antiprotozoal effect of saponins is transitory, as when saponins are deglycosylated to sapogenins by rumen microorganisms they become inactive. We hypothesised that the combination of saponins with glycosidase-inhibiting iminosugars might potentially increase the effectiveness of saponins over time by preventing their deglycosylation in the rumen. Alternatively, modifying the structure of the saponins by substituting the sugar moiety with other small polar residues might maintain their activity as the sugar substitute would not be enzymatically cleaved. The aim of this in vitro study was to evaluate the acute antiprotozoal effect and the stability of this effect over a 24 h incubation period using ivy saponins, a stevia extract rich in iminosugars, ivy saponins with stevia extract, and a chemically modified ivy saponin, hederagenin bis-succinate (HBS). The effects on fermentation parameters and rumen bacterial communities were also studied. Ivy saponins with stevia and HBS had a greater antiprotozoal effect than ivy saponins, and this effect was maintained after 24 h of incubation (P<0.001). The combination of ivy and stevia extracts was more effective in shifting the fermentation pattern towards higher propionate (+39%) and lower butyrate (-32%) and lower ammonia concentration (-64%) than the extracts incubated separately. HBS caused a decrease in butyrate (-45%) and an increase in propionate (+43%) molar proportions. However, the decrease in ammonia concentration (-42%) observed in the presence of HBS was less than that caused by ivy saponins, either alone or with stevia. Whereas HBS and stevia impacted on bacterial population in terms of community structure, only HBS had an effect in terms of biodiversity (P<0.05). It was concluded that ivy saponins with stevia and the modified saponin HBS had a strong antiprotozoal effect, although they differed in their effects on fermentation parameters and bacteria communities. Ivy saponins combined with an iminosugar-rich stevia extract and/or HBS should be evaluated to determine their antiprotozoal effect in vivo.

Glycosylated Triterpenoids as Endosomal Escape Enhancers in Targeted Tumor Therapies

Protein-based targeted toxins play an increasingly important role in targeted tumor therapies. In spite of their high intrinsic toxicity, their efficacy in animal models is low. A major reason for this is the limited entry of the toxin into the cytosol of the target cell, which is required to mediate the fatal effect. Target receptor bound and internalized toxins are mostly either recycled back to the cell surface or lysosomally degraded. This might explain why no antibody-targeted protein toxin has been approved for tumor therapeutic applications by the authorities to date although more than 500 targeted toxins have been developed within the last decades. To overcome the problem of insufficient endosomal escape, a number of strategies that make use of diverse chemicals, cell-penetrating or fusogenic peptides, and light-induced techniques were designed to weaken the membrane integrity of endosomes. This review focuses on glycosylated triterpenoids as endosomal escape enhancers and throws light on their structure, the mechanism of action, and on their efficacy in cell culture and animal models. Obstacles, challenges, opportunities, and future prospects are discussed.

Antiprotozoal Effect of Saponins in the Rumen Can Be Enhanced by Chemical Modifications in Their Structure

The antiprotozoal effect of saponins is transitory, as when saponins are deglycosylated to the sapogenin by rumen microorganisms they become inactive. We postulated that the substitution of the sugar moiety of the saponin with small polar residues would produce sapogen-like analogs which might be resistant to degradation in the rumen as they would not be enzymatically cleaved, allowing the antiprotozoal effect to persist over time. In this study, we used an acute assay based on the ability of protozoa to break down [¹⁴C] leucine-labeled Streptococcus bovis and a longer term assay based on protozoal motility over 24 h to evaluate both the antiprotozoal effect and the stability of this effect with fifteen hederagenin bis-esters esterified with two identical groups, and five cholesterol and cholic acid based derivatives carrying one to three succinate residues. The acute antiprotozoal effect of hederagenin derivatives was more pronounced than that of cholesterol and cholic acid derivatives. Modifications in the structure of hederagenin, cholesterol, and cholic acid derivatives resulted in compounds with different biological activities in terms of acute effect and stability, although those which were highly toxic to protozoa were not always the most stable over time. Most of the hederagenin bis-esters, and in particular hederagenin bis-succinate (TSB24), hederagenin bis-betainate dichloride (TSB37) and hederagenin bis-adipate (TSB47) had a persistent effect against rumen protozoa in vitro, shifting the fermentation pattern toward higher propionate and lower butyrate. These chemically modified triterpenes could potentially be used in ruminant diets as an effective defaunation agent to, ultimately, increase nitrogen utilization, decrease methane emissions, and enhance animal production. Further trials in vivo or in long term rumen simulators are now needed to confirm the in vitro observations presented.

Saponaria officinalis L. extract: Surface active properties and impact on environmental bacterial strains

Plant-derived surfactants are characterised by low toxicity, high biodegradability and environmental compatibility. They therefore have many applications; for instance, they can be used in bioremediation to accelerate biodegradation processes, especially of hydrophobic pollutants. This paper analyses the properties of an extract from Saponaria officinalis L. containing saponins and its impact on bacterial strains isolated from soil, as well as its potential for application in hydrocarbon bioremediation. The tested extract from Saponaria officinalis L. contains gypsogenin, hederagenin, hydroxyhederagenin and quillaic acid aglycone structures and demonstrates good emulsification properties. Contact with the extract led to modification of bacterial cell surface properties. A decrease in cell surface hydrophobicity and an increase in membrane permeability were recorded in the experiments. An increase of up to 63% in diesel oil biodegradation was also recorded for Pseudomonas putida DA1 on addition of 1gL^-1 of saponins from Saponaria officinalis L. Saponaria extract showed no toxic impact on the tested environmental bacterial strains at the concentration used in the biodegradation process.

Rapid, cost-effective and accurate quantification of Yucca schidigera Roezl. steroidal saponins using HPLC-ELSD method

Yucca GRAS-labelled saponins have been and are increasingly used in food/feed, pharmaceutical or cosmetic industries. Existing techniques presently used for Yucca steroidal saponin quantification remain either inaccurate and misleading or accurate but time consuming and cost prohibitive. The method reported here addresses all of the above challenges. HPLC/ELSD technique is an accurate and reliable method that yields results of appropriate repeatability and reproducibility. This method does not over- or under-estimate levels of steroidal saponins. HPLC/ELSD method does not require each and every pure standard of saponins, to quantify the group of steroidal saponins. The method is a time- and cost-effective technique that is suitable for routine industrial analyses. HPLC/ELSD methods yield a saponin fingerprints specific to the plant species. As the method is capable of distinguishing saponin profiles from taxonomically distant species, it can unravel plant adulteration issues.

Synthesis of molecularly imprinted polymers using acrylamide-β-cyclodextrin as a cofunctional monomer for the specific capture of tea saponins from the defatted cake extract of Camellia oleifera

Molecularly imprinted polymers were synthesized using mixed tea saponins as a template and acrylamide-β-cyclodextrin as a cofunctional monomer for the specific binding and purification of tea saponins from the defatted cake extract of Camellia oleifera. The adsorption properties of the prepared polymers were systematically evaluated including adsorption kinetics, adsorption isotherms, and selective recognition characteristics. It showed that the adsorption kinetics followed the pseudo first-order kinetic model (R² = 0.995) with an equilibrium time of 3 h, adsorption isotherm data fitted well with the Langmuir-Freundlich model (R² = 0.984) with an adsorption capacity of 14.23 mg/g. The relative selectivity coefficient (k´) in the presence of the analogues glycyrrhizic acid and glycyrrhetinic acid were 1.16 and 17.21, respectively. The performance of the molecularly imprinted polymers as solid-phase extraction materials was investigated and the results indicated that using acrylamide-β-cyclodextrin as a cofunctional monomer improved both the adsorption capacity and active sites stability of the imprinted polymers. The solid-phase extraction using the polymers as packing materials was subsequently applied for the separation of tea saponins in raw C. oleifera press extract, and targets were obtained with a purity reaching 89%.

Effects of Saponins on Lipid Metabolism: A Review of Potential Health Benefits in the Treatment of Obesity

Obesity is one of the greatest public health problems. This complex condition has reached epidemic proportions in many parts of the world, and it constitutes a risk factor for several chronic disorders, such as hypertension, cardiovascular diseases and type 2 diabetes. In the last few decades, several studies dealt with the potential effects of natural products as new safe and effective tools for body weight control. Saponins are naturally-occurring surface-active glycosides, mainly produced by plants, whose structure consists of a sugar moiety linked to a hydrophobic aglycone (a steroid or a triterpene). Many pharmacological properties have been reported for these compounds, such as anti-inflammatory, immunostimulant, hypocholesterolemic, hypoglycemic, antifungal and cytotoxic activities. The aim of this review is to provide an overview of recent studies about the anti-obesity therapeutic potential of saponins isolated from medicinal plants. Results on the in vitro and in vivo activity of this class of phytochemicals are here presented and discussed. The most interesting findings about their possible mechanism of action and their potential health benefits in the treatment of obesity are reported, as well.

Nutrient intake, digestibility and performance of Gaddi kids supplemented with tea seed or tea seed saponin extract

Objective

An experiment was conducted to determine the nutrient intake, digestibility, microbial protein synthesis, haemato-biochemical attributes, immune response and growth performance of Gaddi kids fed with oat fodder based basal diet supplemented with either tea seed or tea seed saponin (TSS) extract.

Methods

Eighteen male kids, 7.03±0.16 months of age and 19.72±0.64 kg body weight, were distributed into three groups, T₀ (control), T₁, and T₂, consisting of 6 animals each in a completely randomized design. The kids were fed a basal diet consisting of concentrate mixture and oat fodder (50:50). Animals in group III (T₂) were supplemented with TSS at 0.4% of dry matter intake (DMI), and group II (T₁) were supplemented with tea seed at 2.6% of DMI to provide equivalent dose of TSS as in T₂. Two metabolism trials were conducted, 1st after 21 days and 2nd after 90 days of feeding to evaluate the short term and long term effects of supplementation.

Results

The tea seed (T₁) or TSS (T₂) supplementation did not affect DMI as well as the digestibility of dry matter, organic matter, crude protein, neutral detergent fibre, and acid detergent fibre. Nutritive value of diet and plane of nutrition were also comparable for both the periods. However, the average daily gain and feed conversion ratio (FCR) were improved (p<0.05) for T₁ and T₂ as compared to T₀. The microbial protein supply was also higher (p<0.05) for T₁ and T₂ for both the periods. There was no effect of supplementation on most blood parameters. However, the triglyceride and low density lipoprotein cholesterol levels decreased (p<0.05) and high density lipoprotein-cholesterol level increased (p<0.05) in T₂ as compared with T₀ and T₁. Supplementation also did not affect the cell mediated and humoral immune response in goats.

Conclusion

Tea seed at 2.6% of DMI and TSS at 0.4% DMI can be fed to Gaddi goats to improve growth rate, FCR and microbial protein synthesis.

One-pot synthesis of glycyrrhetic acid polyglycosides based on grafting-from method using cyclic sulfite

Glycyrrhetic acid polyglycosides were synthesized in one-pot via cationic ring-opening condensation polymerization of cyclic sulfite (4) initiated by glycyrrhetic acid as an aglycon. Sulfite 4 worked as a practical monomer for the preparation of (1 → 2)-linked polysaccharide skeletons. The chemical stability of 4 was evaluated by the comparison of thermodynamic parameters with those of conventional epoxide (2). The grafting reaction of 4 from glycyrrhetic acid (5) was performed in the presence of TfOH and MS 3A in CH2Cl2 at room temperature. The polymerization degree was moderately controllable by the change of feed ratio of initiator.

In vitro screening of natural feed additives from crustaceans, diatoms, seaweeds and plant extracts to manipulate rumen fermentation

BACKGROUND

Eight natural products from animal, unicellular algae, brown seaweed and plant origins were chosen according to their theoretical antimicrobial activity: Diatomaceous earths (DE), insoluble chitosan (ICHI), soluble chitosan (CHI), seaweed meal (SWM), Ascophyllum nodosum (ASC), Laminaria digitata (LAM), neem oil (NOIL) and an ivy fruit extract rich in saponins (IVY). Dose-response incubations were conducted to determine their effect on rumen fermentation pattern and gas production, while their anti-protozoal activity was tested using (14) C-labelled bacteria.

RESULTS

DE, SWM, NOIL and ICHI had very small effects on rumen function when used at inclusion rate up to 2 g L(-1) . ASC had anti-protozoal effects (up to -23%) promoting a decrease in gas production and methanogenesis (-15%). LAM increased VFA production (+7%) and shifted from butyrate to acetate. CHI also shifted fermentation towards propionate production and lower methane (-23%) and protozoal activity (-56%). IVY decreased protozoal activity (-39%) and ammonia concentration (-56%), as well as increased feed fermentation (+11% VFA concentration) and shifted from acetate to propionate production.

CONCLUSIONS

ASC, LAM, CHI and IVY showed promising potential in vitro as feed additives to improve rumen function, thus more research is needed to investigate their mode of action in the rumen microbial ecosystem. © 2015 Society of Chemical Industry.

Effects of tea saponin on growth and development, nutritional indicators, and hormone titers in diamondback moths feeding on different host plant species

The diamondback moth (DBM) is an important worldwide pest. This insect has been studied for several decades; however, its control remains problematic. Numerous chemical insecticides have become ineffective and chemical residues constitute an important problem. In the present study, we determined the mortality of 3rd instar DBM larvae feeding on three different host plant species and exposed to various concentrations of tea saponin (TS). In addition, we evaluated growth and development parameters, nutritional indicators, and juvenile hormone (JH) and molting hormone (MH) titers in 2nd instar larvae exposed to LC20 and LC50 doses of TS. We found that treatment of DBM larvae with LC20 and LC50 doses of TS led to lower growth rates, decreased feed consumption, reduced frass production, lower pupal weights, reduced percentage pupation, slower adult emergence percentages, and diminished fecundity, but prolonged durations of the larval and pupal periods. The efficiency of conversion of ingested and digested food increased, but the approximate digestibility did not differ significantly between treatments and controls. JH and MH titers were higher after TS treatment; these increases varied according to the host species and TS concentration. Our results indicate that TS represents a potential new alternative insecticide based on its natural origin, low cost, and minimum environmental impact.

Effects of Momordica charantia Saponins on In vitro Ruminal Fermentation and Microbial Population

This study was conducted to investigate the effects of Momordica charantia saponin (MCS) on ruminal fermentation of maize stover and abundance of selected microbial populations in vitro. Five levels of MCS supplements (0, 0.01, 0.06, 0.30, 0.60 mg/mL) were tested. The pH, NH3-N, and volatile fatty acid were measured at 6, 24, 48 h of in vitro mixed incubation fluids, whilst the selected microbial populations were determined at 6 and 24 h. The high dose of MCS increased the initial fractional rate of degradation at t-value = 0 (FRD0) and the fractional rate of gas production (k), but decreased the theoretical maximum of gas production (V F) and the half-life (t0.5) compared with the control. The NH3-N concentration reached the lowest concentration with 0.01 mg MCS/mL at 6 h. The MSC inclusion increased (p<0.001) the molar proportion of butyrate, isovalerate at 24 h and 48 h, and the molar proportion of acetate at 24 h, but then decreased (p<0.05) them at 48 h. The molar proportion of valerate was increased (p<0.05) at 24 h. The acetate to propionate ratio (A/P; linear, p<0.01) was increased at 24 h, but reached the least value at the level of 0.30 mg/mL MCS. The MCS inclusion decreased (p<0.05) the molar proportion of propionate at 24 h and then increased it at 48 h. The concentration of total volatile fatty acid was decreased (p<0.001) at 24 h, but reached the greatest concentration at the level of 0.01 mg/mL and the least concentration at the level of 0.60 mg/mL. The relative abundance of Ruminococcus albus was increased at 6 h and 24 h, and the relative abundance of Fibrobacter succinogenes was the lowest (p<0.05) at 0.60 mg/mL at 6 h and 24 h. The relative abundance of Butyrivibrio fibrisolvens and fungus reached the greatest value (p<0.05) at low doses of MCS inclusion and the least value (p<0.05) at 0.60 mg/mL at 24 h. The present results demonstrates that a high level of MCS quickly inhibits in vitro fermentation of maize stover, while MCS at low doses has the ability to modulate the ruminal fermentation pattern by regulating the number of functional rumen microbes including cellulolytic bacteria and fungi populations, and may have potential as a feed additive applied in the diets of ruminants.

Effects and mode of action of chitosan and ivy fruit saponins on the microbiome, fermentation and methanogenesis in the rumen simulation technique

This study investigates the effects of supplementing a control diet (CON) with chitosan (CHI) or ivy fruit saponins (IVY) as natural feed additives. Both additives had similar abilities to decrease rumen methanogenesis (–42% and –40%, respectively) using different mechanisms: due to its antimicrobial and nutritional properties CHI promoted a shift in the fermentation pattern towards propionate production which explained about two thirds of the decrease in methanogenesis. This shift was achieved by a simplification of the structure in the bacterial community and a substitution of fibrolytic (Firmicutes and Fibrobacteres) by amylolytic bacteria (Bacteroidetes and Proteobacteria) which led to greater amylase activity, lactate and microbial protein yield with no detrimental effect on feed digestibility. Contrarily, IVY had negligible nutritional properties promoting minor changes in the fermentation pattern and on the bacterial community. Instead, IVY modified the structure of the methanogen community and decreased its diversity. This specific antimicrobial effect of IVY against methanogens was considered its main antimethanogenic mechanism. IVY had however a negative impact on microbial protein synthesis. Therefore, CHI and IVY should be further investigated in vivo to determine the optimum doses which maintain low methanogenesis but prevent negative effects on the rumen fermentation and animal metabolism.

Rumen function is generally suboptimal leading to loses in the form of methane and nitrogen, analysis of the rumen microbiome is vital to understand the mode of action of new feed additives to improve rumen function.

The Role of Ciliate Protozoa in the Rumen

First described in 1843, Rumen protozoa with their striking appearance were assumed to be important for the welfare of their host. However, despite contributing up to 50% of the bio-mass in the rumen, the role of protozoa in rumen microbial ecosystem remains unclear. Phylogenetic analysis of 18S rDNA libraries generated from the rumen of cattle, sheep, and goats has revealed an unexpected diversity of ciliated protozoa although variation in gene copy number between species makes it difficult to obtain absolute quantification. Despite repeated attempts it has proven impossible to maintain rumen protozoa in axenic culture. Thus it has been difficult to establish conclusively a role of ciliate protozoa in rumen fiber degradation. The development of techniques to clone and express ciliate genes in λ phage, together with bioinformatic indices to confirm the ciliate origin of the genes has allowed the isolation and characterization of fibrolytic genes from rumen protozoa. Elimination of the ciliate protozoa increases microbial protein supply by up to 30% and reduces methane production by up to 11%. Our recent findings suggest that holotrich protozoa play a disproportionate role in supporting methanogenesis whilst the small Entodinium are responsible for much of the bacterial protein turnover. As yet no method to control protozoa in the rumen that is safe and practically applicable has been developed, however a range of plant extract capable of controlling if not completely eliminating rumen protozoa have been described.

Meta-analysis on Methane Mitigating Properties of Saponin-rich Sources in the Rumen: Influence of Addition Levels and Plant Sources

Saponins have been considered as promising natural substances for mitigating methane emissions from ruminants. However, studies reported that addition of saponin-rich sources often arrived at contrasting results, i.e. either it decreased methane or it did not. The aim of the present study was to assess ruminal methane emissions through a meta-analytical approach of integrating related studies from published papers which described various levels of different saponin-rich sources being added to ruminant feed. A database was constructed from published literature reporting the addition of saponin-rich sources at various levels and then monitoring ruminal methane emissions in vitro. Accordingly, levels of saponin-rich source additions as well as different saponin sources were specified in the database. Apart from methane, other related rumen fermentation parameters were also included in the database, i.e. organic matter digestibility, gas production, pH, ammonia concentration, short-chain fatty acid profiles and protozoal count. A total of 23 studies comprised of 89 data points met the inclusion criteria. The data obtained were subsequently subjected to a statistical meta-analysis based on mixed model methodology. Accordingly, different studies were treated as random effects whereas levels of saponin-rich source additions or different saponin sources were considered as fixed effects. Model statistics used were p-value and root mean square error. Results showed that an addition of increasing levels of a saponin-rich source decreased methane emission per unit of substrate incubated as well as per unit of total gas produced (p<0.05). There was a decrease in acetate proportion (linear pattern; p<0.001) and an increase in propionate proportion (linear pattern; p<0.001) with increasing levels of saponin. Log protozoal count decreased (p<0.05) at higher saponin levels. Comparing between different saponin-rich sources, all saponin sources, i.e. quillaja, tea and yucca saponins produced less methane per unit of total gas than that of control (p<0.05). Although numerically the order of effectiveness of saponin-rich sources in mitigating methane was yucca>tea>quillaja, statistically they did not differ each other. It can be concluded that methane mitigating properties of saponins in the rumen are level- and source-dependent.

Crop management, genotypes, and environmental factors affect soyasaponin B concentration in soybean

Soybean [Glycine max (L.) Merr.] seeds contain soyasaponin B, which has putative health benefits. Studies were conducted in multiple environments in Quebec, Canada to determine the effects of genotypes, environments, and seeding dates on soyasaponin B concentration in mature seeds. A growth chamber study was also conducted to determine the impact of high air temperature imposed at specific growth development stages on soyasaponin B in soybeans. Concentrations of individual and total soyasaponin B were determined using high-performance liquid chromatography. Genotype and environment main effects were the main determinants of soyasaponin B concentration in soybean, genotype × environment interactions accounting for less than 5% of the variation for all soyasaponin. Ranking of 20 early maturing soybean genotypes was thus relatively consistent across four environments, total concentration varying between 2.31 and 6.59 μmol g(-1). Seeding date consistently impacted soyasaponin B concentrations, early seeding date resulting in the highest concentrations. There was an 11% difference in total soyasaponin B concentration of soybeans seeded in mid-May compared to that in late-June. The response to high air temperature was complex and cultivar specific. High temperature stress restricted to the seed filling stages increased total soyasaponin B concentration in one cultivar by 28% when compared to that in control nonstressed plants; however, in another cultivar high temperature applied during all growth stages reduced total concentration by 27%. Results from the present study thus demonstrate that environmental factors and crop management both impact soyasaponin B concentration in soybeans.

Effects of Defaunation on Fermentation Characteristics and Methane Production by Rumen Microbes In vitro When Incubated with Starchy Feed Sources

An in vitro experiment was conducted to examine the effects of defaunation (removal of protozoa) on ruminal fermentation characteristics, CH₄ production and degradation by rumen microbes when incubated with cereal grains (corn, wheat and rye). Sodium lauryl sulfate as a defaunation reagent was added into the culture solution at a concentration of 0.000375 g/ml, and incubated anaerobically for up to 12 h at 39°C. Following defaunation, live protozoa in the culture solution were rarely observed by microscopic examination. A difference in pH was found among grains regardless of defaunation at all incubation times (p<0.01 to 0.001). Defaunation significantly decreased pH at 12 h (p<0.05) when rumen fluid was incubated with grains. Ammonia-N concentration was increased by defaunation for all grains at 6 h (p<0.05) and 12 h (p<0.05) incubation times. Total VFA concentration was increased by defaunation at 6 h (p<0.05) and 12 h (p<0.01) for all grains. Meanwhile, defaunation decreased acetate and butyrate proportions at 6 h (p<0.05, p<0.01) and 12 h (p<0.01, p<0.001), but increased the propionate proportion at 3 h, 6 h and 12 h incubation (p<0.01 to 0.001) for all grains. Defaunation increased in vitro effective degradability of DM (p<0.05). Production of total gas and CO₂ was decreased by defaunation for all grains at 1 h (p<0.05, p<0.05) and then increased at 6 h (p<0.05, p<0.05) and 12 h (p<0.05, p<0.05). CH₄ production was higher from faunation than from defaunation at all incubation times (p<0.05).

Methane storage in tea clathrates

Methane can be stored in tea clathrates, that is kinetics of methane clathrate formation can be significantly accelerated (90% saturation uptake in 20 min) by ingredients (polyphenols and saponins) in tea infusions with a volumetric capacity of up to 172 v/v.

Potential of extracts from Saponaria officinalis and Calendula officinalis to modulate in vitro rumen fermentation with respect to their content in saponins

Saponins have the potential to favorably modulate rumen fermentation, but there is generally a lack of the chemical structures associated with the described effects. The activity of extracts from Calendula officinalis and Saponaria officinalis in the rumen was evaluated in vitro. The S. officinalis root extract, reduced CH4 production by 8.5% and increased total VFA concentration by 25.2%. C. officinalis and S. officinalis root extracts and the S. officinalis aerial part extract decreased the acetate to propionate ratio from 8.6 to 17.4%, according to the extract. An HPLC-ELSD analysis indicated that the saponin content ranged from 43.6 to 57.6 mg/g of dry matter (DM) in the C. officinalis extracts and from 224.0 to 693.8 mg/g of DM in the S. officinalis extracts, expressed as the hederacoside C equivalent. Identification of the saponin compounds present in the extracts by HPLC–MSn suggested that the saponin profile modulated the biological activities, showing the importance of determining the structure of saponins when evaluating extracts.

Protective effect of dietary xylitol on influenza A virus infection

Xylitol has been used as a substitute for sugar to prevent cavity-causing bacteria, and most studies have focused on its benefits in dental care. Meanwhile, the constituents of red ginseng (RG) are known to be effective in ameliorating the symptoms of influenza virus infection when they are administered orally for 14 days. In this study, we investigated the effect of dietary xylitol on influenza A virus infection (H1N1). We designed regimens containing various fractions of RG (RGs: whole extract, water soluble fraction, saponin and polysaccharide) and xylitol, and combination of xylitol with the RG fractions. Mice received the various combinations orally for 5 days prior to lethal influenza A virus infection. Almost all the mice died post challenge when xylitol or RGs were administered separately. Survival was markedly enhanced when xylitol was administered along with RGs, pointing to a synergistic effect. The effect of xylitol plus RG fractions increased with increasing dose of xylitol. Moreover, dietary xylitol along with the RG water soluble fraction significantly reduced lung virus titers after infection. Therefore, we suggest that dietary xylitol is effective in ameliorating influenza-induced symptoms when it is administered with RG fractions, and this protective effect of xylitol should be considered in relation to other diseases.

New Triterpenoid Saponins from the Roots of Saponaria officinalis

Three new triterpenoid saponins (1–3), along with nine known saponins, were isolated from the roots of Saponaria officinalis L. Two of them: vaccaroside D (4) and dianchinenoside B (5) are known, but not previously reported for S. officinalis, and seven others: saponarioside C (6), D (7), F (8), G (9), I (10), K (11), and L (12) have been previously isolated from this plant. The structures of the new saponins were established as 3- O-β-D-xylopyranosyl-16α-hydroxygypsogenic acid-28- O-[β-D-glucopyranosyl-(1→6)]-β-D-glucopyranoside (1), 3- O-β-D-xylopyranosyl-16α-hydroxygypsogenic acid-28- O-[β-D-glucopyranosyl-(1→3)]-[α-D-galactopyranosyl-(1→6)-α-D-galactopyranosyl-(1→6)-β-D-glucopyranosyl-(1→6)]-β-D-glucopyranoside (2) and 3- O-β-D-xylopyranosyl-gypsogenic acid-28- O-[β-D-glucopyranosyl-(1→3)]-[6- O-(3-hydroxy-3-methylglutaryl)-β-D-glucopyranosyl-(1→6)]-β-D-glucopyranoside (3). Their structures were elucidated by extensive spectroscopic methods, including 1D- (1H, 13C) and 2D-NMR (D QF-COSY, TOCSY, ROESY, HSQC and HMBC) experiments, as well as high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), ESI-MS/MS and acid hydrolysis.

Influence of gastrointestinal digestion and edible plant combination on oral bioavailability of triterpene saponins, using a biomimetic digestion and absorption system and determination by HPLC

Saponins have many biological activities, but their overload could cause toxicity to the human body. Bionic gastrointestinal digestion and monolayer liposome extraction were used for oral bioavailability assessment of triterpene saponins (notoginsenoside R1, ginsenosides Rb1 and Rd1) in an edible herb (San-Chi) and its compound herbal medicine (Pien Tze Huang, PZH). The concentrations of affinity-monolayer liposome saponins in the chyme were determined by HPLC and used for oral bioavailability assessment. With the digestion of San-Chi and PZH from the stomach to the intestine, the release of saponins in their chyme was increased. The intestinal absorption ratios of N-R1, G-Rb1, G-Rd1, and total saponins from San-Chi were 86.57, 18.56, 73.30, and 40.20%, respectively, which were more than those from PZH (i.e., 19.56, 10.11, 30.11, and 16.08%). The oral bioavailability of saponins was controlled by saponin species, gastrointestinal digestion, and edible plants combination.

Hepatic photosensitization in buffaloes intoxicated by Brachiaria decumbens in Minas Gerais state, Brazil

The aim of this paper is to report the study of hepatogenous photosensitization in buffaloes during two outbreaks provoked by ingestion of Brachiaria decumbens in Minas Gerais state, Brazil. Ten young buffaloes in outbreak 1 and seven buffaloes in outbreak 2 were intoxicated by B. decumbens. Nine clinically healthy buffaloes raised under the same conditions as the sick animals served as the control group. All animals were subjected to clinical examination, and serum was collected to measure gamma-glutamyl transferase (GGT), aspartate aminotransferase (AST), direct bilirubin (DB), indirect bilirubin (IB) and total bilirubin (TB) as indicators of liver function and urea and creatinine as indicators of renal function. Histopathology of liver fragments from five different animals was carried out. During the outbreaks and every two months for one year, samples of grass from paddocks where the animals got sick were collected for quantitative evaluation of the saponin protodioscin, combined with observations of pasture characteristics and daily rainfall. Clinical signs included apathy, weight loss, restlessness, scar retraction of the ears and intense itching at the skin lesions, mainly on the rump, the tail head, neck and hindlimbs, similar to the signs observed in other ruminants. Only the GGT enzyme presented significantly different (P < 0.01) serum levels between intoxicated animals (n = 17) and healthy animals (n = 9), indicating liver damage in buffaloes bred in B. decumbens pastures. Microscopy of the liver showed foamy macrophages and lesions of liver disease associated with the presence of crystals in the bile ducts, which have also been found in sheep and cattle poisoned by grasses of the genus Brachiaria. During the outbreaks, protodioscin levels were higher than 3%, and shortly after, these levels were reduced to less than 0.80%, suggesting a hepatic injury etiology. The outbreaks took place at the beginning of the rainy season, and there was a positive correlation between saponin and the amount of rainfall, as well as between saponin and the amount of green leaves in the pasture. These findings indicate that the grass was more toxic in this period. This is the first report of photosensitization by B. decumbens in buffalo.

Isolation and structural determination of triterpenoid glycosides from the aerial parts of alsike clover (Trifolium hybridum L.)

Five azukisapogenol glycosides (1-5) have been isolated from the aerial parts of alsike clover (Trifolium hybridum L.), and their structures were elucidated by combined spectroscopic, spectrometric (1D and 2D NMR; HRESIMS, ESI-MS/MS), and chemical methods. Three of them are new compounds and were identified as 3-O-[-α-L-arabinopyranosyl(1→2)]-β-D-glucuronopyranosyl azukisapogenol (1), 3-O-[-β-D-glucuronopyranosyl(1→2)-β-D-glucuronopyranosyl]-29-O-β-D-glucopyranosyl azukisapogenol (2), and 3-O-[-α-L-arabinopyranosyl(1→2)-β-D-glucuronopyranosyl]-29-O-β-D-glucopyranosyl azukisapogenol (3). The remaining two (4, 5) are known compounds but have not been previously described as saponins constituents of the genus Trifolium . Also, azukisapogenol is reported here as a triterpenoid aglycone for the first time in this genus. Finally, the main chemotaxonomic features that may be recognized as specific of Trifolium species were discussed.

Bioactivity of phytochemicals in some lesser-known plants and their effects and potential applications in livestock and aquaculture production systems

Livestock and aquaculture production is under political and social pressure, especially in the European Union (EU), to decrease pollution and environmental damage arising due to animal agriculture. The EU has banned the use of antibiotics and other chemicals, which have been shown to be effective in promoting growth and reducing environment pollutants because of the risk caused to humans by chemical residues in food and by antibiotic resistance being passed on to human pathogens. As a result of this, scientists have intensified efforts in exploiting plants, plant extracts or natural plant compounds as potential natural alternatives for enhancing the livestock productivity. This paper discusses work on the effects of various phytochemicals and plant secondary metabolites in ruminant and fish species. The focus is on (i) plants such as Ananas comosus (pine apple), Momordica charantia (bitter gourd) and Azadirachta indica (neem) containing anthelmintic compounds and for their use for controlling internal parasites; (ii) plants containing polyphenols and their applications for protecting proteins from degradation in the rumen, increasing efficiency of microbial protein synthesis in rumen and decreasing methane emission; for using as antioxidants, antibacterial and antihelmintic agents; and for changing meat colour and for increasing n-3 fatty acids and conjugated linoleic acid in meat; (iii) saponin-rich plants such as quillaja, yucca and Sapindus saponaria for increasing the efficiency of rumen fermentation, decreasing methane emission and enhancing growth; for producing desired nutritional attributes such as lowering of cholesterol in monogastric animals; for increasing growth of fish (common carp and Nile tilapia) and for changing male to female ratio in tilapia; and for use as molluscicidal agents; (iv) Moringa oleifera leaves as a source of plant growth factor(s), antioxidants, beta-carotene, vitamin C, and various glucosinolates and their degraded products for possible use as antibacterial, antioxidant, anticarcinogenic and antipest agents; (v) Jatropha curcas toxic variety with high levels of various phytochemicals such as trypsin inhibitor, lectin, phytate and phorbol esters in seeds limiting the use of seed meal in fish and livestock diets; and the use of phorbol esters as bio-pesticidal agent; and (vi) lesser-known legumes such as Entada phaseoloides seeds containing high levels of trypsin inhibitor and saponins, Sesbania aculeate seeds rich in non-starch polysaccharides and Mucuna pruriens var. utilis seeds rich in l-3,4-dihydroxyphenylalanine and their potential as fish feed; Cassia fistula seeds as a source of antioxidants; and the use of Canavalia ensiformis, C. gladiata and C. virosa seeds containing high levels of trypsin inhinitor, lectins and canavanine. The paper also presents some challenges and future areas of work in this field.

Effects of quillaja and yucca saponins on communities and select populations of rumen bacteria and archaea, and fermentation in vitro

AIMS

The objective of this study was to comprehensively evaluate quillaja (QSP) and yucca saponin (YSP) products with respect to their effects on diversity of rumen bacteria and archaea, abundance of selected microbes, and feed degradability and fermentation.

METHODS AND RESULTS

Both QSP and YSP at doses 0-0.6 g l(-1) tended to increase degradability of feed substrate in in vitro rumen cultures, but to different extents. Neither one of the saponins affected the concentrations of ammonia, total volatile fatty acids, or molar proportion of acetate. However, QSP increased molar proportion of propionate and decreased that of butyrate, whereas YSP tended to decrease that of butyrate. As determined by qPCR, QSP and YSP did not affect the abundance of total bacteria or Ruminococcus albus. The QSP did not affect the abundances of Fibrobacter succinogenes or genus Prevotella, but tended to decrease that of Ruminococcus flavefaciens, whereas YSP significantly increased the abundance of R. flavefaciens and Prevotella, and numerically increased that of F. succinogenes. Both saponins increased archaeal abundance, although to small magnitudes (0.3-0.4 log). The protozoal populations were decreased significantly by QSP, but not by YSP. Based on DGGE and T-RFLP analysis, both saponins altered the bacterial community and species organization, but less so the archaeal community.

CONCLUSIONS

This study demonstrated that saponins, although not effective in mitigating methane emission, may improve feed utilization at low doses, and modulate ruminal microbial communities in a dose-dependent manner.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study suggest that saponins at low doses may directly stimulate the growth of some rumen bacteria including cellulolytic bacteria, thus improving digestibility of feeds, independent of their defaunation activity. In contrast, saponins at high doses modulate rumen fermentation characteristically similar to defaunation.

Pharmacological, genotoxic and phytochemical properties of selected South African medicinal plants used in treating stomach-related ailments

ETHNOPHARMACOLOGICAL RELEVANCE

The evaluated medicinal plants are used in South African traditional medicine in treating stomach-related ailments.

AIMS OF THE STUDY

The study aimed at evaluating the pharmacological, genotoxic and phytochemical properties of the seven selected medicinal plants used for treating stomach-related ailments.

MATERIALS AND METHODS

Ethyl acetate (EtOAc), ethanol (EtOH) 70% and water extracts of the selected plant parts were evaluated for their antimicrobial and anthelmintic activities using microdilution assays. Gram-positive bacteria (Enterococcus faecalis and Staphylococcus aureus), Gram-negative bacterium (Escherichia coli) and Candida albicans were used for antimicrobial assays. Caenorhabditis elegans was used for the anthelmintic assay. Plant extracts were also assayed for their cyclooxygenase-inhibitory activity against cyclooxygenase-1 and -2 enzymes. The Ames test was used to evaluate the genotoxicity of the plant extracts. A spectrophotometric method was used to determine the total phenolics, gallotannins, flavonoids and saponins.

RESULTS

Twelve extracts exhibited minimum inhibitory concentration (MIC) <1 mg/mL against the bacterial test strains, and five extracts exhibited MIC <1 mg/mL against Candida albicans. The EtOAc extract of Tetradenia riparia had the best minimum lethal concentration (MLC) value (0.004 mg/mL) against Caenorhabditis elegans. All the EtOAc extracts exhibited percentage inhibition in the range of 50.7-94.7% against COX-1 and -2 enzymes at 250 μg/mL. All the plant extracts were non-mutagenic towards Salmonella typhimurium tester strains TA98, TA100 and TA1537 without metabolic activation. Phytochemical analysis revealed relatively high amounts of total phenolics, gallotannins and flavonoids in the evaluated plant extracts.

CONCLUSIONS

The general pharmacological activities exhibited by some of the plant extracts in this study support the traditional uses of the selected plants in treating stomach-related ailments. The Ames test showed that all the plant extracts were non-mutagenic but cytotoxicity tests are needed to ascertain the safety for long-term consumption.

Effect of elicitor spray at different reproductive stages on saponin content of soybean

The beneficial health effects of soybeans may be enhanced by increasing bioactive compounds including soyasaponins (ssp). The objective of this study is to elucidate the effect of elicitors sprayed on Ozark variety soybeans, on ssp content. Different concentrations of elicitors, ethyl acetate (EA) and methyl jasmonate (MJ), were sprayed at 4 different growth stages (1-bloom, 2-pod development, 3-seed development, and 4-seed maturity). Seeds were ground, defatted, ssp was extracted and identified and quantified with HPLC. Elicitor and growth stage had an effect on βg and βa contents of soybeans compared with control (P < 0.05). Elicitor had an effect on total ssp content (P < 0.001) and αg and γg content of soybeans compared with control (P < 0.05). Total ssp content of EA 0.05 M, MJ 0.001 M, and 0.005 M sprayed soybeans were higher than EA 0.001 M, which is higher than control (P < 0.05; 3.62, 3.56, 3.56, 3.29, and 2.98 μmol/g soybean, respectively). The overall effect of elicitor on total ssp content was not dependent on growth stage, however, elicitors sprayed at growth stages 1, 2, and 3 showed differences among elicitor applied soybeans. Elicitors applied at growth stage 4 did not have any effect on total ssp content compared to control. Elicitors EA 0.05 M, MJ 0.001, and 0.005 M can be applied on any growth stage to increase total saponin content of soybean variety Ozark. Higher saponin content may improve the beneficial health effects of soybean consumption.

Effects of tea saponins on rumen microbiota, rumen fermentation, methane production and growth performance--a review

Reducing methane emission from ruminant animals has implications not only for global environmental protection but also for efficient animal production. Tea saponins (TS) extracted from seeds, leaves or roots of tea plant are pentacyclic triterpenes. They have a lasting antiprotozoal effect, but little effect on the methanogen population in sheep. There was no significant correlation between the protozoa counts and methanogens. The TS decreased methanogen activity. It seems that TS influenced the activity of the methanogens indirectly via the depressed ciliate protozoal population. The TS addition decreased fungal population in the medium containing rumen liquor in in vitro fermentation, but no such effect was observed in the rumen liquor of sheep fed TS. Tea saponins had a minor effect on the pattern of rumen fermentation and hence on nutrient digestion. When added at 3 g/day in diets, TS could improve daily weight gain and feed efficiency in goats. No positive associative effect existed between TS and disodium fumarate or soybean oil on methane suppression. Inclusion of TS in diets may be an effective way for improving feed efficiency in ruminants.