A Bioinformatics Tool for Efficient Retrieval of High-Confidence Terpene Synthases (TPS) and Application to the Identification of TPS in Coffea and Quillaja

Terpenoids are a class of compounds that are found in all living organisms. In plants, some terpenoids are part of primary metabolism, but most terpenes found in plants are classified as specialized metabolites, encoded by terpene synthases (TPS). It is not obvious how to assign the putative product of a given TPS using bioinformatics tools. Phylogenetic analyses easily assign TPS into families; however members of the same TPS family can synthetize more than one terpenoid-and, in many biotechnological applications, researchers are more interested in the product of a given TPS rather than its phylogenetic profile. Automated protein annotation can be used to classify TPS based on their products, despite the family they belong to. Here, we implement an automated bioinformatics method, search_TPS, to identify TPS proteins that synthesize mono, sesqui and diterpenes in Angiosperms. We verified the applicability of the method by classifying wet lab validated TPS and applying it to find TPS proteins in Coffea arabica, C. canephora, C. eugenioides, and Quillaja saponaria. Search_TPS is a computational tool based on PERL scripts that carries out a series of HMMER searches against a curated database of TPS profile hidden Markov models. The tool is freely available at https://github.com/liliane-sntn/TPS .

Oil-Water Interfacial-Directed Spontaneous Self-Assembly of Natural Quillaja Saponin for Controlling Interface Permeability in Colloidal Emulsions

Assembly of amphiphiles at the interface of two immiscible fluids is of great scientific and technological interest in offering efficient routes to smart vehicles for functional deliveries. Natural Quillaja saponin (QS) has gathered widespread interest within the scientific community as a result of its unique interfacial properties. Herein, spontaneously interface-driven self-assembly (SIDSA) of QS at the oil-water interface was systematically studied by morphology and spectroscopy. It was found to self-assemble into a micrometer-scale network in helical fibers by combined intermolecular π-π stacking and hydrogen bonding among saponins at the liquid-liquid interface. From SIDSA, multilayer films on the surfaces of dispersed droplets were formed and enhanced emulsion stability. Interfacial QS-based films on droplet surfaces were also shown to confine interfacial diffusion processes by serving as transport barriers. Furthermore, they can be exploited to control the release of volatiles from the dispersed liquid phase by regulating the interface film, which is shown by molecular dynamics to occur through a hydrogen-bonded mechanism. These results provide new insight into the interfacial assembly structure that can enable unique controllable release in a broad range of applications in food, beverages, pharmaceuticals, and cosmetics.

Germination rates of four Chilean forest trees seeds: Quillaja saponaria, Prosopis chilensis, Vachellia caven, and Caesalpinia spinosa

Data on the germination rates of four tree species, natively founded in the Chilean Mediterranean-climate zone, were determined by germination in crop chambers. The obtained data were used to interpolate or extrapolate the time taken for 50% of seeds to germinate in each case. These results are useful for regional native forest research and, in a broad sense, for its use in models to study germination dynamics in Mediterranean-climate zones.

What is the aquatic toxicity of saponin-rich plant extracts used as biopesticides?

Saponin-rich extracts from Quillaja saponaria and Chenopodium quinoa have been registered by US EPA as active ingredients in biopesticides, and extract from tea seed powder, Camellia oleifera has been proposed for biocidal use. If saponin-rich biopesticides are efficient against pests, they are most likely also bioactive in the aquatic environment against non-target organisms. The aim of this study was to conduct an effect assessment of saponin-rich plant extracts by using species sensitivity distributions based on acute toxicity tests. The maximal concentrations protecting 95% of the aquatic species (HC₅) of saponins extracted from quillaja bark, tea seed coat and quinoa seed coat were 2.91 ± 1.00, 0.22 ± 0.11 and 22.9 ± 5.84 mg/L, respectively. The 100-fold difference in toxicity between the saponin-rich extracts from different plant species, indicate that saponin toxicity depends on the species it origins from, making "read-across" between saponins a dubious exercise. In addition, the predicted environmental concentrations of different saponins are close to or higher than their water quality standard, which means that the extracts might pose a risk to the aquatic environment if not used cautiously.

Quillaja saponaria bark saponin protects Wistar rats against ferrous sulphate-induced oxidative and inflammatory liver damage

CONTEXT

Saponins from different sources are historically reported in Chinese medicine to possess many beneficial effects. However, insufficient experimental data are available regarding the hepatoprotective potential of Quillaja bark saponin.

OBJECTIVE

The protective effect of Quillaja saponaria Molina (Quillajaceae) bark triterpenoid saponin against iron-induced hepatotoxicity is compared to the standard N-acetylcysteine in adult male Wistar rats.

MATERIALS AND METHODS

Animals were divided into (six) groups, namely a normal control, an N-acetylcysteine control (300 mg/kg/day, p.o., 10 days), a saponin control (100 mg/kg/day, p.o., for 10 days), a hepatotoxicity control (two doses of ferrous sulphate, 30 mg/kg/day each, i.p., on 9th and 10th day), an N-acetylcysteine plus ferrous sulphate (standard treatment) and a saponin plus ferrous sulphate (test treatment) group. Hepatocyte integrity loss markers (serum ALT, AST, ALP, GGT and LDH), oxidative stress markers (hepatic MDA, GSH and NOx), dyslipidaemic markers (serum TC and TG) and hepatocyte functioning markers (serum bilirubin and albumin) were assessed.

RESULTS

Quillaja bark saponin decreased iron-induced elevation of ALT (reaching 57% of hepatotoxicity control), AST (66%), ALP (76%), GGT (60%), LDH (54%), MDA (65%), NOx (77%), TC (70%), TG (54%), and total (54%), direct (54%) and indirect (54%) bilirubin, coupled with increased GSH (219%) and albumin (159%) levels. Histopathological study strongly supported biochemical estimations, while immunohistochemical study showed marked effect on eNOS and iNOS expression.

CONCLUSIONS

Quillaja bark saponin has a good hepatoprotective effect. Amelioration of oxidative stress and suppression of NOS expression, with resultant maintenance of hepatocyte integrity and functioning, may explain this beneficial effect.

Organically versus conventionally grown produce: common production inputs, nutritional quality, and nitrogen delivery between the two systems

One distinguishing conclusion found in most reviews of research studies comparing organically and conventionally grown produce is that variables shared alike by organic and conventional produce during production, harvest, and postharvest handling and storage were not applied. As a result, accurate and meaningful conclusions comparing the nutritional quality of organic and conventional produce are difficult to ascertain. Pairing common production variables such as the physical, biological, and chemical/nutritional attributes of soils, the irrigation sources and amounts, crop varieties, crop maturities and harvest dates, pre- and postharvest processing, handling, and/or storage methods, individually and collectively, provide greater clarity as to how inputs unique to organic and conventional systems affect produce quality. Variables to be paired during production, harvest, and postharvest handling and storage studies comparing organic and conventional produce are discussed along with findings indicating that organic crops often have higher dry matter, ascorbic acid, phenolic, and sugar and lower moisture, nitrate, and protein contents and yields than conventionally grown crops. Recent studies of nutritional quality in organic versus conventional produce also indicate that soil nitrogen delivery rates strongly affect nutritional quality. Nitrogen profiling is a promising new approach to improving the nutritional quality of both organic and conventional produce.

saponin extract, quillaic acid and derivatives in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Quillaja saponaria bark contains a high percentage of triterpene saponins and has been used for centuries as a cleansing and analgesic agent in Chilean folk medicine.

AIM OF THE STUDY

The topical and systemic analgesic effects of a commercial partially purified saponin extract, 3β,16α-dihydroxy-23-oxoolean-12-en-28-oic acid (quillaic acid), methyl 3β,16α-dihydroxy-23-oxoolean-12-en-28-oate and methyl 4-nor-3,16-dioxoolean-12-en-28-oate.

MATERIALS AND METHODS

The samples were assessed in mice using the topical tail-flick and i.p. hot-plate tests, respectively.

RESULTS

All the samples showed activity in both analgesic tests in a dose-dependent manner. The most active against tail flick test was commercial partially purified saponin extract (EC50 27.9 mg%, w/v) and more than the ibuprofen sodium. On hot-plate test, methyl 4-nor-3, 16-dioxoolean-12-en-28-oate was the most active (ED50 12.2 mg/kg) and more than the ibuprofen sodium.

CONCLUSIONS

The results of the present study demonstrated that Quillaja saponaria saponins, quillaic acid, its methyl ester, and one of the oxidized derivatives of the latter, elicit dose-dependent antinociceptive effects in two murine thermal models.

Karaya root saponin exerts a hypocholesterolemic response in rats fed a high-cholesterol diet

Different sources of saponins are known to have hypocholesterolemic activity with varying degrees of efficacy. We hypothesize that karaya root saponin would efficiently reduce cholesterol. The aim of this study is to examine the comparative hypocholesterolemic effect of karaya root saponin in rats fed a high-cholesterol diet. Sixty male Wister-Imamichi rats were divided into 5 groups of 12 rats each constituting of the following: control group, soybean saponin-supplemented group, karaya root saponin-supplemented group, quillaja saponin-supplemented group, and tea saponin-supplemented group. Compared with the control diet, both the karaya root- and quillaja saponin-supplemented diets significantly reduced (P < .05) serum cholesterol and atherogenic index. Karaya root saponin significantly increased the serum high-density lipoprotein cholesterol, high-density lipoprotein cholesterol/cholesterol ratio, and fecal cholesterol concentrations (P < .05). The triacylglycerol concentration was significantly reduced only in the quillaja saponin-supplemented rats (P < .05). All the tea, soybean, karaya root, and quillaja saponins significantly reduced low-density lipoprotein cholesterol, and the greatest reduction was observed with karaya root saponin. Highest fecal bile acid concentration was found with quillaja saponin, whereas highest liver bile acid concentration was observed with karaya root saponin-supplemented rats (P < .05). These results collectively suggest that karaya root saponin can efficiently reduce serum cholesterol concentration in rats.

Exposure of tilapia pituitary cells to saponins: insight into their mechanism of action

Cell permeation and durable effects of triterpenoidal saponin preparations from soybean (SbS), Quillaja saponaria Molina (QsS) and Gypsophila paniculata (GypS), were studied. A concentration-dependent change in hemolysis rates was observed when cells were incubated with QsS or GypS, but not with SbS. Dose dependence was also observed for the leakage of lactate dehydrogenase (LDH; MW 142,000) and of Luteinizing Hormone (LH; MW 35,000) from tilapia pituitary dispersed cells. Exposure of pituitary fragments to a combination of GnRH and GypS or QsS, resulted in a significantly high release of LH. GypS were shown to be more potent in inducing hemolysis of human RBC's and LH release from tilapia pituitary fragments. Interestingly, tilapia pituitary fragments treated with QsS were able to secrete LH in a characteristic manner, in response to a second Gonadotropin Releasing Hormone (GnRH) pulse, while fragments exposed to GypS did not respond to the second hormone pulse. The rapid recovery of pituitary fragments after the removal of QsS, may suggest a rearrangement of membranes rather than pore formation as the mechanism of action of QsS. Understanding the structural features underlying the reversible rearrangement of membranes and the lack of hemolysing activity by specific saponins may lead to the development of novel bioactive drugs.

Hypocholesterolemic property ofYucca schidigera andQuillaja saponaria extracts in human body

This study was undertaken to observe the effects of the blend of partially purified Yucca schidigera and Quillaja saponaria extracts on cholesterol levels in the human's blood and gastrointestinal functions, and to determine if a new cholesterol-lowering drug can be developed by the further purification of the extracts. Ultrafiltration and sequential diafiltration increased the amounts of steroidal saponin in aqueous yucca extract and terpenoid saponin in aqueous quillaja extract from 9.3% and 21.4% to 17.2% and 61.8%, respectively. Taking 0.9 mg of the blend (6:4, v:v) of the resulting filtrates a day for 4 weeks resulted in the decreases in total and LDL cholesterol levels in blood plasma of hyper-cholesterolemic patients with enhancement in gastrointestinal symptoms of patients.

Effects of long term feeding of Quillaja saponins on sex ratio, muscle and serum cholesterol and LH levels in Nile tilapia (Oreochromis niloticus (L))

Seventeen-day-old Nile tilapia fry were fed a standard diet (C) or diets containing 50-700 mg kg(-1) Quillaja saponin (QS) extract (groups S50, S150, S300, S500 and S700). After the first 8 weeks, 30 randomly selected tilapia from each of the treatments were placed in separate aquaria and fed the standard diet without saponins from then on (these were designated S50/C, S150/C, S300/C, S500/C and S700/C). The fish grew from an initial average weight of approximately 30 mg to a final average weight of 79 g during the 6-month feeding period. The difference between the average weight of C-fed tilapia and the treatment with the highest average weight after 6 months was 53.5%. The sex ratio of tilapia in the saponin-fed groups deviated from the normal 50:50 male:female ratio, with the S700 group showing a significantly higher number of males. Quillaja saponin stimulated LH release from dispersed tilapia pituitary cells in vitro. This effect was abolished in the presence of dilute calf serum. Serum LH values did not show any diet-dependent trend in either male or female tilapia in vivo. In both continuously saponin-fed and only-initially saponin-fed groups, the average serum (but not muscle) cholesterol levels in males showed an increasing trend (R(2) values of 0.62 and 0.69) with increasing dietary saponin level. It was concluded that dietary QS has the potential to change the sex-ratio in favour of males. More investigations are required to determine the mechanism of action and the optimum dietary level of QS for maximum effects.

Enhancement of intestinal model compound transport by DS-1, a modified Quillaja saponin

DS-1, a modified Quillaja saponin, has recently been shown to promote the absorption of insulin and aminoglycoside antibiotics via the ocular and nasal route. The purpose of this study is to investigate the effect of DS-1 on intestinal permeability, the mechanism of its action, and reversibility of the effect. The permeation-enhancing activity of DS-1 was evaluated in cultured monolayers of the Caco-2 intestinal epithelial cells by examining its effect on the transepithelial electric resistance (TEER) and on transport of mannitol and a model D-decapeptide. Mucosal addition of DS-1 promptly reduced the TEER of the Caco-2 monolayers, and a propensity of recovery of the TEER was observed upon its removal. DS-1 added at 0.01-0.1% (w/v) increased the transports of both mannitol and D-decapeptide in a dose-dependent manner; a relatively "flat" concentration-dependence was seen at 0.1-0.2%. Visualization studies conducted by confocal laser scanning microscopy (CLSM) seem to suggest that DS-1 enhances the Caco-2 permeability mainly via a transcellular route. Histological examination failed to reveal noticeable morphological alterations in the cell monolayers pretreated with DS-1. The integrity of the Caco-2 monolayers, as assessed by their permeability to mannitol, was found to be recoverable following the mucosal pretreatment of DS-1. These results suggest that DS-1 is an efficacious intestinal permeation-enhancing agent with low adverse effect on the epithelial viability and barrier function.

QS-21 and QS-7: purified saponin adjuvants

QS-21 and QS-7 are two adjuvant-active saponins that can be obtained in high purity from Quillaja saponaria Molina extracts. QS-21 is a highly characterized compound and is known to be a potent adjuvant for antibody and CD8+ CTL response to subunit antigens. Less is known about the activity and structure of the hydrophilic saponin QS-7. Hence, we have carried out a detailed structural and immunological characterization. As with QS-21, QS-7 was shown to be a 3,28-O-bisglycoside quillaic acid, with some differences being a higher degree of glycosylation and a considerably shorter fatty acyl unit in QS-7. These differences were correlated to a lower lytic activity against sheep red blood cells. Different doses of QS-7 were evaluated for stimulation of immune response to the antigen ovalbumin, given three times by subcutaneous route to C57BL/6 mice. QS-7 doses of 40 micrograms or higher were shown to induce a strong CD8+ CTL response reproducibly against E. G7-OVA targets (similar to that induced by a 5-10 micrograms dose of QS-21). QS-7 (at doses above 5 micrograms) was also shown to stimulate CTL against peptide 18 of HIV-1IIIB gp120 after three immunizations of Balb/c mice with recombinant gp120 and different doses of QS-7. These data suggest that a hydrophilic saponin with low lytic activity can stimulate MHC Class I CTL responses although a higher minimum dose may be required for some antigens.

Isolation and quantification of Quillaja saponaria Molina saponins and lipids in iscom-matrix and iscoms

In the iscom, multiple copies of antigen are attached by hydrophobic interaction to a matrix which is built up by Quillaja triterpenoid saponins and lipids. Thus, the iscom presents antigen in multimeric form in a small particle with a built-in adjuvant resulting in a highly immunogenic antigen formulation. We have designed a chloroform-methanol-water extraction procedure to isolate the triterpenoid saponins and lipids incorporated into iscom-matrix and iscoms. The triterpenoids in the triterpenoid phase were quantitated using orcinol sulfuric acid detecting their carbohydrate chains and by HPLC. The cholesterol and phosphatidylcholine in the lipid phase were quantitated by HPLC and a commercial colorimetric method for the cholesterol. The quantitative methods showed an almost total separation and recovery of triterpenoids and lipids in their respective phases, while protein was detected in all phases after extraction. The protein content was determined by the method of Lowry and by amino acid analysis. Amino acid analysis was shown to be the reliable method of the two to quantitate proteins in iscoms. In conclusion, simple, reproducible and efficient procedures have been designed to isolate and quantitate the triterpenoids and lipids added for preparation of iscom-matrix and iscoms. The procedures described should also be useful to adequately define constituents in prospective vaccines.

DS-1, a modified Quillaja saponin, enhances ocular and nasal absorption of insulin

The purpose of this study was to test DS-1, a modified Quillaja saponin, for its efficacy as an absorption enhancer. Anesthetized rats receiving eyedrops or nosedrops formulated with regular pork insulin in saline showed no hypoglycemic response, indicating no systemic absorption of insulin. However, rats receiving eyedrops or nosedrops formulated with insulin plus 0.025-0.10% DS-1 showed rapid absorption of insulin and a concomitant decrease in serum D-glucose levels. No response was observed following sublingual or buccal delivery of insulin. In conclusion, the modified saponin DS-1 was efficacious at enhancing nasal or ocular insulin delivery at extremely low concentrations. The mechanism of DS-1 action is not yet known.

An in vitro study of immunomodulatory effects of some saponins

The in vitro immunomodulatory activities of a number of saponins (crude Quillaja saponin, Quillayanin, Quil-A and glycyrrhizic acid) are described. Addition of these saponin preparations to mouse spleen cell cultures resulted in significant cell proliferation. B-cells were induced to proliferate in the presence of the crude saponin, and T-cells in the presence of Quil-A. On the other hand, Quillayanin and glycyrrhizic acid stimulated both T- and B-lymphocytes equally. The selective proliferation of subtypes of lymphocytes correlated with restimulation responses by polyclonal mitogens. Pretreatment by lymphocytes with crude saponins induced significant T-cell responses to PHA and Con A, and to T-independent B-cell stimulation by LPS. Pulse exposure of spleen cells to Quil-A resulted in enhanced cell proliferation when restimulated with PHA, Con A and PWM. In comparison, similar exposure of lymphocytes to Quillayanin or glycyrrhizic acid produced markedly increased responses to PHA, Con A, PWM and LPS. Incubation of lymphocytes in the presence of Quillaja saponins and Quillayanin caused effector cell generation as determined in a one-way mixed lymphocyte reaction. In the case of lymphocytes cultured in the presence of crude saponins or glycyrrhizic acid, the supernatants contained active soluble factors. This was demonstrated by the observation that the addition of supernatants to spleen cell cultures induced spontaneous cell proliferation, and also amplified their responses to a suboptimal dose of PHA. The experimental data suggest that different components in the Quillaja saponin preparations may have selective effects on various subtypes of cell populations. Glycyrrhizic acid has the most profound immunomodulatory activity in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)