Isolation and evaluation of immunological adjuvant activities of saponins from Polygala senega L

Isolation, purification and structure elucidation of eight saponin compounds from Calotropis gigantea

Identifying the active ingredient from plant extracts and establishing its safety and efficacy remains a challenge, so there is need to develop optimised Isolation and purification method to concentrate the natural product from plant resources. In the key content areas of Pharmaceutical, natural product Industry and food application. Asclepiadaceae perennial herb Calotropis gigantea has a long history of usage in folk medicine. The purpose of this study to isolate, purified and structure elucidation of the saponin compounds. As per the Literature study reported that, the saponin compounds remain a huge source for medicinal, are rich sources of chemical compounds having tremendous diversity with respect to structure, function and mechanism of action. In this study we selected Calotropis gigantea for the separation of the saponin. In the present study we successfully isolated, purified, elucidated the structure and identified the saponin compounds using HPLC and HR LC-MS techniques.

Improved quantitative analysis of tenuifolin using hydrolytic continuous-flow system to build prediction models for its content based on near-infrared spectroscopy

This study used two types of analyses and statistical calculations on powdered samples of Polygala root (PR) and Senega root (SR): (1) determination of saponin content by an independently developed quantitative analysis of tenuifolin content using a flow reactor, and (2) near-infrared spectroscopy (NIR) using crude drug powders as direct samples for metabolic profiling. Furthermore, a prediction model for tenuifolin content was developed and validated using multivariate analysis based on the results of (1) and (2). The goal of this study was to develop a rapid analytical method utilizing the saponin content and explore the possibility of quality control through a wide-area survey of crude drugs using NIR spectroscopy. Consequently, various parameters and appropriate wavelengths were examined in the regression analysis, and a model with a reasonable contribution rate and prediction accuracy was successfully developed. In this case, the wavenumber contributing to the model was consistent with that of tenuifolin, confirming that this model was based on saponin content. In this series of analyses, we have succeeded in developing a model that can quickly estimate saponin content without post-processing and have demonstrated a brief way to perform quality control of crude drugs in the clinical field and on the market.

Paris polyphylla Sm. Induces Reactive Oxygen Species and Caspase 3-Mediated Apoptosis in Colorectal Cancer Cells In Vitro and Potentiates the Therapeutic Significance of Fluorouracil and Cisplatin

Paris polyphylla Sm. (Melanthiaceae) is an essential, vulnerable herb with a wide range of traditional applications ranging from fever to cancer in various communities. The use of P. polyphylla in India is limited to traditional healers. Here, we demonstrated that P. polyphylla extract (PPE) has good phenol, flavonoid, saponin, and steroidal saponin content and anti-oxidant activity with IC₅₀ 35.12 ± 6.1 μg/mL in DPPH and 19.69 ± 6.7 μg/mL in ABTS. Furthermore, PPE induces cytotoxicity in HCT-116 with IC₅₀ 8.72 ± 0.71 μg/mL without significant cytotoxicity inthe normal human colon epithelial cell line, CCD 841 CoN. PPE inhibits the metastatic property and induces apoptosis in HCT-116, as measured by Annexin V/PI, by increasing the production of reactive oxygen species (ROS) and caspase 3 activation. PPE acts synergistically with 5FU and cisplatin in HCT-116 and potentiates their therapeutic significance. Steroidal saponins with anticancer activities were detected in PPE by HR-LCMS. The present study demonstrated that PPE induces apoptosis by increasing ROS and activating caspase 3, which was attributed to steroidal saponins. PPE can be used as a potential natural remedy for colon cancer.

Screening for Astragalus hamosus Triterpenoid Saponins Using HPTLC Methods: Prior Identification of Azukisaponin Isomers

Due to their particular structural characteristics, the extraction and isolation of saponins from plants present a serious challenge. In this study, specific extraction protocols were first implemented to extract the secondary metabolites from Astragalus hamosus and, more precisely, the saponins. Subsequent purification of the extracts was based on a single chromatographic technique, high-performance thin-layer chromatography, applying two development systems: a one-step system that separated molecules according to their polarity and a multiple development system that made it possible to detect the triterpenoid saponins, azukisaponin or soyasapogenol at a retarded Rf of 0.2. The difficulties of detecting the Astragalus hamosus saponins encountered during the extraction and purification of the extracts have been highlighted and the strategy carried out to isolate the saponins has been discussed.

Machine Learning-Assisted Screening of Herbal Medicine Extracts as Vaccine Adjuvants

Adjuvants are important vaccine components, composed of a variety of chemical and biological materials that enhance the vaccine antigen-specific immune responses by stimulating the innate immune cells in both direct and indirect manners to produce a variety cytokines, chemokines, and growth factors. It has been developed by empirical methods for decades and considered difficult to choose a single screening method for an ideal vaccine adjuvant, due to their diverse biochemical characteristics, complex mechanisms of, and species specificity for their adjuvanticity. We therefore established a robust adjuvant screening strategy by combining multiparametric analysis of adjuvanticity in vivo and immunological profiles in vitro (such as cytokines, chemokines, and growth factor secretion) of various library compounds derived from hot-water extracts of herbal medicines, together with their diverse distribution of nano-sized physical particle properties with a machine learning algorithm. By combining multiparametric analysis with a machine learning algorithm such as rCCA, sparse-PLS, and DIABLO, we identified that human G-CSF and mouse RANTES, produced upon adjuvant stimulation in vitro, are the most robust biological parameters that can predict the adjuvanticity of various library compounds. Notably, we revealed a certain nano-sized particle population that functioned as an independent negative parameter to adjuvanticity. Finally, we proved that the two-step strategy pairing the negative and positive parameters significantly improved the efficacy of screening and a screening strategy applying principal component analysis using the identified parameters. These novel parameters we identified for adjuvant screening by machine learning with multiple biological and physical parameters may provide new insights into the future development of effective and safe adjuvants for human use.

Isolation, Characterization and In Silico Studies of Secondary Metabolites from the Whole Plant of Polygala inexpectata Peşmen & Erik

Polygala species are frequently used worldwide in the treatment of various diseases, such as inflammatory and autoimmune disorders as well as metabolic and neurodegenerative diseases, due to the large number of secondary metabolites they contain. The present study was performed on Polygala inexpectata, which is a narrow endemic species for the flora of Turkey, and resulted in the isolation of nine known compounds, 6,3'-disinapoyl-sucrose (1), 6-O-sinapoyl,3'-O-trimethoxy-cinnamoyl-sucrose (tenuifoliside C) (2), 3'-O-(O-methyl-feruloyl)-sucrose (3), 3'-O-(sinapoyl)-sucrose (4), 3'-O-trimethoxy-cinnamoyl-sucrose (glomeratose) (5), 3'-O-feruloyl-sucrose (sibiricose A5) (6), sinapyl alcohol 4-O-glucoside (syringin or eleutheroside B) (7), liriodendrin (8), and 7,4'-di-O-methylquercetin-3-O-β-rutinoside (ombuin 3-O-rutinoside or ombuoside) (9). The structures of the compounds were determined by the spectroscopic methods including 1D-NMR (¹H NMR, ¹³C NMR, DEPT-135), 2D-NMR (COSY, NOESY, HSQC, HMBC), and HRMS. The isolated compounds were shown in an in silico setting to be accommodated well within the inhibitor-binding pockets of myeloperoxidase and inducible nitric oxide synthase and anchored mainly through hydrogen-bonding interactions and π-effects. It is therefore plausible to suggest that the previously established anti-inflammatory properties of some Polygala-derived phytochemicals may be due, in part, to the modulation of pro-inflammatory enzyme activities.

Elucidation of Antioxidant Compounds in Moroccan Chamaerops humilis L. Fruits by GC-MS and HPLC-MS Techniques

The aim of this study was to characterize the phytochemical content as well as the antioxidant ability of the Moroccan species Chamaerops humilis L. Besides crude ethanolic extract, two extracts obtained by sonication using two solvents with increased polarity, namely ethyl acetate (EtOAc) and methanol-water (MeOH-H₂O) 80:20 (v/v), were investigated by both spectroscopy and chromatography methods. Between the two extracts, the MeOH-H₂O one showed the highest total polyphenolic content equal to 32.7 ± 0.1 mg GAE/g DM with respect to the EtOAc extract (3.6 ± 0.5 mg GAE/g DM). Concerning the antioxidant activity of the two extracts, the EtOAc one yielded the highest value (1.9 ± 0.1 mg/mL) with respect to MeOH-H2O (0.4 ± 0.1 mg/mL). The C. humilisn-hexane fraction, analyzed by GC–MS, exhibited 69 compounds belonging to different chemical classes, with n-Hexadecanoic acid as a major compound (21.75%), whereas the polyphenolic profile, elucidated by HPLC–PDA/MS, led to the identification of a total of sixteen and thirteen different compounds in both EtOAc (major component: ferulic acid: 104.7 ± 2.52 µg/g) and MeOH-H₂O extracts (major component: chlorogenic acid: 45.4 ± 1.59 µg/g), respectively. The attained results clearly highlight the potential of C. humilis as an important source of bioactive components, making it a valuable candidate to be advantageously added to the daily diet. Furthermore, this study provides the scientific basis for the exploitation of the Doum in the food, pharmaceutical and nutraceutical industries.

Saponin toxicity as key player in plant defense against pathogens

Microbial pathogens attack every plant tissue, including leaves, roots, shoots, and flowers during all growth stages. Thus, they cause several diseases resulting in a plant's failure or loss of the whole crop in severe cases. To combat the pathogens attack, plants produce some biologically active toxic compounds known as saponins. The saponins are secondary metabolic compounds produced in healthy plants with potential anti-pathogenic activity and serve as potential chemical barriers against pathogens. Saponins are classified into two major groups the steroidal and terpenoid saponins. Here, we reported the significance of saponin toxins in the war against insect pests, fungal, and bacterial pathogens. Saponins are present in both cultivated (chilies, spinach, soybean, quinoa, onion, oat, tea, etc.) and wild plant species. As they are natural toxic constituents of plant defense, breeders and plant researchers aiming to boost plant imm unity should focus on transferring these compounds in cash crops.

Saponins: Extraction, bio-medicinal properties and way forward to anti-viral representatives

Medicinal or herbal plants are widely used for their many favourable properties and are generally safe without any side effects. Saponins are sugar conjugated natural compounds which possess a multitude of biological activities such as medicinal properties, antimicrobial activity, antiviral activity, etc. Saponin production is a part of the normal growth and development process in a lot of plants and plant extracts such as liquorice and ginseng which are exploited as potential drug sources. Herbal compounds have shown a great potential against a wide variety of infectious agents, including viruses such as the SARS-CoV; these are all-natural products and do not show any adverse side effects. This article reviews the various aspects of saponin biosynthesis and extraction, the need for their integration into more mainstream medicinal therapies and how they could be potentially useful in treating viral diseases such as COVID-19, HIV, HSV, rotavirus etc. The literature presents a close review on the saponin efficacy in targeting mentioned viral diseases that occupy a high mortality rate worldwide. This manuscript indicates the role of saponins as a source of dynamic plant based anti-viral remedies and their various methods for extraction from different sources.

Phenolic Profile and Bioactive Potential of Stems and Seed Kernels of Sweet Cherry Fruit

Every year, large quantities of stems and pits are generated during sweet cherry processing, without any substantial use. Although stems are widely recognized by traditional medicine, detailed and feasible information about their bioactive composition or biological value is still scarce, as well as the characterization of kernels. Therefore, we conducted a study in which bioactivity potential of extracts from stems and kernels of four sweet cherry cultivars (Early Bigi (grown under net cover (C) and without net cover (NC)), Burlat, Lapins, and Van) were examined. The assays included antioxidant (by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic) acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and β-carotene-linoleic acid bleaching assays), and antibacterial activities against important Gram negative and Gram positive bacterial human isolates. Profile and individual phenolic composition of each extract were determined by High-performance liquid chromatography (HPLC) analysis. Extracts from stems of cv. Lapins and kernels of Early Bigi NC presented high levels of total phenolics, flavonoids, ortho-diphenols and saponins. Excepting for cv. Early Bigi NC, major phenolic compounds identified in stems and kernels were sakuranetin and catechin, respectively. In cv. Early Bigi NC the most abundant compounds were ellagic acid for stems and protocatechuic acid for kernels. In all extracts, antioxidant activities showed a positive correlation with the increments in phenolic compounds. Antimicrobial activity assays showed that only stem’s extracts were capable of inhibiting the growth of Gram positive isolates. This new data is intended to provide new possibilities of valorization of these by-products and their valuable properties.

Exploring the possible use of saponin adjuvants in COVID-19 vaccine

There is an urgent need for a safe, efficacious, and cost-effective vaccine for the coronavirus disease 2019 (COVID-19) pandemic caused by novel coronavirus strain, severe acute respiratory syndrome-2 (SARS-CoV-2). The protective immunity of certain types of vaccines can be enhanced by the addition of adjuvants. Many diverse classes of compounds have been identified as adjuvants, including mineral salts, microbial products, emulsions, saponins, cytokines, polymers, microparticles, and liposomes. Several saponins have been shown to stimulate both the Th1-type immune response and the production of cytotoxic T lymphocytes against endogenous antigens, making them very useful for subunit vaccines, especially those for intracellular pathogens. In this review, we discuss the structural characteristics, mechanisms of action, structure-activity relationship of saponins, biological activities, and use of saponins in various viral vaccines and their applicability to a SARS-CoV-2 vaccine.

An enquiry into antileishmanial activity and quantitative analysis of polyhydroxylated steroidal saponins from Solanum paniculatum L. leaves

Solanum paniculatum L. is species whose fruits are widely consumed in Brazil as a tonic beverage with higher content of steroidal saponins. In this work, we developed an analytical method for the quantification of the eight saponins present in the 70 % ethanol extract from the leaves using ultra-high-performance liquid chromatography coupled to mass spectrometry (UHPLC-MS). Besides, the eight spirostanic saponins were screened for in vitro antileishmanial activity against promastigote and amastigote forms of Leishmania (L.) amazonensis. Substances 1, 2 and 3 were found to be the most active compounds, with inhibitory concentration (IC₅₀) values of 8.51 ± 4.38, 10.75 ± 6.85 and 10.45 ± 4.21 μM, respectively, against promastigote forms and effective concentration (EC₅₀) values of >25, 17.73 ± 0.99 and 19.57 ± 0.84 μM, respectively, against amastigote forms. The cytotoxic test with compounds 1-3 evidenced low toxicity in murine macrophage cells, with values above 50 μM at concentration lower than 25 μM. These findings show that saponins 1-3 should be evaluated in further studies for the treatment of cutaneous leishmaniasis.

Enhancing the Membranolytic Activity of Chenopodium quinoa Saponins by Fast Microwave Hydrolysis

Saponins are plant secondary metabolites. There are associated with defensive roles due to their cytotoxicity and are active against microorganisms. Saponins are frequently targeted to develop efficient drugs. Plant biomass containing saponins deserves sustained interest to develop high-added value applications. A key issue when considering the use of saponins for human healthcare is their toxicity that must be modulated before envisaging any biomedical application. This can only go through understanding the saponin-membrane interactions. Quinoa is abundantly consumed worldwide, but the quinoa husk is discarded due to its astringent taste associated with its saponin content. Here, we focus on the saponins of the quinoa husk extract (QE). We qualitatively and quantitively characterized the QE saponins using mass spectrometry. They are bidesmosidic molecules, with two oligosaccharidic chains appended on the aglycone with two different linkages; a glycosidic bond and an ester function. The latter can be hydrolyzed to prepare monodesmosidic molecules. The microwave-assisted hydrolysis reaction was optimized to produce monodesmosidic saponins. The membranolytic activity of the saponins was assayed based on their hemolytic activity that was shown to be drastically increased upon hydrolysis. In silico investigations confirmed that the monodesmosidic saponins interact preferentially with a model phospholipid bilayer, explaining the measured increased hemolytic activity.

Recent Advances in Biotransformation of Saponins

Saponins are a class of glycosides whose aglycones can be either triterpenes or helical spirostanes. It is commonly recognized that these active ingredients are widely found in various kinds of advanced plants. Rare saponins, a special type of the saponins class, are able to enhance bidirectional immune regulation and memory, and have anti-lipid oxidation, anticancer, and antifatigue capabilities, but they are infrequent in nature. Moreover, the in vivo absorption rate of saponins is exceedingly low, which restricts their functions. Under such circumstances, the biotransformation of these ingredients from normal saponins—which are not be easily adsorbed by human bodies—is preferred nowadays. This process has multiple advantages, including strong specificity, mild conditions, and fewer byproducts. In this paper, the biotransformation of natural saponins—such as ginsenoside, gypenoside, glycyrrhizin, saikosaponin, dioscin, timosaponin, astragaloside and ardipusilloside—through microorganisms (Aspergillus sp., lactic acid bacteria, bacilli, and intestinal microbes) will be reviewed and prospected.

Discrimination of geographical origin of cultivated Polygala tenuifolia based on multi-element fingerprinting by inductively coupled plasma mass spectrometry

Inorganic elements are important components of medicinal herbs, and provide valuable experimental evidence for the quality evaluation and control of traditional Chinese medicine (TCM). In this study, to investigate the relationship between the inorganic elemental fingerprint and geographical origin identification of cultivated Polygala tenuifolia, 41 elemental fingerprints of P. tenuifolia from four major polygala-producing regions (Shanxi, Hebei, Henan, and Shaanxi) were evaluated to determine the importance of inorganic elements to cultivated P. tenuifolia. A total of 15 elemental (B, Ca, Cl, Cu, Fe, K, Mg, Mn, Na, N, Mo, S, Sr, P, and Zn) concentrations of cultivated P. tenuifolia were measured using inductively coupled plasma mass spectroscopy (ICP-MS). The element composition samples were classified by radar plot, elemental fingerprint, and multivariate data analyses, such as hierarchical cluster analysis (HCA), principle component analysis (PCA), and discriminant analysis (DA). This study shows that radar plots and multivariate data analysis can satisfactorily distinguish the geographical origin of cultivated P. tenuifolia. Furthermore, PCA results revealed that N, Cu, K, Mo, Sr, Ca, and Zn are the characteristic elements of cultivated P. tenuifolia. Therefore, multi-element fingerprinting coupled with multivariate statistical techniques can be considered an effective tool to discriminate geographical origin of cultivated P. tenuifolia.

Search for Anti-angiogenic Substances from Natural Sources

As angiogenesis is critical for tumor growth and metastasis, potent and selective anti-angiogenic agents with novel modes of action are highly needed for anti-cancer drug discovery. In this review, our studies focusing on the search for anti-angiogenic substances from natural sources, such as bastadins, globostellatic acid X methyl esters and cortistatins from marine sponges, and pyripyropenes from marine-derived fungus, together with senegasaponins from medicinal plant, are summarized.

The antibacterial, phytochemicals and antioxidants evaluation of the root extracts of Hydnora africanaThunb. used as antidysenteric in Eastern Cape Province, South Africa

Background

To determine the anti-dysenteric, phytochemicals and antioxidative properties of the root extracts of Hydnora africana. The use of plants for the treatment of dysentery and other diseases in traditional medicine has increased on the basis of these rich traditional medicine systems. Series of pharmacological tests are recommended since the aetiology of many diseases may be due to more than one factor.

Methods

The agar well diffusion method was used to determine the susceptibility of bacterial strains to crude extracts of the plant. The minimum inhibitory concentration was determined by the microdilution test. The presence of phytochemicals and antioxidant was also assessed using standard methods.

Results

The antimicrobial activity of H. africana against all the tested organisms demonstrated a mean zone diameter of inhibition ranging from 0 to 25 mm. The MIC of the extracts ranged from 0.071 to 5.0 mg/mL. Antioxidant activity showed lower ferric reducing activities, moderate nitric oxide, moderate DPPH and higher ABTS scavenging activities of the plant. Phytochemical assay revealed the presence and equivalent quantity of alkaloids, tannins, flavonoids, saponins and phenolic acid in the extracts. The water and methanol extracts were also shown as the best solvents of extraction for the phytochemicals.

Conclusions

The methanol and acetone extracts of H. africana exhibited a significant antibacterial and antioxidant activities, suggesting the presence of either good bioactive potency or the high concentration of the active principle in the extracts which may serve as a guide for selecting bio- medicinal substances of plant origin in antidysenteric drugs.

A polysaccharide isolated from Agaricus blazei Murill (ABP-AW1) as a potential Th1 immunity-stimulating adjuvant

In the present study, a low molecular weight polysaccharide, ABP-AW1, isolated from Agaricus blazei Murill was assessed for its potential adjuvant activity. ABP-AW1 is considered to create a ‘depot’ of antigen at a subcutaneous injection site. ICR mice were immunized with 100 μg ovalbumin (OVA) alone or with 100 μg OVA formulated in 0.9% saline containing 200 μg aluminum (alum) or ABP-AW1 (50, 100 and 200 μg) on days 1 and 15. Two weeks after the secondary immunization, splenocyte proliferation, the expression of surface markers, cytokine production and the OVA-specific antibody levels in the serum were determined. The OVA/ABP-AW1 vaccine, in comparison with OVA alone, markedly increased the proliferation of splenic lymphocytes and elicited greater antigen-specific CD4⁺ T cell activation, as determined by splenic CD4⁺CD69⁺ T cells and Th1 cytokine interferon (IFN)-γ release. The combination of ABP-AW1 and OVA also enhanced IgG2b antibody responses to OVA. In conclusion, these data indicated that ABP-AW1 significantly enhanced the humoral and cellular immune responses against OVA in the mice, suggesting that ABP-AW1 stimulated Th1-type immunity. We suggest that ABP-AW1 may serve as a new adjuvant.

Antimicrobial activity of saponin-rich fraction from Camellia oleifera cake and its effect on cell viability of mouse macrophage RAW 264.7

BACKGROUND

As a by-product of oil production, several million tons of Camellia oleifera cake is discarded every year in China. The aim of this study was to evaluate the antimicrobial activity of a saponin-rich fraction isolated from C. oleifera cake and investigate its effect on the cell viability of RAW 264.7, a macrophage-like cell line present in almost all mouse tissues.

RESULTS

The saponin-rich fraction was isolated from C. oleifera cake in several steps and had a saponin content of 95.42 ± 0.10% (w/w). It showed significant inhibitory activity against the bacteria Staphylococcus aureus, Escherichia coli and Bacillus subtilis and the fungi Mucor racemosus, Aspergillus oryzae, Rhizopus stolonifer, Saccharomyces cerevisiae and Penicillium glaucum, with minimum inhibitory concentrations of 31.3, 31.3, 62.5, 250, 250, 250, 31.3 and 125 µg ml(-1) respectively. In addition, mouse macrophage RAW 264.7 pretreated with the saponin-rich fraction (80-200 µg mL(-1) ) exhibited a significant loss of cell viability in a dose-dependent manner.

CONCLUSION

These results may be useful for the future application of saponins from C. oleifera cake. However, the potential use of the saponin-rich fraction as an antimicrobial agent should be decided according to the target micro-organisms in order to avoid causing harm in humans.

Anti-angiogenic effect of triterpenoidal saponins from Polygala senega

Senegasaponins [senegin II (1), senegin III (2), senegin IV (3), senegasaponin a (4), and senegasaponin b (5)] from Polygala senega were re-discovered as selective anti-proliferative substances against human umbilical vein endothelial cells (HUVECs). Senegasaponins (1-5) showed anti-proliferative activity against HUVECs with IC(50) values in the range 0.6-6.2 μM, and the selective index was 7-100-fold in comparison with those for several cancer cell lines, while the desacyl mixture of senegasaponins (6) and tenuifolin (7) lost anti-proliferative activity, indicating that the 28-O-glycoside moiety and methoxycinnamoyl group were essential for the HUVEC-selective growth inhibition of senegasaponins. Senegin III (2) inhibited the vascular endothelial growth factor (VEGF)-induced in vitro tubular formation of HUVECs and basic fibroblast growth factor (bFGF)-induced in vivo neovascularization in the mouse Matrigel plug assay. Moreover, senegin III (2) suppressed tumor growth in the ddY mice s.c.-inoculated murine sarcoma S180 cells. The analysis of the action mechanism of senegin III (2) suggested that the induction of pigment epithelium-derived factor (PEDF) would contribute to the anti-angiogenic effects of senegasaponins.

Phytochemical screening and polyphenolic antioxidant activity of aqueous crude leaf extract of Helichrysum pedunculatum

We evaluated the in vitro antioxidant property and phytochemical constituents of the aqueous crude leaf extract of Helichrysum pedunculatum. The scavenging activity on superoxide anions, DPPH, H₂O₂, NO and ABTS; and the reducing power were determined, as well as the flavonoid, proanthocyanidin and phenolic contents of the extract. The extract exhibited scavenging activity towards all radicals tested due to the presence of relatively high total phenol and flavonoids contents. Our findings suggest that H. pedunculatum is endowed with antioxidant phytochemicals and could serve as a base for future drugs.

Anti-inflammatory effect of Inonotus obliquus, Polygala senega L., and Viburnum trilobum in a cell screening assay

AIM OF THE STUDY

The purpose of the study was to assess the anti-inflammatory effects of the mushroom Inonotus obliquus (Chaga), Polygala senega (Senega) and Viburnum trilobum (Cranberry) bark extract fractions from locally produced materials in lipopolysaccharide (LPS) induced murine macrophage RAW 164.7 cells.

MATERIALS AND METHODS

Four fractions from each of the three extracts were obtained: (80% ethanol extracted; Fa), (water-soluble polysaccharide fraction; Fb), (Polyphenolic fraction; Fc) and (ETOAc/H(2)O extracted fraction; Fd). These extract fractions were tested in the cell screening system at 50,100 and 500 microg/ml for their ability to inhibit LPS induced inflammatory cytokines IL-1beta, TNFalpha and IL-6. Supernatants from LPS alone treated cells were used as control. The cytokines in the cell culture supernatants following treatments with extract fractions were quantified by ELISA method, using 96 well ELISA plates.

RESULTS

All fractions of the extracts significantly inhibited (p<0.05) the levels of IL-1beta, IL-6 and TNFalpha except the polyphenolic Fc fraction of Senega which showed an increased production of IL-6. Furthermore, each fraction showed a dose-dependant anti-inflammatory effect. Nitric oxide production was not affected by cranberry and senega, while Chaga significantly reduced NO production in murine macrophage cell assay.

CONCLUSIONS

These results demonstrate that the extracts obtained from the root of Polygala senega L., bark of Viburnum trilobum, and the mushroom Inonotus obliquus possess anti-inflammatory properties when tested in a RAW 264.7 macrophage cell system.

Advances in saponin-based adjuvants

Saponins are natural glycosides of steroid or triterpene which exhibited many different biological and pharmacological activities. Notably, saponins can also activate the mammalian immune system, which have led to significant interest in their potential as vaccine adjuvants. The most widely used saponin-based adjuvants are Quil A and its derivatives QS-21, isolated from the bark of Quillaja saponaria Molina, which have been evaluated in numerous clinical trials. Their unique capacity to stimulate both the Th1 immune response and the production of cytotoxic T-lymphocytes (CTLs) against exogenous antigens makes them ideal for use in subunit vaccines and vaccines directed against intracellular pathogens as well as for therapeutic cancer vaccines. However, Quillaja saponins have serious drawbacks such as high toxicity, undesirable haemolytic effect and instability in aqueous phase, which limits their use as adjuvant in vaccination. It has driven much research for saponin-based adjuvant from other kinds of natural products. This review will summarize the current advances concerning adjuvant effects of different kinds of saponins. The structure-activity relationship of saponin adjuvants will also be discussed in the light of recent findings. It is hoped that the information collated here will provide the reader with information regarding the adjuvant potential applications of saponins and stimulate further research into these compounds.

Immunostimulating complexes incorporating Eimeria tenella antigens and plant saponins as effective delivery system for coccidia vaccine immunization

Immunostimulating complexes (ISCOMs) are unique, multimolecular structures formed by encapsulating antigens, lipids, and triterpene saponins of plant origin, and are an effective delivery system for various kinds of antigens. The uses of ISCOMs formulated with saponins from plants collected in Kazakhstan, with antigens from the poultry coccidian parasite Eimeria tenella, were evaluated for their potential use in developing a vaccine for control of avian coccidiosis. Saponins isolated from the plants Aesculus hippocastanum and Glycyrrhiza glabra were partially purified by HPLC. The saponin fractions obtained from HPLC were evaluated for toxicity in chickens and chicken embryos. The HPLC saponin fractions with the least toxicity, compared to a commercial saponin Quil A, were used to assemble ISCOMs. When chicks were immunized with ISCOMs prepared with saponins from Kazakhstan plants and E. tenella antigens, and then challenged with E. tenella oocysts, significant protection was conveyed compared to immunization with antigen alone. The results of this study indicate that ISCOMs formulated with saponins isolated from plants indigenous to Kazakhstan are an effective antigen delivery system which may be successfully used, with low toxicity, for preparation of highly immunogenic coccidia vaccine.

A promising balanced Th1 and Th2 directing immunological adjuvant, saponins from the root of Platycodon grandiflorum

The haemolytic activities and adjuvant potentials of Platycodon grandiflorum saponin (PGS) and its fractions on the cellular and humoral immune responses of ICR mice against ovalbumin (OVA) were evaluated. PGS was subjected to silica gel column chromatography to afford four fractions, and two fractions PGSC and PGSD selected for testing for activities because of containing dominant saponin peaks. PGS, PGSC, and PGSD showed a slight haemolytic effect, with their HD50 value being 37.91+/-2.24, 21.30+/-1.22, 37.58+/-1.86 microg/ml against 0.5% rabbit red blood cell, respectively. ICR mice were immunized subcutaneously with OVA 100 microg alone or with OVA 100 microg dissolved in saline containing Alum (200 microg), Quil A (10 microg), PGS (50, 100 or 200 microg), PGSC, or PGSD (25, 50 or 100 microg) on days 1 and 15. Two weeks later (day 28), concanavalin A (Con A)-, pokeweed (PWM)-, and OVA-stimulated splenocyte proliferation and OVA-specific antibodies in serum were measured. PGS and PGSC significantly enhanced the Con A-, PWM-, and OVA-induced splenocyte proliferation in OVA-immunized mice at three doses (P<0.01 or P<0.001). However, no significant differences (P>0.05) were observed among the OVA group, OVA/Alum group and OVA/PGSD group. OVA-specific IgG, IgG1, and IgG2b antibody levels in serum were significantly enhanced by PGS, PGSC, and PGSD compared with OVA control group (P<0.05, P<0.01, or P<0.001). Moreover, the adjuvant effects of PGSC (50 or 100 microg) on the OVA-specific IgG, IgG1, and IgG2b antibody responses to OVA in mice were more significant than those of Alum. In conclusion, PGS seem to be a promising balanced Th1 and Th2 directing immunological adjuvants which can enhance the immunogenicity of vaccine.

Adjuvant activities of saponins from the root of Polygala senega L.This article is one of a selection of papers published in this special issue (part 2 of 2) on the Safety and Efficacy of Natural Health Products

Eight pure triterpenoid saponin compounds isolated from the root of Polygala senega L., a plant indigenous to the Canadian prairies, were evaluated for their immunological activity in mouse models. The specific antibody responses of the IgG2a subclass increased significantly when isolated P. senega saponins were used as adjuvants in the immunization of mice with OVA antigen. In addition, increased IL-2 levels were observed in spleen cell cultures from P. senega saponin-immunized mice after in vitro secondary antigen stimulation. The saponins were tested for their toxicity in mice by using a haemolytic activity assay and found to be less toxic than Quillaja saponaria saponins that have long been used as adjuvants in vaccine formulations. This study has shown the potential of P. senega saponins to be considered as a natural source of vaccine adjuvants with biological activity equivalent to the current commercially available saponin adjuvants.

Adjuvant effect of green propolis on humoral immune response of bovines immunized with bovine herpesvirus type 5

Despite recent technological advances in vaccine production, most vaccines depend on the association with adjuvant substances. In this study, propolis, which has been attracting the attention of researchers due to its bioactive properties, was evaluated as an immunological adjuvant. The association of 40mg/dose of an ethanolic extract of green propolis with an inactivated oil vaccine against bovine herpesvirus type 5 (BoHV-5), resulted in a significant increase (P<0.01) in the neutralizing antibody levels, comparing to the bovines that received the same vaccine without propolis. Besides, propolis increased the percentage of animals with high antibody titers (above 32). Phenolic compounds such as artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) and the derivatives of cinnamic acid besides other flavonoid substances were abundant in the propolis extract used, and they could be the main substances with adjuvant action. The effect of the green propolis extract on the humoral immune response can be exploited in the development of new vaccines.

Spermicidal activity of extract from Cestrum parqui

OBJECTIVE

The leaf extract of Cestrum parqui was examined for its effects on sperm motility in vitro.

METHODS

Washed sperm were prepared by discontinuous buoyant density gradient centrifugation and incubated with varying concentrations of extract from C. parqui (40-250 microg/mL) at 37 degrees C and 5% CO(2). Sperm motility and viability were assessed at different intervals ranging from 5 to 240 min. Morphological changes in human ejaculated spermatozoa after exposure to the extract were evaluated under transmission electron microscope.

RESULTS

A dose- and time-dependent effect of this extract on sperm motility and viability was observed. The maximal spermicidal effect was observed with a 250-microg/mL dose of the extract. Transmission electron microscope revealed a significant damage to sperm membrane in both head and acrosomal membranes, notable swelling and disruption.

CONCLUSION

The present study indicates that this natural extract has potential spermicidal effect in vitro.

Immunological adjuvant activities of saponin extracts from the pods of Acacia concinna

Pods of Acacia concinna (Leguminosae) contain several saponins. In this study, four saponin fractions which were acetone fraction (AAC), aqueous fraction (WAC), hydromethanolic fraction (HAC) and methanolic fraction (MAC) were generated and their haemolytic activities and surface activities were determined in comparison with quillaja saponin (QS). There were no significant differences between the haemolytic activities of MAC and QS. However, the surface tensions of MAC was significantly lower than QS (p < 0.001). Furthermore, the immunomodulatory effect and the adjuvant potential of MAC on the cellular and humoral immune response of BALB/c mice against ovalbumin were investigated. The splenocyte proliferations induced by MAC were significantly higher than QS at the concentrations of 200, 400, 800 and 1000 microg/ml (p < 0.05). BALB/c mice were immunized subcutaneously either with OVA 20 microg alone or with OVA 20 microg combining with QS (10 microg) or MAC (10 and 40 microg). Ten days after the second immunization, concanavalin A (Con A)-, pokeweed mitogen (PWM)-, and OVA-stimulated splenocyte proliferation and OVA-specific antibodies in serum were measured. The results suggested that MAC (40 microg) could activate T and B cells. In addition, OVA-specific IgG, IgG1 IgG2a and IgG2b antibody levels in serum were significantly enhanced by MAC (40 microg) as compared with OVA control group (p < 0.001). This finding suggested that MAC might be effect on Th1 and Th2 helper T cells. In conclusion, the results indicated that MAC at a dose of 40 microg could be used as vaccine adjuvant to increase immune responses.

Biological activities and distribution of plant saponins

Plant saponins are widely distributed amongst plants and have a wide range of biological properties. The more recent investigations and findings into their biological activities were summarized. Isolation studies of saponins were examined to determine which are the more commonly studied plant families and in which families saponins have been identified.

Mucosal AIDS vaccines

Debates are still being waged over what is the best strategy for developing a potent AIDS vaccine. All the obvious approaches to making AIDS vaccines have been tried in the past two decades without much success. It is clear that new thinking and a revision of prevailing dogmas needs to be in place if we really want a vaccine. Conventional envelope-based antibody-inducing vaccines do not appear to hold promise, and broadly-neutralizing antibodies are now being searched as an alternative to the failed approach with subunit vaccines. The current consensus is that cellular immune responses, especially those mediated by CD8 cytotoxic/suppressor (CTL) and CD4 helper T lymphocytes, are needed to control HIV. Vaccines capable of inducing cell-mediated responses are, therefore, considered critical for controlling the spread of HIV. DNA-based vaccines triggering CTL reaction are currently thought to be an answer, but will they fulfill the promise? In the following paragraphs, a critical assessment of the state of the art will be provided in an attempt to analyze what we know and still don't know. The focus of this review is primarily on mucosal vaccines-a relatively new area in AIDS research. The update on V-1 Immunitor, the first mucosal AIDS vaccine available commercially, is provided within this context. Some of the reviewed concepts may be disputable, but without departure from the uninspiring consensus no substantial progress in the AIDS vaccine field can be envisioned.