Effect of a Total Extract and Saponins from Astragalus glycyphyllos L. on Human Coronavirus Replication In Vitro

Members of the family Coronaviridae cause diseases in mammals, birds, and wildlife (bats), some of which may be transmissible to humans or specific to humans. In the human population, they can cause a wide range of diseases, mainly affecting the respiratory and digestive systems. In the scientific databases, there are huge numbers of research articles about the antiviral, antifungal, antibacterial, antiviral, and anthelmintic activities of medicinal herbs and crops with different ethnobotanical backgrounds. The subject of our research is the antiviral effect of isolated saponins, a purified saponin mixture, and a methanol extract of Astragalus glycyphyllos L. In the studies conducted for the cytotoxic effect of the substances, CC50 (cytotoxic concentration 50) and MTC (maximum tolerable concentration) were determined by the colorimetric method (MTT assay). The virus was cultured in the MDBK cell line. As a result of the experiments carried out on the influence of substances on viral replication (using MTT-based colorimetric assay for detection of human Coronavirus replication inhibition), it was found that the extract and the purified saponin mixture inhibited 100% viral replication. The calculated selective indices are about 13 and 18, respectively. The obtained results make them promising for a preparation with anti-Coronavirus action.

Cycloartane Saponins from Astragalus glycyphyllos and Their In Vitro Neuroprotective, Antioxidant, and hMAO-B-Inhibiting Effects

Astragalus glycyphyllos (Fabaceae) is used in the traditional medicine of many countries against hepatic and cardiac disorders. The plant contains mainly flavonoids and saponins. From a defatted methanol extract from its overground parts, a new triterpenoid saponin, 3-O-[α-L-rhamnopyranosyl-(1→2)]-β-D-xylopyranosyl]-24-O-α-L-arabinopyranosyl-3β,6α,16β,24(R),25-pentahydroxy-20R-cycloartane, together with the rare saponin astrachrysoside A, were isolated using various chromatography methods. The compounds were identified via extensive high resolution electrospray ionisation mass spectrometry (HRESIMS) and NMR analyses. Both saponins were examined for their possible antioxidant and neuroprotective activity in three different in vitro models. Rat brain synaptosomes, mitochondria, and microsomes were isolated via centrifugation using Percoll gradient. They were treated with the compounds in three different concentrations alone, and in combination with 6-hydroxydopamine or tert-butyl hydroperoxide as toxic agents. It was found that the compounds had statistically significant dose-dependent in vitro protective activity on the sub-cellular fractions. The compounds exhibited a weak inhibitory effect on the enzyme activity of human recombinant monoamine oxidase type B (hMAO-B), compared to selegiline.

In Vitro/In Vivo Hepatoprotective and Antioxidant Effects of Defatted Extract and a Phenolic Fraction Obtained from Phlomis Tuberosa

An in vitro/in vivo hepatotoxicity and hepatoprotection evaluation of a defatted extract and a phenolic fraction from Phlomis tuberosa, administered alone and in a carbon tetrachloride (CCl₄)-induced metabolic bioactivation model, was performed. The extract and the phenolic fraction were analysed by high performance liquid chromatography (HPLC) to determine the total flavonoid content, to identify flavonoids and to quantify verbascoside. In addition, total polyphenolics in the samples were expressed as gallic acid equivalents. Applied alone, the extract and the fraction (5, 10 and 50 µg/mL) did not show a statistically significant hepatotoxic effect on isolated rat hepatocytes in vitro. In a CCl₄-induced hepatotoxicity model, the samples exhibited a concentration-dependent, statistically significant hepatoprotective effect, which was most pronounced at 50 µg/mL for both. The phenolic fraction exhibited a more pronounced hepatoprotective effect compared to the extract. Data from the in vitro study on the effects of the extract were also confirmed in the in vivo experiment conducted in a CCl₄-induced hepatotoxicity model in rats. A histopathological study showed that the animals treated with CCl₄ and the extract had an unaltered histoarchitecture of the liver. The effects of the extract were the same as those of silymarin.

Essential oil in Phlomis tuberosa

Phlomis tuberosa L. (Lamiaceae) is a flowering perennial plant, native to Eurasia, and sparsely distributed in Bulgaria. The species has been proved to accumulate flavonoids, iridoids, phenolic glycosides, as well as essential oil. To now, there is no information on the chemical content of Bulgarian essential oil from the plant. The aim was to study the chemical composition of essential oils, obtained from the species. Four different samples were studied – essential oils produced from leaves and herbs, collected in the fields, and from leaves and flowering parts, harvested from the mountainous location. It was found that β-copaene was the major in the essential oil from both the leaves and of the flowering parts collected from Popitza. In addition, the other major constituent in leaf essential oil from Kladnitza was tau-muurolol. The essential oil, produced from the species, harvested from the higher altitude had phytol as the main component. The sesquiterpenoid content in leaf essential oil suggests that this plant substance is appropriate for medicinal use, due to the pharmacological properties of these compounds.

In vitro effects of alcesefoliside and mauritianin, isolated from Astragalus monspessulanus subsp. monspessulanus, on the contractility of a. basilaris

Flavonoids are one of the most popular antioxidants in plants. Their varied pharmacological activities are important for these compounds in order to add and to complement conventional therapy. Alcesefoliside and mauritianin are rare flavonol triglycosides, isolated from the overground part of A. monspessulanus subsp. monspessulanus. The aim of the study was to examine the in vitro effects of the isolated flavonoids on the contractility of a. basilaris. Administered alone, at concentration 10 µM, alcesefoliside and mauritianin did not influence the vascular tone of segment of a. basilaris. The combination of both compounds, at 10 µM, revealed an increased response of the vascular tone of a. basilaris. These effects of the flavonoids suggest their possible beneficial effect as further candidates in the complex therapy of neurodegenerative disease.

In vitro production of flavonoids in cultures of Gypsophila glomerata

Effects of increased concentration of calcium chloride on growth and production of flavonoids in newly established shoot and callus Gypsophila glomerata cultures were studied. The highest impact of CaCl2 on the growth index was determined in callus cultures (GI = 0.92), while in shoot cultures calcium treatment reduced the amount of biomass (GI = 0.38). Total flavonoids in shoot cultures grown on MS medium and MS medium supplemented with double amount of CaCl2 were 0.36 mg/g d. w. In both callus cultures, 2 mg/g d. w. total flavonoids were quantified. Shoots and callus grown on non-modified media accumulated 0.02 mg/g d. w. quercetin derivatives. Unlike these, both shoots and callus grown on calcium-enriched media accumulated 0.03 and 0.05 mg/g d. w. of isorhamnetin derivatives. In vitro shoot cultures grown on MS medium enriched in twice the amount of CaCl2 accumulated the highest amount of saponarin (0.138 mg/mg d. w.).

Flavonoids in in vitro cultures of Astragalus hamosus

Astragalus hamosus contains valuable biologically active compounds, incl. flavonoids. The possibility for in vitro cultivation of the species as a source of important flavonoids was studied. Shoot and callus cultures were established and successfully cultivated on different nutrition media, complemented or not with growth regulators. An ultra-high performance liquid chromatography – high-resolution electrospray ionisation mass spectrometry (UHPLC-HRESIMS) qualitative and quantitative analysis of non-purified methanol extracts of these cultures was performed. It was found that the cultures produced rutin in comparable quantity. Interestingly, both shoots and callus cultures accumulated the rare triglycosides alcesefoliside and mauritianin. The quantity of mauritianin, biosynthesized in shoots, was significantly higher to that in callus cultures. Alcesefoliside, was in lower quantity, compared to mauritianin. In addition, callus cultures produced alcesefoliside trice as the shoots, besides their lower level of differentiation. These findings could serve as initial research to establish the value of in vitro cultures from A. hamosus as an alternative mean of production of pharmaceutically important flavonol glycosides.

A proteomic approach of the different environmental conditions of Listeria monocytogenes

 

Listeria monocytogenes is the ubiquitous food-borne pathogen which causes listeriosis, a disease with a high mortality rate, mostly transmitted through contaminated ready-to-eat foods. To better understand the systemic response of L. monocytogenes exposed at 3 environmental factors (T, pH and NaCl), the proteome of L. monocytogenes strain NRG 1749-2016, isolated from a meat product, was investigated to identify differences in the protein patterns of such pathogen. Four different conditions were carried out as follows: A) T 37 °C, pH 7.0, NaCl 0.5%; B) T 37 °C, pH 5.5, NaCl 7%; C) T 12° pH 7, NaCl 0.5%; D) T 12 °C, pH 5.5, NaCl 7%. The proteins belonging to cytosol (C1) and vesicles (C2) were isolated and purified by CelLytic B Cell Lysis Reagent and CelLytic IB Inclusion Body Solubilization Reagent according manufacturer's instructions. The analysis were conducted by SDS PAGE and Immunoblotting techniques. The protein concentrations were evaluated by Pierce BCA Protein Assay Kit. From preliminary results, the protein banding patterns generated by 1D SDS PAGE were found to be different at visual observation for C1 and C2, in A, B, C and D conditions. The presence of specific antigen-antibody immunocomplexes (Ag-Ab ICs) was identified by Immunoblotting, in C1 at 100, 60, 55, 35 and 25 kDa for all incubated conditions with a positive serum to L. monocytogenes. As regards C2, Ag-Ab ICs at 110 kDa were observed in A and B, Ag-Ab ICs at 80 kDa in C and D, Ag-Ab ICs at 60 kDa in A and D, while Ag-Ab ICs at 40 and 30 kDa in all conditions. The analysis of the proteome profiles shows an intra-strain variation in the protein patterns produced by L. monocytogenes during the adaptation at different environmental conditions. Further analysis will be carried out to better understand the systemic response of L. monocytogenes, in particular in order to characterize the immunogenic proteins highlighted by Immunoblotting and their role in the virulence expression of such pathogen.

Key messages

Understand how L. monocytogenes adapts physiologically to different environmental factors. Development of new detection method of L. monocytogenes and prevention strategies for listeriosis outbreaks.

Antiproliferative and antitumour activity of saponins from Astragalus glycyphyllos on myeloid Graffi tumour

ETHNOPHARMACOLOGICAL RELEVANCE

Astragalus glycyphyllos L. has been extensively used in Bulgarian folk medicine as an antihypertensive, diuretic, anti-inflammatory, anti-tumour, in cases of cardiac insufficiency, renal inflammation, calculosis, etc. AIM OF THE STUDY: To evaluate the possible in vitro/in vivo anti-proliferative/anti-tumour activity of a purified saponins' mixture (PSM) obtained from the plant.

MATERIALS AND METHODS

Viability and proliferative activity of the Graffi myeloid tumour cells was assessed by MTT test. The morphological alterations were visualized and analysed by fluorescent microscopy after intravital double staining. An in vivo model of Graffi tumour bearing hamsters was used to examine the influence of PSM on transplantability, tumour growth, survival and mortality as well as to observe pathomorphological changes.

RESULTS

Graffi tumour cells were sensitive to purified saponins' mixture after 24 and 48 h treatment. The treatment induced a statistically significant decrease of the viability/proliferation of the Graffi tumour cells. These effects were concentration- and time-dependent. Fluorescent microscopy studies showed that these antiproliferative effects were connected to the induction of apoptosis. The in vivo study showed the presence of a stromal component, single mononuclear cells in the stroma. Multiple incorrect mitotic figures were observed in the tumour tissue from the control group. Well-formed stroma with accumulation of mononuclear cells and mitotic cells were found in the group, treated with PSM. The tumour weight was decreased in the group, treated with PMS.

CONCLUSION

The results indicate that PSM exhibited in vitro/in vivo antiproliferative/anti-tumour effects.

Liquid chromatography – high resolution mass spectrometry screening of Astragalus hamosus and Astragalus corniculatus

Astragalus hamosus and Astragalus corniculatus were examined for the presence of flavoalkaloids, acylated and highly glycosylated flavonoids. Non-purified extracts of the overground parts of the species were subjected to ultra-high performance liquid chromatography – high resolution electrospray ionisation mass spectrometry (UHPLC-HRESIMS) analysis and the results were compared to authentic reference substances. A flavoalkaloid of kaempferol was newly identified in an extract of A. hamosus. In addition, three compounds – quercetin and kaempferol flavonoids, acylated with hydroxymethylglutaric acid and alcesefoliside, were found in extracts of A. hamosus and A. corniculatus for the first time.

In vitro effects of synthetic muscimol and an extract from Amanita muscaria on human recombinant MAOB enzyme

The effects of synthetic muscimol and an extract from Amanita muscaria, containing this compound on the activity of human recombinant MAOB enzyme (hMAOB) were studied. Muscimol had statistically significant inducing effect on hMAOB at concentrations 0.25–5 μM, while A. muscaria extract did not influence the enzyme activity at all.

HIGH RESOLUTION LC-MS/MS SCREENING FOR SECONDARY METABOLITES IN BULGARIAN SPECIES OF GENUS Astragalus L

The phytochemical content of some Astragalus species distributed in Bulgarian flora has been previously studied. Among other compounds, flavoalkaloids, acylated flavonoids, flavonoid triglycosides and cycloartane saponins have been isolated so far. The composition of the rest of the representatives of this genus in Bulgaria is not explored yet. The aim of this study was to perform a screening for the presence of selected rare secondary metabolites (flavoalkaloids, acylated flavonoids, flavonoid triglycosides and cycloartane saponins) in selected Astragalus species. Samples were collected in different phenological stages and from different locations in the country. A novel and rapid ultra-high performance liquid chromatography – high resolution electrospray ionisation mass spectrometry (UHPLC-HRESIMS) method was developed and applied. For the first time a flavoalkaloid glycoside was determined from extracts of A. onobrychis var. chlorocarpus and A. glycyphylloides. From A. depressus an acylated derivative of kaempferol was newly identified. The flavonol triglycosides camelliaside A, alcesefoliside and mauritianin were proved in samples of A. glycyphylloides, A. onobrychis var. chlorocarpus and A. cicer for the first time as well.

Toxicological and pharmacological profile of Amanita muscaria (L.) Lam. – a new rising opportunity for biomedicine

Amanita muscaria, commonly known as fly agaric, is a basidiomycete. Its main psychoactive constituents are ibotenic acid and muscimol, both involved in ‘pantherina-muscaria’ poisoning syndrome. The rising pharmacological and toxicological interest based on lots of contradictive opinions concerning the use of Amanita muscaria extracts’ neuroprotective role against some neurodegenerative diseases such as Parkinson’s and Alzheimer’s, its potent role in the treatment of cerebral ischaemia and other socially significant health conditions gave the basis for this review. Facts about Amanita muscaria’s morphology, chemical content, toxicological and pharmacological characteristics and usage from ancient times to present-day’s opportunities in modern medicine are presented.

Bulgarian species of genus Astragalus as potential sources of mauritianin

Mauritianin is a relatively rare flavonoid, but several studies revealed its pharmacological potential. In this study overground parts of ten Astragalus species were investigated for mauritianin content to find a reliable source of the compound. The quantity of the flavonoid in each extract was determined by a novel high performance liquid chromatography-high resolution mass spectrometry method. For the first time mauritianin is reported in A. cicer, A. onobrychis, A. glycyphyllos, A. glycyphylloides, A. corniculatus and A. ponticus. Only in A. depressus the compound was not found. Significant differences in mauritianin content (from 4 to 1642 ng/mg dry weight) of the samples were observed. Noteworthy, A. onobrychis var. chlorocarpus and A. cicer could be considered as a potential source of the compound, substituting the rare A. monspessulanus subsp. monspessulanus.

Induction of flavonoid biosynthesis by in vitro cultivation of Astragalus glycyphyllos L

Establishment of in vitro cultures from Astragalus glycyphyllos, determination of biomass and analysis of total flavonoids, rutin and camelliaside A were performed. To increase flavonoid production various combinations of plant hormones and light/dark regimen were investigated. Suspension cultures with exogenous quercetin were evaluated for possible increase in flavonoid production. Shoots, calli and suspensions were successfully established. Rutin and camelliaside A were proved in highest amount in shoots. Calli, cultivated on modified G48 medium, with double amount of Ca2+ and Mg2+, achieved higher total flavonoid content (2.37 and 2.03 mg/g DW). Suspensions cultures, cultivated on modified G48 medium with 10, 20 and 30 mg/mL quercetin achieved higher total flavonoid content (0.09, 0.10 and 0.13 mg/mg DW). Biotransformation of quercetin to isoquercitrin was achieved. The highest concentration of isoquercitrin (56.73 ng/mg DW) was observed on suspensions cultures cultivated on modified G48 medium, with 20 mg/mL quercetin.

Neuroprotective and antioxidant activities of saponins’ mixture from Astragalus glycyphylloides in a model of 6-hydroxydopamine-induced oxidative stress on isolated rat brain synaptosomes

The aim of the study was to investigate the possible neuroprotective and antioxidant activity of purified saponins’mixture (PSM), isolated fromAstragalus glycyphylloides(Fabaceae), in a model of 6-hydroxydipamine (6-OHDA)-induced oxidative stress on isolated rat brain synaptosomes. Synaptosomes were incubated with 3 different concentrations of PSM: 60 µg/mL; 6 µg/mL; 0.6 µg/mL. The effects of PSM were compared to those of silymarin (S), at the same concentrations. The main parameters, characterized functional and metabolic status of synaptosomes, were investigated: viability (MTT-test) and level of reduced glutathione (GSH). At isolated rat brain synaptosomes, in conditions of 6-OHDA-induced oxidative stress (150 μМ), PSM revealed statistically significant, concentration-dependent, neuroprotective and antioxidant effects, compared to those of silymarin. Effects were most prominent at concentration 60 µg/mL. These neuroprotective effects of PSM might be due to the possible activity as scavenger of reactive oxygen species (ROS), produced by p-quinone (toxic metabolite of 6-OHDA).

Effects of Amanita muscaria extract on different in vitro neurotoxicity models at sub-cellular and cellular levels

Muscimol is the main compound found in Amanita muscaria. Several studies have proven that muscimol has suppressive effects on essential tremor, without impairing speech and coordination. The effects of muscimol in Parkinson-affected patients is also described in a number of studies. These studies describe the free radical scavenging and antioxidant activity of the mushroom extract. We have evaluated the possible neuroprotective effects of a standardized extract from A. muscaria, containing high amounts of muscimol, on different models of neurotoxicity in rat brain microsomes, mitochondria, synaptosomes as well as on neuroblastoma cell line SH-SY5Y. The possible inhibitory effect on human recombinant monoaminoxidase-B (hMAOB) enzyme was also studied. The extract revealed statistically significant neuroprotective effects on the in vitro neurotoxicity models and no inhibitory activity on hMAOB.

Bone protective effects of purified extract from Ruscus aculeatus on ovariectomy-induced osteoporosis in rats

Ruscus aculeatus is a source of steroidal saponins that could mimic sex hormones and could help alleviate the risk of fracture in osteoporotic patients. The aim of the present study was to evaluate the in vitro effects of an extract from R. aculeatus (ERA) on the proliferation of human osteoblast-like SaOS-2 cell line and to investigate the effects of the ERA administered orally for 10 weeks at three doses (50, 100 and 200 mg/kg) on the bone structure of rats with estrogen deficiency induced by bilateral ovariectomy. Bone turnover markers, hormones, histopathological and radiological disturbances were evidenced in the ovariectomized rats. ERA recovered most of the affected parameters in a dose-dependent manner similar to diosgenin and alendronate used as positive comparators. The main active compounds of ERA (ruscogenin and neoruscogenin) were docked into the Vit. D receptor and oestrogen receptors alpha and beta, and stable complexes were found with binding scores equal to those of estradiol and diosgenin. The findings of this study provide for the first time an insight into the effects of ERA on bone structure and suggest that ERA could be developed as a potential candidate for the prevention of postmenopausal osteoporotic complications.

In silico and in vivo studies of Astragalus glycyphylloides saponin(s) with relevance to metabolic syndrome modulation

Triterpenoids are well known modulators of metabolic syndrome. One of the suggested modes of action (MoAs) involves peroxisome proliferator-activated receptor gamma (PPARγ) binding. In this study we aimed to: (i) evaluate in silico potential metabolites and PPARγ-mediated MoA of the sapogenin of the main saponin present in a purified saponins' mixture (PSM) from Astragalus glycyphylloides; (ii) estimate in silico and in vivo PSM's toxicity; and (iii) investigate in vivo antihyperglycaemic, hypolipidaemic, antioxidant and hepatoprotective effects of PSM. Metabolites and toxicity were predicted using Meteor and Derek Nexus expert systems (Lhasa Limited) and PPARγ binding was investigated using the software MOE (CCG Inc.). PSM's acute oral toxicity was evaluated in mice and the pharmacological effects were assessed in streptozotocin-induced diabetic spontaneously hypertensive rats (SHRs). Liver histopathology was studied as well. PPARγ weak partial agonism was predicted in silico for 24 probable/plausible Phase I metabolites which docking poses were clustered in 12 different binding modes with characteristic protein-ligand interactions. PSM's beneficial effects on the levels of blood glucose, triglycerides, and total cholesterol, on oxidative stress markers and liver histology in diabetic SHRs were comparable to those of the PPARγ ligand pioglitazone. PSM's safety profile was confirmed in silico and in vivo.

Molecular determinants of PPARγ partial agonism and related in silico/in vivo studies of natural saponins as potential type 2 diabetes modulators

The metabolic syndrome, which includes hypertension, type 2 diabetes (T2D) and obesity, has reached an epidemic-like scale. Saponins and sapogenins are considered as valuable natural products for ameliorating this pathology, possibly through the nuclear receptor PPARγ activation. The aims of this study were: to look for in vivo antidiabetic effects of a purified saponins' mixture (PSM) from Astragalus corniculatus Bieb; to reveal by in silico methods the molecular determinants of PPARγ partial agonism, and to investigate the potential PPARγ participation in the PSM effects. In the in vivo experiments spontaneously hypertensive rats (SHRs) with induced T2D were treated with PSM or pioglitazone as a referent PPARγ full agonist, and pathology-relevant biochemical markers were analysed. The results provided details on the PSM modulation of the glucose homeostasis and its potential mechanism. The in silico studies focused on analysis of the protein-ligand interactions in crystal structures of human PPARγ-partial agonist complexes, pharmacophore modelling and molecular docking. They outlined key pharmacophoric features, typical for the PPARγ partial agonists, which were used for pharmacophore-based docking of the main PSM sapogenin. The in silico studies, strongly suggest possible involvement of PPARγ-mediated mechanisms in the in vivo antidiabetic and antioxidant effects of PSM from A. corniculatus.

Production of Δ7-Sterols from In Vitro Root Cultures of Endangered Gypsophila trichotoma

Species from the genus Gypsophila are known for their medicinal, industrial and decorative applications. G. trichotoma Wend. is an endangered plant species for the Bulgarian flora according to the Red Data Book. Δ7-Sterols, which are unusual and rare in the plant kingdom, are present in the roots of this species. In previous studies different in vitro cultures were established from aerial parts of the species. The objective of this study was to explore the possibility for production of Δ7-sterols from in vitro cultured roots of G. trichotoma. The root cultures were grown on six modified MS media and the quantity of sterols was analyzed. These findings will serve to solve the important matter of the role of nutrients on sterols biosynthesis.

Production of Δ⁷-Sterols from In Vitro Root Cultures of Endangered Gypsophila trichotoma

Species from the genus Gypsophila are known for their medicinal, industrial and decorative applications. G. trichotoma Wend. is an endangered plant species for the Bulgarian flora according to the Red Data Book. Δ⁷-Sterols, which are unusual and rare in the plant kingdom, are present in the roots of this species. In previous studies different in vitro cultures were established from aerial parts of the species. The objective of this study was to explore the possibility for production of Δ⁷-sterols from in vitro cultured roots of G. trichotoma. The root cultures were grown on six modified MS media and the quantity of sterols was analyzed. These findings will serve to solve the important matter of the role of nutrients on sterols biosynthesis.

Antidiabetic and antioxidant effects of saponarin from Gypsophila trichotoma on streptozotocin-induced diabetic normotensive and hypertensive rats

BACKGROUND

Diabetes and hypertension are diseases that often coexist, which increases the risk of chronic organ damages and cardiovascular complications.

PURPOSE

To evaluate the effects of saponarin, isolated from Gypsophila trichotoma Wend, on blood pressure, glycemia, body weight, and liver biochemical parameters related to oxidative stress in diabetic normotensive Wistar Kyoto rats (NTR) and spontaneously hypertensive rats (SHR).

METHODS

Diabetes was induced by administration of streptozotocin (40 mg/kg, i.p.). The following biochemical parameters: reduced glutathione (GSH), malondialdehyde (MDA), total cytochrome P450, aniline hydroxylase (AH) activity, as well as the activities of antioxidant enzymes such as glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) were measured in the livers of euthanized rats.

RESULTS

Saponarin exerted slight antihypertensive activity in non-diabetic SHR, judged by 19% (p<0.05) decrease of the initial blood pressure. However, such effect was not observed in streptozotocin-induced diabetic SHR (SHR-D). Streptozotocin-induced diabetes was evidenced by 78% (p<0.05) and by 171% (p<0.05) increase in blood glucose level in NTR and SHR, respectively. In non-diabetic SHR the initial MDA quantity was by 36% (p<0.05) higher and the initial GSH levels were by 28% (p<0.05) lower in comparison to non-diabetic NTR. Significant decrease in the activities of GPx, GR, and GST was measured in the livers of all diabetic rats. Treatment with saponarin ameliorated the above mentioned liver parameters in both diabetic strains, however its effects were less pronounced in the diabetic SHR group.

CONCLUSION

Taken together our data indicate that diabetes and hypertension in combination are more difficult to be modulated by saponarin.

Flavoalkaloids and Flavonoids from Astragalus monspessulanus

A new flavonol tetraglycoside, quercetin-3-O-[α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)]-β-D-galactopyranosyl]-7-O-β-D-glucopyranoside (1), and two new flavonol alkaloids, N-(8-methylquercetin-3-O-[α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)]-β-D-galactopyranosyl])-3-hydroxypiperidin-2-one (2) and N-(8-methylkaempferol-3-O-[α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)]-β-D-galactopyranosyl])-3-hydroxypiperidin-2-one (3), were isolated from the aerial parts of Astragalus monspessulanus ssp. monspessulanus. Two rare flavonoids with an unusual 3-hydroxy-3-methylglutaric acid moiety, quercetin-3-O-α-L-rhamnopyranosyl-(1→2)-[6-O-(3-hydroxy-3-methylglutaryl)-β-D-galactopyranoside (4) and kaempferol-3-O-α-L-rhamnopyranosyl-(1→2)-[6-O-(3-hydroxy-3-methylglutaryl)-β-D-galactopyranoside (5), were isolated from the aerial parts of A. monspessulanus ssp. illyricus. In addition, the eight known flavonoids alangiflavoside (6), alcesefoliside (7), mauritianin (8), quercetin-3-β-robinobioside (9), cosmosine (10), apigenin-4'-O-glucoside (11), trifolin (12), and rutin (13) were isolated from aerial parts of A. monspessulanus ssp. monspessulanus. Their structures were elucidated via NMR and HRESIMS data. In a model that tested t-BuOOH-induced oxidative stress on isolated rat hepatocytes, flavonoids 1-13 had statistically significant cytoprotective activity similar to that of silymarin, tested at 60 μg/mL. The most prominent effects were observed for flavonoids 1, 4, 7, and 12.

Experimental liver protection of n-butanolic extract of Astragalus monspessulanus L. on carbon tetrachloride model of toxicity in rat

OBJECTIVE

To investigate the hepatoprotective potential of n-butanolic extract of Astragalus monspessulanus L. (EAM) against in-vitro/in-vivo carbon tetrachloride (CCl4)-induced liver damage in rats. Silymarin was used as a positive control.

METHODS AND RESULTS

The in-vitro experiments were carried out in primary isolated rat hepatocytes first incubated with CCl4 (86 µmol/l). Hepatic injury was discerned by a decrease in cell viability and cell glutathione (GSH) levels, an increase in lactate dehydrogenase leakage into the medium, and an elevation in malondialdehyde (MDA) quantity. Cell pre-incubation with EAM (1 µg/ml and 10 µg/ml) significantly ameliorated the CCl4-induced liver damage. In-vivo rats were challenged orally with CCl4 (10% solution in olive oil) alone and after 7 days pre-treatment with EAM (100 mg/kg body weight per day, oral gavage). CCl4 damage was judged by an increased production of MDA, depletion of cell GSH, and a decrease in cell antioxidant defense system. EAM pre-treatment normalizes the activities of the antioxidant enzymes and the levels of GSH and MDA. These data are supported by the histopathological examination.

CONCLUSION

These results indicate that EAM has a similar significant protective effect, in vitro and in vivo, against CCl4 induced hepatotoxicity in rat as silymarin.This may be due to its antioxidant and membrane stabilizing properties.

Effects of rhamnocitrin 4-β-D-galactopyranoside, isolated from Astragalus hamosus on toxicity models in vitro

BACKGROUND

Astragalus hamosus L. (Fabaceae) is used in herbal medicine as emollient, demulcent, phrodisiac, diuretic, laxative, and good for inflammation, ulcers, and leukoderma. It is useful in treating irritation of the mucous membranes, nervous affections, and catarrh.

OBJECTIVE

Rhamnocitrin 4-β-D-galactopyranoside (RGP), isolated from A. hamosus, was investigated for its possible protective effect on different models of toxicity in vitro on sub-cellular and cellular level.

MATERIALS AND METHODS

The effects of RGP were evaluated on isolated rat brain synaptosomes, prepared by Percoll reagent and on rat hepatocytes, isolated by two-stepped collagenase perfusion.

RESULTS

In synaptosomes, RGP had statistically significant protective effect, similar to those of silymarin, on 6-hydroxy (OH)-dopamine-induced oxidative stress. These results correlate with literature data about protective effects of kempferol and rhamnocitrin on oxidative damage in rat pheochromocytoma PC12 cells. In rat hepatocytes, we investigate the effect of RGP on two models of liver toxicity: Bendamustine and cyclophosphamide. In these models, the compound had statistically significant cytoprotective and antioxidant activity, similar to those of silymarin.

CONCLUSION

According to these results, we can suggest that such cytoprotective effect of RGP might be due to an influence on bendamustine and cyclophosphamide metabolism in rat hepatocytes. In isolated rat hepatocytes, in combination with bendamustine and cyclophosphamide and in 6-OH-dopamine-induced oxidative stress in isolated rat synaptosomes, RGP, isolated from A. hamosus, was effective protector and antioxidant. The effects were closed to those of flavonoid silymarin-the classical hepatoprotector and antioxidant.

Cytotoxicity of gypsogenic acid isolated from Gypsophila trichotoma

Background:

Gypsophila trichotoma Wend. (Caryophyllaceae) is a medicinal plant which is protected in Bulgaria by the Biodiversity Law. Previous studies have showed the presence of triterpene saponins, sterols, flavonoids, triterpens, etc.

Objective:

Gypsogenic acid, isolated from Gypsophila trichotoma roots, was evaluated for cytotoxic activity.

Materials and Methods:

The structure of the compound was elucidated by spectral methods. The cell survival fraction was determined by the MTT dye reduction assay, performed with some modifications.

Results:

Gypsogenic acid was tested in a panel of human tumor cell lines and was found to inhibit the proliferation of malignant cells. It was active against leukemic cells with lymphoid (SKW-3 and BV-173) or myeloid phenotype (HL-60, K-562, and LAMA-84), as well as against the EJ bladder carcinoma cell line. Bcr-Abl expressing myeloid cells (LAMA-84 and especially K-562) displayed lower sensitivity. HL-60/Dox cells were less sensitive to gypsogenic acid than the parent cell line, which shows that gypsogenic acid is probably a substrate of MRP-1.

Triterpenoid Saponins from Astragalus corniculatus

Two new triterpenoid saponins were isolated from the ethanolic extract of the aerial parts of Astragalus corniculatus Bieb. The structures of the saponins were elucidated as 3β -O-[O-4-oxopentopyranosyl-( 1 → 2)-β -D-glucopyranosyl]-21α-hydroxyolean-12-ene-28-oic acid (1) and 21α- hydroxyolean-12-ene-28-oic acid 3β -4-oxo-pentopyranoside (2) by chemical and spectral methods.

Protective effects of the apigenin-O/C-diglucoside saponarin from Gypsophila trichotoma on carbone tetrachloride-induced hepatotoxicity in vitro/in vivo in rats

This study investigated the hepatoprotective activity of saponarin, isolated from Gypsophila trichotoma Wend., using in vitro/in vivo hepatotoxicity model based on carbone tetrachloride (CCl₄)-induced liver damage in male Wistar rats. The effect of saponarin was compared with those of silymarin. In vitro experiments were carried out in primary isolated rat hepatocytes. Cell incubation with CCl₄ (86 μmol l⁻¹) led to a significant decrease in cell viability, increased LDH leakage, decreased levels of cellular GSH and elevation in MDA quantity. Cell pre-incubation with saponarin (60-0.006 μg/ml) significantly ameliorated CCl₄-induced hepatic damage in a concentration-dependent manner. These results were supported by the following in vivo study. Along with decreased MDA quantity and increased level of cell protector GSH, seven day pre-treatment of rats with saponarin (80 mg/kg bw; p.o.) also prevented CCl₄ (10%, p.o.)-caused oxidative damage by increasing antioxidant enzyme activities (CAT, SOD, GST, GPx, GR). Biotransformation phase I enzymes were also assessed. Administered alone, saponarin decreased EMND and AH activities but not at the same extent as CCl₄ did. However, pre-treatment with saponarin significantly increased enzyme activities in comparison to CCl₄ only group. The observed biochemical changes were consistent with histopathological observations where the hepatoprotective effect of saponarin was comparative to the effects of the known hepatoprotecor silymarin. Our results suggest that saponarin, isolated from Gypsophila trichotoma Wend., showed in vitro and in vivo hepatoprotective and antioxidant activity against CCl₄-induced liver damage.

A New Sulfated Triterpene Saponin from Gypsophila trichotoma

A new sulfated triterpeniod saponin, 3- O-sulfooleanolic acid 28- O-[ β-glucopyranosyl-(1→3)]-[ β-glucopyranosyl-(1→6)]- β-glucopyranosyl ester (1), along with three known Δ7-sterols: stigmast-7-en-3 β-ol (2), stigmast-7-en-3- O-β-D-glucopyranoside (3) and stigmast-7-en-3-on (4) were isolated from the roots of Gypsophila trichotoma Wend. (Caryophyllaceae). Their structures were elucidated by chemical and spectral methods. Compound 1 caused concentration-dependent inhibition of malignant cell proliferation against different human tumor cell lines.

One test microbial diagnostic microarray for identification of Mycoplasma mycoides subsp. mycoides and other Mycoplasma species

The present study describes the use of microarray technology for rapid identification and differentiation of Mycoplasma mycoides subsp. mycoides from other mycoplasmas that may be pathogenic to ruminants, including those of the Mycoplasma mycoides cluster, genetically and antigenically strictly correlated with Mycoplasma mycoides subsp. mycoides. A microarray containing genetic sequences of 55 different bacterial species from Acholeplasma, Mycoplasma, Spiroplasma and Ureaplasma genera was constructed. Sequences to genes of interest were collected in FASTA format from NCBI. The collected sequences were processed with OligoPicker software. Oligonucleotides were then checked for their selectivity with BLAST searches in GenBank. The microarray was tested with ATCC/NCTC strains of Mycoplasma spp. of veterinary importance in ruminants including Mycoplasma belonging to the mycoides cluster as well as Mycoplasma mycoides subsp. mycoides and Mycoplasma mycoides subsp. capri field strains. The results showed that but one ATCC/NCTC reference strains hybridized with their species-specific sequences showed a profile/signature different and distinct from each other. The heat-map of the hybridization results for the nine genes interrogated for Mycoplasma mycoides subsp. mycoides demonstrated that the reference strain Mycoplasma mycoides subsp mycoides PG1 was positive for all of the gene sequences spotted on the microarray. CBPP field, vaccine and reference strains were all typed to be M. mycoides subsp. mycoides, and seven of the nine strains gave positive hybridization results for all of the nine genes. Two Italian strains were negative for some of the genes. Comparison with non-Mycoplasma mycoides subsp. mycoides reference strains showed some positive signals or considerable homology to Mycoplasma mycoides subsp. mycoides genes. As expected, some correlations were observed between the strictly genetically and antigenically correlated Mycoplasma mycoides subsp. mycoides and Mycoplasma mycoides subsp. capri strains. Specifically, we observed that some Italian Mycoplasma mycoides subsp. mycoides strains were positive for two out of the three Mycoplasma mycoides subsp. capri genes, differently from what has been observed for other European or African Mycoplasma mycoides subsp. mycoides strains. This study highlighted the use of microarray technology as a simple and effective method for a single-step identification and differentiation of Mycoplasma mycoides subsp. mycoides from other mycoplasmas that may be pathogenic to ruminants, including those of the Mycoplasma mycoides cluster, genetically and antigenically strictly correlated with Mycoplasma mycoides subsp. mycoides. The opportunity to discriminate several mycoplasmas in a single analysis enhances diagnostic rapidity and may represent a useful tool to screen occasionally mycoplasmas affecting animal farming in territories where diagnostic laboratory support is limited. The heat-map of the hybridization results of the comparative genomic hybridizations DNA-designed chip clearly indicates that the microarray performs well for the identification of the tested Mycoplasma mycoides subsp. mycoides reference and field strains, discriminating them from other mycoplasmas.

Hepatoprotective effects of saponarin, isolated from Gypsophila trichotoma Wend. on cocaine-induced oxidative stress in rats

The antioxidant effect of saponarin, which is the main flavone isolated from Gypsophila trichotoma Wend., and its protection against cocaine hepatotoxicity were investigated in male Wistar rats. The animals were treated with cocaine (40 mg/kg i.p.) alone and also after 3 consecutive days of pretreatment with saponarin (80 mg/kg p.o.). After 18 hours the rats were sacrificed by decapitation. The production of thiobarbituric acid reactive substances, reduced glutathione (GSH) and the activity of the following antioxidant enzymes: catalase, superoxide dismutase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase were assessed in liver homogenate. Administered alone, cocaine induced significant hepatotoxicity manifested with GSH depletion and reduced antioxidant defences. Saponarin pretreatment, however, decreased cocaine toxicity both by increasing GSH levels and antioxidant enzyme activities. The results of this study proved the antioxidant activity of saponarin and its protective effect against cocaine-induced oxidative stress and hepatotoxicity.

Flavonoids from Astragalus hamosus

A new flavonol glycoside 7-O-methyl-kaempferol 4'-beta-D-galactopyranoside (rhamnocitrin 4'-beta-D-galactopyranoside) (1) was isolated from the aerial parts of Astragalus hamosus. The known flavonols hyperoside (2), isoquercitrin (3) and astragalin (4) were also identified. Structures of the compounds were elucidated by chemical and spectral methods.