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)]-ß-D-xylopyranosyl]-24-O-α-L-arabinopyranosyl-3ß,6α,16ß,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.

Anticancer Secondary Metabolites: From Ethnopharmacology and Identification in Native Complexes to Biotechnological Studies in Species of Genus Astragalus L. and Gloriosa L.

Some of the most effective anticancer compounds are still derived from plants since the chemical synthesis of chiral molecules is not economically efficient. Rapid discovery of lead compounds with pronounced biological activity is essential for the successful development of novel drug candidates. This work aims to present the chemical diversity of antitumor bioactive compounds and biotechnological approaches as alternative production and sustainable plant biodiversity conservation. Astragalus spp., (Fabaceae) and Gloriosa spp. (Liliaceae) are selected as research objects within this review because they are known for their anticancer activity, because they represent two of the largest families respectively in dicots and monocots, and also because many of the medicinally important plants are rare and endangered. We summarized the ethnobotanical data concerning their anticancer application, highlighted the diversity of their secondary metabolites possessing anticancer properties such as saponins, flavonoids, and alkaloids, and revealed the potential of the in vitro cultures as an alternative way of their production. Since the natural supply is limited, it is important to explore the possibility of employing plant cell or organ in vitro cultures for the biotechnological production of these compounds as an alternative.

A Study on the Safety and Effects of Amorpha fruticosa Fruit Extract on Spontaneously Hypertensive Rats with Induced Type 2 Diabetes.

Metabolic syndrome is characterized by a variety of diagnostic criteria: obesity, dyslipidemia, type 2 diabetes, and arterial hypertension. They contribute to the elevated risk of cardiovascular morbidity and mortality. The potential for Amorpha fruticosa L. (Fabaceae) to improve diabetes and metabolic disease is promising, based on in vitro tests. This is why a further investigation of the species is needed. Additionally, a toxicity review in relation to safety revealed that to date, there are no published data regarding the toxicity of A. fruticosa towards humans. This species could provide abundant and cheap resources because it is an aggressive invasive plant that grows almost unrestrictedly. The objective of this study was to evaluate the acute toxicity of a purified extract of A. fruticosa (EAF), and to assess its antioxidant, antihypertensive, and antihyperglycemic activity in streptozotocin-induced diabetic spontaneously hypertensive rats (SHRs). The EAF was slightly toxic (LD50 = 2121 mg/kg, b.w.) when administered orally, and moderately toxic (LD50 = 316 mg/kg, b.w.) at intraperitoneal administration, both in mice. The oral administration of EAF (100 mg/kg) for 35 days to SHRs caused significant decreases in the systolic pressure, blood glucose levels, and MDA quantity. It also increased the hepatic level of the endogenous antioxidant GSH, not only in diabetic SHRs, but also in the control group. An additional potential benefit to human health might be conferred through the environmental management of A. fruticosa based on its large-scale use for medicinal purposes, as this aggressive invasive species brings problems to natural habitats in many European countries.

Beneficial effects of the fructus Sophorae extract on experimentally induced osteoporosis in New Zealand white rabbits.

Sophora japonica is a source of several flavonol, flavone and isoflavone glycosides that are reported to positively affect menopausal symptoms including osteoporotic complications. In the present study fructus Sophorae extract (FSE) was administered orally for three months at a dose of 200 mg kg-1 in ovariectomized (OVX) New Zealand rabbits. 3D computed tomography scans and histopathological images revealed microstructural disturbances in the bones of the castrated animals. FSE recovered most of the affected parameters in bones in a manner similar to zoledronic acid (ZA) used as a positive control. The aglycones of the main active compounds of FSE, daidzin, and genistin, were docked into the alpha and beta estrogen receptors and stable complexes were found. The findings of this study provide an insight into the effects of FSE on bone tissue loss and suggest that it could be further developed as a potential candidate for the prevention of postmenopausal osteoporotic complications.

Hepatoprotective and antioxidant effects of alcesefoliside from Astragalus monspessulanus

Abstract The hepatoprotective potential of alcesefoliside (AF) from Astragalus monspessulanus was investigated. Iron sulphate/ascorbic acid (Fe2+/AA) lipid peroxidation was induced in rat liver microsomes and pre-incubated with AF and silybin (100, 10 and 1 µmol). Pronounced effects were observed in 100 µmol. In vivo experiments were carried out on rats, challenged orally with carbon tetrachloride (CCl4) alone and after pre-treatment and followed by curative treatment with AF (10 mg/kg). The activity of the serum and antioxidant enzymes, together with reduced glutathione (GSH) levels and malonedialdehyde (MDA) quantity were measured. Microsomal incubation with Fe2+/AA increased MDA production. The pre-incubation with AF reduced the formation of MDA, comparable to silybin. These findings were supported by the in vivo study where CCl4-induced liver damage was discerned by significant increase in serum enzymes and in MDA production as well as by GSH depletion and reduced antioxidant enzymes activity. The AF pre-treatment and consecutive curative treatment normalizes the activity of the serum and antioxidant enzymes alike, as well as the levels of GSH and MDA. Histological examination of AF-treated livers showed a decrease in the abnormal accumulation of lipids in hepatocytes as well as reduced alterative changes in their structure in a model of CCl4-induced toxicity.

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.

A new tetracyclic saponin from Astragalus glycyphyllos L. and its neuroprotective and hMAO-B inhibiting activity.

A new tetracyclic saponin, 17(R),20(R)-3ß,6α,16ß-trihydroxycycloartanyl-23-carboxylic acid 16-lactone 3-O-ß-D-glucopyranoside (1) together with one known flavonoid, camelliaside A (2) were isolated from the aerial parts of Astragalus glycyphyllos L. Their structures were determined by chemical, HRESIMS and NMR methods. On 6-hydroxydopamine in vitro model on isolated rat brain synaptosomes, compounds 1-2 had statistically significant neuroprotective activity similar to that of Silibinin, tested at 100 µM. Saponin 1 possessed the most prominent neuroprotective and antioxidant effects in this in vitro model. On human recombinant monoamine oxidase type B enzyme compound 1 displayed strong inhibiting activity, compared to Selegiline (1 µM). It could be concluded that the new epoxycycloartane saponin 1 could be a promising leading structure in respect of neurodegenerative diseases.

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.

Alcesefoliside protects against oxidative brain injury in rats

ABSTRACT This study investigated the possible antioxidant and neuroprotective effects of alcesefoliside, isolated from Astragalus monspessulanus L., Fabaceae, against carbon tetrachloride (CCl4)-induced brain injury in Wistar rats. Iron sulphate/ascorbic acid lipid peroxidation was induced in rat brain microsomes and pre-incubated with alcesefoliside and silybin. Male rats were treated in vivo with alcesefoliside and with silymarin alone; animals challenged with CCl4; and pre-treated with alcesefoliside or silymarin in respective doses for 7 days, challenged with CCl4, followed by curative treatment (additional 14 days). The activity of acetylcholine esterase and the antioxidant enzymes: superoxide-dismutase, catalase, glutathione-peroxidase, glutathione reductase and glutathione-S-transferase as well as the biomarkers of oxidative stress malondialdehyde and reduced glutathione were measured. The alcesefoliside pre-treatment and consecutive curative treatment normalizes the activity of the antioxidant enzymes as well as levels of malondialdehyde and reduced glutathione. The observed effects on tissue level correlate with the histopathological observations of the brain. They were comparable to the effects of silymarin, used as a positive control. The results showed that alcesefoliside has a neuroprotective effect against CCl4-induced brain toxicity in rats.

In vitro/in vivo antioxidant and hepatoprotective potential of defatted extract and flavonoids isolated from Astragalus spruneri Boiss. (Fabaceae).

The aim of the current study was to evaluate the effect of a defatted extract (EAS) and three flavonoids, isolated from Astragalus spruneri Boiss. (Fabaceae) using in vitro/in vivo models of liver injury. The EAS was characterized by HPLC and flavonoids (14 mg/g dw) and saponins (8 mg/g dw) were proved. The flavonoids (ASF1, ASF3 and ASF5) were isolated from the same extract and partially identified by LC-MS. In in vitro models of non-enzyme induced (Fe2+/AA) lipid peroxidation in isolated liver microsomes and CCl4-induced metabolic bioactivation and t-BuOOH-induced oxidative stress in isolated rat hepatocytes, both EAS and the flavonoids exerted similar to silybin (positive control) an antioxidant and cytoprotective activity, discerned by decreased MDA production in the microsomes and by preserved cell viability and GSH levels as well as by decreased LDH activity and MDA quantity in isolated rat hepatocytes. The antioxidant and hepatoprotective effect of EAS has been confirmed in vivo against CCl4-induced liver injury in rats. EAS restored the GSH levels and the activity of the antioxidant enzymes CAT and SOD, affected by CCl4 administration, as well as decreased the production of MDA. The effect of EAS was commensurable with those of silymarin.

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.

Flavonoids from the Genus Astragalus: Phytochemistry and Biological Activity.

Flavonoids, the most common plant polyphenols are widely distributed in every species and possess a broad range of pharmacological activities. The genus Astragalus is the largest in the Fabaceae family with more than 2,500 species spread. They are known to contain different metabolites such as flavonoids, saponins, and polysaccharides. Plants from the genus have been used in the traditional medicine of many countries for centuries. This paper is focused on the large group of flavonoid compounds. Details on structure as well as information about the pharmacological properties of flavonoids, isolated from Astragalus species have been discussed. This review is based on publications until the first half of 2014 and includes also the results from our phytochemical investigations of the genus.