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.

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.

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.

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 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.

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.