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.

Astragalus glycyphyllos is a widely distributed plant found in Bulgaria that has been used in the folk medicine of the country for decades as an antihypertensive, diuretic, and anti-inflammatory. This review article is focused on the traditional usage, phytochemical studies, pharmacological activity, and biotechnology of this species. Recent progress in the phytochemical investigation led to the identification of different flavonoids, triterpenoid saponins, sterols, volatiles, etc. Many pharmacological studies, performed on extracts and pure compounds, revealed promising antiproliferative, cytotoxic, immunomodulatory, antiviral, and neuroprotective activities in vitro and an in vivo hepatoprotective effect on a model of CCl₄-induced liver damage. Based on its popularity in traditional Bulgarian medicine, the species represents a promising subject for further investigations.

For centuries, plants have been a leading point in the identification of potential therapeutic agents. Monoamine oxidase inhibition is a key mechanism in the treatment of various neurological and psychiatric diseases. Some triterpenoid saponins are reported to inhibit this enzyme. An extract from the aerial parts of Astragalus glycyphyllos was purified and separated by chromatographic techniques, which led to the isolation of one triterpene saponin. Its structure was analysed by ultra-high-performance liquid chromatography coupled with high-resolution electrospray ionisation mass spectrometry. The compound was subjected to a pharmacological study where human recombinant monoamine oxidase enzymes type A and B (hMAOA and hMAOB) were used. On the activity of hMAOA, the saponin had no effect, but on hMAOB, it exhibited statistically significant inhibition in comparison to the control, Selegiline. The compound could have potential in other models, so further investigations are required.

Two cycloartane-type saponins 3-O-[α-L-rhamnopyranosyl-(1→2)]-β-D-xylopyranosyl]-24-O-α-L-arabinopyranosyl-3β,6α,16β,24(R),25-penta­hydroxycycloartane and Astrachrysoside A, obtained from the aerial parts of A. glycyphyllos, were tested in vitro for their possible hepatoprotective and antioxidant effects. Three models were used: isolated liver microsomes (non-enzyme-induced lipid peroxidation) and hepatocytes (t-BuOOH-induced oxidative stress and CCl₄-induced metabolic bioactivation). Both compounds (50 µM) exhibited statistically significant activity in all of the models, compared to the control. The saponins` hepatoprotective activity was even more pronounced in the metabolic bioactivation model. In addition, the compounds (1 µM) were evaluated for possible inhibitory activity on three isoforms of cytochrome P450. Both saponins exhibited noticeable inhibition on CYP3A4, mild inhibition oF CYP2D6, and no activity on the CYP1A2 isoform was observed.

Camelliaside A is a rare kaempferol glycoside with proved neuroprotective and antioxidant effects. In the present study, a rapid and precise HPLC-UV method for its quantitation was developed and validated. Separations were carrier over a C ₁₈ column with a gradient a gradient elution with 0.5% trifluoroacetic acid and acetonitrile as the mobile phase. Statistical parameters were calculated to prove the methods' applicability. The method was used to determine this secondary metabolite's quantity in two closely related Astragalus species – A. glycyphyllos L. and A. glycyphylloides DC. The results showed great differences with 0.13% of camelliaside A found in the first, and only 0.01% of it in the second examined taxon. This is the first report on the chemical differences in the bioaccumulation of this metabolite in both plants.

Pulmonaria rubra Schott (Boraginaceae) is a scarcely investigated congener of the medicinal species P. officinalis. This study aimed to characterize the lipophilic constituents of the dichloromethane extract from P. rubra aerial parts (PR-DCM) and to evaluate its antioxidant and neuroprotective activity in vitro , as well as its effects on monoamine oxidase (MAO) and major cytochrome P450 (CYP) isoforms. GC–MS analysis after silylation enabled the identification of virtually the entire extract (99.99% of the total peak area), revealing a profile dominated by non-volatile lipids, including unsaturated and saturated fatty acids (notably linolenic and palmitic acids), long-chain aliphatic alcohols, phytol, and phytosterols such as β-sitosterol and campesterol, while steam-distillable volatiles were negligible. In isolated rat brain synaptosomes, mitochondria, and microsomes, PR-DCM (up to 200 μg/mL) did not show intrinsic toxicity or pro-oxidant effects, but significantly counteracted 6-OHDA-, t -BuOOH-, and Fe ²⁺ /ascorbic acid-induced decreases in reduced glutathione and increases in malondialdehyde. At a concentration of 1 μg/mL, PR-DCM did not significantly inhibit human recombinant MAO-A, MAO-B, CYP1A2, CYP2D6, or CYP3A4. Overall, PR-DCM emerges as a promising source of lipophilic antioxidants with neuroprotective potential and a favorable in vitro safety and interaction profile, warranting further isolation of active components and confirmation in neuronal and in vivo models.