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The dried stem bark of Berberis kansuensis is a commonly used Tibetan herbal medicine for the treatment of diabetes. Its main chemical components are alkaloids, such as berberine, magnoflorine and jatrorrhizine. However, the role of gut microbiota in the in vivo metabolism of these chemical components has not been fully elucidated. In this study, an ultra-high performance liquid chromatography method coupled with Orbitrap mass spectrometry (UHPLC-Orbitrap-MS) technology was applied to detect and identify prototype components and metabolites in rat intestinal contents and serum samples after oral administration of a B. kansuensis extract. A total of 16 prototype components and 40 metabolites were identified. The primary metabolic pathways of the chemical components from B. kansuensis extract were demethylation, desaturation, deglycosylation, reduction, hydroxylation, and other conjugation reactions including sulfation, glucuronidation, glycosidation, and methylation. By comparing the differences of metabolites between diabetic and pseudo-germ-free diabetic rats, we found that the metabolic transformation of some chemical components in B. kansuensis extract such as bufotenin, ferulic acid 4-O-β-D-glucopyranoside, magnoflorine, and 8-oxyberberine, was affected by the gut microbiota. The results revealed that the gut microbiota can affect the metabolic transformation of chemical constituents in B. kansuensis extract. These findings can enhance our understanding of the active ingredients of B. kansuensis extract and the key role of the gut microbiota on them.

A fixed combination of Berberis aristata and Silybum marianum (Berberol) has been used by patients with dyslipidaemia. The aim of the present meta-analysis was to systematically evaluate the efficacy and safety of a fixed combination of B. aristata and S. marianum (Berberol) on serum lipid levels compared to placebo in a meta-analysis based on randomised, controlled trials. The meta-analysis was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, using the PICO (patients, intervention, comparison, outcome) format, and it was registered in the International Prospective Register of Systematic Reviews. The Cochrane Central Register of Controlled Trials, PubMed, Embase, and Web of Science databases were searched for relevant studies. Placebo-controlled clinical studies involving adult patients with a condition of dyslipidaemia and receiving a fixed combination of B. aristata and S. marianum were included. Four randomised trials, including a total of 491 patients, were pooled in statistical analysis. According to the present meta-analysis, Berberol significantly lowered the low-density lipoprotein level, total cholesterol, fasting plasma glucose levels, and the Homeostatic Model Assessment index compared to placebo; however, its effects on the high-density lipoprotein level, triglyceride level, and body mass index were not statistically significant by the end of a 3-month treatment period. Berberol appeared to be safe, and it did not increase the levels of alanine transaminase, aspartate transaminase, and creatine kinase enzymes. Berberol is an effective and presumably safe complementary therapy for the treatment of dyslipidaemia; however, the evidence supporting its use is very limited. The optimum dose and duration of treatment are unclear. A comprehensive evaluation of efficacy and safety is required in further high-quality clinical studies involving larger patient populations.

A bioassay-guided fractionation and chemical investigation of the trunk of Berberis koreana led to the isolation and identification of three new triterpenoids, 2 α,3 α,19 α-trihydroxy-urs-12-en-24-formyl-28-oic acid (1), 2 α,3 β,21 α-trihydroxy-urs-12-en-28-oic acid ( 2), and 3 β-acetyloxy-1-oxo-olean-12-en-28-oic acid (3), along with seven known triterpenoids (4-10). The structures of these new compounds were determined through spectral analysis, including extensive 2D-NMR data. The new compounds 1-3 showed significant cytotoxicity against the A549, SK-OV-3, SK-MEL-2, and HCT-15 human tumor cell lines with IC(50) values ranging from 7.17 to 48.73 µM.

The compounds 8-ethyl- (2), 8-butyl- (3), 8-hexyl- (4), 8-octyl- (5), 8-decyl- (6) and 8-dodecylberberine chloride (7) were synthesized and tested for their antimicrobial activity in vitro to evaluate structure-activity relationships. Substitution of the alkyl groups at C-8 led to significant changes in the antimicrobial activity. All compounds were more potent against the tested microorganisms than berberine (1), especially against Gram-positive bacteria. The antimicrobial activity increased as the length of aliphatic chain was elongated and then decreased gradually when the alkyl chain exceeded eight carbon atoms. 8-octylberberine (5) displayed the highest antimicrobial activity of all compounds. The toxicity of compounds 2 - 7 was stronger than that of 1. However, upon elongating the aliphatic chain, the toxicity decreased gradually.

Plants of the genus Berberis are commonly used in nutrition and phytomedicine. The purpose of this study was to investigate radical scavenging properties and antioxidant activity of roots, leaves and twigs of Croatian barberry (B. croatica Horvat), an endemic illyric-balcanic species, and compare it to antioxidant activity of common barberry, (B. vulgaris L.). Ethanolic extracts of roots, twigs and leaves of B. croatica and B. vulgaris collected at four locations in Croatia (two locations per species) were investigated. Content of total phenols and flavonols were determined by using Folin Ciocalteu and aluminium chloride method, respectivelly. Antioxidant activity was established using following methods: radical scavenging activity of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free-radical, reducing power and beta-carotene-linoleic acid assay as well as electron paramagnetic resonance (EPR) spectroscopy. In all the analyses the leaf extracts were found to possess most marked antioxidant activities, not significantly different from positive control butylated hydroxyanisole (BHA) (ANOVA, p>0.05). Activity of twigs and roots extracts was somewhat less pronounced then the activity of leaves extracts. This investigation revealed no statistically significant differences in antioxidant activities between plant species (p>0.05). With the exception of the beta-carotene-linoleic acid assay, antioxidant activity in all the applied assays correlated well with content of total phenols and flavonols (r2>0.83). That suggests that those compounds play an important role in overall antioxidant activity of investigated plant organs.

For the structure-activity relationship study on berberrubine derivatives, a series of compounds bearing 9-O-acyl- and 9-O-alkyl-substituents were synthesized and tested for antimicrobial activity against Gram-positive, Gram-negative bacteria and fungi. Octanoyl, decanoyl, lauroyl derivatives among the acyl analogs and hexyl, heptyl, octyl, nonyl, decyl, undecyl derivatives among the alkyl analogs showed strong antimicrobial activity against Gram-positive bacteria and fungi. As a whole, alkyl analogs were more active than acyl analogs for antimicrobial activity. Synthesized derivatives had no activity on Gram-negative bacteria. Too short or too long substituents decreased activity. These results suggest that the presence of lipophilic substituents with moderate sizes might be crucial for the optimal antimicrobial activity.

The effects of hydrastine derivatives on dopamine biosynthesis in PC12 cells were investigated. Treatments of PC12 cells with (1R,9S)-beta-hydrastine hydrochloride [(+)-beta-hydrastine HCl] and (1R,9S)-beta-hydrastine [(-)-beta-hydrastine] showed 50.6 % and 33.1 % inhibition of dopamine content at a concentration of 10 microM for 48 h. However, (1S,9R)-beta-hydrastine [(+)-beta-hydrastine] and hydrastinine hydrochloride did not reduce dopamine content. The IC(50) values of (1R,9S)-beta-hydrastine hydrochloride and (1R,9S)-beta-hydrastine were 9.3 microM and 20.7 microM , respectively. Next, the intracellular mechanisms of (1R,9S)-beta-hydrastine hydrochloride in PC12 cells were investigated. Dopamine content decreased at 6 h and reached a minimal level at 24 h after the exposure of PC12 cells to 20 microM (1R,9S)-beta-hydrastine hydrochloride. Tyrosine hydroxylase (TH) activity was inhibited at 6 h following the treatment with (1R,9S)-beta-hydrastine hydrochloride, and was maintained at a reduced level for up to 36 h in PC12 cells (17 - 27 % inhibition at 20 microM), whereas TH mRNA level was not found to alter for 24 h. However, the level of intracellular Ca++ concentration decreased by treatment with (1R,9S)-beta-hydrastine hydrochloride at 20 microM by 18.4 % inhibition relative to the control level in PC12 cells. These results suggest that (1R,9S)-beta-hydrastine hydrochloride contributes partially to the decrease in dopamine content by the inhibition of TH activity in PC12 cells.

Using the example of berberine in cell cultures of THALICTRUM and BERBERIS species, the transport and secretion of natural products in plant cell cultures is reviewed. Topics discussed are the subcellular localization of berberine biosynthesis, transport of berberine to vacuoles, extracellular release of berberine, mechanism of berberine secretion, uptake and transport of exogenous berberine, and the release of berberine by immobilized cells.