Novel berberine-based pharmaceutical salts with fatty acid anions: Synthesis, characterization, physicochemical properties

Interactions of three berberine mid-chain fatty acid salts with bovine serum albumin (BSA): Spectroscopic analysis and molecular docking

In this paper, the interaction of three berberine mid-chain fatty acid salts ([BBR][FAs]), viz. berberine caproate ([BBR][CAP]), berberine heptylate ([BBR][HEP]) and berberine octoate ([BBR][OCT]), with bovine serum albumin (BSA) was studied by means of UV-visible absorption spectroscopy, fluorescence spectroscopy, fourier transform infrared spectroscopy (FT-IR) and molecular docking techniques. Fluorescence experiments revealed that three berberine salts quench the fluorescence of BSA by static quenching mechanism resulted from a stable [BBR][FAs]-BSA complex formation. The stoichiometric numbers of [BBR][FAs]-BSA complexes were found to be 1:1. Synchronous and three-dimensional fluorescence spectra as well as FT-IR demonstrated that the binding of [BBR][FAs] altered the microenvironment and conformation of BSA. The binding average distance from [BBR][FAs] to BSA (3.2-3.5 nm) was determined according to Förster energy transfer theory. Site probe investigation showed that [BBR][FAs] bound to BSA active site I (sub-domain IIA). The binding promotes the esterase-like activity of BSA. The molecular docking results confirmed the fluorescence competition findings and provided the type of binding forces. Furthermore, the relationship between the anionic chain length of [BBR][FAs] and the interaction was explored, and the positive correlation was found.

Carane-3,4-diol Derivatives as Potential Water-Based Herbicides

Twelve novel carane-3,4-diol derivatives were designed, synthesized, and evaluated for their herbicidal activities against Lolium multiflorum Lam. and Brassica campestris for the first time. The relationships between the chemical structural factors, including types, the number or the carbon chain length of functional groups, associated with the lipophilicity and the herbicidal activity of the tested compounds were also discussed. The results showed that most of newly synthesized compounds had a dose-dependent, herbicidal activity against the root and shoot growths of Lolium multiflorum Lam. and Brassica campestris. Compared to carane-3,4-diol, most of the target derivatives possessed improved lipophilicity and certain solubilities in representative solvents with different polarities. Particularly, ester derivatives 3a-3b and 3e can be dissolved or dispersed in water, but also displayed higher herbicidal activity against Lolium multiflorum Lam. and Brassica campestris than other ester derivatives. The 50 % inhibitory concentration (IC50) value of compound 3e against shoot growth of Brassica campestris (0.485 mmol/L) was superior to that of commercial herbicide glyphosate (1.14 mmol/L), indicating that the potential application as a water-based herbicide for Brassica campestris control.

Development of Berberine-Loaded Nanoparticles for Astrocytoma Cells Administration and Photodynamic Therapy Stimulation

Berberine (BBR) is known for its antitumor activity and photosensitizer properties in anti-cancer photodynamic therapy (PDT), and it has previously been favorably assayed against glioblastoma multiforme (GBM)-derived cells. In this work, two BBR hydrophobic salts, dodecyl sulfate (S) and laurate (L), have been encapsulated in PLGA-based nanoparticles (NPs), chitosan-coated by the addition of chitosan oleate in the preparation. NPs were also further functionalized with folic acid. All the BBR-loaded NPs were efficiently internalized into T98G GBM established cells, and internalization increased in the presence of folic acid. However, the highest mitochondrial co-localization percentages were obtained with BBR-S NPs without folic acid content. In the T98G cells, BBR-S NPs appeared to be the most efficient in inducing cytotoxicity events and were therefore selected to assess the effect of photodynamic stimulation (PDT). As a result, PDT potentiated the viability reduction for the BBR-S NPs at all the studied concentrations, and a roughly 50% reduction of viability was obtained. No significant cytotoxic effect on normal rat primary astrocytes was observed. In GBM cells, a significant increase in early and late apoptotic events was scored by BBR NPs, with a further increase following the PDT scheme. Furthermore, a significantly increased depolarization of mitochondria was highlighted following BBR-S NPs’ internalization and mostly after PDT stimulation, compared to untreated and PDT-only treated cells. In conclusion, these results highlighted the efficacy of the BBR-NPs-based strategy coupled with photoactivation approaches to induce favorable cytotoxic effects in GBM cells.

Improvement of anticancer effect of berberine by salt formation modifications

BACKGROUND

Berberine is a quaternary isoquinoline alkaloid that possesses a significant therapeutic effect on a variety of cancers. However, due to poor bioavailability, an increased dose is often required to achieve therapeutic goals. To improve the activities of natural berberine, most modifications were focused on the positive isoquinoline unit by grafting long aliphatic chains or heterocycles. However, the negative part is ignored. At this point, the strategy of salt formation modifications with short- and medium-chain fatty acids was proposed in this article.

PURPOSE

Using salt modification to enhance the antitumor activity of berberine and explore the mechanism.

METHODS

Four short- and medium-chain fatty acid salts of berberine were prepared from berberine hydrochloride by salt formation modification with the sodium salt of butyric, caproic, octanoic, and decanoic acid, respectively. The cytotoxicity of four berberine salts on B16-F10, A549, HepG2, and U373 cancer cell lines was explored. Through cell localization, Mitochondrial membrane potential assay, and Western blotting analysis explored the mechanism of berberine salt-induced apoptosis. Its anticancer activity in vivo was demonstrated by the mouse xenograft model.

RESULTS

The four berberine fatty acid salts exhibited an enhanced inhibitory effect on B16-F10, A549, HepG2, and U373 cancer cell lines, particularly on B16-F10 cells. Meanwhile, the four berberine fatty acid salts can inhibit the migration of B16-F10 cells. The four berberine fatty acid salts induce cancer cell apoptosis through the mitochondrial pathway, which was confirmed by the mitochondrial colocalization, the decreased mitochondrial membrane potential as well as activation of caspase-3, cytochrome C (Cyt-C), and down-regulated expression of B-cell lymphoma 2 (Bcl-2). Most importantly, the four berberine fatty acid salts inhibited tumor growth in the in vivo B16-F10 melanoma model without generating side effects intraperitoneally.

CONCLUSIONS

This study revealed that salt formation modification may be an effective strategy to optimize the anticancer property of berberine hydrochloride and demonstrated the four berberine fatty acid salts induced apoptosis through the mitochondrial apoptotic pathway.