Interactions of amino acids with aluminum octacarboxyphthalocyanine hydroxide. Experimental and DFT studies

The influence of albumin and amino acids (l-serine, glycine, l-histidine, l-tryptophan, l-cysteine) on the properties of aluminum octacarboxyphthalocyanine hydroxide (Al(OH)PcOC) was investigated in a phosphate buffer (pH 8.0). Particular attention was paid to the spectroscopic properties and photostability of Al(OH)PcOC. The effect of albumin or amino acids on the photodegradation of Al(OH)PcOC was examined in water using red light: 685 nm and daylight irradiation. Analysis of kinetic curves indicated that interaction with those molecules increases the photostability of Al(OH)PcOC. The molecular structure of Al(OH)PcOC complexes (in vacuum and in water) with axially or equatorially coordinated amino acids was studied by the B3LYP/6-31G* method, and the effects on molecular structure and electronic absorption spectrum were investigated on the basis of the density functional theory. The calculation results revealed that axial coordination significantly reduces the non-planarity of the phthalocyanine ring, and, thus, alters the electronic structure. On the other hand, hydrogen bonding of phthalocyanine side COOH groups with amino acids, in equatorial complexes, does not change the structure within the center of the phthalocyanine, and causes only a slight increase in UV–vis bands intensity, which is in perfect agreement with experimental data. [Figure not available: see fulltext.

Hepatocellular cancer cell lines, Hep-3B and Hep-G2 display the pleiotropic response to resveratrol and berberine

Purpose: Human carcinoma cells with different p53 status exposed to a combination of bioactive substances, resveratrol and berberine, revealed different responses in cell viability via p53-dependant apoptosis pathway activation. Materials and methods: Using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay, we investigated various and opposing effects in hepatocellular carcinoma cells, Hep-G2 and Hep-3B with different p53-status. Results: Cells decreased in viability after treatment with dose-dependent concentrations of resveratrol and berberine. Hep-3B p53 mutants were more sensitive in comparison to the p53 wild type Hep-G2 cell line. A synergistic effect was observed after treatment of Hep-3B cells with a combination of resveratrol/berberine ratios in favor of resveratrol (2:1, 3:1). The results suggest that an effective concentration of berberine, in the presence of resveratrol, could be decreased even to 50% (half the IC50 for berberine) in cancer treatment. Combined treatment with berberine and resveratrol, at the investigated concentrations and fractions, significantly reduces the viability of wild type p53 Hep-G2 and null p53-mutant Hep-3B cells by 20% and 40%, respectively. Conclusions: Stronger toxic effects on viability and proliferation were observed in Hep-3B cells what is consistent with the assumptions that null p53-mutants activate apoptosis canonical pathway. In conclusion, p53 status in human hepatocellular cancer cell lines modulates responses to plant-derived therapies

Interactions of amino acids with aluminum octacarboxyphthalocyanine hydroxide. Experimental and DFT studies

The influence of albumin and amino acids (l-serine, glycine, l-histidine, l-tryptophan, l-cysteine) on the properties of aluminum octacarboxyphthalocyanine hydroxide (Al(OH)PcOC) was investigated in a phosphate buffer (pH 8.0). Particular attention was paid to the spectroscopic properties and photostability of Al(OH)PcOC. The effect of albumin or amino acids on the photodegradation of Al(OH)PcOC was examined in water using red light: 685 nm and daylight irradiation. Analysis of kinetic curves indicated that interaction with those molecules increases the photostability of Al(OH)PcOC. The molecular structure of Al(OH)PcOC complexes (in vacuum and in water) with axially or equatorially coordinated amino acids was studied by the B3LYP/6-31G* method, and the effects on molecular structure and electronic absorption spectrum were investigated on the basis of the density functional theory. The calculation results revealed that axial coordination significantly reduces the non-planarity of the phthalocyanine ring, and, thus, alters the electronic structure. On the other hand, hydrogen bonding of phthalocyanine side COOH groups with amino acids, in equatorial complexes, does not change the structure within the center of the phthalocyanine, and causes only a slight increase in UV–vis bands intensity, which is in perfect agreement with experimental data. [Figure not available: see fulltext.