Determination of secondary metabolites and antioxidant activity of some boraginaceae species growing in Iran

Purpose: To evaluate the antioxidant potential, flavonoids, and total phenols as well as cyanidin 3- glucoside and delphinidin 3-glucoside contents of some Boraginaceae species that grow in Iran.Methods: The aqueous and ethanol extracts of the plants were prepared. The free radical scavenging activity of the extracts was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical method. Total phenolic and flavonoid contents of the extracts were assessed by Folin-Ciocalteu and aluminium chloride colorimetric assays, respectively. Furthermore, cyanidin 3-glucoside and delphinidin 3- glucoside contents of the extracts were determined using high- performance liquid chromatography (HPLC) method.Results: The most powerful free radical scavenging activity with 50 % inhibitory concentration (IC50) of 23.13 ± 1.90 μg mL-1 was exerted by the ethanol extract of Nonea caspica, while the weakest IC50 of 364.38 ± 14.18 μg mL-1 was shown by the aqueous extract of Onosma sericeum. Total phenolic content varied among the plants, ranging from 270.33 ± 2.60 to 3.40 ± 0.28 mg GAE g-1 dry weight. The ethanol extracts of Nonea caspica and Anchusa arvensis displayed the highest total flavonoid content (252.60 ± 1.80 and 29.13 ± 1.05 mg QE g-1 dry weight, respectively). The highest contents of cyanidin and delphinidin 3-glucosides were found in the ethanol extracts of Nonea caspica and Anchusa arvensis, respectively.Conclusion: The results show that some of the plants have potent antioxidant activities which may justify the ethno-therapeutic usage of these plants by traditional healers.Keywords: Boraginaceae, Polyphenol, Antioxidant activity, Cyanidin 3-glucoside, Delphinidin 3- glucoside, Nonea caspica, Onosma sericeum, Anchusa arvensi

Inhibition of telomerase activity and cell growth by free and nanoliposomal forms of punicalagin in human leukemia cell line K562

Purpose: To prepare punicalagin-loaded nanoliposome and compare its anti-telomerase activity in K562 cell line with that of free punicalagin.Methods: Punicalagin-loaded nanoliposomes were prepared by extrusion method, and the efficiency of punicalagin entrapment was determined by high-performance liquid chromatography (HPLC) method. The anti-proliferation effect of the punicalagin in the free and nanoliposomal forms at various doses (0 - 100 μg/mL) and times (0 - 72 h) on K562 cell line was investigated using 3-(4,5 dimethylthiazol-2-yl)- 2,5-diphenyl tetrazolium bromide ((MTT) assay. Changes in telomerase activity, following treatment with punicalagin, of the free and nanoliposomal forms were measured by telomeric repeat amplification protocol-enzyme-linked immunosorbent assay.Results: The entrapment efficiency of punicalagin was 86.7 ± 1 %. Treatment of K562 cells with punicalagin, particularly in the nanoliposomal form, resulted in significant induction of apoptosis and inhibition of cell growth. Furthermore, the telomerase activity of the nanoliposomal punicalagin-treated cells was significantly inhibited in a time- and dose-dependent manner.Conclusion: Punicalagin shows a novel mechanism of anti-telomerase activity, particularly in the nanoliposomal form, and may provide a basis for the future development of anti-cancer therapy.Keywords: Punicalagin, Apoptosis, Anti-proliferative, Nanoliposome, Telomerase, Leukemi