Intercalation of Rhodamine B into Calf Thymus DNA in presence and absence of olive leaf extract: A fluorescence study

Abstract

Aqueous olive leaf extract (AOLE) of the Mediterranean tree Olea europaea is stated to have several therapeutic properties including: antifungal, antimicrobial, hypotensive and hypoglycemic actions as well as to use in treatment of some cancer cases as breast, skin and pancreatic cancers. Experimentally, the olive leaf extract is capable to protect nuclear calf thymus and human genomic DNA in vitro to Rhodamine B toxicity. Thus, this study was aimed to evaluate the protective effect of AOLE against toxic DNA damage induced by Rhodamine B using different techniques as UV−VIS Spectroscopy and fluorometry. Genomic DNA was used in a concentration of 75µg/ ml. DNA was extracted from peripheral lymphocytes of anticoagulated blood (EDTA) samples by Proteinase K digestion and phenol/chloroform extraction. Dried leaves of Olea europaea (from West part of Libya) were grinded with distilled water; the resulting aqueous solution was then filtered and used. The protective effect of the AOLE was evaluated for its ability to decrease the amount of Rhodamine B available for binding with double stranded DNA. Thus, DNA resulted in a significant decrease in fluorescence intensity of Rhodamine B. Comparing to control samples, pre-and post-treatment with AOLE, significantly attenuated the binding ability of Rhodamine B to the DNA (p<0.01). Treatment with 5g/15 ml of AOLE was enough to prevent Rhodamine B toxicity to the DNA. The cytoprotective and antioxidant properties were detected in AOLE by a fluorescence method. The antioxidant activity of AOLE was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and the IC 50 was 65±2.3μg/ml. In conclusion, this study suggests that AOLE induced a genoprotective effect by increasing the antioxidant capacity and the chemical interaction between Rhodamine B and constituents of AOLE.

Natural Deep Eutectic Solvents (NaDESs) as Alternative Green Extraction Media for Ginger (Zingiber officinale Roscoe)

“…The interaction of plant extracts, rich in bioactive phytochemicals, with DNA has also been studied in effort to further exploit the extracts as obtained, without isolating the natural products. For example, the grape-seed extract prevents oxidationinduced DNA damage [41], whereas the olive leaf extract [42] and fresh-cut yam slices [43] interact with calf Thymus DNA (ctDNA). In order to develop new drugs which specifically target DNA, it is necessary to understand the different binding ways in which a molecule is capable of binding.…”

“…Among these interactions, intercalation is one of the most important DNA binding modes as it invariably leads to cellular degradation. In addition, the coordination geometry and the type of ligand donor atom also play key roles in determining the binding extent of DNA [42,44]. Haris et al [45] recently reported the interaction of 6-gingerol with ctDNA using experimental as well as molecular modeling techniques.…”