Background: Rumex rothschildianus is the sole member of a unique section of the genus Rumex, in the family Polygonaceae. This species is a very rare small dioecious annual, endemic to Palestine that is traditionally used as food and for the treatment of various diseases. Therefore, the current investigation aimed to screen the chemical constituents, antioxidants, anti-α-amylase, anti-α-glucosidase, antilipase, and cytotoxic effects of four solvents fractions of R. rothschildianus leaves.
Methods: Dried powder of R. rothschildianus leaves was extracted in four solvents with different polarities. Several qualitative and quantitative phytochemical tests were performed to determine the components of the extracts. The colorimetric analysis was used for the quantitative determination of phenols, flavonoids, and tannins. In-vitro assays were performed to evaluate the extracts for antioxidant, anti-α-amylase, anti-α-glucosidase, and antilipase inhibitory activities, as well as cytotoxicity by MTS assay against cervical carcinoma cells line (HeLa) and breast cancer cell line (MCF7).
Results: The acetone fraction of R. rothschildianus leaves showed the most significant antioxidant activity, due to having the highest content of flavonoids and phenolics, with an IC50 value of 6.3 ± 0.4 μg/ml, compared to 3.1 ± 0.9 μg/ml for Trolox, and regarding lipase inhibition activity the acetone fraction showed the most potent activity with an IC50 value of 26.3 ± 0.6 μg/ml, in comparison with orlistat positive control IC50 12.3 μg/ml. The same extract was the most potent inhibitor of α-amylase and α-glucosidase, with IC50 values of 19.1 ± 0.7 μg/ml and 54.9 ± 0.3 μg/ml, respectively, compared to 28.8, 37.1 ± 0.3 μg/ml of acarbose, respectively. The hexane fraction showed 99.9% inhibition of HeLa cells and 97.4% inhibition for MCF7 cells.
Conclusion: The acetone fraction of R. rothschildianus leaves might provide a source of bioactive compounds for the treatment of oxidative stress. Similarly, the hexane fraction indicates the promising antitumor potential of R. rothschildianus. Clearly, these initial indications need further purification of potentially active compounds, and ultimately, in-vivo studies to determine their effectiveness.
Keywords: Amylase; Anti-proliferative activity; Antioxidant; Lipase; Phytochemistry; Rumex rothschildianus; Trolox.