br The cytotoxicity of C curetum
The cytotoxicity of C. curetum on the HeLa cell line was significantly induced by 0.125 mg/ml of the C. curetum acetone fraction (p ≤ 0.0001) by approximately 90%, while 10 mg/mL of the C. curetum aqueous fraction significantly induced cytotoxicity (p ≤ 0.0001) by
Porcine pancreatic lipase inhibitory activity and the IC50 values of the C. curetum hexane, acetone, methanol and aqueous fractions in addition to the reference anti-obesity drug Orlistat.
Conc. Orlistat Hexane fraction Acetone fraction Methanol fraction Aqueous fraction
Fig. 6. Porcine pancreatic lipase inhibitory activity of the four C. curetum fractions and Orlistat.
approximately 90%. Moreover, 10 mg/ml of the methanol fraction significantly induced cytotoxicity (p ≤ 0.0001) by approximately 85%. In addition, the highest cytotoxic reactivity on HeLa 1898-66-4 was obtained with the 0.625 mg/mL C. curetum hexane fraction, which significantly induced cytotoxicity in cancer cells by (p ≤ 0.0001) approximately 95%.
In a study by Patel et al., the methanolic extract of Solanum nigrum at 10 mg/mL reduced viability by 65% in HeLa cancer cell line while at 0.0196 mg/mL led to only a 38% reduction . Moreover, another study carried out by Nemati et al. showed that 0.5 mg/mL of Consolida orientalis, Ferula assa-foetida, Coronilla varia, and Orobanche orientalis ethanolic extracts exhibited cytotoxic eﬀects against HeLa cancer by 7.59%, 25.30%, 54.42%, and 42.66%, respectively .
In summary, only the 0.5 mg/mL of the C. curetum acetone and hexane fractions exhibited pronounced cytotoxic eﬀects on the Colo-
205 cancer cell line. Moreover, 0.625 mg/ml of the C. curetum hexane fraction exhibited potential cytotoxic eﬀects against the cervical epi-thelial carcinoma (HeLa) cell line.
However, the exact mechanism of action that is responsible for the initiation of cytotoxicity and α-amylase, α-glucosidase, porcine pan-creatic lipase enzymes inhibitory activity needs to be addressed. Thus, further studies on C. curetum aqueous, acetone and hexane fractions as a novel therapeutic agent having antidiabetic, anti-obesity and antic-ancer eﬀects, originating from plants, are warranted. In addition, fur-ther in vivo clinical studies should be carried out to evaluate their ef-fectiveness on humans.
These results show that the C. curetum aqueous fraction contains the highest contents of flavonoids, tannins, and phenols, while the aqueous and methanol fractions have the highest α-amylase enzyme inhibitory activity in comparison with the reference anti-diabetic drug Acarbose. Moreover, the methanolic fraction has the best anti-glucosidase ac-tivity, even more than Acarbose. In addition, the hexane fraction has the highest anti-lipase activity compared with Orlistat. Additionally, the C. curetum acetone and hexane fractions showed the best cytotoxic eﬀects against the Colo-205 cancer cell line and the hexane fraction induced the highest cytotoxic eﬀect against HeLa cancer cells. Overall, this study revealed that C. curetum has potential α-amylase, α-glucosi-dase, porcine pancreatic lipase inhibitory and cytotoxic activity on HeLa and Colo-205 cancer cell lines, indicating the presence of biolo-gically active and cytotoxic compounds in this plant species. This study provides only basic data, so further studies are necessary for the iso-lation and identification of biologically active substances in the C. curetum aqueous, methanol, acetone and hexane fractions.
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Fig. 7. The cytotoxic eﬀects of various extracts derived from C. curetum on Colo-205 cells. Colo-205 cells were treated with various con-centrations of the acetone, hexane, water and methanol extracts obtained from C. curetum and incubated for 24 h. Cytotoxicity was de-termined by the MTS assay. Results are de-picted as relative quantities (RQs) compared to the control (with only media; C). #P < 0.0001 and **P < 0.01. Error bars represent SD.
Declaration of Competing Interest
The authors declare that there are no conflicts of interest.
The Financial support of An-Najah National University to undertake this work under grant number ANNU-1718-Sc030 is highly acknowl-edged.
Fig. 8. The cytotoxic eﬀect of various extracts derived from C. curetum on HeLa cells. HeLa cells were treated with various concentrations of the acetone, hexane, water and methanol extracts obtained from C. curetum and in-cubated for 24 h. Cytotoxicity was determined by the MTS assay. Results are depicted as re-lative quantities (RQs) compared to the control (with only media; C). #P < 0.0001 and **P < 0.01. Error bars represent SD.