Evaluation of Antiulcer and Cytotoxic Potential of the Leaf, Flower, and Fruit Extracts of Calotropis procera and Isolation of a New Lignan Glycoside

Abstract

Calotropis procera is traditionally used for treating many diseases including ulcers and tumors. It was thus deemed of interest to investigate and compare the antiulcer and cytotoxic activities of C. procera leaf, flower, and fruit extracts in an attempt to verify its traditional uses. Phytochemical studies on the fruits, flowers, and leaves of C. procera, collected from the desert of Saudi Arabia, led to the isolation of one new lignan 7'-methoxy-3'-O-demethyl-tanegool-9-O-β-d-glucopyranoside and five known compounds from the flowers, four compounds from leaves, and a flavonoid glycoside and a lignan glycoside from the fruits. The structures of compounds were determined by spectroscopic techniques. Ethanol extracts of the three parts of C. procera were evaluated for their antiulcer activity and we found that the leaf extract possessed a powerful antiulcer activity which could be considered as a promising drug candidate. All the extracts and the isolated compounds were evaluated for their cytotoxic activity against MCF-7, HCT-116, HepG-2, and A-549 human cancer cell lines. Compound 2 was highly active on all the cell lines, whereas compounds 5 and 11 were more selective on colon and liver cell lines. Compound 10 demonstrated a significant activity on liver and lung cancer cell lines.

Figure 1

Chemical structure of compound 1.

Figure 2

Key HMBC (arrows) and ¹H-¹H COSY (thick lines) correlations of compound 1.

Figure 3

Effect of Cp extracts on the changes in gastric wall mucus induced by 80% ethanol. Six rats were used in each group. ^∗p < 0.05, ^∗∗∗p < 0.001 versus control (80% ethanol only) group, Student's t-test, (a) as compared to the control group and (b) as compared to the 80% ethanol only group.

Figure 4

Effect of Cp extracts on GSH concentration in gastric ulcer induced by 80% ethanol. Six rats were used in each group. ^∗p < 0.05, ^∗∗p < 0.01, and ^∗∗∗p < 0.001 versus control (80% ethanol only) group, Student's t-test, (a) as compared to the control group and (b) as compared to the 80% ethanol only group.

Figure 5

Effect of Cp extracts on MDA concentration in gastric ulcer induced by 80% ethanol. Six rats were used in each group. ^∗∗p < 0.01, ^∗∗∗p < 0.001 versus control (80% ethanol only) group, Student's t-test, (a) as compared to the control group and (b) as compared to the 80% ethanol only group.

Figure 6

Light micrographs illustrating the effect of Cp extracts on ethanol-induced gastric lesions in rats. (a) Ethanol-induced gastric mucosal necrosis and congestion. (b) Pretreatment of rats with ranitidine, 50 mg/kg. (c) Pretreatment of rats with Cp leaves, 200 mg/kg. (d) Pretreatment with Cp leaves, 400 mg/kg. (e) Pretreatment with Cp fruits, 200 mg/kg. (f) Pretreatment with Cp fruits, 400 mg/kg. (g) Pretreatment with Cp flowers, 200 mg/kg. (h) Pretreatment with Cp flowers, 400 mg/kg.