Assessment of Antiproliferative Potential of Hexalobus crispiflorus (Annonaceae)

Background: Hexalobus crispiflorus root aqueous extract (HC) is used to treat breast cancer in Nigeria.

Aim: To evaluate the antiproliferative effects of HC using Sorghum bicolor seed radicle as test subject.

Materials and Methods: Ten millilitres each of one to seven mg/ml HC in distilled water was poured into 9 cm wide Petri dishes overlaid with cotton wool and filter paper. Twenty viable seeds of Sorghum bicolor (Guinea corn) were spread on each plate and incubated in the dark. The lengths (mm) of the radicles emerging from the seeds were measured at 48, 72, and 96 h. The control seeds were treated with 10 ml of distilled water containing no extracts. The experiments were carried out in triplicates. The mean radicle lengths (mm) and percentage inhibition were determined. HC was characterized using colour reactions and HPLC-UV-DAD.

Results: Phytochemical investigation revealed the presence of tannins, saponins, glycosides, alkaloids, flavonoids, terpenes and steroids. HPLC spectrum gave nine peaks with caffeic acid and rutin eluting at 5.22 and 7.76 minutes respectively. HC significantly (P < 0.001) inhibited S. bicolor seed growth over a period of 48 – 96 h against the control seeds. At 96 h, HC dose-dependently inhibited seed growth, gave inhibition of 35.41%, 40.67%, 58.24%, 61.34% and 63.68% for seeds treated with 1 mg/ml, 2 mg/ml, 4 mg/ml, 6 mg/ml and 7 mg/ml respectively with IC50 of 3 mg/ml. Methotrexate 0.176 mg/ml as positive control gave inhibition of 99.11% at 96 h.

Conclusion: This result indicates the propensity of HC to inhibit the proliferation of S. bicolor seed radicle, hence provide preliminary evidence for its use to treat breast cancer.