Evaluation of Anti-cancer Potential of Abelmoschus esculentus (Okra).

Introduction: Abelmoschus esculentus (okra) from the Malvaceae family is widely used in culinary applications and is reported to have many potential therapeutic effects attributed to the compounds isolated from it. In this work, we set out to explore its seed proteome for the isolation of lectins and characterize them Method: A protein of about 21kDa was isolated and purified using chromatography techniques from the ammonium sulphate crude protein extract. It was evaluated for hemagglutination activity on rabbit erythrocyte suspension, trypsin inhibitory activity using chemical assay, and evaluation of anti-cancer activity using cell lines. Mass and transcriptome analysis were done to deduce the complete sequence of the isolated protein.

Results: Using functional, mass, and transcriptome analysis, the protein was identified as AEL (Abelmoschus esculentus lectin), which was reported earlier. Only a partial sequence of AEL was known, and in this work, we have deduced its complete sequence. It showed significant anti-- cancer activity against HeLa (cervical cancer) and T84 (colon cancer) with MIC (Minimum inhibitory concentration) of 20μg/ml and 40% and 30% reduction in cell viability at 100μg/ml and insignificant effect on ACHN (adenocarcinoma) cell lines. No significant effect was seen with the tested doses on normal control human cell lines HEK293 (human embryonic kidney cells). The purified protein shows specificity for lactose and galactose in the hemagglutination assay and trypsin inhibition activity.

Discussion: Studies of okra seed proteome lead to purification of AEL, a 21 kDa protein with dual hemagglutination activity and trypsin inhibitory activity. It showed potential anticancer activity in cervical, colon cancer cell lines and minimal effects on adenocarcinoma and control cell lines, suggesting specificity. The complete sequence of AEL was elucidated which will aid in its bioinformatics analysis, was isolated from okra seeds.

Conclusion: There are very few reported dual-acting lectins with potential anticancer activity, and this work will help understand their mechanistic interactions better.