Neem Flower Extracts as a Source of Bioactive Compounds: In-vitro Antitumor and Larvicidal Evaluation, Biomolecular...

The study investigates the photophysical properties, biomolecular interaction, and in vitro anti-tumor property of Azadirachta indica flower (Neem) extracts, isolation of the n-hexadecanoic acid (HDA), and its density functional theory calculations. Petroleum ether (P1) and acetone (P2) extracts of neem flower were subjected to ultraviolet-visible and fluorescence studies; among these, P1 had better fluorescence properties than P2 with a quantum yield of 0.18. The DNA binding and ethidium bromide quenching studies revealed that the phytochemicals that are present in the extracts follow intercalator binding. P1 is found to have good binding properties with bovine serum albumin. Further, the evaluation of in vitro cytotoxicity with human epithelioid cervix carcinoma cells reveals that P1 has high antitumor activity with the lowest IC₅₀ value (7.52 ± 0.53 µM). The larvicidal potency of P1 and P2 extracts was evaluated against Aedes aegypti and Anopheles stephensi, and showed very good activity with ≥95% and 100% of mortality rates by 24 and 48 h, respectively. From the potential P1 extract, HDA has been isolated and confirmed. Further, its in-silico properties were investigated to support the DNA interaction, which has been proved in the photophysical studies. All the studies confirm that the bioefficacy of P1 extract could be the implicit natural therapeutic agent of the future.