Phytoconstituents from Piliostigma foveolatum (Dalzell) Thoth. leaves induce antiproliferative effect, apoptosis, and cell cycle arrest in Hop-62 cells

Abstract

The study evaluated the therapeutic potential of ethanolic leaf extract of Piliostigma foveolatum (Dalzell) Thoth. (EEBF), its toluene, ethylacetate, methanol soluble fractions (viz. TFBF, EFBF, MFBF), and isolated phytoconstituents against lung cancer. Four compounds were isolated from MFBF by column chromatography and preparative HPLC. Structures were elucidated by IR, ¹³C-NMR, ¹H-NMR, mass spectroscopy and identified as Quercetin, Kaempferol, Isorhamnetin, and ß-glucogallin. EEBF and its biofractions exhibited remarkable antiproliferative activity with GI₅₀<85µg/mL, while isolated Quercetin, Kaempferol, Isorhamnetin, and ß-Glucogallin displayed GI₅₀ values of 56.15 ± 1.16 $\mu$M, 68.41 ± 3.98 $\mu$M, 55.08 ± 0.57 $\mu$M and 58.99 ± 12.39 $\mu$M respectively. MFBF demonstrated significant apoptotic activity with 42.24 ± 0.57% cells in early and 4.61 ± 0.88% cells in late apoptosis comparable to standard Doxorubicin. Kaempferol exhibited 23.03 ± 0.37% cells in early and 2.11 ± 0.55% cells in late apoptosis, arresting Hop-62 cells in S-phase. In silico molecular docking, revealed that isolated constituents effectively bound to the same binding site of caspase-3 as Doxorubicin, highlighting their apoptotic mode of action.

Graphical Abstract

Keywords:

• Phytoconstituents
• preparative HPLC
• antiproliferative
• apoptosis
• Hop-62
• caspase-3

Acknowledgements

The authors are thankful to Dr. Satyanarayan S. Hebbar for the authentication of the leaf sample, Principal of Goa College of Pharmacy, Government of Goa and authorities of Central research laboratory, Maratha Mandal’s NGH Institute of dental sciences and research center- Belagavi, Honeychem Pharma Pvt. Ltd.- Bengaluru and Sophisticated Analytical Instrumentation Facility, Punjab University-Chandigarh for facilitating the research.

Disclosure statement

The authors declare no conflicts of interest.

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Funding

The author(s) reported there is no funding associated with the work featured in this article.