Fruits and barks extracts of Zanthozyllum heitzii a spice from Cameroon induce mitochondrial dependent apoptosis and Go/G1 phase arrest in human leukemia HL-60 cells.
BACKGROUND
Zanthoxylum heitzii is a spice used to prepare several dishes and to treat tumors, syphilis, malaria, cardiac palpitations, urogenital infections in the west region of Cameroon, but the antitumor mechanisms and chemical composition are not yet investigated. This study was aimed to determine the antiproliferative effects of four extracts from the fruits and barks of Zanthoxyllum heitzii (Rutaceae) on apoptosis in human promyelocytic cells, their mechanisms and the chemical composition. The 3-(4, 5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to determine the fifty percent inhibition (IC50) concentration of the cell lines after treatment. The effect on morphology was observed using a light or fluorescence microscopy. The rate of apoptosis and the cell cycle were measured using flow cytometry (FCM). The phytochemical analysis of the extract was carried with HPLC/MS methods.


RESULTS
The phytochemical analysis of the extracts indicated the presence of four known polyphenols (Syringic acid, Juglon, Luteolin and Myricetin) in both fruits and barks of Z. heitzii but in different quantities. Syringic acid and Myricetin concentrations were between 17-21 fold higher in the fruits than the stem bark. Rhamnetin (393.35 μg/mL) and Oleuropein (63.10 μg/mL) were identified only in the stem barks of Z. heitzii. Among the four extracts tested for cytotoxicity properties, only the methanol extract of fruits and barks significantly inhibited cell proliferation of HL-60 cells with IC50 value of 20 μg/mL and 12 μg/mL respectively. HL-60 cells treated with Z. heitzii extracts significantly produced reactive oxygen species (ROS) with concurrent loss of mitochondrial membrane potential (MMP). Modifications in the DNA distribution and enhanced of G1/G0 phase cell cycle arrest were observed in a concentration dependent manner.


CONCLUSIONS
Polyphenols from Z. heitzii plant exert inhibitory effect on HL-60 cells through the reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential and cell cycle destabilization.
Department of Biochemistry and Physiological Sciences, Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, PO BOX 1364, Yaoundé, Cameroon. apieme@yahoo.fr.|Cancer Pharmacology Division, Indian Institute of Integrative Medicine, Canal Road, Jammu, 18001, India. apieme@yahoo.fr.
Constant Anatole
CA
Pieme
Cancer Pharmacology Division, Indian Institute of Integrative Medicine, Canal Road, Jammu, 18001, India. santoshkumarguru@gmail.com.
Guru Kumar
GK
Santosh
Laboratory for TB research, Biotechnology Centre, Faculty of Science, University of Yaoundé 1, PO BOX 812, Yaoundé, Cameroon. etekwu@yahoo.fr.|Department of Biology, Faculty of Sciences and Arts, University of Balikesir, Cagis Campus, Balikesir, 10145, Turkey. etekwu@yahoo.fr.
Emmanuel Mouafo
EM
Tekwu
Department of Biology, Faculty of Sciences and Arts, University of Balikesir, Cagis Campus, Balikesir, 10145, Turkey. tulaskun@yahoo.com.
Tülin
T
Askun
Department of Biology, Faculty of Sciences and Arts, University of Balikesir, Cagis Campus, Balikesir, 10145, Turkey. haticeaydeniz@gmail.com.
Hatice
H
Aydeniz
Department of Biochemistry and Physiological Sciences, Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, PO BOX 1364, Yaoundé, Cameroon. jngogang@yahoo.fr.
Jeanne Yonkeu
JY
Ngogang
Cancer Pharmacology Division, Indian Institute of Integrative Medicine, Canal Road, Jammu, 18001, India. sbhushan@iiim.ac.in.
Shashi
S
Bhushan
Cancer Pharmacology Division, Indian Institute of Integrative Medicine, Canal Road, Jammu, 18001, India. aksaxena@iiim.ac.in.
Ajit Kumar
AK
Saxena
D017209:Apoptosis / Q000187:drug effects*; D002163:Cameroon; D049109:Cell Proliferation / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D005434:Flow Cytometry; D005638:Fruit / Q000737:chemistry*; D059585:G1 Phase Cell Cycle Checkpoints / Q000187:drug effects*; D018922:HL-60 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D013058:Mass Spectrometry; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008856:Microscopy, Fluorescence; D008928:Mitochondria / Q000502:physiology*; D024301:Plant Bark / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification; D059808:Polyphenols / Q000032:analysis; D017382:Reactive Oxygen Species / Q000032:analysis; D017365:Spices / Q000032:analysis; D013778:Tetrazolium Salts; D013844:Thiazoles; D032106:Zanthoxylum / Q000737:chemistry*
D010936:Plant Extracts; D059808:Polyphenols; D017382:Reactive Oxygen Species; D013778:Tetrazolium Salts; D013844:Thiazoles; C022616:thiazolyl blue