Growth inhibitory effect of Leptospermum scoparium (manuka) chloroform extract on breast and liver cancer cell lines

Abstract

Objective: Research has demonstrated that Leptospermum scoparium possesses various therapeutic benefits. This study set out to determine whether or not L. scoparium extracts had any effect on the ability of HepG2 and MCF-7 breast cancer cells to survive.

Materials and methods: The antiproliferative activity of L. scoparium extracts was explored using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assays. The most active fraction was selected to investigate its effects on apoptosis induction using flow cytometry and quantitative real-time polymerase chain reaction. The constituents of this fraction were characterized using GC-MS analysis.

Results: Research demonstrated that the chloroform fraction of L. scoparium (LSCF) significantly impacted the HepG2 and MCF-7 cancer cell lines. Treatment with LSCF led to a notable rise in both early and late apoptotic cells. Furthermore, there was an upregulation in the mRNA levels of P53, Bax, and caspases, while the expression of Bcl-2 mRNA saw a decrease. The analysis of LSCF revealed the primary components to be cis-calamenene, beta-eudesmol, cyclododecane, and alpha-muurolene.

Conclusion: The study showed the promising antiproliferative activity of L. scoparium, suggesting its potential application for cancer treatment.

Keywords: Antiproliferative; GC-MS; LDH; Leptospermum scoparium; MCF-7; MTT; apoptosis.

Figure 1.. Manuka tree, L. scoparium (Accessed on July 2019).

Figure 2.. Effect of LSCF on HepG2 and MCF-7 cells using MTT assay. Cells were treated with different concentrations of extract for 48 h and the absorbance of the MTT formazan was determined at 540 nm in an ELISA reader. Data represent means ± SD.

Figure 3.. Cytotoxicity of LCSF on HepG2 and MCF-7 cells evaluated by LDH assay. LDH activity was determined at 490 nm in an ELISA reader. Values represent means ± SD (*p < 0.05) was considered significant compared to control) of three independent experiments carried out in triplicates.

Figure 4.. Effect of LSCF on HepG2 cells using annexin V-FITC/PI double staining. HepG2 cells were treated with 15 and 30 µg/ml for 24 h. (A) Hepg2 cells in different stages (A4) Early-stage apoptotic cells, (A3) viable cells (A2) cells in the late stage of apoptosis (A1) cells undergoing necrosis. (B) Apoptotic rate (%) of cell populations in different stages. Results are presented as the mean ± SD.

Figure 5.. Effect of LSCF on MCF-7 cells using annexin V-FITC/PI double staining. MCF-7 cells were treated with 20 and 40 µg/ml) for 24 h. (A) (A4) Early-stage apoptotic cells, (A3) viable cells (A2) cells in late stage of apoptosis (A1) cells undergoing necrosis. (B) Apoptotic rate (%) of cell populations in different stages. Results are presented as the mean ± SD.

Figure 6.. Effect of LSCF on the expression of apoptosis-associated genes in HepG2 and MCF-7 cells. (A) Relative expression of p53, and caspases 3, 8, 9, Bax, and Bcl2 genes in HepG2 cancer cells treated with 15 and 30 µg/ml concentrations for 24 h compared with the control (untreated cells). (B) Relative expression of the same genes in MCF-7 cancer cells treated with 20 and 40 µg/ml concentrations for 48 h. *p < 0.05, **p < 0.01, and ***p < 0.001 compared with the control (untreated cells). Data are presented as the mean ± standard deviation.

Figure 7.. GC-MS spectra of LSCF.