Momordica charantia L. induces non-apoptotic cell death in human MDA-MB-436 breast and A549 lung cancer cells by disrupting energy metabolism and exacerbating reactive oxygen species' generation

ETHNOPHARMACOLOGICAL RELEVANCE

Bitter melon, Momordica charantia L. (MC), is an ethnomedicinal plant cultivated in different climes. It's cytotoxic effect on several cancer cell lines has been evaluated. However, there have been contrasting reports on the actual mechanism (s) involved in the observed cell death induced by MC.

AIMS OF THE STUDY

To probe the mechanism of cell death induction in MDA-MB-436 (Breast) and A549 (lung) cancer cell lines treated with fractions (ethyl acetate, dichloromethane and hexane) derived from the aqueous extract of MC.

MATERIALS AND METHODS

Aqeous extract of the leaves of MC were fractionated using solvents of different polarities (ethyl acetate (D3), n-hexane (D4), dichloromethane (D5)). The cells were incubated with 100 and 125 μg/mL of the fractions 24 hours. Combination of fluorescence microscopy, enzyme assays, Western blot analyses and flow cytometry were employed in the study.

RESULTS

Treatment of the cells with MC fractions reduced Mitochondrial Membrane Potential (MMP) and intracellular ATP levels, while increasing reactive oxygen species levels without classical biochemical and morphological apoptotic features were seen. However, the fractions failed in upregulating either caspase-3 activation or cytochrome c release in the cancer cells.

CONCLUSION

Overall, these results suggest that the cytotoxic effect of MC on the selected cancer cells is mediated by loss of mitochondrial function via loss of respiration leading to cell death rather than by the classical release of cytochrome c or caspase-3 activated apoptosis.

Identical mitochondrial somatic mutations unique to chronic periodontitis and coronary artery disease

Context:

The inflammatory processes involved in chronic periodontitis and coronary artery diseases (CADs) are similar and produce reactive oxygen species that may result in similar somatic mutations in mitochondrial deoxyribonucleic acid (mtDNA).

Aims:

The aims of the present study were to identify somatic mtDNA mutations in periodontal and cardiac tissues from subjects undergoing coronary artery bypass surgery and determine what fraction was identical and unique to these tissues.

Settings and Design:

The study population consisted of 30 chronic periodontitis subjects who underwent coronary artery surgery after an angiogram had indicated CAD.

Materials and Methods:

Gingival tissue samples were taken from the site with deepest probing depth; coronary artery tissue samples were taken during the coronary artery bypass grafting procedures, and blood samples were drawn during this surgical procedure. These samples were stored under aseptic conditions and later transported for mtDNA analysis.

Statistical Analysis Used:

Complete mtDNA sequences were obtained and aligned with the revised Cambridge reference sequence (NC_012920) using sequence analysis and auto assembler tools.

Results:

Among the complete mtDNA sequences, a total of 162 variations were spread across the whole mitochondrial genome and present only in the coronary artery and the gingival tissue samples but not in the blood samples. Among the 162 variations, 12 were novel and four of the 12 novel variations were found in mitochondrial NADH dehydrogenase subunit 5 complex I gene (33.3%).

Conclusions:

Analysis of mtDNA mutations indicated 162 variants unique to periodontitis and CAD. Of these, 12 were novel and may have resulted from destructive oxidative forces common to these two diseases.