Research

Carcinogenic nitrosamines in traditional beer as the cause of oesophageal squamous cell carcinoma in black South Africans

Charles Isaacson, Pride Mothobi, Martin Hale, Lomas Kumar Tomar, Charu Tyagi, Pradeep Kumar, Yahya Essop Choonara, Mario Altini, Viness Pillay

Abstract


Background. Before the 1930s, squamous cell carcinoma (SCC) of the oesophagus was almost unknown among black South Africans. From the 1930s the annual frequency rose. A dietary cause was sought, the staple diet of black people having changed from sorghum to maize (corn), with traditional beer being brewed from maize. Carcinogenic N-nitrosamines in traditional beer were suggested as a cause of SCC of the oesophagus, with Fusarium moniliforme, a corn saprophyte, thought to play a role. 

Objectives. To confirm the presence of N-nitrosamines in traditional beer and demonstrate a mechanism for the oncogenesis of oesophageal carcinoma. 

Methods. Analysis by high-performance liquid chromatography was conducted for the identification of nitrosamines in traditional beer samples, and molecular docking studies were employed to predict the affinity between N-nitrosamines and the S100A2 protein. 

Results. Carcinogenic N-nitrosamines were identified in all six samples of traditional beer examined (N=18 analyses), and docking studies confirmed a high affinity of the nitrosamine N-nitrosopyrrolidone with the S100A2 protein. This may result in the altered expression of the S100A2 protein, leading to tumour progression and prognosis. 

Conclusion. It is suggested that carcinogenic N-nitrosamines in traditional beer are a major factor in the causation of SCC of the oesophagus in black South Africans. N-nitrosamines have been shown to produce cancer experimentally, but there has not been conclusive epidemiological evidence that N-nitrosamines are carcinogenic to humans. This study is the first to demonstrate the potential link between N-nitrosamines and a human tumour.


Authors' affiliations

Charles Isaacson, Department of Anatomical Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; National Health Laboratory Service, Johannesburg, South Africa

Pride Mothobi, Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

Martin Hale, Department of Anatomical Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; National Health Laboratory Service, Johannesburg, South Africa

Lomas Kumar Tomar, Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

Charu Tyagi, Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

Pradeep Kumar, Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

Yahya Essop Choonara, Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

Mario Altini, Department of Anatomical Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

Viness Pillay, Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Sciences, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa

Full Text

PDF (302KB)

Keywords

Squamous carcinoma; Oesophagus; Nitrosamines; Traditional beer; HPLC; Molecular docking

Cite this article

South African Medical Journal 2015;105(8):656-658. DOI:10.7196/SAMJnew.7935

Article History

Date submitted: 2015-02-03
Date published: 2015-09-21

Article Views

Abstract views: 500
Full text views: 254

Comments on this article

*Read our policy for posting comments here