1. Mech Ageing Dev. 1984 Oct 31;27(3):341-58.

Effect of dietary 2-mercaptoethanol on the life span, immune system, tumor
incidence and lipid peroxidation damage in spleen lymphocytes of aging BC3F1

Heidrick ML, Hendricks LC, Cook DE.

The age-related decline in immune function, which is thought to be responsible
for the increased incidence with age of certain diseases, including cancer, has
been attributed primarily to a loss of T-lymphocyte function. As free radical
reactions may contribute to cellular deterioration and loss of cell function with
age, we investigated the effect of adding an immunopotentiating antioxidant,
2-mercaptoethanol (2-ME), to the diet of BC3F1 mice in a longitudinal study. For 
the study, young mice were divided into two groups, one of which received the
2-ME-supplemented diet. Approximately every 3 months for 2.5 years, mice from
each group were sacrificed and the spleen lymphocytes assessed for immune
function (proliferative response to concanavalin A, phytohemagglutinin, and
lipopolysaccharide and the humoral response to sheep red blood cells). The
accumulation of fluorescent products indicative of free radical damage was
measured in the spleen lymphocytes and the cytochrome P-450 content and activity 
assessed in the liver. The effect of the 2-ME-supplemented diet on the mean and
maximum life span and tumor incidence was also determined. The results showed
that the animals fed the 2-ME diet had an increased mean and maximum life span
and a postponed onset and decreased incidence of tumors. In general the
T-cell-dependent immune responses were higher in the 2-ME-fed mice compared to
the controls when the animals were young. No difference was observed between the 
two groups during mid-life. The responses declined in both groups during the
latter half of the life span, but the responses of the 2-ME-fed animals declined 
to a lesser extent. The accumulation of fluorescent products of lipid
peroxidation damage was also delayed in the lymphocytes of the 2-ME-fed mice.
Cytochrome P-450 content and activity in the liver was not different in the two
groups. The results suggest that the antioxidant activity of 2-ME delayed the
accumulation of free radical damage in spleen lymphocytes, which resulted in a
delay in the decline of immune function and was associated with the decreased
tumor incidence and increased life span.

PMID: 6334792  [Indexed for MEDLINE]