Uric acid, an important antioxidant contributing to survival in termites

<div><p>Reactive oxygen species (ROS) are generated spontaneously in all organisms and cause oxidative damage to biomolecules when present in excess. Accumulated oxidative damage accelerates aging; enhanced antioxidant capacity may be a positive factor for longevity. Recently, numerous studies of aging and longevity have been performed using short-lived animals, however, longevity mechanisms remain unknown. Here we show that a termite <i>Reticulitermes speratus</i> that is thought to be long-lived eusocial insect than other solitary insects uses large quantities of uric acid as an antioxidant against ROS. We demonstrated that the accumulation of uric acid considerably increases the free radical-scavenging activity and resistance against ultraviolet-induced oxidative stress in laboratory-maintained termites. In addition, we found that externally administered uric acid aided termite survival under highly oxidative conditions. The present data demonstrates that in addition to nutritional and metabolic roles, uric acid is an essential antioxidant for survival and contributes significantly to longevity. Uric acid also plays important roles in primates but causes gout when present in excess in humans. Further longevity studies of long-lived organisms may provide important breakthroughs with human health applications.</p></div

Detection and characterisation of the termite antioxidant.

<p>(A) Chromatogram from HPLC analyses and (B) free radical scavenging activities of collected samples fractionated by HPLC; the evident peak of activity was meshed with the highest peak of the HPLC chromatogram. (C) MS-spectra from LC-MS/MS analyses; fragment ion peaks of standard uric acid (upper panel) were completely matched with those of samples from termite soldiers (lower panel).</p

Strong antioxidants in termites <i>Reticulitermes speratus</i>.

<p>(A) Free radical scavenging activities in various species of insects; soluble extracts from <i>R</i>. <i>speratus</i>, mantis (<i>Tenodera aridifolia</i>), fruit fly (<i>Drosophila melanogaster</i>), silkworm (<i>Bombyx mori</i>), hornet (<i>Vespa simillima</i>) and ant (<i>Pristomyrmex punctatus</i>) were used for DPPH radical scavenging assays. Male–female, male–female paired young primary reproductives; Female–female, female–female paired young primary reproductives. Black boxes indicate male and grey boxes indicate female (n = 3–6). (B) The antioxidant activity of termite soldiers after the control, heat (boiled), and proteinase (Pro K) treatments (n = 3–6). (C) The ascorbic acid contents of termite workers and soldiers (n = 3). (D) Data are presented as means ± s.e.m. Statistical significance was assayed using the unpaired <i>t</i>-test followed by Holm’s adjustment [no significance (ns)].</p