Ghrelin-NPY hunger system and Ninjin-yoei-to: toward healthy longevity

Abstract

Herbal medicine has not been fully accepted by mainstream medicine because of the complex nature of the formulae. However, the stringent quality control, such as that in Japan, and reproducibility of preclinical and clinical findings, together with few adverse events in aged patients, have made herbal medicine such as Ninjin’yoeito (NYT) more and more attractive for the treatment of frailty and related conditions. Klotho, originally identified as a putative aging-suppressor gene, extends lifespan and accelerates aging when disrupted. Klotho-deficient mice display multiple pathologies resembling human aging, including calcified atherosclerosis and shortened lifespan. We have recently found that NYT extends the lifespan of Klotho-deficient mice nearly 30% and improves many of the aging-related pathologies. An important action of NYT is the activation of ghrelin-neuropeptide Y (NPY) hunger system that triggers the adaptive response to starvation. The ghrelin-NPY system is dysfunctional in aging and frailty which could be improved by NYT. This review is the summary of the recent work by us and others focusing on anorexia-cachexia syndrome, frailty and herbal medicine.