I'm posting this after reading the article, linked by Burak in another thread, where it is suggested that piperine activates AMPK. From there I envisaged a longevity-boosting effect since AMPK downregulates mTOR.
As it turns out, piperine has been observed to boost mTOR rather than decreasing it in some context, like in peritoneal resident macrophages. In this case boosting mTOR equals to boosting immunity since upregulation of macrophages potentiates the anti-bacterial activity in that substrate. Piperine improves the cellular absorption of leucine, whose signal is necessary to mTOR activation.
Oncotarget. 2015 Oct 20; 6(32): 32468–32483.
Published online 2015 Oct 2. doi: 10.18632/oncotarget.5957
PMCID: PMC4741706
Piperine metabolically regulates peritoneal resident macrophages to potentiate their functions against bacterial infection
Hao Pan,#1 Li-Hui Xu,#2 Mei-Yun Huang,1 Qing-Bing Zha,3 Gao-Xiang Zhao,1 Xiao-Feng Hou,1 Zi-Jian Shi,3 Qiu-Ru Lin,1 Dong-Yun Ouyang,1 and Xian-Hui He1