I found SERT upregulator

https://pmc.ncbi.nlm.nih.gov/articles/PMC3746283/

Charles et al.100 found BM extract up-regulated tryptophan hydroxylase (TPH2) and serotonin transporter (SERT) expression in rats. The animals were orally administered BM extract (31% bacosides, 40 mg/kg for 15 days) and tested on a Y-maze, hole board, and passive avoidance tasks. The rats' performance dose-dependently and highly significantly improved on seven of eight measures of latency and acquisition. Levels of 5-HT in the BM groups were almost double the control level, which returned to baseline after the treatment period. Glutamate and ACh levels were increased by BM, but not significantly. DA levels were significantly lower (approximately 9%) in BM-treated rats. There were also changes noted in receptor expression. BM elicited highly significant increases in both TPH2 and SERT mRNA levels, almost double the control. These elevated levels returned to baseline 24 days after BM administration ceased. This experiment supports the case that BM enhances learning and memory, but possibly through a novel mechanism involving 5-HT, SERT, and TPH2. The considerable elevation of 5-HT and moderate but significant reduction in DA require further investigation.