A new meta-analysis pooled data from animal studies to see if a traditional Chinese herbal formula called Si-ni-san could affect depression-like behaviors. The analysis included 384 rodents across multiple experiments. Researchers looked at common behavioral tests, such as sucrose preference and forced swim tests, as well as changes in brain chemicals and stress hormones.
In the behavioral tests, animals given Si-ni-san showed increased sucrose preference, which suggests less anhedonia, and reduced immobility time in forced swim and tail suspension tests, which suggests less despair-like behavior. The analysis also found increases in monoamine neurotransmitters, reductions in HPA axis hormones, and decreases in pro-inflammatory cytokines. However, the safety of Si-ni-san was not reported in these studies.
The authors note several important limitations. There was substantial heterogeneity across the studies, meaning the results varied widely. There was also a risk of bias, and the phytochemical makeup of the herbal formula was not well characterized. Because this is a preclinical meta-analysis in animals, the findings cannot be directly applied to humans. The results are hypothesis-generating and do not prove that Si-ni-san treats depression in people.
What this means for readers: This research is early and does not provide evidence that Si-ni-san is an effective or safe treatment for depression in humans. Anyone considering herbal remedies for depression should talk with their doctor first.
