Therapeutic Potential of Gotu Kola (Centella asiatica), Phosphatidylcholine, and Taurine in Mood Disorders: A Systematic Scoping Review.

INTRODUCTION: Mood disorders are a leading cause of disability, with a substantial proportion of patients failing to respond adequately to first-line medications. Complementary interventions are thus being explored to augment standard treatment strategies. This review aimed to systematically map and describe the existing literature on the therapeutic potential of gotu kola (Centella asiatica), phosphatidylcholine, and taurine - the active nutraceutical constituents of Neurotain® Plus - in mood disorders and to assess whether the available evidence is sufficient to support subsequent meta-analyses.

METHODS: A scoping review was conducted in accordance with the JBI methodology and reported following the PRISMA-ScR guideline. PubMed, Web of Science, and Scopus were systematically searched for studies evaluating the mood-related behavioral effects of gotu kola, phosphatidylcholine, and taurine. The protocol for this review was prospectively registered in the Open Science Framework (<ext-link ext-link-type="doi" xlink:href="https://doi.org/10.17605/OSF.IO/ETRZP" xmlns:xlink="http://www.w3.org/1999/xlink">https://doi.org/10.17605/OSF.IO/ETRZP</ext-link>).

RESULTS: Of the 2,238 identified citations, 29 were included: 12 on gotu kola (three human studies, n = 91; nine animal studies), three on phosphatidylcholine (two human studies, n = 7; one animal study), and 14 on taurine (one human study, n = 130; 13 animal studies); none evaluated any combination of these compounds. Across included studies, substantial methodological heterogeneity in design, population, intervention, and outcome measures indicates that the current evidence base remains insufficient to support quantitative synthesis. For gotu kola, two randomized trials in healthy participants (n = 58) reported improvements in alertness, while an open-label study in generalized anxiety disorder patients (n = 33) reported reductions in anxiety and depressive symptoms. Animal studies consistently demonstrated antidepressant-like effects in stress-induced models, whereas effects in non-stressed rodents were generally neutral; findings for anxiety-related outcomes were variable. For phosphatidylcholine, limited human evidence from patients with bipolar disorder suggested improvements in manic symptoms and mood stability, including sustained euthymia or remission, while an animal study demonstrated antidepressant-like effects and reversal of stress-induced cognitive impairment. For taurine, a case-control study found no association between dietary taurine intake and depression. Animal studies generally demonstrated antidepressant- and anxiolytic-like effects, particularly in stress-induced models, although findings were mixed and at times context-dependent. No serious adverse events were reported in any included human study.

CONCLUSION: This review identified preliminary, hypothesis-generating evidence suggesting that gotu kola, phosphatidylcholine, and taurine may exert mood-related behavioral effects individually. However, the current evidence base remains limited, consisting primarily of animal experiments and small-scale human investigations exhibiting substantial methodological limitations and heterogeneity, precluding meaningful meta-analytic synthesis. The absence of studies evaluating the full three-component Neurotain® Plus formulation or any combination of its constituents represents an important gap in the existing literature. Randomized clinical trials and mechanistic investigations are warranted to clarify the therapeutic relevance, safety, and potential interactions of these compounds.