Medicinal seeds Ziziphus spinosa for insomnia: A randomized, placebo-controlled, cross-over, feasibility clinical trial

To evaluate the feasibility of implementing a clinical trial protocol of the herbal seeds Ziziphus spinosa (ZS) for people with insomnia. A randomized, double-blind, placebo controlled, cross-over feasibility trial in Melbourne, Australia. After two-week run-in participants were randomized to either ZS (encapsulated granules; 2 g daily) or placebo for four weeks. After four-weeks wash-out, participants swapped to the other treatment for four weeks. Sleep quality assessed by the Insomnia Severity Index and Pittsburgh Sleep Quality Index (PSQI). Quality of life, mood, functional impairment and sleep parameters were also assessed. Twelve participants were randomized and completed both periods of cross-over (six in each sequence). Feasibility endpoints were acceptable. Improvements for sleep quality measured on the PSQI were statistically significant during the ZS treatment periods compared to placebo (t = −2.276, df = 10, 95 % CI −3.3 to −0.04, p = 0.046). There was no evidence of any significant carryover effects. However, there were period effects. Other outcomes showed no statistically significant difference between the treatments. Subjective sleep parameters measured on sleep diaries showed improvements after ZS in terms of total sleep time, sleep efficiency and sleep onset latency, but not after placebo. ZS was well tolerated with only minor adverse events. ZS is an acceptable and well-tolerated herbal candidate for the treatment of insomnia. The feasibility objectives of this study were achieved and ZS improved both subjective sleep quality and quantity compared to placebo. ZS should be explored in future clinical trials.