Recent research has established correlations between stress, anxiety, insomnia and excess body weight and these correlations have significant implications for health. Substantial and prolonged stress and anxiety can cause adverse health effects to the immune function, hormone levels, enzymes and gastrointestinal function. Recently links have been established between chronic stress and obesity [1, 2]. Increased levels of the stress hormone, cortisol, have been correlated to increased eating of high caloric foods and sweets. Additionally, among people who identified themselves as "stress eaters," weight gain tended to increase over time . It is also known that stress worsens insomnia, and insomnia has been linked to overweight and obesity [4, 5]. Among 6,115 people, ages 32–59, comparisons were made between the weights of those who slept for a normal period of time (7–9 hours) and those who slept for shorter or longer periods of time. Those who slept for shorter periods of time than normal were more likely to be obese and those who slept for longer periods of time were less likely to be obese. Those who slept 2–4 hours per night, 5 hours per night or 6 hours per night were respectively 73%, 50% and 23% more likely to be obese. Those who slept for 10 or more hours were 11% less likely to be obese .
Interventions for stress and anxiety range from nutritional support to the use of medications such as benzodiazepines and selective serotonin reuptake inhibitors. Recently a United States Patent (No 6,582,735) was granted for the use of an extract of Magnolia officinalis bark for stress related conditions involving elevated cortisol, such as control of body weight, sleep disturbances and restlessness.
Extracts of Magnolia officinalis bark and its active constituent, honokiol, have been studied in various mouse models that have compared the activity to diazepam (a benzodiazepine anxiolytic used to treat anxiety disorders since the 1960's) [6–8]. The studies found that honokiol had an anxiolytic effect without the common side effects of diazepam (motor dysfunction, sedation or amnesia). The Magnolia officinalis bark extract and an extract of Phellodendron amurense bark were tested in an animal model for stress, the Chick Social Separation Stress Procedure, with positive results . Both extracts reduced distress vocalization and stress-induced analgesia without causing sedation. Berberine, a constituent of the Phellodendron extract, has demonstrated a significant anxiolytic effect in the black and white and the elevated plus maze tests in mice . Berberine has also demonstrated an antidepressant effect in the forced swim test in mice .
The subject of this study, Relora® (Next Pharmaceuticals, Inc, Salinas, CA), is a proprietary dietary supplement formulation consisting of a blend of extracts of Magnolia officinalis bark and Phellodendron amurense bark standardized to honokiol and berberine, respectively.
In previously conducted trials by the study sponsor (unpublished in-house data), Relora has demonstrated some efficacy for reducing perceived anxiety and enhancing feelings of well-being. One study also measured the effects of Relora on salivary cortisol and found that it had some effect on morning cortisol while also raising dehydroandrostenedione levels (DHEA).
The purpose of this study was to conduct a placebo-controlled clinical trial to determine the effects of Relora on anxiety using psychometric questionnaires, cortisol levels and sleep (questionnaires). A part of this study that investigated the effects of Relora on stress-related changes in body weight has previously been published .