Supplementation with an extract of soursop leaves alleviated pain symptoms, depression, and anxiety in a mouse model of fibromyalgia, researchers report.
Their study, “Diets supplemented with Annona muricata improve the symptoms of fibromyalgia,” was published in the journal PharmaNutrition.
Fibromyalgia symptoms such as chronic muscular pain, depression, and anxiety can affect patients’ health-related quality of life.
The medicinal properties of soursop extract are well-reported in the literature, according to the study’s authors. Its benefits in easing symptoms of inflammation, pain, diabetes, infections, and cancer have been validated in laboratory tests. However, its role in relieving fibromyalgia symptoms has not been very well-explored.
Soursop is the common name of the Annona muricata L, a tree native to the central and South America, found especially in the Amazon region.
Researchers supplemented the standard diet of mice with different concentrations of soursop leaf extract (15% and 30%) for four weeks, after which fibromyalgia was experimentally induced in the mice to test the effectiveness of the extract in preventing fibromyalgia symptoms. Intermittent cold stress (ICS) was used to induce fibromyalgia-like symptoms.
A total of 60 mice were included. They were divided into six groups that all received the standard diet with or without varying supplements. These six mouse groups included healthy controls, ICS controls, and four ICS groups that received either 0.5% acetaminophen (commonly known as paracetamol), 15% soursop extract, 30% soursop extract, or a combination of 0.5% acetaminophen plus 30% soursop leaf extract.
Compared with the healthy controls, the ICS mice had significantly worse muscle strength, inflammation, and altered behavior, the team noted.
Impact of the extract on increased sensitivity to pain (hyperalgesia), a distinct symptom of fibromyalgia, was tested in the mice. The researchers found that both concentrations of the soursop leaf extract significantly reduced hyperplasia compared with the standard diet alone. Both mechanical and heat-induced hyperalgesia was markedly reduced in the group that received soursop extract, the team found.
Exploratory behavior is an indicator of anxiety and is measured using the hole-board task, which measures the mice’s willingness to put their heads through holes in a board. The study found that both the 15% and 30% soursop leaf extract significantly improved the exploratory response of the ICS mice.
Assessment of behavioral changes in the mice served as indicators of both anxiety and depression. Soursop extract and acetaminophen consumption considerably alleviated depression and anxiety in the mice as indicated by improved behavior.
“The [soursop extract] reduced symptoms of chronic inflammation and fatigue of animals treated with the ICS, whereby, in certain cases, the results were similar to those of the control group used [acetaminophen],” the researchers wrote.
According to a press release, “the next step will be to carry out clinical tests with patients, to corroborate the extract’s activity and establish a safe and effective dose in humans.”
“The consumption of extract of Annona muricata L. leaves in pharmaceutical form and in the correct dosage can reduce the chronic pain, anxiety, and depression that accompany this disease,” said Ana María Quilez, PhD, from the medicinal plants research group at the University of Seville, which carried out the study.