Data are available from both controlled and uncontrolled studies that have investigated the effects of artichoke leaf extract in hyperlipidemia. Most studies use Hepar SL forte® orValverde Artischoke bei Verdauungsbeschwerden (artichoke dry extract) containing 450 g of herbal extract as a coated tablet.
Data from five uncontrolled studies and case series suggests that artichoke leaf extract and cynarin have lipid-lowering effects and a possible role as adjunctive therapy in hyperlipidaemia.
A Cochrane systematic review that analysed the results of two controlled studies concluded that artichoke leaf extract appears to have a modest positive effect on the levels of total cholesterol and LDL; however, there is insufficient evidence to recommend it as a treatment option for hypercholesterolaemia and trials with larger samples sizes are still required.
One of the studies was a randomised, placebo-controlled, double-blind, multicentre trial involving 143 subjects with total cholesterol levels >7.3 mmol/L (>280 g/dL). A dose of 1800 mg artichoke leaf extract was administered daily for 6 weeks. Active treatment resulted in 18.5% decrease in serum cholesterol compared with 8.6% for placebo, a result that was significant. No differences were observed between the groups for blood levels of either HDL or triglycerides. Although dietary habits were recorded, the food intake was not strictly controlled in the entire patient sample. The second randomised, placebo-controlled, double-blind study involved 44 healthy volunteers and compared 1920 mg artichoke extract daily to placebo over a 12-week treatment period. No significant effects on serum cholesterol levels were observed in this study; however, subgroup analyses suggested that patients with higher initial total cholesterol levels experienced a significant reduction in total cholesterol levels compared to placebo.
ESCOP approves the use of artichoke leaf as an adjunct to a low-fat diet in the treatment of mild to moderate hyperlipidaemia (ESCOP 2003).
A double-blind, randomised, placebo controlled trial of 247 patients with functional dyspepsia (persistent or recurrent pain or discomfort in the upper abdomen with one or more of the following symptoms: early satiety, postprandial fullness, bloating, and nausea) found that treatment with two capsules of 320 mg artichoke leaf extract LI 220 (HeparSL(R) forte) taken three times daily significantly improved overall symptoms over the 6 weeks compared with the placebo. Additionally, active treatment significantly improved global QOL scores compared with the placebo.
A randomised, open study of 454 subjects investigated the efficacy of a low-dose artichoke leaf extract (320 mg or 640 mg daily) on amelioration of dyspeptic symptoms and improvement of QOL. Both doses achieved a significant reduction of all dyspeptic symptoms, with an average reduction of 40% in global dyspepsia score. Although no differences in primary outcome measures were reported between the two treatment groups, the higher dosage resulted in greater improvements in anxiety.
An uncontrolled study of 553 patients with non-specific digestive disorders (dyspeptic discomforts, functional biliary colic, and severe constipation) experienced a significant reduction of symptoms after 6 weeks of treatment with artichoke extract. Symptoms improved by an average of 70.5%, with strongest effects on vomiting (88.3%), nausea (82.4%), abdominal pain (76.2%), loss of appetite (72.3%), constipation (71.0%), flatulence (68.2%), and fat intolerance (58.8%). In 85% of patients the global therapeutic efficacy of artichoke extract was judged by the physicians as excellent or good.
The German Commission E approves artichoke leaf and preparations made from artichoke leaf as a choleretic agent for dyspeptic problems.
IRRITABLE BOWEL SYNDROME
Artichoke leaf extract appears to have substantial benefits in IBS, according to the available evidence; however, large controlled studies are required to confirm these observations.
A subgroup of patients with IBS symptoms was identified from a sample of subjects with dyspeptic syndrome who were being monitored for 6 weeks. Analysis of the data revealed 96% of patients rated artichoke leaf extract as better than or at least equal to previous therapies administered for their symptoms. Physicians also provided favourable reports on its effects in these patients.
More recently, a study of 208 adults with IBS observed before and after a 2-month intervention period of changes in symptoms. A significant reduction in the incidence of IBS by 26.4% and a significant shift in self-reported usual bowel pattern toward ‘normal’ were also reported after treatment. The Nepean Dyspepsia Index (NDI) total symptom score significantly decreased by 41% after treatment and a significant 20% improvement in the NDI total QOL score.
REDUCING ALCOHOL-INDUCED HANGOVER
Artichoke extract does not prevent the signs and symptoms of alcohol-induced hangover in healthy adults according to a small randomised, double-blind, crossover trial. The dose used in the study was 960 mg taken immediately before and after consuming alcohol for 2 days.
• 1:2 liquid extract: 3-8 miyday in divided doses.
• 6 g daily of dried cut leaves, pressed juice of the fresh plant or equivalent.
ACCORDING TO CLINICAL STUDIES
• Hyperlipidaemia: 4-9 g/day of dried leaves or 1800 mg/day artichoke leaf extract.
• Dyspepsia: artichoke leaf extract 640 mg/day.
• IBS: artichoke leaf extract 640 mg/day.