Goldenseal has not been significantly investigated under clinical trial conditions, so evidence is derived from traditional, in vitro and animal studies. Many of these have been conducted on the primary alkaloids. All results are for the isolated compound berberine, and although this compound appears to havevarious demonstrable therapeutic effects, extrapolation of these results to crude extracts of goldenseal is premature. It should also be noted that equivalent doses of the whole extract of goldenseal are exceptionally high.
A double-blind, placebo-controlled, randomised trial examined the effect of berberine alone (100 mg four times daily) and in combination with tetracycline for acute watery diarrhea in 400 patients. Patients were divided into four groups and given tetracycline, tetracycline plus berberine, berberine or placebo; 185 patients tested positive for cholera and those in the tetracycline and tetracycline plus berberine groups achieved a significant reduction in diarrhea after 16 hours and up to 24 hours. The group given berberine alone showed a significant reduction in diarrhea volume (1 L) and a 77% reduction in cAMP in stools. Noticeably fewer patients in the tetracycline and tetracycline plus berberine groups excreted vibrios in their stool after 24 hours and interestingly no statistically significant improvements for patients with non-cholera diarrhea in the tetracycline or berberine group were shown. A later randomised, double-blind clinical trial compared 200 mg of berberine four times daily plus tetracychne, with tetracychne alone in 74 patients with diarrhea resulting from V. cholerae. There were no statistically significant differences between the two groups.
An RCT evaluated the effect of berberine sulfate in 165 men with E. coli or V. cholerae-induced diarrhea as compared to tetracychne. Patients with E. coli were given a single 400 mg dose and those with V. cholerae were given either a single 400 mg dose or 1200 mg (400 mg every 8 hours), combined with tetracychne. Berberine reduced mean stool volumes by 48% in the E. coli group as compared to control over 24 hours. Patients in the V. cholerae group who received 400 mg of berberine as a single dose also had a reduction in stool volume after 16 hours as compared to placebo. The combination of berberine and tetracychne did not show any statistical improvement over tetracychne alone in the V. cholerae group.
A follow-up randomised, placebo-controlled trial was designed to evaluate the antisecretory and antimicrobial potential of various antidiarrheal agents including berberine, in patients with active diarrhea due to vibrio cholerae or enterotoxic E. coli. Berberine at a lower dose of 200 mg resulted in a reduction in stool volume of between 30% and 50% without significant side-effects. Berberine was again shown to be more effective in the treatment of diarrhea resulting from E. coli than in cholera.
Berberine may also be effective in the treatment of giardiasis. A comparison controlled study of 359 children aged between 4 months and 14 years compared berberine (10 mg/kg/day) with metronidazole (20 mg/kg/day) for up to 10 days. Negative stool samples were evident in 90% of children receiving berberine after 10 days with 83% remaining negative after 1 month’s duration. The results were comparative with the metronidazole (Flagyl) group (95% after 10 days and 90% after 1 month), without side-effects. In a similar study, 40 children aged 1-10 years with giardiasis were given berberine (5 mg/kg/day), metronidazole (10 mg/kg/day) or placebo (vitamin B syrup) for 6 days. In the berberine group 48% of children were symptom-free after 6 days and 68% had no giardia cysts on stool analysis as compared to the metronidazole group who experienced a 33% reduction in symptoms and a 100% clearance rate for cysts. These results show that berberine may be more effective than Flagyl for symptom relief, but not as effective for clearing the organism from the gastrointestinal tract. The aforementioned study used a higher dose of berberine (10 mg/kg/day), which produced better results; however, the equivalent amount of goldenseal for either dose would be exceedingly high based on an average berberine content of 5%, which would be inappropriate.
Small intestinal transit time was evaluated in 30 healthy subjects in a controlled study. Transit time was significantly delayed from 71.10 ± 22.04 minutes to 98.25 ± 29.03 minutes after oral administration of 1.2 g of berberine. These results suggest that the antidiarrheal effect of berberine might be partially due to its ability to delay small intestinal transit time.
In a RCT, oral doses of 0.5 g of berberine, given twice daily for 3 months in 32 hypercholesterolaemic patients, resulted in a 29% reduction in serum cholesterol, a 35% reduction in triglycerides and a 25% reduction in LDL-cholesterol. HDL-cholesterol levels remained unchanged. Berberine also significantly improved liver function as noted by liver enzyme levels.
CHRONIC CONGESTIVE HEART FAILURE
The efficacy and safety of berberine in chronic congestive heart failure was studied in a randomised, double-blind, controlled study in 1 56 patients with chronic heart failure. All patients received conventional treatment and 79 patients in the treatment group also received 1.2-2.0 g/day of berberine for 8 weeks. Quality of life was greatly improved in the berberine group in comparison to controls, as measured by a significant increase in left ventricular ejection fraction, less fatigue and a greater capacity to exercise. A significant reduction in mortality was also noted during the 24-month follow-up (7 in the treatment group as compared to 13).
The acute cardiovascular effects of intravenous berberine (0.02 and 0.2 mg/kg/min for 30 minutes) were studied in 12 patients with refractory congestive heart failure. At the lower dose, a 14% reduction in heart rate was noted, whereas 0.2 mg/kg resulted in a 48% decrease in systemic vascular resistance and a 41% decrease in pulmonary vascular resistance. Right atrium and left ventricular end-diastolic pressures were reduced by 28% and 32%, respectively. Cardiac index, stroke index, and left ventricular ejection fraction were also significantly enhanced.
A controlled clinical trial of 51 patients with ocular trachoma infections investigated the effectiveness of berberine over 3 weeks with a 1 -year follow-up. Subjects who used the 0.2% berberine either by itself or combined with sulfacetamide demonstrated significant symptom improvement and tested negative for Chlamydia trachomatis, with no relapse after 1 year.
A later comparison controlled clinical study also evaluated the effectiveness of the topical treatment of berberine for trachoma in 32 microbiologically confirmed patients. A 0.2% berberine solution (2 drops in each eye, three times daily) was found to be more effective than sulfacetamide (20%) in reducing both the course of the trachoma and the serum antibody titres against C. trachomatis. Berberine eyedrops were compared to berberine plus neomycin ointment, sulfacetamideand placebo in a double-blind, controlled clinical trial in 96 primary school children. Patients in the berberine group were asked to use 2 drops (0.2% berberine) of the solution in each eye, three times daily and to additionally apply a berberine ointment (0.2%) at night for 3 months. Children treated with only the berberine had an 87% clinical response rate, compared to 58% in the berberine and neomycin group; however, only 50% tested negative in follow-up microbiological tests.
Traditionally, it is used as a bitter digestive stimulant that improves bile flow and liver function.
• Tincture (1:3): 2.0-4.5 mL/day or 1 5-30 mL/week. Tincture (1:10): 6-12 mL/day
• Dried rhizome and root: 1.5-3 g/day by decoction
• Eyewash: 0.2% berberine solution, 2 drops in each eye, three times daily