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. DIARRHOEA
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 diarrhoea in 400 patients (Khin-Maung et al 1985). 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 diarrhoea after 16 hours and up to 24 hours. The group given berberine alone showed a significant reduction in diarrhoea 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 diarrhoea in the tetracycline or berberine group were © 2007 Elsevier Australia
shown. A later randomised, double-blind clinical trial compared 200 mg of berberine four times daily plus tetracycline, with tetracycline alone in 74 patients with diarrhoea resulting from V. c/io/erae(Khin-Maung etal 1987). There were no statistically significant differences between the two groups.
An RCT evaluated the effect of berberine sulfate in 165 men with E. coll or V. c/io/eraeinduced diarrhoea as compared to tetracycline (Rabbani et al 1987). Patients with E. coil were given a single 400 mg dose and those with V. choleraewere given either a single 400 mg dose or 1200 mg (400 mg every 8 hours), combined with tetracycline. Berberine reduced mean stool volumes by 48% in the E. co//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 tetracycline did not show any statistical improvement over tetracycline alone in the V. cholerae group.
A follow-up randomised, placebo-controlled trial was designed to evaluate the antisecretory and antimicrobial potential of various antidiarrhoeal agents including berberine, in patients with active diarrhoea due to vibrio cholerae or enterotoxic E. coll (Rabbani 1996). 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 diarrhoea resulting from E. coll 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 (Gupte 1975). 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 (Choudry et al 1972). 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 (Gupte 1975) used a higher dose of berberine (10 mg/kg/day), which produced better results; however, the equivalent amount of goldenseal for Goldenseal 636
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 (Yuan et al 1994). 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 antidiarrhoeal effect of berberine might be partially due to its ability to delay small intestinal transit time.
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