Evaluation of acute administration of natural products with potential diuretic effects, in humans

Abstract

In order to evaluate the potential diuretic effect of two natural products, Elephantopus scaber and Alpinia speciosa, a trial administration was carried out in ten healthy volunteers and the effects compared to the those of a placebo. The substances were given on different days, with a seven day interval between doses. The amount of substance administered to the subjects was five times the usual dose i.e. 7.5 g/100 ml and 0.8 g/100 ml respectively. The following parameters were measured: urinary and plasma sodium, potassium, uric acid, calcium, phosphate, urea, creatinine. The subjects were also examined clinically and total urinary volume was assessed. The only significant findings (p < 0.05) was a slight diuresis with Alpinia speciosa, which also lowered the diastolic (p < 0.05) and systolic (p < 0.01) blood pressures. No effect on electrolytes or renal function parameters was observed, and this probably excludes any renal tubular or glomerular effect from these substances.

Herbal medicines as diuretics: A review of the scientific evidence

“…It was also shown to be quite toxic, with an LD 50 of 2 and 6 mg kg −1 when given intra-peritoneally and orally, respectively, and it had mixed effects on intestinal transit times; times were decreased by an aqueous extract and increased by a hydro-alcoholic extract. The second study was an acute, placebo-controlled trial (6 h) in 10 subjects (Laranja et al, 1991). The results of this study supported those of Poli et al (1992) as UV and urinary, and plasma, electrolytes (i.e., calcium, phosphate, uric acid, sodium and potassium) were unchanged.…”

“…This is extremely important and potentially very useful in countries that have limited resources for the production and importation of modern medicines (Doan et al, 1992) as they are accessible, cheap and applicable to the local population. Our evidence is also of potential use in generating monographs and recommendations on their use (Englert and Harnischfeger, 1992;Laranja et al, 1991). Another areas where the current knowledge can be applied include the substantiation of marketed products (e.g., Urol mono ® ; Leuschner, 1995), where the evidence can be quite limited.…”

“…Although, this latter effect needs further corroboration in controlled human intervention trials Allium sativum +ve/- (Ribeiro et al, 1988) +ve/- (Sharafatullah et al,1986), 0/0 (Pantoja et al, 1996), 0/0 (Pantoja et al, 1991) Low Most studies have been conducted in acute animal studies and show no real effects. Such evidence does not seem to warrant further trials at the present time Elephantopus scaber 0/0 (Laranja et al, 1991) 0/- (Poli et al, 1992) Low The single study in humans showed little effect on diuresis and natriuresis although questions still remain relating to the effect of higher doses Foeniculum vulgare 0/0 (Caceres et al, 1987), +ve or 0/+ve or 0 (El Bardai et al, 2001), +ve or 0/+ve or - (Beaux et al, 1997) Medium Evidence for a diuretic effect with Foeniculum vulgare seems mixed at the present time and this relates to a number of factors that have contributed to these studies, including: dose; the animal model used; the method and time at which diuresis was measured; and, the route of administration Fraxinus excelsior 0/0 (Casadebaig et al, 1989), +ve/+ve (Eddouks et al, 2005) Medium These studies are conflicting and require further clarification. Such studies need to construct dose-response curves; determine the effect of different extract preparations; and, account for the possible effect of differing animal models Hibiscus sabdariffa -/+ve (Herrera-Arellano et al, 2004) +ve/+ve (Caceres et al, 1987), +ve or 0/- (Onyenekwe et al, 1999) 0/- (Odigie et al, 2003) Medium This evidence is again mixed and studies are needed to assess diuretic and natiuretic effects are measured concurrently, and the effect of acute and chronic ingestion of Hibiscus sabdariffa Imperata cylindrica 0/0 (Doan et al, 1992) −ve/0 (Sripanidkulchai et al, 2001) Low Imperata cylindrica would not seem to act as a diuretic as it had no effect on diuresis or natriuresis Olea europaea 0/- (Ribeiro et al, 1988), 0/- (Somova et al, 2003) Low Studies have only assessed urinary output and shown no effect.…”

“…Indeed, it has been used as an analgesic, anti-emetic, anti-inflammatory, anti-microbial. It has been used in conditions such as bronchitis, smallpox, diarrhoea and suggested to have cytotoxic and anti-tumoral properties (Laranja et al, 1991;Avani and Neeta, 2005;Xu et al, 2006).…”

“…Two studies have tested its diuretic properties; ine in conscious rats (Poli et al, 1992) and the other in a human trial (Laranja et al, 1991). Poli et al (1992) gave Elephantopus scaber to conscious rats and showed no effect on UV after 3 h. Its effect on UNa not tested.…”