Eating green potatoes has reportedly led to
poisoning attributed to potato glycoalkaloids (
PGA), primarily
alpha-solanine and
alpha-chaconine. Concentrations of
PGA increase during the greening of potatoes but are reportedly much higher in potato
tops (leaves). As it is known that members of the UK Bangladeshi community consume potato
tops, a study of the toxic hazard that may be associated with the consumption of green potato
tops has been carried out.
PGA in seven potato varieties were determined by HPLC. Tubers protected from light contained 0.05-0.65 mg/100 g
alpha-solanine and 0.3-0.63 mg/100 g
alpha-chaconine. Concentrations in leaf samples ranged from 0.64 to 22.6 mg
alpha-solanine/100 g and 0.06 to 55.7 mg
alpha-chaconine/100 g. Aqueous leaf extracts were cytotoxic to Chinese hamster ovary cells and lysed human, rat and hamster blood cells with no difference in sensitivity among species.
Oral administration of potato
tops to rats, mice and Syrian hamsters had no adverse effects at the highest practicable dose. A mixture of
alpha-solanine and
alpha-chaconine (1:1, w/w) given orally at doses of up to 50 mg/kg
body weight to hamsters had no effect, but a single ip injection of 25 mg/kg
body weight or greater was lethal, with
bleeding in the gut. High concentrations of cytotoxic
PGA were found in some potato
tops, but their effect in laboratory animals was minimal. It is concluded that the consumption of moderate quantities of potato
tops (2-5 g/kg
body weight/day) is unlikely to represent an acute health hazard to humans.