sTwenty four and forty hour brine shrimp toxicity test:
The 24 h brine shrimp toxicity test has been used for more
than 20 years for the assessment of the cytotoxicity of
plant materials (Meyer et al., 1982). Replicate samples of
the aqueous seed extract were prepared at a concentration
of 1 mg/mL in 3% NaCl, pH 8. A green tea infusion was
prepared in the same manner to serve as a well known
food control. Brine shrimp (Artemia salina) eggs were
hatched in salt water (3% NaCl) and nauplii were
transferred to vials containing 15 mL of test solution.
These were incubated for 24 h at room temperature.
Following incubation, the numbers of active nauplii were
counted and mean percent survival calculated for both
samples, with corresponding standard deviations.
Additional incubation to 40 h was also carried out to
determine the effect of longer exposure times. The
concentration resulting in lethality to 50% of the nauplii
(LC50) was determined from survival rates. In this test, as
well as in the reverse mutation and primary DNA damage