Toxicity Evaluation Of Selected Malaysian Weeds Using Brine Shrimp Lethality Assay

Weed is a plant that is growing where it is not wanted, it can have strong and healthy growth, and is able to overgrow valued plants by overcrowding, thus depleting soil nutrients and moisture that would otherwise be available to preferred plants. Weeds typically produce large numbers of seeds, assisting their spread. They are often excellent at surviving and reproducing in disturbed environments and are commonly the first species to colonise and dominate in these conditions. Despite the negative impacts of weeds, some plants usually thought of as weeds may actually provide some benefits. Some attributes include soil stabilization, habitat and feed for wildlife, nectar for bees, aesthetic qualities, add organic matter, provide genetic reservoir, human consumption, and provide employment opportunities. Weeds such as mahang (Macarangga gigantea), subang nenek (Sphilanthes acmella), tahi ayam (Lantana camara), kancing baju (Bidens pilosa), senduduk (Melastoma malabathricum), gelenggang (Senna alata), and tahi babi (Ageratum conyzoides) are known for their traditional use, namely to treat worm infestation, viral and bacterial infection, diarrhea, inflammation, and other metabolic disorders. Brine Shrimp Lethality Assay is an invitro assay employs to test the toxicity properties of plants extracts/compounds; based on number of dead naupli when introduced to the test extract/compound. The extract/ compound is considered not-toxic when the LC₅₀ value is >5000 μg/ ml. LC₅₀ value is the Lethal Concentration of the extract that killed 50 % of the Artemia naupli population. It showed that five out of seven weeds tested have LC₅₀ value of >5000 μg/ ml; except for Macarangga gigantea (LC₅₀ value of >2500 μg/ ml) and Bidens pilosa (LC₅₀ value of 1250 > LC₅₀ > 25000 μg/ ml). (author)