Proposition of a low cost field assay to determine antiproliferative properties of indigenous plants using Dugesia dorotocephala (brown planaria)

摘要

Cancer is a major health problem, not only in developed countries, but also in developing countries where the number of cancer-related ailments is growing. Chemotherapy is the most commonly used treatment option but side effects associated with its use necessitates the search for alternatives. Over 80% of the population in developing countries relies on ethnomedicinal plants for primary healthcare including cancer. There are concerns about the safety and efficacy of such ethnomedicines but unfortunately, the prerequisite laboratory set up for such evaluation is usually lacking. An inexpensive, sensitive, field oriented assay would greatly facilitate and improve research into alternative anticancer plant based medicinal therapies. This study proposes to evaluate the suitability of Dugesia dorotocephala as an alternative laboratory method for antiproliferative properties of indigenous plant extracts. Brown planaria, D. dorotocephala maintained under laboratory settings were divided into three groups, each containing a minimum of three planaria. Each planaria was dissected into two using a sterile scalpel. The tail section was transferred into a 24 well plate, after measuring its length in mm. Root and bark extracts of Colophospermum mopane and Schinziophyton rautanenii were prepared at concentrations (5 and 20 µg/ml) and incubated with dissected planaria for 8 days, fresh extracts were replaced every two days and the planaria was observed for its length in addition to the development of eye spots. Planaria regeneration was observed in control wells receiving no treatment, however, a growth promoting effect was exhibited by S. rautanenii root extract in a time and concentration dependant manner at 5 µg/ml. An anti-proliferative effect was observed for S. rautanenii bark extracts and this was observed at both concentrations, with the higher extract of 20 µg/ml exhibiting more growth antiproliferative activity. The extract of C. mopane root had a cytotoxic effect at concentration 20 µg/ml, causing planaria death. The use of Planaria represents an inexpensive, quantifiable, field oriented method to evaluate the effect of indigenous plant extracts in the absence of cell culture. This method is capable of distinguishing between different treatments, extract concentrations as well as time points.