Cancer is one of the leading causes of increasing global mortality with uprising health concerns and threats. Unfortunately, conventional chemotherapy has substantial side effects, limiting its relevance and prompting a quest for safe and efficient alternatives. For thousands of years, plants have provided a rich reservoir for curing a variety of ailments, including cancer. According to the World Health Organization, medicinal plants would be the best source of medications. However, only 25% of drugs in the present pharmacopoeia are derived from plants. Hence, further research into different plants is required to better understand their efficacy. Twenty extracts of widely distributed Middle Eastern plants were screened for the cytotoxic effect against lung cancer cell lines (A549). Eleven plants showed IC50 below 25 μg/mL, consequently, the bioactive extracts were further fractionated by graded precipitation using absolute ethanol. All fraction A (FA; crude polysaccharides precipitate) showed potent IC50, 0.2-5.5 μg/mL except the FA of Brassica juncea, Silybum marianum, and Phaseolus vulgaris, whereas FB fractions (filtrate) of Anastatica hierochuntica, Plantago ovate, Tussilago farfara, and Cucurbita moschata had lower efficacy than other fractions with IC50 values in the range of 0.1-7.7 μg/mL. The fractions of FA Taraxacum officinale and FB Ziziphus spina possess the most potent cytotoxic activity with IC50, 0.2 and 0.1 μg/mL, respectively. Moreover, cell cycle analysis of both fractions revealed an arrest at G1/S-phase and activation of apoptosis rather than necrosis as the mode of cell death. Therefore, T. officinale and Z. spina fractions may pave the way to manage lung carcinoma as an alternative and complementary food regimen.
Keywords: Anastatica hierochuntica; Artemisia herba; Taraxacum officinale; Ziziphus spina; apoptosis; cell cycle.