## 6 Pharmacological Properties of _Apium_ Plants
### Anticancer Activities of Apium Plants  
Cancer is an important health issue throughout the world. Due to the side effects of anticancer drugs, scientists have started to focus on natural products. The discovery of anticancer natural products of plant origin such as vinblastine, vincristine, and podophyllotoxins prompted the research community to explore plant-derived natural products such as flavonoids, terpen, alkaloids, etc. due to their diverse pharmacological properties including cancer chemopre effective. Other _Apium_ species also yield similar effects. For example, in a study performed on flavonoidal fractions of _A. leptophyllum_ fruits, it was shown that the fractions had chemopreventive potential on 7,12-dimethylbenz[a]anthracene (DMBA) induced carcinogenesis in mice. DMBA is a polycyclic aromatic hydrocarbon, which acts as a procarcinogen and is an ultimate carcinogen after metabolic activation. The activity of the plant might be due to the modulation of cutaneous lipid peroxidation or enhancement of total antioxidant capacity. Flavonoid fractions were also found to be effective in suppressing skin tumor growth at a dose of 20 mg/kg [100]. Combinations of plants with other plant-based natural products are also seen in the literature. For example, _A. gravelens_ is known to be present in the herbal-marine mixture called HESA along with _Carum carvi_, _Penaeus laticulatus_, and other marine products, which are used to improve the quality of life in colon and breast cancer patients in the Near East [161]. Chemoprevention is one of the strategies that can revert or delay the response of carcinogens. Dietary factors contribute to about a third of potentially preventive cancers, long known as preventive effects of plant-based products on tumorigenesis and other chronic diseases [162]. Plants provide important and valuable compounds against this terrifying disease, and therefore using them against cancer and also consuming certain food plants would be beneficial in our fight against cancer. Several works concerning the in vitro anticancer studies of _Apium_ plants are present in the literature, in particular, those regarding both the plant species directly and some compounds previously extracted from _Apium_ species. Among the anticancer activity studies on the total species, those concerning _A. gravelens_ L. are the most important and well known. Nevertheless, other similar works are present about _A. gravelens_ var. _rapaceum_ (Mill.) Pair. (unresolved name) and _A. nodiforum_ (L.) Lag. With respect to _A. gravelens_, its seeds have widely demonstrated its in vitro efficacy as potent anticancer agents. In particular, its crude extracts in _n_-hexane, ethanol, and water showed a concentration-dependent effect on the growth inhibition (GI) of rhabdomyascroma cell lines with the _n_-hexane extract as the most efficient one. In fact, the GI percentage for this extract was 68.70% and 81.71% for the concentration of 100 and 200 ug/mL, respectively. Indeed, the GI values for the ethanolic extract and the aqueous extract at the same concentrations were lower, i.e., 59.23% and 63.09% for the former and 56.64% and 61.33% for the latter. An important result from this study was that the power of inhibiting the cell growth started only at concentrations higher than 100 ug/mL. In fact, at lower concentrations, the effects for all three extracts were minimal. On the other hand, all the crude extracts showed a very slight or no effect on the growth inhibition of murine L20B cells, not even reaching GI values of 10% in most cases. All these calculations were made by using cultures containing only the RPMI-1640 medium as a control [163]. Less notable results were observed in three other works. The first one by [PERSON] et al. studied the effect of the ethanol extract on the LNCaP prostate cancer cell lines with GI values less than 50% [164].