10.5 Anticancer Activity of Plants/Plant Extracts
Cancer is currently one of the leading causes of death worldwide and it is estimated
that there are more than 1.6 million deaths occurred due to invasive cancer in 2013
(Siegel et al. 2013 ). The economic burden of cancer has necessitated the search for
new, safe, affordable, and effective anticancer drugs. Purified asiatic acid fraction
fromCentella asiaticawhen tested in vitro on human melanoma SK-MEL-2 cells
showed induction of apoptosis and decline in their viability in a time and dose
dependent manner (Park et al. 2005 ). Similarly, induction of apoptosis in Hela
cervical cancer cell line was recorded with Goniothalamin isolated from
Goniothalamus macrophyllus(Aied et al. 2013 ). Ethanolic extract ofAtractylis
lanceashowed inhibition of HEP-G2 liver cancer cell lines in a concentration and
time dependent manner (Wei et al. 2013 ). Apoptosis of cancer cell in human
intestinal epithelium was observed in presence of sesquiterpenes, Salograviolide-A
isolated from Centaurea ainetensis (El-Najjar 2008 ). Kundusen et al. ( 2011 )
demonstrated decrease in tumor volume and increase in weight of Swiss albino
mice as a function of treatment with methanolic leaf extract ofCitrus maxima.
Similarly, ethanolic extract of plant,Derris scandensresulted in death of human
colon cancer cell line HT-29 in in vitro (Arunee et al. 2014 ). Both the aqueous and
methanolic extract of plantFicus religiosa showed cytotoxicity to HT-29 and
MDA-MB-435S cancer cells in in vitro (Uddin and Grice 2011 ). Decrease in
growth of breast cancer cell lines as a function of treatment with aqueous leaf
extract ofTaraxacum officinale(Sigstedt et al. 2008 ), suppression of proliferation
of prostrate, breast, ovary, colon, lung, and bladder cancer cell lines by isolated
flavonoids fromSilybum marianum(Agarwal et al. 2006 ) and death of human
T-47D cancer cell lines by chloroform extract of plant,Physalis minima(Ooi et al.
2010 ) are few other example from many such studies carried out using different
plant/extracts and cancer cell lines.
10.5.1 Anticancer Compounds from Endophytes
Endophytic fungi have been reported to produce a myriad of anticancer substances
(Table10.4). The bioactive potential of the endophytic fungi wasfirst recognized
when world’sfirst multibillion dollar anticancer drug, Paclitaxel (Taxol), was
obtained from an endophytic fungus. Taxol is known to be a potent chemothera-
peutic agent, used for a variety of cancers including ovarian and breast cancers
(Weaver 2014 ). Wani et al. ( 1971 )first isolated and chemically characterized the
Taxol from the bark of yew plant (Taxus brevifolia). However, the amount of taxol
produced by the slow growing African yew is very small and a number of plants
need to be sacrifice to obtain a few milligrams of compound. The cost of the taxol
obtained from the plant source was a major constrain for its clinical use (Gangadevi
et al. 2009 ). Stierle et al. ( 2001 )first reported an alternative source for Taxol
226 S.I. Mohammed et al.