Against HeLa human carcinoma

Participation of Br in marine terpene biosynthesis (Section II.C) is reflected in the impressive number (several hundred) of halogenated terpenes, some with useful biological activities, that have been identified. For example, the poly halogenated sesquiterpenes isoobtusol (14) and isoobtusol acetate (15), isolated from the red alga Laurencia obtussa, showed potent activity against HeLa 229 human carcinoma cells1011. 

The potential cytotoxic activities of forty-six Strychnos alkaloids, including harmine, were tested on different cancer or normal cells cultured in vitro. At a concentration of 1-10 pg/ml, harmine showed modest activity against L 1210 cells derived from DB A/2 mouse ascites tumor and cultured HeLa cells derived from human carcinoma. The alkaloid displayed only slight activity against cultured flow 2002 cells derived from normal embryonic human lungs, and was inactive against cultured B16 melanoma cells derived from C57BL mouse melanoma [273]. 

Nemorosone and its methyl derivatives as mixture were evaluated against the human cervix carcinoma (HeLa), the human larynx carcinoma (HEp-2), prostate carcinoma (PC-3) and central nervous system carcinoma (U-251) cell lines [94]. Cuesta-Rubio et al. found that the natural product nemorosone was active against the four cell lines (IC50 values of 3.3, 3.1, 7.2 and 3.9 pM, respectively). When the mixture of methyl derivatives was used, the required concentration to reach IC50, in the cellular lines, was between ten and thirty times more concentrated. These results suggest that the presence of the keto-enolic equilibrium in nemorosone plays an important in its cytotoxicity. 

The volume of work on the antitumor activity and cytotoxicity of ILs and ILBSs is limited, with more publications on the effects ILs than their surface-active counterparts. Although discussion on the former class of compounds is outside the scope of the present article, we note that imidazolium-, phosphonium-, and ammonium-based ILs have been employed against 60 human tumor cell lines, including brain tumor cells, [83], human hepatocellular liver carcinoma [84], HeLa cancer cells [85], and human melanoma cell lines [86],... 

The cytotoxicity of diploicin (77) was evaluated by Millot and coworkers in 2009 against B16 (murine melanoma) and HaCaT (human keratinocyte) cell lines [100]. Pannarin (66), a secondary metabolite from lichen Diploicia canescens, was tested by two different research groups for its inhibitory potential against DU-145 prostate carcinoma [100] and M14 (human melanoma) cell lines with positive results [96]. Recently, the cytotoxicity of proto-lichesterinic acid (8) against HeLa cell lines has been evaluated by Brisdelli and coworkers. Its activity is based on its abdity to induce cell death through activation of caspases-3, -8, and -9 [101]. 

In another study, the EO of the leaves of the Euphorbiaceae Croton flavens L. (yellow balsam) from Guadeloupe, a native plant from the Caribbean area, was analyzed by Sylvestre et al. (2006) and as main components viridiflorene (12.2%), germacrone (5.3%), (E )-Y-bisabolene (5.3%), and P-caryophyllene (4.9%) ascertained. The EO was found to be active against human lung carcinoma cell line A-549 and human colon adenocarcinoma cell line DLD-1. Three of the 47 components of the EO, namely a-cadinol, P-elemene, and a-humulene, showed also a cytotoxic activity against tumor cell lines. Yu et al. (2007) tested the EO of the rhizome of the Aristolochiaceae Aristolochia mollissima for its cytotoxicity on four human cancer cell lines (ACHN, Bel-7402, Hep G2, HeLa). The rhizome oil possessed a significantly greater cytotoxic effect on these cell lines than the oil from the aerial plant. 

The cell growth inhibitory activity, antitumor activity, and toxicity of M-16 and M-18, the major metabolites of a new mitomycin C (MMC) derivative, KW-2149 (124), in both mice and humans were compared with those of KW-2149 and MMC in vitro and in vivo. The growth inhibitory activity of M-18, a symmetric disulfide dimer, active against human uterine cervix carcinoma HeLa S3 cells was almost equivalent to that of KW-2149, and their IC50 values were about tenfold smaller than that of MMC. The activity of M-16, a Me sulfide form, was almost equivalent to that of MMC. 

---