*4.7. Anticancer Activity (In Vivo and In Vitro)*

*M. koenigii* possesses potential secondary metabolites that could be developed as anticancer agents. In one study, the cytotoxic activity was evaluated for three extracts: hexane, ethyl acetate, and methanol of *M. koenigii* leaves against the HeLa cell line. The extracts were reported as being potently cytotoxic in nature in HeLa cancer cells. These results established the potential of *M. koenigii* as an anticancer agent in vitro [11]. Additional evidence for the anticancer activity of *M. koenigii* has been obtained from rodent cancer cell lines, as well as different in vivo cancer models [12–14,22–24,114,115]. In an early study, histopathological evidence showed that *M. koenigii* extract treatment generated a decline in neoplasms in the colon [85]. A methanolic extract of *M. koenigii* was reported to have the ability to reduce proliferation in breast cancer cell lines [116]. The total alkaloid extracted from *M. koenigii* leaves has been shown to have promising cytotoxic activity in breast cancer cells, with an IC50 of 14.4 μg/mL [117]. The anticancer activity of mahanine and isomahanine in human oral squamous cell carcinoma CLS-354 has also been reported [96].

Girinimbine, another *M. koenigii*-derived carbazole alkaloid, showed growth inhibitory activity in human hepatocellular carcinoma and lung cancer cells in vitro [118]. Rutin, quercetin, kaempferol, and apigenin, present in leaf extracts of *M. koenigii*, showed the dose-dependent inhibition of endogenous 26S proteasome activity in MDA-MB-231 cells [52]. Therefore, *M. koenigii* contains remarkable anticancer compounds, especially mahanine, which has been reported to show anticancer activity targeting different signaling pathways [46]. Girinimbine, a carbazole alkaloid, has been found to have a good role in total leukocyte migration and result in an appreciable reduction in pro-inflammatory cytokine levels. The various activities of *M. koenigii* against different cancer cell lines are shown in Figure 2.

**Figure 2.** Apoptosis induced by *M. koenigii* bioactive compounds in cancer. Bcl2: B-cell lymphoma 2; Bcl2-XL: B-cell lymphoma-extra-large; P-Bad: P plasmid araB araA araD; ROS: reactive oxygen species; Chk1/2: checkpoint kinase; Go/G1: cell cycle phase; JAK1: janus kinase 1; STAT3: signal transducer and activator of transcription 3; AKT: protein kinase B (also known as AKT); mTOR: mammalian target of rapamycin; P53/p57: tumor protein; Hsp90: heat shock protein.
