Four Togolese plant species exhibiting cytotoxicity and antitumor activities lightning polytherapy approach in cancer treatment

BACKGROUND: Cancer is leading to premature deaths across the globe. Therapeutic approaches are still being developed to enhance the survival of cancer patients. In our previous study, extracts from four Togolese plants, namely, Cochlospermum planchonii (CP), Piliostigma thonningii (PT), Paullinia pinnata (PP), and Securidaca longipedunculata (SL), actually used in traditional medicine for cancer treatment, showed beneficial health effects against oxidative stress, inflammation, and angiogenesis. PURPOSE: In the present study, we aimed to investigate the cytotoxicity and antitumor activities of these four plant extracts. MATERIAL AND METHODS: Breast, lung, cervical, and liver cancer cell lines were exposed to the extracts, and viability was assessed using the Sulforhodamine B method. P. pinnata and S. longipedunculata with significant cytotoxicity were selected for in vivo tests. The acute oral toxicity of these extracts was assessed using BALB/c mice. The antitumor activity was evaluated using the EAC tumor bearing mice model, wherein mice were orally treated with extracts at different concentrations for 14 days. The standard drug was cisplatin (3.5 mg/kg, i.p), single dose. RESULTS: Cytotoxicity tests revealed that SL, PP, and CP extracts have more than 50% cytotoxicity at 150 μg/mL. The acute oral toxicity of PP and SL at 2000 mg/kg did not show any toxic signs. At therapeutic doses of 100 mg/kg, 200 mg/kg and 400 mg/kg of PP and 40 mg/kg, 80 mg/kg, and 160 mg/kg of SL, extracts showed beneficial health effects by modulating several biological parameters. SL extract significantly reduced tumor volume (P < 0.001), cell viability, and normalized hematological parameters. SL also demonstrated a strong anti-inflammatory activity similar to the standard drug. The SL extract also revealed a significant increase of the life span of treated mice. PP extract reduced the tumor volume and significantly improved the values of endogenous antioxidants. Both PP and SL extracts also exerted significant anti-angiogenic potency. CONCLUSION: The study indicated that polytherapy would be a panacea for the efficient use of medicinal plant extracts against cancer. This approach will make it possible to act simultaneously on several biological parameters. Molecular studies of both extracts targeting key cancer genes in several cancer cells are currently underway.