Natural Health Products (NHP’s) and Natural Compounds as Therapeutic Agents for the Treatment of Cancer; Mechanisms of Anti-Cancer Activity of Natural Compounds and Overall Trends

Abstract

Most cancer therapeutics, such as tubulin-targeting chemotherapy drugs, cause cytotoxic, non-selective effects. These harmful side-effects drastically reduce the cancer patient’s quality of life. Recently, researchers have focused their efforts on studying natural health products (NHP’s) which have demonstrated the ability to selectively target cancer cells in cellular and animal models. However, the major hurdle of clinical validation remains. NHP’s warrant further clinical investigation as a therapeutic option since they exhibit low toxicity, while retaining a selective effect. Additionally, they can sensitize cancerous cells to chemotherapy, which enhances the efficacy of chemotherapeutic drugs, indicating that they can be utilized as supplemental therapy. An additional area for further research is the investigation of drug–drug interactions between NHP’s and chemotherapeutics. The objectives of this review are to report the most recent results from the field of anticancer NHP research, and to highlight the most recent advancements in possible supplemental therapeutic options.

Natural Products in Preventing Tumor Drug Resistance and Related Signaling Pathways

“…Moreover, it has been found that nontoxic concentrations of matrine sensitized multidrug-resistant K562 cells in two ways, namely, the reactivation of apoptosis and inhibition of drug efflux [ 142 ]. Matrine can downregulate the phosphorylation of NF-κB, restore pro-apoptotic factors, and inhibit anti-apoptotic factors, thus promoting endogenous apoptosis [ 143 ]. Matrine can also induce mitochondrial damage by promoting the proapoptotic genes Bax, Bid, Bad, and Bim, and downregulating the apoptosis-inhibiting genes Bcl-2, Mcl-1, and Bcl-XL to promote endogenous Apoptosis.…”

Nutraceuticals and Cancer: Potential for Natural Polyphenols

“…Beside the differences found in the diets described, the common denominator seems to be the high consumption of fruit and vegetables that is constantly present, and which guarantees a reduced onset of cancer [36,37]. To date, it is known that several natural bioactive compounds possess anticancer properties [38,39]. It is important to highlight that there are more than 100 natural plant-based compounds currently in clinical use as anticancer drugs [40].…”

Synergistic Effect Induced by Gold Nanoparticles with Polyphenols Shell during Thermal Therapy: Macrophage Inflammatory Response and Cancer Cell Death Assessment

“…However, the drugs routinely used are rather toxic [ 21 ]. A good alternative is the application of natural anticancer compounds, like polyphenols [ 22 ]. Phenolic hydroxyl group-containing molecules indeed showed several anticancer effects, thanks to their antioxidant [ 23 , 24 ], anti-inflammatory [ 25 ], and anti-angiogenic properties [ 26 , 27 ].…”