Cancer:
Lung, breast, prostate, leukemia, colorectal., esophageal., ovarian, myeloma, pancreatic, stomach, uterine
Action: Anti-angiogenic, chemo-sensitizer, multi-drug resistance reversal., anti-inflammatory, anxiolytic, anti-depressant, inhibits VEGF, anti-metastatic, synergistic effects with other cancer treatments
Honokiol is a phenolic compound purified from plants of the Magnolia genus, including Magnolia officinalis (Rehder & Wilson) and Magnolia grandiflora (L.), that exhibits anti-cancer effects in experimental models with various types of cancer cells, including esophageal., ovarian, breast, and lung cancer, as well as myeloma and leukemia. It is speculated that this compound causes cancer cell death in part through targeting mitochondria (Munroe et al., 2007; Chen et al., 2009; Fried & Arbiser, 2009).
Inhibits Angiogenesis, MDR, Anti-inflammatory, Inhibits VEGF
Honokiol is one of two dominant biphenolic compounds isolated from Magnolia spp. bark, and is the most widely researched active constituent of the bark. In vivo studies suggest that honokiol's greatest value is in its multiple anti-cancer actions. In vitro research suggests honokiol has potential to enhance current anti-cancer regimens by inhibiting angiogenesis, promoting apoptosis, providing direct cytotoxic activity, down-regulating cancer cell signaling pathways, regulating genetic expression, enhancing the effects of specific chemotherapeutic agents, radio-sensitizing cancer cells to radiation therapy, and inhibiting multi-drug resistance.
Honokiol also shows potential in preventive health by reducing inflammation and oxidative stress, providing neurological protection, and regulating glucose; in mental illness by its effects against anxiety and depression; and in helping regulate stress response signaling. Its anti-microbial effects demonstrate potential for partnering with anti-viral/antibiotic therapy, and treating secondary infections.
Honokiol may occupy a distinct therapeutic niche because of its unique characteristics: the ability to cross the blood brain barrier (BBB) and blood cerebrospinal fluid barrier (BCSFB), high systemic bioavailability, and its actions on a multiplicity of signaling pathways and genomic activity. There is a need for research on honokiol to progress to human studies and on into clinical use.
The preclinical research on honokiol's broad-ranging capabilities shows its potential as a therapeutic compound for numerous solid and hematological cancers, including its effectiveness in combating multi-drug resistance (MDR) and its synergy with other anti-cancer therapies. Research thus far shows no toxicity or serious adverse effects in animal models.
Honokiol has also been shown to inhibit spread of cancer cells through the lymph system by inhibiting one of the primary pathways involved in growth stimulation related to vascular endothelial growth factor (VEGF) (Wen et al., 2009).
Inhibits Angiogenesis, Gastric Cancer
A 2012 in vivo study in PLoS One showed that honokiol, by inhibiting angiogenic pathways such as STAT-3, dampened peritoneal dissemination of gastric cancer in mice (5 mg/kg delivered intraperitoneally) (Liu et al., 2012).
Induces Apoptosis; Leukemia
Honokiol induces cell apoptosis in several cell lines, such as leukemia cell lines HL-60, colon cancer cell lines RKO, lung cancer cell lines A549 and CH27 (Hirano et al., 1994; Wang et al., 2004; Hibasami et al., 1998; Konoshima et al., 1991;Yang et al., 2002; Kong et al., 2005). It also has remarkable in vivo anti-tumor activities in tumor mouse models (Bai et al., 2003). Honokiol has demonstrated potent anti-angiogenic and anti-tumor properties against aggressive angiosarcoma by blocking of VEGF-induced VEGF receptor 2 autophosphorylation (Konoshima et al., 1991; Yang et al., 2002).
MDR
Honokiol has also been found to down-regulate the expression of P-glycoprotein at mRNA and protein levels in MCF-7/ADR, a human breast MDR cancer cell line. The down-regulation of P-glycoprotein is accompanied with a partial recovery of the intracellular drug accumulation (Xu et al., 2006).
Prostate Cancer
In addition, it has been shown that prostate cancer cells that failed to respond to hormone withdrawal responded to honokiol-induced apoptosis. It was found to significantly induce death in cells surrounding primary and metastatic prostate cancers, the prostate stromal fibroblasts, marrow stromal cells, and bone marrow-associated endothelial cells. Honokiol is hence a promising nontoxic agent that could be used as an adjuvant with low-dose docetaxel for the treatment of hormone-refractory prostate cancer and its distant bone metastases (Shigemura et al., 2007).
Anti-metastatic
Honokiol inhibited the activity of MMP-9, which may be responsible, in part, for the inhibition of tumor cell invasiveness (Nagase et al., 2001).
Breast Cancer
The development of more targeted and low toxic drugs from traditional Chinese medicines for breast cancer are needed due to most of the anti-breast cancer drugs often being limited because of drug resistance and serious adverse reactions. Results have shown that honokiol inhibited the rate of breast cancer MDA-MB-231 cell growth (Nagalingam et al., 2012).
Synergistic Effects with Other Cancer Treatments
One of the most promising benefits of honokiol is its ability to synergize with other cancer treatments. Clinical trials are desperately needed to validate the potential synergy that has been demonstrated in vitro and in vivo.
Chemotherapy
• A 2013 in vitro study published in the International Journal of Oncology showed that honokiol synergized chemotherapy drugs in Multi-drug-resistant breast cancer (Tian et al., 2013). A 2011 in vitro study published in PLoS One found that honokiol enhanced the apoptotic effects of the anti-cancer drug gemcitabine against pancreatic cancer (Arora et al., 2011).
• In vivo research published in Oncology Letters in 2011 found honokiol enhanced the action of cisplatin against colon cancer (Cheng et al., 2011).
• A 2010 in vitro study from the Journal of Biological Regulators and Homeostatic Agents showed that honokiol resensitized cancer cells to doxorubicin in Multi-drug-resistant uterine cancer (Angelini et al., 2010).
• A 2010 in vitro study published in Toxicology Mechanisms and Methods showed honokiol performed synergistically with the drug imatinib against human leukemia cells (Wang et al., 2010).
• 2008 in vivo research published in the International Journal of Gynecological Cancer showed honokiol to potentiate the activity of cisplatin in murine models of ovarian cancer (Liu et al., 2008).
• 2005 in vitro research published in Blood showed honokiol enhanced the cytotoxicity induced by fludarabine, cladribine, and chlorambucil, indicating it is a potent inducer of apoptosis in B-CLL cells (Battle et al., 2005).
Radiation treatment
• 2012 in vitro research published in Molecular Cancer Therapeutics showed that honokiol was able to sensitize cancer cells to radiation treatments (Ponnurangam et al., 2012).
• A 2011 in vitro study published in American Journal of Physiology Gastrointestinal and Liver Physiology showed honokiol sensitized treatment-resistant colon cancer cells to radiation therapy (He et al., 2011).
Inhibition of multi-drug resistance
Honokiol has been shown to interact with genes that are involved with mechanisms of drug efflux, thus reversing MDR in experimental models. The exact mechanisms of action in this regard are thought to be related to effects of blocking of NF-kB activity, but other mechanisms may also be involved (Xu et al., 2006).
References
Source