PHYTOCHEMICALS

Eat Quercetin Rich Foods

Quercetin is probably one of the most available nutrients found in many foods in an effective dose to help people fight cancer and build their immune systems.  Green onions and leeks are very high in quercetin.  Pack a few green onions in your lunch and sauté a leek for dinner and add to a meal.  Quercetin capsules are also available.  LipoMicel supplements are reported to be more bioavailable.   

On my journey to find the best course for my battle with cancer I wrote this paper focusing on the benefits of quercetin in relation to cancer. 

Conventional chemotherapy has been successful in significantly reducing cancer tumors in recent years.  The side effects of conventional synthetic chemotherapy are as risky as cancer. Many people die from the toxicity of conventional chemotherapy drugs.  The current research focused on understanding the molecular pathways of cancer and looks to provide natural chemopreventative treatment, such as phytochemicals. Studies have identified a transmembrane tyrosine kinase receptor (HER2) expressed from cancer cells and cyclooxygenase-2 (COX-2), which is an enzyme that increases the rate of production of chemical messengers that cause inflammation, as cancer targets for phytochemicals.  Some phytochemicals have been found to provide therapeutic action, reduced toxicity, and function as a multi-agent angiogenic preventing cancer resistance. The phytochemical quercetin has been found to have a high binding action with the albumin protein, which is the most prominent protein in human serum. Quercetin inhibits kinesis involved in cancer’s intracellular signaling. Phytochemicals also activate a variety of cell signaling pathways in the body's defense system.  Quercetin has been found to reduce cytokine. Elevated levels of cytokine were associated with cancer. Quercetin has reduced bioavailability due to rapid metabolism and poor water solubility. Nanocarriers are currently being studied to overcome these barriers. Nanoparticles, such as silica, poly (2-hydroxyethyl methacrylate (PHEMA), and poly (lactic-co-glycolic acid) (PLGA) have enhanced biocompatibility and deliver phytochemicals to a particular tissue, vascular beds, and cells.  The therapeutic actions of nanoparticles will allow precise targeting of cancer cells.

 Cancer has become an epidemic in our society.  One out of five people will have cancer in their lifetime.  Worldwide 1.6 million new cancer diagnoses were predicted for 2016.  There have been over 100 types of cancer identified. Cancer cells referred to as “rebellious teenagers”, do not follow the rules in apoptosis, which is the process of programmed cell death.  Chemotherapy drugs are effective for a time in killing the cancer cells and anti-angiogenesis. The cancer cells adapt to the chemotherapy drugs and continue cell proliferation. The new cancer target for chemotherapy drugs is angiogenesis (Wang et al. 2018).  Angiogenesis is the growth of blood vessels from the tumor. These blood vessels allow the tumor to feed off the nutrients of the body enabling it to grow and metastases. Chemotherapy drugs have been very successful in reducing the size of the tumor by preventing angiogenesis.  Chemotherapy drugs have short-term and long-term side effects. The short-term side effects, controlled with medication, are usually not life-threatening. The long-term side effects are detrimental. Long-term side effects include kidney failure, neuropathy, damage to RNA and DNA, inflammation, reduction in red blood cell production, and cancer.  Researchers are investigating phytochemicals as replacement therapy for synthetic chemotherapy drugs.

        Quercetin is a phytochemical in the flavonoid family.  Quercetin is a scavenger of free radicals in the body (Wang et al. 2015).  Quercetin is a flavone, found in onion, capers, peppers, broccoli, berries, lovage, dill, cilantro, and apples.  Quercetin is anti-inflammatory, chemo-preventative, and found to provide pro-apoptotic action (Chirumbolo 2012). Several studies have been conducted to identify the molecular pathways associated with the anti-cancer effects of quercetin.  It is important to understand the method of the therapeutic action of quercetin to utilize it as an effective cancer treatment. There are conflicting studies on the bioavailability of quercetin in the body. Some studies have found that although quercetin is an effective chemopreventative in vitro, the amount measured in the plasma is not substantial to be active in the body.  Others have found that with extended use there are sufficient quantities of quercetin detected in body tissue. Quercetin has poor water solubility indicating that it is not a suitable candidate for treatment for cancer. The gastral processes in the stomach are another barrier to the oral ingestion of quercetin. Research is being conducted using nanocarriers to transport quercetin to the site of cancer to bypass these obstacles.

        Quercetin is a cancer chemopreventative agent.  There is a growing interest in researching the chemopreventative actions of quercetin.  The challenge is to find the molecular pathway to induce the therapeutic actions of quercetin on cancer in the human body.  The second challenge will be establishing phytochemicals as chemopreventative agents in the conventional medical field. Successful studies will face the political issues of the large companies in pharmaceuticals, as the mainstream treatment for cancer is chemotherapy drugs.  Pharmaceutical companies make $100 billion in anticancer drugs, and this is expected to rise to $150 billion by 2020 (Prasad, V., Jesus, K., & Mailankody, S., 2017).

Quercetin has many anti-cancer therapeutic actions, including anti-inflammatory, pro-apoptotic activity, antioxidant, hepatoprotective, antimicrobial, and cell proliferation.  Quercetin activates a variety of cell signaling pathways in the body's defense system. Free radicals cause over-oxidation in cells creating an environment for cell mutation. Mutated cells take on enough glucose to mimic a healthy cell, avoiding cell proliferation.  Quercetin hunts down and cleans out the free radicals preventing cell mutation. An overexpression of COX increases the production of cytokines which causes inflammation. Numerous studies have found quercetin to inhibit COX expression. Quercetin has also been found to downregulate levels of HSP 90 protein which has been found to promote cancer.

Conflicting studies of quercetin’s efficacy in vivo and in vitro demands further research.  Some studies show that there is not enough quercetin found in the blood and body tissues when ingested to have chemopreventative action.  Ingesting high-dose supplements have been shown to cause renal issues. It is not feasible to ingest the required quantities of food to create the anti-cancer therapeutic action.  Although, conflicting data is showing significant amounts of quercetin in human tissue with regular ingestion of onions and supplement forms. A combination of phytochemicals provides broader therapeutic actions on cancer.  Green tea, quercetin, curcumin, cruciferous, resveratrol, vitamin C, amino acids, and other micronutrients have been found to suppress several types of cancers. The poor water solubility and rapid metabolism are complications that create barriers to the absorption of quercetin in the body.     

Current research focusing on nano delivery looks promising to improve quercetin bioavailability and water solubility.   Nano-delivery increases stability, circulation time, and the ability to target cancer cells. PHEMA is compatible with skin and human tissue.  The US Food and Drug Administration (USFDA), and European Medicines Agency (EMA) approved PLGA nanoparticles. Further research demonstrating the efficacy of phytochemicals administered by nanoparticles could revolutionize the treatment of cancer.  The cancer cells could be singled out without the detrimental side effects enabling cancer survivors’ quality of life.

       Quercetin has chemopreventative action.  There are several barriers when quercetin is ingested, including rapid metabolism and poor water solubility.  Current research continues to focus on finding alternatives for delivery to target tumors. Research shows nanocarriers to be the solution.  Further research is suggested to determine the proper effective dosage without toxicity. KMiller  12/2017

The Allium genus has antibacterial, antioxidant, anticancer and anti-inflammatory properties.  The phenolic compounds found in this genus are responsible for this therapeutic action. Allium vegetables have also been found to have anticancer properties believed to be attributed to the organosulfur Diallyl trisulfide (DATS).  Historical records, as early as 2600 BC reflect the high regard of the medicinal properties of Garlic Allium sativum of the Allium genus. Egyptians were known to take an oath edifying garlic and onions as holy and miraculous plants.  Common names for garlic that are still in use today include Russian penicillin, natural antibiotic, and vegetable Viagra.  Historical use includes dysentery, cholera, influenza, and any general epidemic. Garlic is widely distributed and cultivated all over the world.  Garlic is native to Middle Asia (Petrovska & Cekovska, 2010).
Onion Allium cepa is also a member of the Allium genus. The bulb of the onion A. cepa is a bud surrounding a stem.  The leaves are fleshy and tightly overlapping, with a thin layer of papery leaf forming the skin of the onion.  The major producers in America are Texas, New York, and California (Cwynar, n.d.). Onions were used in folk medicine for flu, cold, and sneezing.  Historically, they were believed to keep away bad air, demons, and evils. Egyptians believed that the spherical shape and concentric rings of the onion symbolized eternal life (Upadhyay, 2016).
Historical records show that plants from the Allium genus have been used for colds, coughs, bronchial, and cancer.  Garlic and onion are the prominent medicinal plants of the Allium genus. Garlic’s compounds include sulfur (alliin, allicin, diallyl sulfide, ajoene, etc.) among many other amino acids, fructosans, minerals, and vitamins (Petrovska & Cekovska, 2010).   Processing raw garlic or onion by cutting or chewing ruptures the vacuoles containing alliinase. Alliinase, an enzyme, converts alliin into allicin and other thiosulfinates, responsible for the odors of garlic. Allicin decomposes into compounds including DATS.  Allicin is used for respiratory diseases as it is excreted by the respiratory organs. DATS is an organosulfur compound that modulates disease states such as cancer, infection, and metabolic syndrome. Studies show that DATS regulates multiple cancer hallmark pathways including; cell cycle, apoptosis, angiogenesis, invasion, and metastasis.  Studies show that consuming garlic for twelve weeks during the cold season reduces the risk of catching a cold or lessens the length and severity. (Puccinelli & Stan, 2017). Gram-negative microorganisms including Pseudomonas aeruginosa, which is an infection of the respiratory system were sensitive to garlic (Yusha’a, Garba, & Shamsuddeen, 2008).
The compounds found in onions include phenolics and flavonoids that have anti-inflammatory, anticancer, and antioxidant properties (Upadhyay, 2016).  Onions are made up of 89% water, 1.5% protein, and vitamins B1, B2, and C. They also contain potassium and selenium. Polysaccharides, such as fructosans, saccharose, peptides, flavonoids (quercetin) and essential oils have also been identified.  There are some sulfur compounds including thiosulfinates. The carbohydrates in onions play a significant role in the immune system. Acetic acid found in the bulb is antibacterial and an expectorant. Allicin, kaempferol, oleanolic acid, quercetin and vanillic acid located in the bulb have antibacterial, antibiotic, anti-inflammatory, and antioxidant.  antiallergic, anticancer, antihistaminic, and antiviral. The antioxidants produced in onions are lost after cooking (Upadhyay, 2016).