Lycopene
Lycopene belongs to the family of carotenoids. It has a structure that consists of a long chain of conjugated double bonds, with two open end rings. The structure lycopene is the longest of all carotenoids.
Lycopene, a non-cyclized tetraterpene, is the biosynthetic precursor of all the carotenoids and xanthophylls. A very heat-stable, oil-soluble compound, it is highly concentrated in red Tomato products, especially paste and catsup; lesser amounts are found in Wolfberries (also called Goji berries; Lycium spp.), Watermelon, Pink Grapefruit, Papaya, and Pink Guava. Epidemiological studies show an inverse relationship between lycopene status and cancer risk. Accumulating evidence suggests that lycopene is a strong antioxidant and may help to prevent prostate cancer, lung cancer, stomach cancer, and possibly other types (including cancers of the bladder, breast, cervix, pancreas, colorectal, and oral cavity) as well.
Cardiovascular Disease: There is a fair amount of epidemiologic evidence to document a possible correlation between lycopene ingestion and protection from cardiovascular disease. Similarly, there is fair documentation to indicate a possible effectiveness of lycopene in reducing cholesterol in adults and animals. Lcopene may have anticholesterol effects due to inhibition of HMG CoA reductase activity and antineoplastic activity due to its inhibition of DNA synthesis, antioxidant effects, modulation of intercellular communication, and induction of cell differentiation. Lycopene has the highest singlet oxygen-quenching capacity in vitro (antioxidant).
Lycopene is susceptible to oxidation and elevated temperature,exposure to light, oxygen, pH extremes and active surfaces will degrade it. Lycopene also undergoes cis-trans isomerization the cis form is less thermo-stable. Twenty percent to 57% of lycopene has been lost in processing tomato fruit pulp according to some studies, but others have shown lycopene to be relatively heat stable. Lycopene is more stable in the tomato or fruit than it is in isolated form. Store at room temperture, awa from heat, moisture, and direct light.
Note: An analysis of six commercially available brands revealed that lycopene content varied from the labeled dosage by as much as 43%.
Antioxidant activity is a key factor in Helicobacter pylori eradication [R]. As ROS scavenger, lycopene prevents oxidative stress-induced DNA damage in infected gastric cells and consequently inhibits apoptosis [R].
The susceptibility of low-density lipoproteins to oxidation was not changed by increased lycopene plasma concentrations caused by supplementation with Tomato juice. Fifteen renal transplant patients were given either a synthetic orange drink or Tomato juice for 4 weeks in a crossover study. Plasma lycopene levels increased significantly. LDL oxidation was measured by fluorescent lipid oxidation products and by TNARS in the serum. The lag time to LDL oxidation was also measured. None of the measures showed decreased LDL oxidation. (Sutherland et al., 1999)
Effects of meals & smoking on lycopene & lipid peroxidation: The serum level of lycopene were reduced when exposed to the oxidative stress of a meal or smoking. The lipid peroxidation expressed as TBARS was taken in 20 healthy human subjects before and after a meal. Serum lycopene levels between smokers and non-smokers were not statistically different but after smoking three cigarettes, serum lycopene levels dropped 40% and TBARS increased lipid peroxidation 40%. After a meal, lycopene levels dropped 25% compared to fasting levels. Eating a meal and smoking, both of which produce oxidative stress, reduced lycopene levels. (Rao & Agarwal, 1998
Lycopene has antifungal activity against Candida Albicans.
Lycopene: a biologically important carotenoid for humans?
Distribution
Lycopene is the red pigement of ripe tomatoes. Tomatoes contribute over 85% of the lycopene intake by women (Chug-Ahuja, 1993). Lycopene is also found in guava, pink grapefruit, rose hips, red oranges and watermelon.
HEALTH BENEFITS OF LYCOPENE
Lycopene is a very efficient antioxidant, which can neutralize oxygen derived free radicals. The oxidative damage caused by these free radicals has been linked to many degenerative diseases such as cardiovascular diseases, premature aging, cancer and cataracts. In many countries it is legally allowed to advertise foods containing tomato lycopene as "containing antioxidants for the maintenance and support of healthy cells". Lycopene is generally known for its protective action against prostate cancer.
Anti-cancer
In vitro-studies have shown the anti-cancer properties of lycopene against many cancer cells, including cancer cells of prostate, stomach, lung, colon and skin. There are numerous studies about the effect of lycopene on cancer and prostate cancer in particular. Using Pubmed as a retrieval base, more than 80 scientific studies have the names lycopene and prostate in their title. Most of the in-vitro experiments using cultured prostate cancer cells demonstrate a protective effect. However, most literature review studies or clinical studies are less conclusive and often contradictory. Lycopene also shows anti-mutagenic action against chemically induced DNA damage.
Antibacterial and antifungal
Lycopene possesses antibacterial and antifungal properties. Lycopene can help to reduce inflammation of the gums and can help to fight infections of Candida albicans.
Diabetes
Diabetes patients may suffer from complications as vascular disease, diabetic neuropathies or infections. Lycopene helps to protect diabetes patients against cardiovascular disease and may improve the immune response.
However, the consumption of lycopene seems not to reduce the risk of diabetes mellitus type 2.
Antioxidant
Lycopene has a structure similar to that of the well-known antioxidant beta-carotene, but its antioxidant activity is much stronger. Treatment of cells will lycopene protects cells against DNA damage and lipid peroxidation.
Arteriosclerosis
Lycopene inhibits platelet aggregation and reduces the production of foam cells which play an important role in the development of arteriosclerosis. Lycopene helps to prevent arteriosclerosis by reducing inflammatory agents in rats increased risk of venous thrombosis.
Antitoxic
In laboratory conditions, lycopene shows antitoxic properties against many toxins such as aflatoxin, cyclosporine and cadmium.
Clinical Summary
A natural pigment synthesized by plants and microorganisms, lycopene is used primarily as an antioxidant and also to prevent and treat cancer, heart disease, and macular degeneration. Lycopene is classified as a non-provitamin A carotenoid, other examples being lutein and zeaxanthin. Alpha-carotene, betacarotene, and beta-cryptoxanthin are classified as provitamin A carotenoids because they can be converted into retinol.
Small clinical trials suggest possible benefit against exercise-induced asthma and benign prostatic hyperplasia (BPH) . However, no optimal dosage has been established. Data from observational studies indicate an inverse association of lycopene consumption with risk of developing cardiovascular disease (CVD) , with a randomized study reporting improvements in endothelial function in CVD patients, but not in healthy volunteers.
In animal models, lycopene enhanced antitumor efficacy of docetaxel against prostate cancer . Epidemiologic studies suggest an inverse relationship between lycopene consumption and risk of cancer , particularly lung , stomach , prostate , and hormone-positive breast cancers . A consistent association between lycopene consumption and endometrial cancer risk has yet to be reported.
Clinical data on lycopene supplementation for prostate cancer prevention remain inconclusive. Whereas low intake of tomato sauce was associated with advanced prostate cancer in patients with low-grade cancer at diagnosis , other studies indicate that lycopene or tomato-based regimens do not prevent prostate cancer . In men with high-grade prostatic intraepithelial neoplasia (PIN), a lycopene-rich extract did not confer any benefits ; and high doses of lycopene, green tea catechins, and selenium were actually associated with higher prostate cancer incidence . Also, variable results were reported for lycopene supplementation in prostate cancer patients . One study suggests that increasing lycopene intake may alter the serum metabolome of men at risk of prostate cancer . Given these mixed results, more studies are needed to determine whether lycopene has protective effects in prostate cancer.
Mechanism of Action
Lycopene is a natural pigment synthesized by plants and microorganisms. Referred to as a nonprovitamin A carotenoid, it is not known to have any vitamin A activity. Biological actions include antioxidant activity via singlet oxygen quenching and peroxyl radical scavenging, induction of cell to cell communication, and growth control, although this appears to occur with less efficiency than with beta-carotene . Preventive consumption of lycopene attenuated effects of acetaminophen-induced liver injury in a murine model.
Proposed mechanisms of cancer-preventive effects include inhibition of cancer growth, induction of differentiation by modulation of cell cycle regulatory proteins, alterations in insulin-like growth factor-1 or vascular endothelial growth factor levels, prevention of oxidative DNA damage, and possible enhancement of carcinogen metabolizing enzymes . In human liver adenocarcinoma cells, antimetastatic activity was attributed to down regulationof NADPH oxidase 4 (NOX4), which produces reactive oxygen species.
Other possible mechanisms for all carotenoids include immune enhancement as well as inhibition of mutagenesis and transformation, and premalignant lesions. Carotenoids are also associated with decreased risk for macular degeneration and cataracts, and some types of cancers and cardiovascular events.
Dose
Daily Dose: When lycopene is supplemented on its own, dosing recommendations range from 5 to 10 mg daily.
For hypercholesterolemia: 60 mg daily.