Antiangiogenic Phytochemicals Constituent of Diet as Promising Candidates for Chemoprevention of Cancer


Abstract

Despite the extensive knowledge on cancer nature acquired over the last years, the high incidence of this disease evidences a need for new approaches that complement the clinical intervention of tumors. Interestingly, many types of cancer are closely related to dietary habits associated with the Western lifestyle, such as low fruit and vegetable intake. Recent advances around the old-conceived term of chemoprevention highlight the important role of phytochemicals as good candidates for the prevention or treatment of cancer. The potential to inhibit angiogenesis exhibited by many natural compounds constituent of plant foods makes them especially interesting for their use as chemopreventive agents. Here, we review the antitumoral potential, with a focus on the antiangiogenic effects, of phenolic and polyphenolic compounds, such as quercetin or myricetin; terpenoids, such as ursolic acid or kahweol; and anthraquinones from Aloe vera, in different in vitro and in vivo assays, and the available clinical data. Although clinical trials have failed to assess the preventive role of many of these compounds, encouraging preclinical data support the efficacy of phytochemicals constituent of diet in the prevention and treatment of cancer, but a deeper understanding of their mechanisms of action and better designed clinical trials are urgently needed.

Concluding Remarks and Future Challenges

The use of nontoxic plant-derived natural compounds as chemopreventive agents in cancer has become an attractive approach in the last years, since it represents a low-cost, easily accessible, and broad-spectrum alternative to conventional drugs. Additionally, the high number of bioactive compounds contained in plant foods that display antitumor and antiangiogenic effects in experimental models should prompt us to undoubtedly assess the feasibility of their use in cancer prevention.

While broad experimental evidence obtained for these compounds clearly points to their capability to target events involved in cancer initiation and progress, their application to cancer prevention is still far away from being clinically established. For many of these compounds, clinical trials are still very limited, contradictory, inconclusive, or even inexistent, making it extremely difficult to clarify the level of efficacy of these compounds in cancer prevention, if any, as well as their preventive role on the population and the suitable regimens needed to achieve the desired health benefits. In this context, a significant effort is needed to improve the design of clinical trials, paying special attention to the target population, as well as to the pharmacokinetics and pharmacodynamics of the compounds. In terms of cancer treatment, however, the use of these compounds in combination with typical therapeutic agents comes as a rather interesting approach, as it would allow the reduction in the aggressiveness and side effects caused by these drugs, while also improving their effects.

Undoubtedly, a deeper understanding of the mechanism of action of the compounds in the context of the hallmarks of cancer is necessary, mainly attending to the pleiotropic character of their reported biological actions. In line with this, it is worth encouraging basic, translational, and clinical research to better integrate the available information to improve the outcome of clinical trials, and eventually determine the health benefits and efficacy of plant-derived bioactive compounds in the chemoprevention of cancer.

Full of antioxidants and anti-inflammatory compounds, cabbage needs to be a regular in your kitchen


Full of antioxidants and anti-inflammatory compounds, cabbage needs to be a regular in your kitchen

 

With its high concentrations of antioxidants and anti-inflammatory compounds, cabbage is one of the healthiest vegetables you can eat. As a cruciferous veggie, in the same family as broccoli, Brussels sprouts and cauliflower, it also contains glucosinolates, phytochemicals that break down into indoles, sulforaphane and other cancer-preventive substances.

Different types of cabbage (red, green and Savoy) contain different patterns of glucosinolates, which suggests you should try to eat a variety of cabbage for the best health effects. Its variety is another one of cabbage’s pluses — it comes in hundreds of different types and is incredibly versatile. Eaten raw, cabbage is a mainstay of cole slaw and other summer salads. It’s also one of the most popular base vegetables for creating your own homemade sauerkraut.

 

Cooked lightly and quickly, cabbage also makes an excellent side dish to virtually any protein source and can be seasoned in a number of different ways depending on the type of cuisine. You may be tempted to rely on your local grocery store for cabbage, but growing your own is so much more rewarding, both in terms of freshness and flavor. What’s more, growing cabbage is incredibly easy, and if you time your planting right you can expect to harvest it during the summer as well as the late cold-weather season.

Choose the Right Varieties for the Growing Season

Cabbage is one of those vegetables that taste better after a frost. This is because as temperatures drop, the cold causes the plants to break down energy stores into sugar, leading to a sweeter, tastier flavor. Some types of cabbage can even be grown in temperatures as low as 26 degrees F.

Most winter veggies are planted in mid- to late summer so they are strong and ready for when the temperatures drop, and then ripe for harvest in winter or early spring. Timing this depends on how long each plant takes to reach maturity, however, and this is where choosing the proper varieties is key.

While some cabbage plants reach maturity in 90 days, early varieties take just 60 days to reach maturity. Further, you’ll probably want to plant a crop to harvest during the summer months, as well.

 

As Rodale’s Organic Life noted, “Cabbage thrives in cool weather. In most areas, you can plant an early crop for fresh eating and a late crop — usually the more problem free and tastier of the two — primarily for winter storage. Choose early varieties such as ‘Primax’ for summer harvest; midseason and late-season cultivars for storage.” Additional recommended varieties, according to The Old Farmer’s Almanac, include the following:

  • “If you are planting for a fall harvest, try red or Chinese cabbage. Good varieties include ‘Ruby Perfection’ and ‘Lei-Choy.’
  • For quick harvest time, try ‘Golden Acre,’ ‘Primo’ or ‘Stonehead.’
  • ‘Early Jersey Wakefield’ resists splitting.
  • Disease-resistant varieties include ‘Blue Vantage’ and ‘Cheers.’”

Other considerations in cabbage variety include size, color and texture. With its variety of cool hues and ruffled and crinkled leaves, many people plant cabbage as much for its ornamental appeal as they do for its culinary uses. Some of the more popular varieties to consider include:

Savoy cabbage, which has dark green, crinkled outer leaves Red cabbage, which contains antioxidant anthocyanins that give it its purple color
Napa cabbage, also called Chinese cabbage, matures quickly and has a mild flavor Green cabbage, which comes in a variety of sizes with differing times to maturity
Pointed cabbage, which forms conical heads, helping to protect it from insects Mini cabbages, such as the “Gonzales” variety, which can be harvested when they’re 6 inches in diameter, making them ideal for small gardens

It’s Easy to Start Cabbage From Seed

While you can purchase cabbage plants at most garden centers, it’s easy to grow them yourself from seed. Start seeds indoors eight to 10 weeks before your last frost of the spring for summer harvests, and 12 to 14 weeks before your first fall frost for late varieties. “Place in a sunny spot or under lights with temperatures between 60 degrees and 70 degrees F, and keep the soil uniformly moist. When daytime temperatures reach 50 degrees F and seedlings have three leaves, plant them outdoors,” Rodale’s Organic Life recommends. In addition, they note:

“Plant seedlings in the garden slightly deeper than they grew in flats. Space 6 to 12 inches apart in rows 1 to 2 feet apart. Wide spacings produce bigger heads, but young, small cabbages are tastier. To get both, plant 6 inches apart and harvest every other one before maturity. Stagger plantings at 2-week intervals for a longer harvest. tart your late crop in midsummer, sowing seeds in flats or directly in the garden. Space these seedlings farther apart than the spring crop.”

As for seeds, look for non-GMO, organic seeds or consider saving seeds from your own crop. The latter may be a challenge, as cabbage produces seed in its second year (it’s a biennial crop). This means only areas with mild winters will allow the seedlings to survive through the winter and produce seeds come summer. An alternative is to transfer cabbage plants in a cool place for the purpose of harvesting seeds the next growing season, according to Mother Earth News:

“In colder climates, growers dig cabbage plants and move them to a cool root cellar for winter, burying the plants’ roots in buckets of moist sawdust. The stored heads are trimmed and replanted in early spring.”

Cabbage Planting Tips

A sunny, well-drained spot works best, and healthy soil will help your cabbage plants to thrive. Adding organic compost to your soil is recommended, as is a layer of mulch or wood chips to help lock in moisture. If your cabbage leaves start to yellow, adding compost tea, which is basically the liquid from compost steeped in water, to the soil as an extra feeding may boost plant growth and encourage faster maturation.

Cabbage plants are heavy feeders, meaning they deplete the soil of nutrients relatively quickly. Because of this, it’s best to plant them apart from other heavy feeders like broccoli and cauliflower. In addition, rotate crops each year to discourage diseases. Excess water (including heavy rain) can cause cabbages to split. If you notice a split starting, or expect a heavy rain to hit, use a spade to sever the plant’s roots in one or two spots, or twist the plant, pulling up slightly, to dislodge the roots.

Both methods will slow the plant’s growth, preventing splitting and bolting. If the cabbage does split, don’t worry — it can still be used to make sauerkraut. As for pests, many, including harlequin bugs, slugs, snails and cabbage worms can be removed by hand (be sure to check the undersides of leaves). Damage from cutworms can be prevented by placing a “collar” made from a plastic cup around young seedlings (push it down about 1 inch into the soil). Common diseases to watch out for include the following:

“Black leg, a fungal disease, forms dark spots on leaves and stems. Black rot symptoms include black and foul-smelling veins. Club root prevents water and nutrient absorption. Fusarium wilt, also known as yellows, produces yellow leaves and stunted heads. Remove and destroy plants affected by these diseases. If club root has been a problem in your garden, test soil pH before planting and add ground limestone if needed to raise the pH to at least 6.8.”

Simple Harvest Tips

When the cabbage head is firm to the touch, use a sharp knife to cut it from the stalk. Heads that don’t feel firm are not yet ready for harvest. Smaller cabbage heads will often grow from the stem, provided you leave the outer leaves and roots, so don’t pull it out of the ground yet. If you’re not interested in encouraging a second crop to grow, the loose outer leaves can be tossed into your compost pile or eaten — it’s up to you.

Once the harvest is complete, pull the stem and root from the ground and compost the remainders (as long as the plant is healthy; avoid throwing diseases plants into your compost bin). Store cabbage in your refrigerator for two weeks or in cold storage (32 degrees to 40 degrees F) for five or six months (the latter being perfect for your winter harvest).

If you’re wondering how much cabbage to grow, Mother Earth News recommends about three cabbage plants per person for enjoying fresh and four plants per person (in addition) for storing cabbage to make sauerkraut. Cabbage is best prepared as close to raw as possible, sometimes called tender-crisp, to preserve its many nutrients.

Cabbage can also be juiced and fermented, which will provide your body with healthy amounts of beneficial bacteria and, if certain starter cultures are used, vitamin K2.

Ready to Enjoy? Healthy Cabbage Crunch Salad

There are many reasons to give cabbage a regular appearance at your mealtimes. It contains powerful antioxidants like vitamins A and C and phytonutrients such as thiocyanates, lutein, zeaxanthin, isothiocyanates and sulforaphane, which stimulate detoxifying enzymes and may protect against breast, colon and prostate cancers. Cabbage also contains a wealth of anti-inflammatory nutrients to help keep inflammation in check.

Among them are anthocyanins, a type of polyphenol that, as mentioned, is particularly plentiful in red cabbage, although all types of cabbage contain anti-inflammatory polyphenols. Cabbage also contains healthy amounts of B vitamins, including folate (which is better than the synthetic form known as folic acid found in many supplements), vitamin B6, vitamin B1 and vitamin B5.

B vitamins are not only important for energy, they may also slow brain shrinkage by as much as seven-fold in brain regions specifically known to be most impacted by Alzheimer’s disease.

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If you’re looking for a recipe to enjoy your cabbage raw that’s a bit different than typical cole slaw recipes, try this healthy Cabbage Crunch Recipe. With fresh ginger, miso paste and ground sesame, along with both red and green cabbage, it’s packed with both intense flavor and valuable nutrition.

Ingredients (serves 6)

  • 1/2 head red cabbage, chopped finely
  • 1/2 head white cabbage, chopped finely
  • 1/2 red onion, chopped
  • 1/2 cup chopped cilantro
  • 1/2 jalapeno pepper, minced (optional)

For the Dressing:

  • 1 teaspoon gomasio (ground sesame with salt)
  • 1 cup almond butter
  • 1/2 cup cilantro, chopped
  • 1 tablespoon toasted sesame oil
  • 1 tablespoon minced fresh ginger
  • 1/2 jalapeno pepper, chopped (optional)
  • Juice of half a lemon
  • 1 tablespoon apple cider vinegar
  • 1 tablespoon seasoned rice vinegar
  • 1 cup olive oil
  • 1 tablespoon white miso paste* (optional)

Procedure

  1. Mix the cabbage with the chopped onions. Add cilantro and jalapeno.
  2. Place all the dressing ingredients into a food processor and blend briefly. Mix into salad mix and serve.

An ancient pear endemic to Italy is a little-known superfood with high concentrations of antioxidant compounds


Image: An ancient pear endemic to Italy is a little-known superfood with high concentrations of antioxidant compounds

The Apennine mountains of central Italy are home to an ancient and rare variant of the European pear (Pyrus communis) called the Cocomerina pear. A study conducted by local researchers revealed that this pink-fleshed pear is a superfood bursting with natural antioxidants.

“Cocomerina” is derived from “cocomero,” the term for watermelon. This variant of pear is called that because of its sweet-smelling and pink flesh, which grows more vivid in color as the fruit ripens.

It is one of the so-called “ancient fruits,” which are very old and only found in a few small areas. The Cocomerina variant of the European pear is restricted to the Apennine area of Romagna and Tuscany. The early-ripening cultivar is harvested in August, while the late-ripening one is collected in October.

Many pears contain large amounts of anthocyanins, flavonoids, and polyphenols.  These plant-based compounds have powerful antioxidant properties that protect cell tissue and membranes from free radicals. (Related: The strange-looking tropical fruit graviola is a POWERFUL superfood against cancer.)

Methodology

Researchers from the Universita di Urbino – Carlo Bo (UdU Carlo Bo) studied the nutritional value of the Cocomerina pear. They harvested ripe specimens of the early-ripening cultivar, as well as both ripe and unripe examples of the late-ripening cultivar.

The cores were removed from the sample fruits before they were chopped up and prepared into fruit extracts. Each extract was analyzed to determine the amount and types of anthocyanins, flavones, flavonoids, flavonols, and polyphenols that it contained.

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Armed with the knowledge of the bioactive plant compounds present in the fruits, the researchers tested the extracts for their antioxidant activity. They measured the effectiveness of each extract when it came to scavenging DPPH free radicals, as well as its capacity to absorb oxygen radicals.

Furthermore, they evaluated the ability of the extracts to prevent inflammation. In the 5’-lipoxygenase assay, they measured the amount of extract required to inhibit 50 percent of the inflammatory activity of lipoxygenase.

Phytochemical content of Cocomerina pear extract

To begin with, the UdU Carlo Bo researchers noted the different amounts of phytochemicals found in the cultivars of the Cocomerina pear. The late-ripening cultivar has higher levels of polyphenolic compounds. Likewise, its ripe fruits contain more polyphenols than unripe samples.

The unripe fruits of the late-ripening cultivar have the best number of flavonoids. Interestingly, the ripe fruits of both ER and LR strains contain similar levels of flavonoids.

When it came to flavones and flavonols, the ripe fruit of the early-ripening cultivar demonstrated the highest level. Dihydroflavonol levels were much higher in the late cultivar, however.

Comparison of the unripe and ripe fruits of the late-ripening cultivar showed that the levels increased alongside the maturity of the fruit. So ripe fruits of the Cocomerina pear contains more phytochemicals than unripe fruits.

The amount of anthocyanin in late-ripening cultivar is 126 times greater than in the early-ripening one. Ripe LR cultivars contain more anthocyanins than unripe ones.

Free radical scavenging and antioxidant activity

All three extracts were able to scavenge DPPH free radicals. The ethanolic extracts made from the unripe and ripe pears of the late-ripening cultivar were much more effective.

Next, the extracts were also effective at inhibiting the activity of the inflammatory enzyme 5’-lipoxygenase. Again, the late-ripening cultivar’s extracts displayed greater effectiveness.

The antioxidant activity was greatest in the ripe fruits of the late-ripening cultivar. When compared with commercial pear cultivars, the Cocomerina pear extracts showed comparable or superior activity.

The researchers concluded that the Cocomerina pear possesses significant antioxidant and anti-inflammatory activities. These health benefits could encourage the conservation and recovery of this ancient fruit.

For more stories about cocomerina pear and other fruits that serve as superfoods, check out Fruits.news.

Sources include:

Science.news

Academic.OUP.com

TAndFOnline.com

Pubs.ACS.org