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Tag Archive | "sunscreen"

Sunscreen in plants


By Ranger Steve Mueller

By Ranger Steve Mueller

A red pigment called anthocyanin has been considered a sunscreen that protects plants from becoming sunburned, much like the sunscreens we use to protect us, from ultraviolet radiation (UV).

Look at newly emerging leaves from buds and notice the red color of the delicate tissues that have not yet “hardened.” When leaves expand from the bud, they are somewhat like a water balloon. They fill with water but the plant cannot build the necessary support tissues that rapidly. Feel newly expanded leaves to notice how delicate they are. The cellular tissues remain thin for days.

The leaves of trees and shrubs expand rapidly but it takes much longer to reinforce cells with cellulose and other strengthening tissues. The first line of defense to protect delicate tissues from UV radiation would reasonably be found in the protective outer cell layer called the epidermis. This layer lacks the green chlorophylls that make leaves green and it also has a low concentration of anthocyanin. Anthocyanin is more abundant deeper in leaf tissues called palisade cells, where vertical rows of cells stand next to each other and circulate green chloroplasts to capture sun energy. It also is more abundant in photosynthetic cells beneath the palisade cells know as spongy mesophyll cells. Studies are trying to understand the mystery UV protection.

Think of the palisade cells like a series of farm silos packed closely together to fill a checkerboard. They are tall and slim. Imagine each silo filled with water and beach balls. The balls represent the chloroplasts that form a moving loop inside silo like an internal Ferris wheel. The chloroplasts are like seats on the Ferris wheel following others as they rise to the top and circulate back down to bottom. The spongy mesophyll cells below the palisade cells are more globular in water filled spaces between cells.

UV can cause damage to DNA in the cells of the two layers, just like damage can cause cancer in our skin tissues. Anthocyanin filters radiation to varying degrees and helps protect plants. Melanin in our skin serves that function and is built when our skin is exposed to UV and makes us tan.

Shade tolerant plants in the understory of forests are protected from intense sun radiation by the forest canopy. When trees are clear cut, the ground plants are suddenly exposed to UV and respond. They produce large quantities of anthocyanin and become intensely red. Unfortunately, it is not adequate to save them and most succumb to sunburn. Plants adapted to tolerate open sunny nature niches colonize the new sunny habitat. When you see a clear-cut forest, stop to notice how red the ground plants become when exposed.

Explore with family members to notice new growth on dogwood shrubs, maples, sassafras, oaks, and cherries. Choose any tree or shrub and feel how soft and delicate new tissues are and that they are pigmented red until they harden and feel sturdy. It is universal that the new tissues concentrate anthocyanin. The water-soluble pigment has other functions also but it plays a role as protective sunscreen. Phenolic acids in corn and other crops are UV-absorbing compounds so anthocyanin is not the only sunscreen. More mysteries are waiting discovery.

Declining levels of ozone in the upper atmosphere have generated concern because more UV radiation is entering the lower atmosphere where we live. In our latitudes, UV has risen by 3 to 5 percent in recent decades. Closer to the poles it has risen 6 to 8 percent. Increased skin cancer in people is occurring. People are not the only species impacted by UV radiation but we tend to think we are isolated from nature niches. That is not now nature works. What happens to plants happens to people. We do not live alone and sustainable care for other life is essential for our own health. Food and forest productivity depend on how we care for ozone layers.

Natural history questions or topic suggestions can be directed to Ranger Steve (Mueller) at odybrook@chartermi.net Ody Brook Nature Sanctuary, 13010 Northland Dr, Cedar Springs, MI 49319-8433. 616-696-1753.

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New ways sunscreen prevents signs of aging


To be really effective, sunscreen should help prevent and repair sun damage and be so sheer it can be worn under makeup every day.

(NAPS)—Skin care experts have long considered sunscreen one of the best ways to prevent skin damage and signs of aging, but the latest sunscreen technology means this invaluable beauty tool offers even more benefits.

Recent research into the properties of a molecule called NIA-114™ (niacin in the form of nicotinic acid) found that when added to sunscreen it repaired past UV damage while helping to protect against future damage. That can lead to healthier skin, visibly improved tone and texture, fewer discolorations and a stronger skin barrier.

By now, sunscreen users have become savvy about the SPF ratings. SPF stands for Sun Protection Factor and the number reflects how long it will protect your skin from burning by UVB rays.

Some sunscreen labels also list a “PA” ranking, which refers to the amount of protection the sunscreen offers from the UVA rays, which are the ones that contribute to premature aging and wrinkling of the skin. The more plus symbols listed after the PA on the label, the more protection the product offers from UVA rays and long-term skin damage.

For example, new StriVectin- SH Age Protect has UVB shields (SPF 30) plus the highest PA grade UVA protection available (PA +++) to help prevent free radical damage and wrinkle formation.

It contains NIA-114™, plus a blend of botanical antioxidants (blueberry and goji berry extracts) to protect against collagen degradation and free radicals. A calming blend of rose and cucumber ex­tracts soothes the skin while soybean extract and cera­mides strengthen skin’s natural moisture barrier and panthenol (vitamin B5) revitalizes and conditions skin.

This daily, oil-free sunscreen treatment strengthens the skin’s natural protective layer to help prevent new photoaging.

Remember that the sun can age your skin even on cloudy days. That’s why it’s important to wear an effective sunscreen every day—one that both protects and repairs skin.

Apply in the morning on cleansed face and neck and reapply as needed or after towel drying, swimming or perspiring.

StriVectin-SH Age Protect SPF 30/PA +++ has been awarded the Skin Cancer Foundation’s Seal of Recommendation, which verifies the safety and efficacy of sun protection products.

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