Pomegranate Extract Both Orally Ingested and Topically Applied to Augment the SPF of Sunscreens

The skin is the most environmentally-stressed organ in mammals, particularly in humans. Not only is the skin subjected to toxic chemicals and hostile environments, but it is also the only organ directly exposed to ultraviolet light (UVL) in the presence of oxygen (1). Lengthy exposure of the skin to UVL typically damages the skin, resulting in sunburn, photoaging and carcinogenesis.

Ultraviolet light exposure in the presence of oxygen results in the creation of free radicals. In the skin, these radicals frequently trigger the release of inflammatory mediators, commonly manifested as sun burn; cytoskeletal alterations, breaking down the collagen in the skin which may also result in structural DNA changes, such as DNA strand breaks and dimer formation (2). The body attempts to neutralize the free radicals generated by UV light through the use of antioxidants. Antioxidants are commonly found in two forms: enzymatic and non-enzymatic. Superoxide dismutase (SOD), catalase, and glutathione peroxidase are some of the natural enzymatic antioxidants used by the body. SOD accelerates the spontaneous reduction of superoxide free radicals into peroxides and oxygen. Catalase then further decomposes hydrogen peroxide and free organic hydroperoxides. Some non-enzymatic antioxidants, such as Vitamin E (tocopherol), Vitamin A (beta-carotene), and Vitamin C (ascorbic acid) have each been individually applied to assist the skin in scavenging free radicals and neutralizing the harmful effects of UV light (3). Conventional skin protection efforts typically attempt to either shield the skin from UV light to prevent the production of free radicals or provide additional agents capable of neutralizing the free radicals.

Topical applications are one attempt to help shield the skin from the sun’s harmful UV effects. These sunscreens often are water- or oil-based lotions or ointments that incorporate photo-protectant materials such as titanium and zinc oxide which protect by mechanically blocking the sun’s energy from reaching the surface of the skin. Although the most widely used form of protection against exposure to sunlight, these topical applications tend to suffer from several drawbacks. First, large amounts of photo-protective materials are usually incorporated into the topical applications, some of which have recently become suspected of having toxicity or otherwise being harmful under these conditions. Furthermore, the effectiveness of such topical applications is dependent upon a constant and uniform coverage of the skin, which is often difficult to obtain. Many individuals fail to use these topical sunscreens on a regular or continual basis, as is required under prolonged UV exposure. Finally, sunscreens and other topical applications do not consistently provide good protection for all types of ultraviolet light.
Various conventional supplements have attempted to boost the body’s natural antioxidant activity using vitamins, minerals, and herbs. Vitamin C, for example, is believed to reduce sun damage, and Vitamin E has been used topically as an anti-inflammatory agent and for protection of cells from UVL. Also, carotenoids may have usefulness as antioxidants, protecting against both free radicals and singlet oxygen, a highly reactive, diamagnetic excited state of dioxygen. Moreover, it is thought that minerals are typically needed to maintain the effectiveness of the body’s enzymatic antioxidants. Both copper and zinc are thought to be necessary in the proper functioning of SOD(4). Manganese is believed to be a cofactor in the mitochondrial form of SOD. Also, selenium is thought to be necessary for glutathione peroxidase activity, one of the enzymatic antioxidants found naturally in the body. Unfortunately, few experiments into the skin-protecting effects of these antioxidants have provided scientific or conclusive results.

In particular, a study that orally administered vitamin E supplements to participants and then tested their response to the sun found that Vitamin E did not mitigate the UV damage, despite the fact that the subjects were given thirteen times the recommended daily allowance (5). Furthermore, beta-carotene has been reported to have beneficial effects in some studies, but has had no effect in others. Finally, another study noted the photo-protective effect of the oral administration of butylated hydroxy toluene, but little effect was shown using Vitamin C or E.

Certain herbs have also been found helpful in protecting the skin from the sun’s harmful effects. Herb extracts such as burdock root, echinacea, yellow dock root and grape seed possessed detoxifying properties that have been individually applied to help the body eliminate harmful free radicals. Burdock root contains the active ingredient inulin, and is useful in treating cancerous skin conditions, as well as inflammation. Echinacoside and caffeoyl derivatives present in echinacea act as antioxidants, which protect the skin when applied topically (6). Yellow dock root contains the active constituent chrysarobin, which has been used in the treatment of chronic skin diseases, such as eczema, leprosy, psoriasis, and cancer (8). Potent bioflavanoids, known as oligomeric proanthocyanidins (OPCs), are found in grape seeds. These OPCs are thought to be potent antioxidants possessing 20 times the antioxidant power of Vitamin C and 50 times the antioxidant power of Vitamin E. These herbs have been individually used both topically and orally to protect the skin from various afflictions.

Other studies have attempted to demonstrate the synergistic effect of a mixture of antioxidants. In one study, the subjects were given selenium and copper along with a vitamin supplement of vitamin A and E (4). Although the supplements did protect the skin cells to some extent against ultraviolet light induced cell damage, they did not prevent UVL-induced erythema, i.e., redness.

Pomegranate (Punica granatum L) a native plant of Northern Africa, widely distributed throughout the Caucasian Mountains is one of the oldest drugs known. P granatum was mentioned in the papyrus Ebers of Egypt written in about 1550 BC. Heppocrat has described its medicinal powers. Doctors in Greece prescribed pomegranate juice as remedy with multiple activities: anti-inflammatory; as a potent anthelmintic, chronic diarrhea, dysentery, anti-intestinal worms, and as a cough suppressant. Anti-bacterial activity of polyphenols extracted from pomegranate has been reported by several scientific groups (8). In Mediterranean and Caucasian Folk medicine, pomegranate extract is used to strengthen the human capillary system, for anti-atherosclerosis, as an anti-asthma agent, and for tonsillitis and bronchitis (9). It has been reported that pomegranate extract mixture with aloe extract activates bone tissue regeneration after injury.

Pomegranate is rich in a different group of polyphenolics. Italian researchers reported the presence of anthocyanidins such as pentoside of malvidine and petunidin, delphinidin 3-glucoside, delphinidin 3,5-glucoside, and cyanidin 3-glucoside and cyandin 3,5diglucoside (10). Santagati identified delphinidin and cyanidin 3-glucosides in the seed coat, and observed that the ratio between the delphinidin and cyanidin derivitives favored the cyaniding in fruit from the hilly regions but not in fruit trees grown in the plants (11). The analysis of biochemical composition performed at several Russian and Spanish Universities indicates that polyphenols (35-40 %) and 5-10 % Ellagic acid are the main constituents of pomegranate extract.

Ellagic acid is a naturally occurring phenolic constituent of many plants that is important in the human diet, especially fruits and nuts. Interest in Ellagic acid has increased greatly during the last decade due to its effectiveness as an antimutagen and anticarcinogen and its potential as an inhibitor of chemically induced cancer (12).

Test Materials:

1. SPF-4 Lotion, Lot #rRL 108-0526-F Homosalate
2. SPF-4 lotion with Antioxidants, Lot #rRL 108-0526-G Homosalate
3. SPF-8 Lotion, Lot #rRL 108-0525-C Octyl Methoxycinnamate
4. SPF-8 Lotion with Antioxidants, Lot #rRL 108-0525-D Octyl Methoxycinnamate
5. Pomegranate Capsules – 30 mg. Standardized Pomegranate Extract

CERTIFICATE OF ANALYSIS

Product Name: Standardized Pomegranate Extract
Part of Plant Used: Whole Fruit
Assay: Ellagic Acid – 5 % via HPLC
Solubility: 100 % In Water and Alcohol
Total Polyphenolics: minimum 40 %

Method:

Eight healthy male and female volunteers who met the inclusion criteria were enrolled in this portion of the study (5 females and 3 males ages 18-60 with skin type I to III). Exclusion criteria included people with abnormal response to sun, pregnant or lactating women, and subjects exhibiting any visible skin disease.

The irradiation procedure was based on the method outlined in the FDA monograph of proposed rules for sunscreen testing using a Xenon Arc Solar Stimulator as the source of ultraviolet light.

On Day 1 the minimal erythema dose was determined. On Day 2, after determining the minimal erythema dose (MED, a 2 mg/cm2 portion of the sunscreen formulation (test materials 1 to 4) was applied to the appropriate designated test site and spread evenly over the site using a fingercot. The sunscreen formulations were applied using a randomization table generated by the testing facility. After product application, irradiation of the sites was begun no less than 15 minutes and no longer than 30 minutes after application.

On Day 3, all test sites were evaluated approximately 16 to 24 hours after irradiation to determine minimal erythemal response. After evaluation of the test sites, the subjects were instructed to ingest their assigned antioxidant capsule.

On Days 4-9, subjects returned to the clinic to ingest their assigned antioxidant. All dosing of the capsules was performed under supervision at the clinic.

On Day 10, four (4) 5 x 10 cm test site areas were outlined with a surgical marking pen on the subject’s back between the scapulae and the beltline, lateral to the midline. These areas were designated as sites 1-4, with an additional site designated for a concurrent MED determination (unprotected control).

The application and irradiation procedure performed on Day 2 was repeated as described above.

On day 11 all test sites were evaluated approximately 16 to 24 hours after irradiation to determine minimal erythemal response.

Statistical Methodology:

The SPF is defined as the ratio of the amount of energy or time required to produce an MED on protected skin (treated with sunscreen formulation) to the amount of energy or time needed to produce an MED on untreated skin and is calculated as follows:

SPF = MED Sunscreen Formulation
MED Unprotected Control

The t-Test (Dependent) was used to determine if the pre-ingestion mean SPF values of the sunscreen formulations were significantly different from the post-ingestion mean SPF values of the sunscreen formulations. Significance was observed if P< 0.050.

Conclusions:

The post SPF values of Test Materials: 2) SPF-4 Lotion with Antioxidants, Lot #rRL 108-0526-G Homosalate and 3) SPF-8 Lotion, Lot #rRL 108-0525-C Octyl Methoxycinnamate were significantly increased over pre-treatment SPFs after ingesting Test Material: 5) Pomegranate Capsule for one week at a dose of one capsule per day. Also adding pomegranate extract to the sunscreens increased the SPF of the product.

One Pomegranate Capsule per Day

Test Material Pre-SPF Post-SPF % Change Signif.

1 5.81 28.8% P