Potent Antioxidant Protection*
Goji berry possesses a unique combination of flavonoids, vitamins, minerals and polysaccharides that are thought to be responsible for the antioxidant and anti-aging properties attributed to Goji. Studies have been conducted which characterize some of these antioxidant nutrients and show possible beneficial effects of the berry and its extracts on various systems and organs.
In a study published in 2004, scientists undertook an experiment to assess whether Goji berries contained compounds that would be known to exert potential beneficial effects on skin complexion and anti-aging properties. After analyzing the berry, leaf and roots of the Goji plant, they found that the Goji berry contained a unique analog of vitamin C known as 2-O-(beta-D-glucopyranosyl) ascorbic acid. They determined that this compound was unique to the berry and not found in the other parts of the plant. Furthermore, the vitamin C compound was present in levels equivalent to those found in citrus fruits such as lemons. However, the question remained as to whether this vitamin C analog served as a precursor to vitamin C when ingested in the body. A further experiment in rats was performed to determine the intestinal absorption and tissue uptake of this vitamin C analog. The results showed that some of the compound was indeed metabolized into vitamin C in the blood, while the rest was absorbed intact. These studies suggested that the compound was easily transported from the blood into cells and tissues, where it is activated to active vitamin C. Therefore, the vitamin C from Goji berries seems to be highly absorbable and targeted for delivery to the cells that utilize it.1
Zeaxanthin is a carotenoid that is widely distributed in fruits and vegetables and, along with lutein, is present in significant amounts in the macula of the human eye. Studies suggest that the presence of zeaxanthin is highly desirable for healthy visual function. Goji berries are used in traditional Chinese herbalism to support eye health and are also known to contain a high level of zeaxanthin dipalmitate. Researchers compared the bioavailability of this naturally esterified zeaxanthin to that of an unesterified form in 12 individuals who underwent a 23-day study in which they received one form or the other, and then switched. Administration was done on day one followed by a three-week washout period. The individuals were then crossed over to get the other form on day 23 in a single administration. Analysis revealed that the esterified zeaxanthin from Goji berry caused a higher increase in plasma levels than the non-esterified form, indicating higher bioavailability.2
A second study confirmed these findings. In this study, fourteen individuals consumed 15 grams of whole Goji berries daily for 28 days. These individuals were compared to thirteen age and sex-matched controls who did not consume the berries. Fasting blood samples were taken for all individuals before and after the 28-day period. Results indicated that zeaxanthin plasma levels increased 2.5-fold in the group who consumed the berries daily, suggesting the high bioavailability of zeaxanthin from the berries.3
Goji berry was also studied on various measures of antioxidant activity. Researchers subjected three Chinese herbs, one of which was Goji berry, to various assays of reactive oxygen scavenging potential. The results indicated that all of the herbs had significant free radical scavenging properties, however, Goji berries showed the most potent scavenging effect in the assays. Goji berry was especially strong at inhibiting the formation of superoxide anion and scavenging free radicals. The researchers concluded that among these herbs, Goji could be considered the best antioxidant to promote healthy aging.4
An interesting study was performed in human skin cultures to determine the mechanism of the potentially protective effect of Goji berry extracts. Researchers found that bathing human skin cultures with an extract from Goji berry impacted the function of several enzymes that promote skin aging. This provides evidence of an anti-aging and antioxidant effect of Goji berry extract in these human skin cultures. Researchers also noted that when these skin cultures were subjected to suboptimal growth conditions (lack of adequate nutrients), supplementing the medium with this Goji berry extract allowed the skin to maintain normal metabolic functions.5 Goji berry extract contains numerous compounds that confer potent antioxidant protection to various tissues.*
Maintains Healthy Immune Function*
Goji berries contain a unique profile of polysaccharides that work together to impact cell-signaling functions, thereby facilitating immune cell communication. Along with its antioxidant activity, Goji berry extract has the ability to maintain healthy immune function.*
The polysaccharide complex of Goji berry seems to be a powerful immune stimulator. Preliminary studies indicate that these polysaccharides may have wide-ranging benefits to immune health. One such study showed that certain polysaccharide components of Goji berry had the ability to influence cytokine production in human PMN cells (a class of white blood cells) when the extract was exposed to human blood samples. These effects suggest an immune-enhancing action of the polysaccharide fraction tested.6
A second study conducted in mice tested the immune-modulating effects of the same polysaccharide fraction of Goji berry in these animals. Goji berry extract, given orally once daily for ten days, was shown to influence a wide variety of immune parameters, favoring both humoral and cellular immune responses in a beneficial fashion. This was accomplished, in part, through up-regulation of cytokine and antibody production in these animals after administration of the polysaccharide extract. These changes were not seen in the control group.7
Goji berry extract has the ability to promote health through its immune-enhancing and antioxidant qualities.* Research into mechanisms of action are revealing that this ancient food, revered as a health tonic for centuries, may hold great importance for supporting the health and function of a number of bodily organs and systems.
1.Toyoda-Ono Y, Maeda M, Nakao M, Yoshimura M, Sugiura-Tomimori N, Fukami H. 2-O-(beta-D-Glucopyranosyl)ascorbic acid, a novel ascorbic acid analogue isolated from Lycium fruit. J Agric Food Chem. 2004 Apr 7;52(7):2092-6.
2.Breithaupt DE, Weller P, Wolters M, Hahn A. Comparison of plasma responses in human subjects after the ingestion of 3R,3R'-zeaxanthin dipalmitate from wolfberry (Lycium barbarum) and non-esterified 3R,3R'-zeaxanthin using chiral high-performance liquid chromatography. Br J Nutr. 2004 May;91(5):707-13.
3.Cheng CY, Chung WY, Szeto YT, Benzie IF. Fasting plasma zeaxanthin response to Fructus barbarum L. (wolfberry; Kei Tze) in a food-based human supplementation trial. Br J Nutr. 2005 Jan;93(1):123-30.
4.Wu SJ, Ng LT, Lin CC. Antioxidant activities of some common ingredients of traditional chinese medicine, Angelica sinensis, Lycium barbarum and Poria cocos. Phytother Res. 2004 Dec;18(12):1008-12.
5.Zhao H, Alexeev A, Chang E, Greenburg G, Bojanowski K. Lycium barbarum glycoconjugates: effect on human skin and cultured dermal fibroblasts. Phytomedicine. 2005 Jan;12(1-2):131-7.
6.Gan L, Zhang SH, Liu Q, Xu HB. A polysaccharide-protein complex from Lycium barbarum upregulates cytokine expression in human peripheral blood mononuclear cells. Eur J Pharmacol. 2003 Jun 27;471(3):217-22.
7.Gan L, Hua Zhang S, Liang Yang X, Bi Xu H. Immunomodulation and antitumor activity by a polysaccharide-protein complex from Lycium barbarum. Int Immunopharmacol. 2004 Apr;4(4):563-9.