In Traditional Chinese Medicine, goji has been used to stimulate the immune system, improve sight, protect the liver, improve circulation, increase longevity and protect against heart disease among other actions. Lycium barbarum is classified as a Yin tonic herb and also as a blood tonic due to its protective and nourishing action.
- Hair coloration protection
Containing large amounts of polysaccharides, amino acids and vitamins, Goji deserves consideration as an energizing and stimulating ingredient which may provide strength and energy to cells to perform thier metabolic functions. In an ex vivo study on the properties of the most common Chinese tonic plants (Ko, KaM., 2006), Goji was reported to have the ability to increase ATP generation by approximately 20%.
Another study on the immunological properties of Chinese plants (Xiao, PG. et al, 1993) stated that goji increases the percentage of T cells, promotes lymphocyte proliferation and macrophage phagocytosis, and increases antibody levels in the body. These effects are associated to its polysaccharides, as it has been described that these compounds act by increasing cytokines, the tumor necrosis factor, natural killer cells, T and B lymphocytes, the granulopoiesis and thrombopoiesis, among others (Winston, D. et al, 2007).
Antioxidant and antiaging activity
A number of studies have demonstrated the antioxidant activity of Goji fruit. This activity is caused by several factors: it has the ability to capture superoxide radicals (35-82%, depending on the applied goji concentration) and also its ability to inhibit lipid peroxidation was demonstrated in vitro (22-70%, depending on concentration) (Wu, SJ. et al, 2004).
Another subsequent study (Li, XM, et al, 2007) published on the Journal of Ethnopharmacology showed that:
- After having observed the levels of endogenous lipid peroxidation and immune function in old adult mice, and a decrease in antioxidant activities (measured by superoxide dismutase (SODa, catalase (CATa, V 01a04/09 40861a4 glutathione peroxidase (GSHaPx) and the TAOC, total antioxidant capacity), it was detected that normal levels were restored in groups treated with goji polysaccharides.
- Lycium barbarum polysaccharides had antioxidant activities comparable to those of vitamin C and, moreover, if vitamin C was added to the treatment with polysaccharides, a greater in vivo antioxidant activity of polysaccharides was observed.
- Goji was useful to compensate the decrease of the total antioxidant capacity, the immune function and the activities of antioxidant enzymes, thereby reducing the risk of accelerated lipid peroxidation, caused by age.
Another recent study (Zhao, H. et al, 2005) demonstrated that its antioxidant activity is also transferred to skin. It was observed that, in the presence of glycoconjugates from Goji, the level of metalloproteinases-I of the skin matrix was three or four times lower than the level showed by the control group. This decrease was not due to reduced skin activity, since the metabolic activity remained constant, so Goji selectively inhibited metalloproteinases-I. Knowing that they are excessively expressed in the aging process, Goji is of note in its ability to prevent it and stop it.
The same study also found that in fibroblasts cultures in suboptimal conditions, the presence of Goji glycoconjugates improved the general morphology of fibroblasts, becoming even very similar to their morphology under optimal conditions. Moreover, type I collagen in these cultures was also measured to determine whether the addition of Goji prevented the decrease suffered in suboptimal conditions (60% less). The result was very positive, because with Goji the collagen was restored to the levels observed in cultures under optimal conditions and it was confirmed that this is a dose-dependent response. In addition, some of the glycoconjugates have a low molecular weight and, therefore, they can easily penetrate skin.