Goji Berries as a Potential Natural Antioxidant Medicine

Goji berries are high antioxidant potential fruits which alleviate oxidative stress to confer many health protective benefits such as preventing free radicals from damaging DNA, lipids, and proteins.

The health benefits of goji berries include enhancing hemopoiesis, antiradiation, antiaging, anticancer, improvement of immunity, and antioxidation. 

Many pharmacological functions related to the eyes, kidney, and liver particularly have been promoted by the consumption of goji berry in populations [3].

One of the recommended therapies in the treatment of atrophic gastritis is to consume twice daily with 10 g Lycium fruits each time. Besides that, 15 g of goji berries per day is considered beneficial to supply adequate zeaxanthin which is estimated at 3 mg/day as a dietary supplement for eye health [4]. 

Goji berries are gradually being regarded as a functional food in many Asian countries as well as throughout Europe [3]. They also have been marketed as a health food in the western countries [6]. Goji berries recently gained a growing popularity as a “superfruit” in North America and European countries because of their potential health-promoting properties.

For example, goji berries have been used to increase longevity and for the benefits to liver, kidney, and vision since ancient times [2]. Due to the rich medical properties and chemical composition, goji berry has been consumed as an important food of a health-promoting diet for hundreds of years.

Bioactive Compounds of Goji Berries

The nutrients in goji berries are included 46% of carbohydrate, 16% of dietary fiber, 13% of protein, and 1.5% of fat. Thus, goji berries can be an excellent source of macronutrients. Micronutrients which included minerals and vitamins can be found in goji berries as well. There are studies that reported the presence of riboflavin, thiamine, nicotinic acid, and minerals such as copper, manganese, magnesium, and selenium in goji berries [7].

The high biological activity components in goji berries are polysaccharides, carotenoids, and phenolics [8]. These functional components are related with the health-promoting properties of goji berries.

The most important group of compounds present in goji berries is polysaccharides. Polysaccharides comprise 5–8% of dried fruits, and they are found in the water-soluble form of highly branched L. barbarum polysaccharides [1]. These six kinds of monosaccharides (i.e., arabinose, galactose, glucose, rhamnose, mannose, xylose, and galacturonic acid) are found in goji berries [5].

Some chemical compounds of goji berries.

Composition
Moisture (%) 10.3
Crude protein (%) 8.9
Crude oil (%) 4.1
Fiber (%) 7.3
Total phenol (mg GAE/100 mL) 3.4
Antioxidant activity (%) 20.8
Myristic acid (%) 0.1
Stearic acid (%) 2.9
Palmitic acid (%) 8.2
Arachidic acid (%) 1.8
Oleic acid (%) 21.7

Pharmacological Properties of Goji Berries

Goji berries have become popular over the years due to its public acceptance as a “superfood” with highly advantageous antioxidant and nutritive properties. A superfood is a “nutrient-rich” food considered to be especially beneficial for health or well-being. The carotenoid content of goji berries had been drawn a lot of attention due to its beneficial effects including antioxidant property on vision, retinopathy, and macular degeneration.

Berry fruits are rich in antioxidant phytochemicals [1112], and these antioxidants are capable of performing a number of functions.

The dietary intake of berry fruits has been shown to have a positive impact on human health, performance, and disease [1524]. All these fruits support the immune system and are rich in nutrients. Overall, they have a significant concentration of phytosterols, monounsaturated fats, antioxidants, essential amino acids, trace minerals, dietary fiber, and fat- and water-soluble vitamins [25].

Goji berry polysaccharides, for instance, are a well-known traditional Chinese medicine and tonic food for many years. In connection with it health benefits, Lycium barbarum polysaccharides (LBPs) are one of the most valuable functional components [526]. In recent years, L. barbarum is being used not only in China but also worldwide as a health dietary supplement in several forms including juice and tea [27]. Consuming products made from L. barbarum might help to decrease blood lipid concentration, promote fertility, and improve immunity [17192729].

Vision-Protective Effect

The mixture of highly branched polysaccharides and proteoglycans in LBPs has been reported to exert ocular neuroprotective effects [3031]. Goji berries, which contain a specific profile of carotenoid species [232], have high carotenoid metabolites, with zeaxanthin making up almost 60% of the total carotenoids in the fruit [33]. Carotenoids are main natural pigments accountable for the yellow, red, and orange colours of many types of fruits and vegetables [34]. They also have many biological actions including the pro-vitamin A’s antioxidant activity.

The protective characteristics of goji berry extracts on retina cells have been shown in the early stage of the retina degeneration in both human and animal studies [1]. Consumption of dietary L. barbarum has been shown to be retinoprotective.

Goji berries have also been shown to exhibit macular benefits in a randomized controlled study of healthy elderly participants [43]. It was observed that after 90 days of daily dietary supplementation with 13.7 g lacto-wolfberry (LWB) (a proprietary milk-based formulation of goji berry) elevated plasma antioxidant and zeaxanthin levels group, by 26% and 57%, respectively, in supplemented subjects [43].

Lipid-Lowering Effect

The lipid-lowering health benefit of LBP and its purified constituents have been demonstrated in animals with limited clinical studies in humans. Ming et al.’s research showed that abnormal lipid peroxidation parameters were returned to near normal level and lipid peroxidation accumulation was inhibited after administrating LPS to mice fed on HFD. This suggests that LBP seems to play an imperative role in lipid metabolism [52].

Allergic and Anaphylactic Reactions

Larramendi et al. [67] further reported a study involving 31 subjects in Spain. The subjects included five patients reporting allergenic symptoms on intake of goji berries, six tolerating the berries, and 20 never having eaten goji berries. All subjects underwent skin prick tests with goji berries, as well as with peach peel and plant food panallergens as biomarkers of cross-reactivity between unrelated foods. They reported that the skin tests to goji berries were positive in 24 subjects (77%). Positivity to goji berries was related with positivity to peach peel and to the panallergen-nonspecific LTPs.

Anticancer, Antitumour, Immunostimulatory, and Modulatory Effects

Goji berries have been utilised in traditional Chinese medicine to prevent the onset and progression of cancer for so many years, due to its rich phytochemical and antioxidant composition [1]. Some of its ingredients might have a better therapeutic effect on cancer than other foods. Hsu et al. [68] have reported that the L. barbarum carotenoid nanoemulsion was more effective in inhibiting HT-29 cancer cells as compared to that of the carotenoid extract.

Furthermore, both nanoemulsion and extract could upregulate p53 and p21 expression and downregulate CDK1, CDK2, cyclin A, and cyclin B expression and arrest the cell cycle at G2/M. Moreover, attributing to most of the biological effects of the fruits including anticancer, antitumour, and immunomodulatory and properties, goji berries are unusually rich in water-soluble peptide-conjugated polysaccharides (i.e., LBPs) [6971].

They have the ability to enhance or potentiate the host defence mechanisms in a way to inhibit tumour growth without harming the host. Research work conducted by Tang et al. [41] and Gan et al. [69] established that compounds in goji berries have proapoptotic and antiproliferative activity against cancer cells.

Neurological Protective Effect

The neurological protective effect of goji berries has been demonstrated in an experimental study including human clinical trial. Glutamate has been shown to be excitotoxic and is being implicated in many neurodegenerative diseases including Parkinson’s disease and Alzheimer’s disease [6172]. Thus, reduction of glutamate toxicity is considered a therapeutic strategy for those neurodegenerative diseases.

Cardiovascular Protective Effect

In an experiment to investigate the role of LBP in the reduction of myocardial injury in ischemia/reperfusion among rats, the rat heart LBP significantly reduced the myocardium Bax-positive rate; also, through dose-dependent methods, the apoptosis of myocardial cell and increase in Bcl-2 positive rate suggest that LBP can prevent further development and deterioration of CVD [76].

Antiaging Effects

In a recent review, Gao et al. [79] have discussed the various components contributing to the antiaging properties of L. barbarum. These notable components are LBPs, betaine, β-carotene, zeaxanthin, 2-O-β-D-glucopyranosyl-L-ascorbic acid (AA-2βG), and flavanoids [79]. L. barbarum contains betaine (a natural amino-acid).  Betaine has been shown to be an anti-inflammation agent associated with colon carcinogenesis. It also has been shown to possess a tumour-preventing effect on colitis-associated cancer in mice induced by azoxymethane.

Adverse Effects of Goji Berries

Apart from the allergic and anaphylactic reactions, other side effects that consumers should be aware of are to be mentioned. These include the presence of organic toxic substances and risk of interactions with other prescriptions besides allergy. Atropine, a toxic alkaloid, is naturally present in goji berry. The content was reported to be at toxic level. In a further work by Adam and co-workers, the atropine concentration in eight samples of goji berries using HPLC-MS was found to be maximally 19 ppb (w/w). Therefore, its content is far below toxic levels (Adam et al., 2006).

Arroyo-Martinez et al. described a case report of toxic hepatitis related to the use of goji. The symptoms reported included nonbloody diarrhea, asthenia, and colic abdominal pain. The patient had a mild mucocutaneous jaundice and a generalized erythematous and pruriginous maculopapular rash. The patient consumed goji berry tea 3 times a day [86]. The liver function tests were elevated. Goji berries have been shown to modulate the expression of CYP2C9 and CYP2E1 and have an immunomodulatory property [2]. However, another possible change in goji composition is contamination, during its production and post-marketing. Thus, the toxic side effects of post-marketing surveillance are another area of concern.

Conclusion

Similar to other plants [8791], goji berries are a high antioxidant potential fruits which alleviate oxidative stress to confer many health protective benefits such as preventing free radicals from damaging DNA, lipids, and proteins. There is a better protection through synergistic and additive effects in fruits and herbal products from a complex mixture of phytochemicals than from a single phytochemical. The health benefits of goji berries include enhancing hemopoiesis, antiradiation, antiaging, anticancer, improvement of immunity, and antioxidation.

Study Source: https://www.ncbi.nlm.nih.gov/

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By | 2019-08-12T11:46:24+02:00 August 12th, 2019|Health Tips, Remedies, TNR|