Pearl contains mainly calcium carbonate and magnesium carbonate, which accounted for 91%, followed by silica, calcium phosphate, aluminum oxide and ferric oxide as well as some trace elements such as sodium, magnesium, manganese, selenium, aluminum, and copper. It also contains essential amino acids such as histidine, lysine, arginine, valine, threonine, proline, methionine, leucine, phenylalanine, tryptophan and non-essential amino acids such as aspartic acid, glycine, alanine, glutamic acid, tyrosine, and serine [5], [6].

Proteins, peptides, and amino acids also contribute to the body antioxidant defense system [7].Furthermore, the presence of trace elements (calcium, magnesium, selenium) in pearl powder also favors antioxidant activity, by acting as cofactors to antioxidant enzymes [10].

During clinical trial 20 healthy volunteer subjects were recruited and randomly separated into two groups, each group of participants in the trial period, took daily 6 capsules of pearl powder (Exp group) or a placebo. However, no marked changes were noted in anthropometric parameters. Meanwhile, the total antioxidant capacity was increased substantially in the experimental group in comparison with placebo group it might be the reason for a concomitant rise in the total antioxidant capacity. Kim and his coworker [30] suggest that essential amino acids such as histidine, proline, alanine, and leucine have been reported to contribute to the scavenging of free radicals, thereby increasing total antioxidant capacity. By correlating with the in vitro antioxidant studies, the presence of protein (essential amino acids and peptide) in pearl powder might be the reason for a concomitant increase in the total antioxidant capacity

Conclusions

From the present data, the abundant presence of protein content (amino acids and minerals) in pearl powder demonstrated an increased total antioxidant capacity, antioxidant activity, total thiols (SH group) and glutathione content with suppressing lipid peroxides products (TBARS).

Moreover, the protein extract of pearl powder supplementation can significantly prolong the lifespan of C. elegans owing to antioxidant activity. The results of both in vivo and in-vitro highlight that pearl powder is a potent antioxidant and in the future can be employed for treating various age-related degenerative diseases/disorders.