**4. Conclusion**

*Phytochemicals in Human Health*

in the previous section in this chapter, these bioactive compounds demonstrated antioxidant and anti-inflammatory properties. For the enhancement of the knowledge of skin antiaging properties, the bioactive compounds in the pigmented rice extract have been elucidated in a number of research laboratories. Skin aging is a process characterized by progressive physiological and structural changes in the skin. These changes could be considered as individually intrinsic and extrinsic factors, such as those associated with age, lifestyle, diet, and sunlight. Additionally, certain environmental factors can contribute to skin aging [101]. In the skin aging process, the level of degradative enzymes, such as elastase and collagenase, in skin fibroblasts are elevated, and this can lead to a loss of skin firmness and the appearance of wrinkles [102]. Mature skin in the elderly or those with sun-exposed skin can cause dark spot formations on the skin or result in the over-synthesis of melanin [103]. Hence, natural or herbal products that can exert skin benefits, including scavenging reactive oxygen species (ROS), the suppression of extracellular matrix degradation enzymes, and the inhibition of melanin synthesis, can be applied in

*Schematic diagram of anti-inflamm-aging properties of pigment rice.*

skincare products for their beneficial skin anti-aging properties.

As pigmented rice has been reported to possess antioxidant properties, the extracts could be used for skin-anti-aging purposes. In a study by our research group, red rice extract showed anti-photoaging activity by protecting UV-induced collagen and hyaluronic acid degradation in human skin fibroblasts [21]. The red rice extract also inhibited collagenase and MMP-2 activity. In another study our group [22] has elucidated the skin antiaging properties of the main bioactive compounds in red rice extract including proanthocyanidin, catechin, hydroxybenzoic acid, vanillic acid, and oryzanol. The results showed that collagenase and MMP-2 activity were strongly inhibited by proanthocyanidin and catechin, whereas hydroxybenzoic acid, vanillic acid, and oryzanol had no effect. Both proanthocyanidin and catechin significantly induced the synthesis of collagen and hyaluronic acid, which is an important biological target for skin antiaging agents. Proanthocyanidins

**16**

**Figure 6.**

In this chapter, the by-products of rice processing, such as germ and bran, contain a wide range of biologically active compounds that can be recovered and used in a variety of approaches in nutraceuticals. This is in correlation with an increasingly deeper understanding of the predominant bioactive compounds found in pigmented rice, particularly anthocyanin and proanthocyanidin found in black and red rice, respectively. The dietary intervention and other high-value applications in functional food and cosmetic products have been attracting ever-growing attention in recent decades. The need for scientific evidence of pigmented rice bioactive compounds in different cultivars is encouraging for future perspectives within the new global business era of nutraceutical and agriculture expansion.

Most of the studies on the biological properties of black or red rice bioactive compounds have been conducted through an in vitro approach; however, only a few reports have been applied in preclinical or in animal studies. Further investigations will be needed to produce evidence on the efficacy of pigmented rice in terms of the anticancer activities and anti-inflammation properties in sub-chronic cases, especially among the aging members of the society in which sub-chronic inflammation commonly leads to noncommunicable diseases in later life. In addition, scientific studies have determined that the skin antiaging properties of pigmented rice should be useful and available in clinical studies for their efficacy and their further development in skincare products.
