**3.4 Anti-inflamm-aging properties**

Inflamm-aging, a state of chronic, low-level systemic inflammation, is a widespread feature of human aging and a major risk factor for disabilities and mortality in aging individuals [89, 90]. Inflamm-aging is characterized by an overall increase in plasma levels of pro-inflammatory cytokines, such as IL-6 and TNF-α, and

**15**

*Anthocyanins and Proanthocyanidins in Natural Pigmented Rice and Their Bioactivities*

subsequently can increase major inflammatory markers such as C-reactive protein (CRP) and serum amyloid A. This generalized pro-inflammatory status potentially triggers the onset of the most important age-related diseases such as cardiovascular diseases, atherosclerosis, metabolic syndrome, type 2 diabetes, obesity, neurode-

Since the anti-inflammatory effects of phytochemical components in black rice and red rice (anthocyanins and proanthocyanidins) are able to target many inflammatory signaling pathways, such as the MAP kinase and AMP-activated protein kinase (AMPK) and mTOR pathway, the result can also decrease free radical production by their antioxidant activity, inhibiting NF-κB activation and reducing the expression of inflammatory mediators (NO, iNOS, and pro-inflammatory cytokines) [7, 31, 93, 94]. Therefore, this has made natural pigmented rice a promising candidate as an anti-inflamm-aging agent. Some relevant studies have found that a Mediterranean diet (a diet involving high consumption of vegetables, fruits, and whole grains such as pigmented rice, olive oil, and fish, but low in the intake of saturated fats and other animal fats) can modulate the multi-interconnected processes that are involved in inflammatory responses such as free radical production, NF-κB activation, and the expression of inflammatory mediators by balancing between pro- and anti-inflammaging activities as well as maintaining healthy gut microbiota homeostasis and epigenetic modulation of oncogenesis through specific microRNAs [95, 96]. Several studies have identified a number of actions of anthocyanins in a phytochemical diet in the context of neuroinflammation and neurodegeneration in aging individuals. It was also recently reported in an experimental model of multiple sclerosis that anthocyanins (100 mg/kg) could effectively suppress the secretion of pro-inflammatory mediators and protect cellular components against oxidative damages that were induced by demyelination [97]. Anthocyanins also protect neuronal cells from prooxidant and pro-inflammatory damage via the modulation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and the inhibition of NF-κB pathways [98]. Moreover, anthocyanins also exhibited a similar degree of anti-inflammatory effects, and these compounds suppressed the expression and secretion of pro-inflammatory mediators in macrophages by inhibiting the nuclear

Red rice extracts that contain high levels of proanthocyanidins were also found to have neuroprotective effects and anti-inflamm-aging effects that are similar to those of anthocyanins. Previous studies have found that in primary hippocampal neuronal cells that had been treated with proanthocyanidins (14 μg/ml) and exposed to LPS, the major neuroprotective effects of proanthocyanidins were involved with a reduction of NF-κB, p38, and JNK [100]. In brief, the consumption of foods rich in polyphenols has been associated with the prevention of chronic diseases. In particular, anthocyanins, proanthocyanidins that act through various mechanisms that modulate the inflammatory signaling pathways, result in a reduction of inflammation that is often seen in aging individuals. A schematic diagram of the proposed mechanism of anti-inflamm-aging properties of black rice and red rice is presented in **Figure 6**. From the aforementioned results, it has been determined that black rice and red rice with their anti-inflamm-aging properties have a therapeutic potential that would likely need to be further investigated in geriatrics

Many studies have shown that bioactive compounds found in pigmented rice, such as proanthocyanidin, catechin, vanillic acid, and oryzanol, may be useful in the cosmetic and nutraceutical industries as skin antiaging agents. As mentioned

*DOI: http://dx.doi.org/10.5772/intechopen.86962*

translocation of NF-κB [99].

and gerontology fields.

**3.5 Skin anti-aging properties**

generation, sarcopenia, frailty, and cancer [91, 92].

**Figure 5.** *Schematic diagram of anticancer properties of red rice proanthocyanidins.*

#### *Anthocyanins and Proanthocyanidins in Natural Pigmented Rice and Their Bioactivities DOI: http://dx.doi.org/10.5772/intechopen.86962*

subsequently can increase major inflammatory markers such as C-reactive protein (CRP) and serum amyloid A. This generalized pro-inflammatory status potentially triggers the onset of the most important age-related diseases such as cardiovascular diseases, atherosclerosis, metabolic syndrome, type 2 diabetes, obesity, neurodegeneration, sarcopenia, frailty, and cancer [91, 92].

Since the anti-inflammatory effects of phytochemical components in black rice and red rice (anthocyanins and proanthocyanidins) are able to target many inflammatory signaling pathways, such as the MAP kinase and AMP-activated protein kinase (AMPK) and mTOR pathway, the result can also decrease free radical production by their antioxidant activity, inhibiting NF-κB activation and reducing the expression of inflammatory mediators (NO, iNOS, and pro-inflammatory cytokines) [7, 31, 93, 94]. Therefore, this has made natural pigmented rice a promising candidate as an anti-inflamm-aging agent. Some relevant studies have found that a Mediterranean diet (a diet involving high consumption of vegetables, fruits, and whole grains such as pigmented rice, olive oil, and fish, but low in the intake of saturated fats and other animal fats) can modulate the multi-interconnected processes that are involved in inflammatory responses such as free radical production, NF-κB activation, and the expression of inflammatory mediators by balancing between pro- and anti-inflammaging activities as well as maintaining healthy gut microbiota homeostasis and epigenetic modulation of oncogenesis through specific microRNAs [95, 96].

Several studies have identified a number of actions of anthocyanins in a phytochemical diet in the context of neuroinflammation and neurodegeneration in aging individuals. It was also recently reported in an experimental model of multiple sclerosis that anthocyanins (100 mg/kg) could effectively suppress the secretion of pro-inflammatory mediators and protect cellular components against oxidative damages that were induced by demyelination [97]. Anthocyanins also protect neuronal cells from prooxidant and pro-inflammatory damage via the modulation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and the inhibition of NF-κB pathways [98]. Moreover, anthocyanins also exhibited a similar degree of anti-inflammatory effects, and these compounds suppressed the expression and secretion of pro-inflammatory mediators in macrophages by inhibiting the nuclear translocation of NF-κB [99].

Red rice extracts that contain high levels of proanthocyanidins were also found to have neuroprotective effects and anti-inflamm-aging effects that are similar to those of anthocyanins. Previous studies have found that in primary hippocampal neuronal cells that had been treated with proanthocyanidins (14 μg/ml) and exposed to LPS, the major neuroprotective effects of proanthocyanidins were involved with a reduction of NF-κB, p38, and JNK [100]. In brief, the consumption of foods rich in polyphenols has been associated with the prevention of chronic diseases. In particular, anthocyanins, proanthocyanidins that act through various mechanisms that modulate the inflammatory signaling pathways, result in a reduction of inflammation that is often seen in aging individuals. A schematic diagram of the proposed mechanism of anti-inflamm-aging properties of black rice and red rice is presented in **Figure 6**. From the aforementioned results, it has been determined that black rice and red rice with their anti-inflamm-aging properties have a therapeutic potential that would likely need to be further investigated in geriatrics and gerontology fields.

#### **3.5 Skin anti-aging properties**

Many studies have shown that bioactive compounds found in pigmented rice, such as proanthocyanidin, catechin, vanillic acid, and oryzanol, may be useful in the cosmetic and nutraceutical industries as skin antiaging agents. As mentioned

*Phytochemicals in Human Health*

rice germ and bran [7–9, 13].

**3.4 Anti-inflamm-aging properties**

*Schematic diagram of anticancer properties of red rice proanthocyanidins.*

the degradative enzymes MMP-2 and MMP-9 [14]. Interestingly, Chen et al. [87] compared the relationship of the bioactive compounds with the growth inhibitory effects of pigmented rice bran extracts. The results revealed that the light brown bran had no effect, the purple bran exhibited a minor effect on leukemia and cervical cancer cells, and the red bran exhibited strong inhibitory effects on leukemic, cervical, and stomach cancer cells. High concentrations of protocatechuic acid and anthocyanins in purple bran and proanthocyanidins in red rice bran have been singled out for their growth inhibitory effects against human cancer cells.

Many studies on anticancer properties have been reported in Thai rice cultivars. In an important study, Kum Phayao black rice cultivar was found to be highly cytotoxic to human HepG2 cells when compared with other Northern Thai purple rice cultivars [12]. In yet another study, the alcoholic extracts of black-purple rice grain cultivar Kum Doi Saket demonstrated an antimutagenic activity against aflatoxin B1 in Ames tests [88]. The therapeutic potential of black rice anthocyanin for treating inflammatory diseases that are associated with cancer has been proposed for its mechanism via the inhibition of the MAPK signaling pathway [31]. A very recent study conducted by our research group revealed that the proanthocyanidinrich fraction isolated from the red rice germ and bran of the Kum Doi Saket cultivar grown in the northern part of Thailand significantly reduced the cell viability of HepG2 cells (IC50 value at 20 μg/ml) [13]. The proanthocyanidin-rich fraction could inhibit cell proliferation and induce cell apoptosis by increasing the apoptotic proteins, such as cleaved PARP-1, cleaved caspase 8, and cleaved caspase-3, and decreasing the anti-apoptotic protein survivin without p53 protein changes. A schematic diagram of this mechanism is presented in **Figure 5**. In addition, our previous studies have demonstrated that red rice grain extracts with high proanthocyanidin content displayed an anti-metastasis effect on invasive human breast carcinoma cells MDA-MB231 [16] and human fibrosarcoma HT1080 cell lines [15]. In addition, proanthocyanidins in other colored plants, such as grapes and blackberries, have demonstrated anticancer, anti-inflammatory, and antioxidant activities to a similar extent as the proanthocyanidins that are found in red

Inflamm-aging, a state of chronic, low-level systemic inflammation, is a widespread feature of human aging and a major risk factor for disabilities and mortality in aging individuals [89, 90]. Inflamm-aging is characterized by an overall increase in plasma levels of pro-inflammatory cytokines, such as IL-6 and TNF-α, and

**14**

**Figure 5.**

#### **Figure 6.**

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

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 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

**17**

development in skincare products.

**Acknowledgements**

**4. Conclusion**

*Anthocyanins and Proanthocyanidins in Natural Pigmented Rice and Their Bioactivities*

inhibiting the growth of culture B16-F10 mouse melanoma cells.

new global business era of nutraceutical and agriculture expansion.

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

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

This work was supported by Chiang Mai University and The Excellent Center for Research and Development of Natural Products for Health, Chiang Mai University.

and γ-oryzanol could reduce the melanin content in B16-F10 melanoma cells. Some studies have proposed the use of red rice callus or stem cells as a source of materials for replenishing the aging body in a series of experiments. The results demonstrated the efficacy of red rice callus in cosmetic products on 28 volunteer subjects aged 30–55 years and proved to promote skin lightening, hydration, and elasticity. On the other hand, a study performed involving five different varieties of Thai pigmented rice demonstrated that all rice crude extracts with 50% ethanol exhibited a weak level of activity on tyrosinase inhibition [23]. This result is similar to our findings which demonstrated that proanthocyanidin and oryzanol could reduce melanin content but had no effect on mushroom tyrosinase activity [22]. However, our results have produced experimental data to support that proanthocyanidin decreased cellular tyrosinase activity leading to a decrease in melanin content. As has been mentioned previously, proanthocyanidin is highly present in red rice germ and bran and is very similar in chemical structure to the oligomers of catechin and epicatechin that are found in grape seeds and red wine. It is noteworthy to cite the findings of a study that found that the oral administration of grape seed extract was effective in lightening UV-induced pigmentation of guinea pig skin by a reduction in the number of 3,4-dihydroxyphenylalanine (DOPA)-positive melanocytes, Ki-67 positive, proliferating cell nuclear antigen (PCNA)-positive melanin-containing cells in the basal epidermal layer of the UV-irradiated skin in grape seed extract-fed guinea pigs. In addition, this study has demonstrated that grape seed extract effectively inhibited mushroom tyrosinase activity and inhibited melanogenesis without

*DOI: http://dx.doi.org/10.5772/intechopen.86962*

*Anthocyanins and Proanthocyanidins in Natural Pigmented Rice and Their Bioactivities DOI: http://dx.doi.org/10.5772/intechopen.86962*

and γ-oryzanol could reduce the melanin content in B16-F10 melanoma cells. Some studies have proposed the use of red rice callus or stem cells as a source of materials for replenishing the aging body in a series of experiments. The results demonstrated the efficacy of red rice callus in cosmetic products on 28 volunteer subjects aged 30–55 years and proved to promote skin lightening, hydration, and elasticity. On the other hand, a study performed involving five different varieties of Thai pigmented rice demonstrated that all rice crude extracts with 50% ethanol exhibited a weak level of activity on tyrosinase inhibition [23]. This result is similar to our findings which demonstrated that proanthocyanidin and oryzanol could reduce melanin content but had no effect on mushroom tyrosinase activity [22]. However, our results have produced experimental data to support that proanthocyanidin decreased cellular tyrosinase activity leading to a decrease in melanin content. As has been mentioned previously, proanthocyanidin is highly present in red rice germ and bran and is very similar in chemical structure to the oligomers of catechin and epicatechin that are found in grape seeds and red wine. It is noteworthy to cite the findings of a study that found that the oral administration of grape seed extract was effective in lightening UV-induced pigmentation of guinea pig skin by a reduction in the number of 3,4-dihydroxyphenylalanine (DOPA)-positive melanocytes, Ki-67 positive, proliferating cell nuclear antigen (PCNA)-positive melanin-containing cells in the basal epidermal layer of the UV-irradiated skin in grape seed extract-fed guinea pigs. In addition, this study has demonstrated that grape seed extract effectively inhibited mushroom tyrosinase activity and inhibited melanogenesis without inhibiting the growth of culture B16-F10 mouse melanoma cells.
