**6. Nutrition related to immune function**

Along with the development of science and technology, nutrients that are known to have immunomodulating effects are prebiotics, proteins/amino acids, fats/fatty acids, vitamins and minerals.

#### **6.1 Protein amino acids related to immune function contained in coconut fruit for the treatment of infectious diseases and sepsis**

The protein contained in the flesh of young coconuts contains 15 types of amino acids, 10 of which include essential amino acids. The ten essential amino acids are threonine (THR), tyrosine (TYR), methionine (MET), valine (VAL), phenylalamine (PHE), ileucine (ILE), leucine (LEU), lysine (LYS), histidine (HIS). and arginine (ARG). HIS and ARG are not essential for adults, but essential for children. In addition, the amino acid content of Glutamate (GLU) in all types of coconut ranged from 3.59–4.02%, which was the highest compared to other types of amino acids. Thus, consuming young coconut flesh in addition to being able to fulfill some of the essential amino acid needs while at the same time obtaining GLU amino acids where these amino acids are important nutrients in infectious conditions [33].

Glutamine (GLU) has many roles in the immune system. Glutamine supplementation has been reported to have multiple benefits, including increasing nitrogen retention and reducing muscle cell mass loss, enhancing immune function, thereby reducing the risk of infection and maintaining organ glutamine. Glutamine is an essential nutrient for enterocytes and immune cells through its antioxidant and cytoprotective effects. Glutamine maintains the protective function of the gut, provides antioxidant and cytoprotective effects, stimulates nucleotide synthesis,

#### *Potential Natural Product from Tropical Fruits: A Mixture Young Coconut Fruit and Kaffir… DOI: http://dx.doi.org/10.5772/intechopen.99005*

maintains the killing of neutrophil bacteria, and increases the proliferation and secretion of lymphocytes and macrophages. Intense immune activity and/or hypercatabolism, as occurs in burns, trauma and sepsis, is associated with increased glutamine consumption and a drastic decrease in plasma glutamine concentrations. Loss of glutamine concentration during the body's defense processes can lead to severe impairment of immune function. Hypoglutaminemia is an independent predictor of mortality and/or poor clinical outcome in critically ill patients [63, 64].

Glutamine is the most common free amino acid in the body with various involvements in gluconeogenesis, ammoniagenesis in the kidney, and the integrity of the intestinal mucosa. Glutamine is also conditionally important during catabolic conditions as it provides oxidative energy for cell division, increases antioxidant production, and acts as a major fuel for intestinal cells and the immune system [17, 65].

Glutamine supplementation has been shown to have multiple benefits, including increasing nitrogen retention and reducing muscle mass loss, maintaining the permeability and structure of the gastrointestinal mucosa, enhancing immune function thereby reducing the risk of infection and maintaining organ glutamine [66, 67].

Sepsis is accompanied by increased consumption, impaired synthesis, and decreased supply of the semi-essential amino acid arginine. This state of arginine deficiency impairs immune homeostasis and increases the risk of nosocomial infections. L-arginine supplementation is thought to contribute to restoring physiological processes such as its role for protein synthesis, organ perfusion, and wound healing in septic patients [68].

Meanwhile, arginine is an essential amino acid which during pathophysiological stress such as sepsis and trauma, its synthesis decreases. The immunomodulatory effect of arginine lies in increasing the function of B and T lymphocytes and their macrophages. Arginine is also involved in many anabolic processes involved in wound growth and healing, as it participates in connective tissue synthesis, changes in blood flow, and angiogenesis [16, 65].

Arginine can stimulate the release of growth hormone, prolactin, and insulin, as well as increase the number of T cells and improve T cell function. During catabolic disease serum arginine levels decrease due to reduced food intake, increased uptake in the endothelium, liver, and intestines and increased metabolism [69]. In addition, increased arginase expression leads to arginine depletion and decreased T cell activation and immunocompetence, and an increased risk of infection. So it is hypothesized that arginine supplementation can inhibit arginase and prevent these negative symptoms [70].

#### **6.2 Fatty acids related to immune function contained in coconut fruit for the treatment of infectious diseases and sepsis**

Clinical trials have shown that unsaturated fatty acids can be considered as powerful disease-modifying nutrients in patients with acute lung injury and sepsis [71, 72]. In particular, feeding with polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA), and docasahexaenoic acid (DHA) has been found to attenuate the production of various cytokines, chemokines, and other effectors [73]. Moreover, the recent discovery of resolvin produced by EPA and DHA has shed more light on the resolution of inflammation, as a possible mechanism of the anti-inflammatory action of the 3 PUFAs during systemic inflammation [74].

To determine the fat quality of young coconut flesh, Rindengan *et al*. [75] have analyzed the fatty acid and amino acid composition of young coconut flesh. In addition, young coconut flesh contains carbohydrates, crude fiber, galactomannan, phospholipids and a number of macro and micro minerals. Coconut fruit contains unsaturated fatty acids (ALT) oleic or omega 9 and essential ALTJ linoleic or omega 6. In general, products on the market such as formula milk include the weight of the two types of fatty acids. Omega 9 and omega 6 fatty acids occur naturally in several types of plant foods [75]. Omega 6 is one type of essential fatty acid that must be obtained from food because it cannot be metabolized in the body. In the body, omega 6 will be metabolized into arachidonic acid (AA). AA and linoleic (omega 6) ranks 2nd and 3rd of the four types of fatty acids that support brain intelligence. Docosahexanoic acid (Docosahexaenoic acid, DHA) is in first place and linolenic acid (omega 3) is fourth. Linolenic acid is an essential that must be obtained from food and in the body will be metabolized into DHA [76].

Given the high content of omega 9 and omega 6 fatty acids in young coconut meat, young coconuts can be an alternative to meet the needs of these two types of fatty acids. Seeing the nutritional potential that is also contained in the flesh of young coconuts, it is better not only to consume coconut water but together with coconut meat. Omega 6 essential unsaturated fatty acids (ALTJ) (linoleic) are classified as double ALTJ (Polyunsaturated fatty acids, PUFAs) [33].

## **6.3 Vitamins, Carotenoids and Flavonoids related to immune function contained in coconuts for the treatment of infectious diseases and sepsis**

#### *6.3.1 Vitamin B*

Vitamin B12, vitamin B6, folic acid and niacin are B vitamins that are beneficial for the immune system. Vitamin B6 contributes in the proliferation of lymphocytes, the formation of lymphoid tissue and in the antibody response. Vitamin B12 plays a role in augmenting the performance of phagocytes and T cell proliferation. Folic acid together with vitamin B12 can affect Natural Killer cells [24, 77, 78].

#### *6.3.2 Vitamin C*

Vitamin C is an enzyme catalyst and antioxidant. In addition, vitamin C is a regulator of immune cell activation to maintain the viability of immune cells. Vitamin C functions in the synthesis of nitric oxide produced by macrophages, regulates phagocytosis by reducing free radical production and increasing the activity of immune cells (natural killer) [79].

Vitamin C has important vascular protective effects by inhibiting oxidative stress, modulating intracellular signaling pathways, and maintaining homeostatic nitricoxide levels [80]. Vitamin C is also an important cofactor for the production of endogenous norepinephrine, epinephrine, and vasopressin [81]. Septic patients usually have very low or undetectable serum vitamin C levels [82].

Vitamin C can reduce the expression of iNOS ascorbate and can overcome radicals produced by the immune system. Ascorbate also reduces or prevents endotoxin translocation from the gut and is directly bactericidal, and can increase circulating GSH concentrations in the liver. Ascorbate also prevents the reduction of enzymes in the liver and is responsible for endotoxin clearance [26]. In a study conducted by Crimi *et al*., administration of high doses of vitamin C and vitamin E can reduce mortality by 67.5% to 45.7% [83].

#### *6.3.3 Vitamin E*

Vitamin E (tocotrienol or -tocopherol) is a powerful antioxidant that can assist monocyte/macrophage-mediated immune responses and IL-2 [79]. Vitamin E and other antioxidants increase CD4 cells. Vitamin E inhibits the synthesis of prostaglandins produced in cells after membrane oxidation, prevents fatty acid peroxidation

and is an immunoregulator of arachidonic acid metabolism through the synthesis of prostaglandins and leukotrienes. Vitamin E also affects T cells, B cells and monocytes and regulates the response of the cyclic element AMP that binds to protein [84].
