Oryzanol
The γ-oryzanol component in rice bran and RBO has the most potential as a nutraceutical, pharmaceutical, and cosmoceutical. This fraction contains ferulate (4-hydroxo-3-methoxycinnamic acid) esters of sterols (campesterol, stigmasterol, and β-stigmasterol), and triterpene alcohols (cycloartenol, 24-methylene cycloartanol, cyclobranol).81–83
γ-Oryzanol was first isolated from RBO by Kaneko and Tsuchiya in 1954,84 and was named because it was first discovered in RBO (Oryza Sativa L.). The most accessible natural source of γ-oryzanol is rice.85 γ-Oryzanol is a white or slightly yellowish tasteless crystalline powder with little or no odor, and has a melting point of 137.5–138.5°C.81 It is insoluble in water, slightly soluble in diethyl ether and n-heptane, and practically soluble in chloroform.86 Initially it was reported to be a single component in rice bran,103 but it is now known to be a mixture of at least 10 components.87,88 Cycloartenyl ferulate, 24–methylene cycloartanyl ferulate, and campesteryl ferulate (Figure 35.1) are the three major components.
The concentration of γ-oryzanol in RBO ranges from 115 to 780 ppm, depending on the degree and method of processing.89 γ-Oryzanol content in rice bran is 13–20 times (w/w) higher than that of total tocopherols and tocotrienols.90 It has been observed that about 20% of the unsaponifiable fraction in RBO is oryzanol. Different extraction methods can result in different levels of these components, because some tocotrienols and tocotrienol-like compounds are bound to cellular components in the rice bran.67,91
The complete role of γ-oryzanol as a functional ingredient has not so far been thoroughly observed; on the other hand, health claims including antioxidant activity,81 reduction of serum cholesterol,92 reduction of cholesterol absorption,65 increase of HDL cholesterol,23 inhibition on platelet aggregation,93 inhibition of tumor promotion,94 and menopausal syndrome treatment89 have been investigated.
For its antioxidant property, at the molecular and cellular levels, antioxidants serve to deactivate certain particles called free radicals. One in vitro study found that γ-oryzanol was more than four times as effective at stopping tissue oxidation as was vitamin E. The nutritional function of the γ-oryzanol components may be related to their antioxidant property because of the ferulic acid structure. Ferulic acid is a phenolic acid antioxidant.95–99
The antioxidant capacities of γ-oryzanol components were studied by using a linolenic acid model.100 The three major components of γ-oryzanol (24-methylene cycloartanyl ferulate, cycloartenyl ferulate, and campesteryl ferulate) evidenced significant antioxidant activity when they were mixed with linoleic acid in a molar ratio of 1 : 100 and 1 : 250, but not in a molar ratio of 1 : 500. Antioxidant activities of tocopherols, tocotrienol, and γ-oryzanol oxidation were studied, and the highest antioxidant activity was found for 24-methylene cycloartanyl ferulate. All the three major γ-oryzanol componeents had activities higher than that of any of the four vitamin E components (α-tocopherol, α-tocotrinol, γ-tocopherol and γ-tocotrienol).30 Inhibition of cholesterol autoxidation by the non-saponifiable fraction in rice bran was studied by Kim et al.101 in an aqueous model system.
One of the most important properties of γ-oryzanol is its cholesterol-lowering property. There are several studies on humans and animals showing that the RBO has the property of lowering low density lipoprotein cholesterol and total serum cholesterol and increasing high density lipoprotein cholesterol to some extent either by influencing the absorption of dietary cholesterol or by enhancing the conversion of cholesterol to fecal bile acids and sterols. Further studies confirmed that the γ-oryzanol component of RBO is responsible for the hypocholesterolemia.102–107
The mechanism of the cholesterol-lowering action of γ-oryzanol was investigated.67 Hamsters were rendered cholesterolemic by feeding them chow-based diets (containing coconut oil and 0.1% cholesterol with or without γ-oryzanol) for 7 weeks. Relative to control animals, oryzanol administration resulted in a significant reduction of plasma total cholesterol (28%) and non-high density lipoprotein cholesterol (non-HDL-C; 34%) levels, and a 25% reduction in cholesterol adsorption. Aortic fatty streak formation was reduced by 67% in the γ-oryzanol treated animals. It was concluded that γ-oryzanol was at least partly responsible for the cholesterol-lowering action of RBO, and is associated with the reduction in aortic fatty streak formation. It has been reported108 that the serum total, LDL + VLDL cholesterol, and free esterified levels of rats maintained on a 10% RBO diet were lower than those of rats maintained on a 10% ground nut oil diet. Addition of 5% γ-oryzanol to the diet containing rice bran further reduced the serum cholesterol. These studies concluded that the cholesterol-lowering property of RBO might be due to γ-oryzanol and/or other non-saponifiable constituents present in RBO. Moreover, hypertriglyceridemia induced by fructose was lower in animals maintained on a 0.5% γ-oryzanol containing diet than in the corresponding controls. Blending of RBO with other vegetable oils in suitable proportions was reported to magnify the hypocholesterolemic activity, compared with the effect of each oil alone.101 γ-Oryzanol may also lower the plasma cholesterol level. Although the mechanism underlying this effect is not known at present, the presence of γ-oryzanol and tocopherols in the rice bran is thought to be responsible for this favorable effect. The blending may have a practical significance. The effect of γ-oryzanol on atheroma formation in hypercholesterolemic rabbits has also been studied.109 The effect of RBO and γ-oryzanol in the treatment of hyperlipoproteinemia has been investigated.23 When added to a high cholesterol diet, it also inhibits platelet aggregation, preventing heart attacks and strokes. The nutritional and biochemical aspects of the hypolipidemic action of RBO have been reviewed, including the physiological, antioxidant, and hypocholesterolemic properties of γ-oryzanol.110
Regarding effects on serum TSH (thyroid stimulating hormone), a single oral dose (300 mg) of γ-oryzanol extracted from rice bran oil produced a significant reduction in the elevated serum TSH level in hypothyroid patients. Similarly, chronic treatment with γ-oryzanol resulted in a decreased serum TSH level in six of eight patients. There was no change in the serum level of thyroxine-iodine and triiodothyronine during the study. In addition, there was no difference in the serum TSH response to thyroid releasing hormone in hypothyroid patients and normal subjects. These observations suggest that γ-oryzanol inhibits serum TSH levels in patients with primary hypothyroidism, possibly by a direct action at the hypothalamus rather than the pituitary.23
Effects on muscle, γ-oryzanol/ferulic acid, inposine, chromium, and medium chain triacyl glycerol are used as ergogenic aids by strength/power athletes.111 The effect of γ-oryzanol supplementation during resistance exercise training has been explained by Fry and colleagues.112 These findings have created an interest in using γ-oryzanol as a sports supplement.
The carcinogenic potential of γ-oryzanol was studied in F344 rats113 and B6C3F1 mice.114 The findings indicate that, under the experimental conditions described, γ-oryzanol was not carcinogenic in F344 rats and B6C3F1 mice. The inhibitory effect of cycloartenol ferulate, a component of rice, on tumor promotion in two-stage carcinogenesis in mouse skin was studied.94 According to this study, the active components of rice bran (sitosterol ferulate, 24-methylcholesterol ferulate, cycloartenol ferulate, and 24-methylenecycloartanol ferulate) markedly inhibited the TPA-induced inflammation in mice.
Cycloartenol ferulate, a component of γ-oryzanol in RBO, shows marked inhibition of the tumor promoting effect of TPA in 7,12-dimethylbenz[a]anthracene-initiated mice. The modifying effects of phytic acid and γ-oryzanol on the promotion stage of rat carcinogenesis, and RBO anticancer properties, were studied.28,115
In addition to γ-oryzanol, bioactive components from RBO have been shown to play a protective role against the alteration caused by a hypercholesterolemic diet. Male Sprague-Dawley rats were fed for 4 weeks with a normal diet, high-cholesterol diet, or high-cholesterol diet supplemented with the concentrated bioactive components from RBO. The high-cholesterol diet increased serum cholesterol in rats, compared with those fed on the normal diet. Serum HDL cholesterol was significantly increased in rats on the bioactive components from RBO group. Supplementation with bioactive compounds from RBO also lowered the activities of a biomarker of damage in liver function (aspartate transaminase). It was found that bioactive components from RBO have a significant practical value for protecting against the alterations caused by a hypercholesterolemic diet, and antioxidative ingredients which suppress lipid peroxidation.102Read more
Rice Bran Antioxidants in Health and Wellness
Md. Shafiqul Islam, … Masatoshi Hori, in Wheat and Rice in Disease Prevention and Health, 2014
Rice Bran Antioxidants for Gastrointestinal Complaints
Rice bran γ-oryzanol has therapeutic potency for many gastrointestinal diseases. Colorectal cancer is an important public health problem, and one of the most fearsome complications of inflammatory bowel diseases (IBDs) – mainly ulcerative colitis (UC) but also Crohn’s colitis. Many basic medical scientific studies for gastrointestinal diseases have been reported since 1962. Rice bran γ-oryzanol has been reported to inhibit gastric secretion and experimental ulcers in rats.14 The inhibitory effects of γ-oryzanol on gastric secretions were slightly effective for histamine-stimulated acid secretion, non-effective for carbachol-stimulated secretion, and significantly inhibited tetragastrin-stimulated secretion. It was further revealed that the effect of γ-oryzanol on acid secretion stimulated by tetragastrin was prevented by vagotomy but not by splanchnicotomy. Therefore, this scientific evidence suggests that the gastric antisecretory effect of γ-oryzanol is mediated by the vagus nerve, which plays a role in the action of gastrin.14 In another study, pretreatment with γ-oryzanol (100 mg/kg, s.c., once daily × 5) depressed the gastric secretion stimulated by insulin or 2-deoxy-D-glucose, but the potency was less than that with atropine (10 mg/kg, s.c.). γ-Oryzanol had no effect on the decrease in the serum glucose level or on the increase in the gastrin level induced by insulin injection, while atropine enhanced these responses. Therefore, it is considered that the inhibitory action of γ-oryzanol on gastric secretion may be due to depression of the vagus system, but the mode of action is different from that of atropine.15 Rice bran γ-oryzanol, cycloartenyl ferulate, and ferulic acid (the metabolite of γ-oryzanol) were extensively studied in dextran sulfate sodium (DSS)-induced colitis mice. γ-Oryzanol, cycloartenyl ferulate, and ferulic acid ameliorate colonic inflammation in DSS-induced colitis in mice.16 This amelioration was associated with inhibition of myeloperoxidase (MPO) activity, decreased production of cytokines such IL-1β, TNF-α, and IL-6, and inhibition of COX-2 and NF-κB activity in colitis tissue. Still, the medical treatment of IBD relies on the use of aminosalicylates, corticosteroids, immunosuppressive drugs (azathioprine, 6-mercaptopurin, methotrexate, cyclosporin), and antibiotics. However, aminosalicilates (5-amino salicylic acid [5-ASA] derivatives) and/or glucocorticoids remain the principal means of therapy for IBD at different stages of the disease. 5-ASA-based agents are usually well tolerated but frequently induce side effects, such as acute pancreatitis, abdominal pain, diarrhea, nausea, headache, anemia, renal failure, and anaphylaxis. Therefore, rice bran γ-oryzanol and its components are prominent candidate seed compounds for treatment of gastrointestinal complaints.
γ-Oryzanol
Christelle Lemus, … Alexios Leandros Skaltsounis, in Wheat and Rice in Disease Prevention and Health, 2014
Classification and Biosynthesis of γ-Oryzanol
Chemically, γ-oryzanol is a mixture of structurally related components, and specifically esters of ferulic acid with phytosterols and triterpene alcohols, also referred as steryl ferulates. Steryl ferulates have been identified in rye, corn, triticale, barley, and wheat, but their richest source is rice, and specifically RBO.12 The most abundant steryl ferulates in RBO, comprising almost 95% of γ-oryzanol, are campesterol, β-sitosterol, cycloartenol, and 24-methylenecycloartenol esters (Fig. 32.2). Although the constituents of γ-oryzanol were identified as steryl esters of ferulic acid, Fang’s work has recently revealed the presence of caffeate esters of cycloartenol and campesterol as well.13
Numerous others steryl ferulates have been reported to be present in γ-oryzanol in low concentrations, detected and identified via several spectroscopic methods, and most of these are presented in Table 32.1.
TABLE 32.1. Basic γ-Oryzanol Components Identified Using MS and NMR Techniques
| Empty Cell | R1 | R2 | Name | Formula | M (g/mol) | Ref(s) |
|---|---|---|---|---|---|---|
| F | 24-Methylenecycloartanyl ferulate | C41H60O4 | 616.45 | Fang et al.13, Akihisa et al.22, Xu and Godber75, Berger et al.187 | ||
| F | Cycloartenyl ferulate | C40H58O4 | 602.43 | Fang et al.13, Akihisa et al.22, Xu and Godber75, Berger et al.187 | ||
| C | Cycloartenyl caffeate | C39H56O4 | 588.42 | Fang et al.13 | ||
| F | Cycloartanyl ferulate | C40H60O4 | 604.45 | Fang et al.13 | ||
| F | Cyclobranyl ferulate | C41H60O4 | 616.45 | Berger et al.187 | ||
| F | (24)-cycloart-25-ene-3β,24-diol-3β-trans ferulate | C39H56O5 | 604.41 | Angelis et al.17 | ||
| F | Cycloart-23-Z-ene-3β,25-diol-3β-trans ferulate | C39H56O5 | 604.41 | Angelis et al.17 | ||
| F | Cycloeucalenyl ferulate | C40H58O4 | 602.43 | Fang et al.13, Akihisa et al.22 | ||
| F | Campesteryl ferulate | C38H56O4 | 576.42 | Fang et al.13, Xu and Godber75, Berger et al.187 | ||
| C | Campesteryl caffeate | C37H54O4 | 562.40 | Fang et al.13 | ||
| F | Sitosteryl ferulate | C39H58O4 | 590.43 | Fang et al.13, Akihisa et al.22, Xu and Godber75, Berger et al.187 | ||
| F | Stigmasteryl ferulate | C39H56O4 | 588.42 | Fang et al.13, Akihisa et al.22, Xu and Godber75, Berger et al.187 | ||
| F | Δ7-Stigmastenyl ferulate | C39H56O4 | 588.42 | Xu and Godber75 | ||
| F | Δ7-Sitostenyl ferulate | C39H58O4 | 590.43 | Fang et al.13, Xu and Godber75 | ||
| F | Δ7-Campestenyl ferulate | C39H56O4 | 576.42 | Fang et al.13, Xu and Godber75 | ||
| F | Gramisteryl ferulate | C39H56O4 | 588.42 | Akihisa et al.22 | ||
| F | Citrostadienyl ferulate | C40H58O4 | 602.43 | Akihisa et al.22 | ||
| F | Campestanyl ferulate | C38H58O4 | 578.43 | Fang et al.13, Xu and Godber75 | ||
| F | Sitostanyl ferulate | C39H60O4 | 592.45 | Fang et al.13, Akihisa et al.22, Xu and Godber75 | ||
With regard to the structural composition, it seems clear that steryl ferulates biogenetically originated from the esterification of ferulic acid with sterols and/or triterpene alcohols. The steryl ferulates principally differ at the triterpenoid moiety, which represents the bulkier part of the molecule, while both sterols and triterpene alcohols consist of a four-ring cyclopentanophenanthrene skeleton with a hydroxyl group at position 3. Their biosynthesis initiates with acetyl-CoA and implicates the enzymatic controlled formation of isopentenyl diphosphate (IPP) via mevalonic acid. IPP is then involved in the production of prenyl diphosphate homologues (DMAPP, GPP) by a succession of elongation reactions. Condensation of three molecules of IPP from geranyl diphosphate (GPP) produces squalene, which is epoxided to oxidosqualene, a common precursor of sterols and triterpene alcohol14 (Fig. 32.3). Several labeled experiments led to the determination of pathways involved in triterpene biogenesis via lanosterol or cycloartenol.15
Structurally, the number of methyl groups attached on C-4 allows differentiation of the sterol ferulates from the triterpene alcohol ferulates, the former having no methyl or just one methyl (4-methylsterol) group on C-4, and the latter containing two methyl groups at the tetracyclic ring system. In the case of triterpene alcohol ferulate esters, a cyclopropane in position C-9/C-10 is also usually present.16 The composition of the side chain of sterols and triterpene alcohols of γ-oryzanol varies with the different derivatives (Table 32.1). Recently, a new group of γ-oryzanol, designated as polar γ-oryzanol has been suggested by Angelis et al. and generally it concerns hydroxylated derivatives characterized by alkyl groups attached to C-24. Specifically, three hydroxylated triterpene alcohol ferulates ([24R] and [24S]-cycloart-25-ene-3β,24-diol-3β-trans ferulate, and cycloart-23Z-ene-3β,25-diol-3β-trans ferulate) have been isolated and identified.17 The presence of such hydroxylated ferulates was also mentioned previously by Fang et al.13
The γ-oryzanol ferulates are characterized by the trans configuration of the ferulic acid part. Ferulic acid (FA) is a derivative of cinnamic acid (4-hydroxy-3-methoxycinnamic acid), and is one of the most abundant phenolic acids in plants. FA is rarely found in its free form, but is generally linked to sugars, polysaccharides, or proteins.18 This moiety is also responsible for the characteristic ultraviolet absorption observed in RBO. Biogenetically, this phenolic unit comes from the methoxylation of the m-hydroxyl group of caffeic acid, catalyzed by the enzyme O-methyltransferase.19 This suggests that the enzyme involved in the biosynthesis of steryl ferulates could accept caffeic acid as a substrate and thus explain the presence of caffeate esters in γ-oryzanol (Fig. 32.4). As with many natural phenols, FA possesses antioxidant activity,20 and has been found to exhibit beneficial effects against cancer, diabetes, and Alzheimer disease.21 Although the steryl ferulates are generally characterized by a trans configuration of the ferulic acid, several authors have also shown the presence of cis derivatives.13,17,22 However, Fang et al. suggest the possibility that these cis derivatives might be artifacts due to a cis–trans isomerization which may occur during the production of rice bran because of the long wavelength UV radiation.13
As mentioned previously, γ-oryzanol compounds are formed through esterification between ferulic (or caffeic) acid and a triterpene (sterol or triterpene alcohol). In order to investigate this hypothesis, Sato23 performed synthesis of the γ-oryzanol steryl ferulates (14C labeled), starting with the formulation of guaiacol with 14C-labeled formaldehyde to give vanillin-14C. Condensation of this latter with malonic acid followed by acetylation gave 4′-acetylferulic acid-14C, which was treated with 2SOCl2 forming 4′-acetylferulic acid chloride-14C. The nucleophilic reaction between the triterpenyl alcohols (obtained by saponification of γ-oryzanol) and the chloride-14C produced γ-oryzanol-14C with a yield of 97% after crystallization. Akihisa22 has also proposed a synthesis of eight steryl ferulates contained in γ-oryzanol. Thus, 4-propionyl ferulate, obtained by condensation of trans-ferulic acid and propionic anhydride in an alkaline medium, was added to stigmasterol, yielding a 4-propionyl ferulate of stigmasterol. Finally, basic hydrolysis of the propionyl ester moiety gave trans-stigmasteryl ferulate. Using the same synthetic pathway, trans-gramisteryl ferulate and trans-citrostadienyl ferulate were prepared from the corresponding free sterols. It should be mentioned that the author has also prepared the corresponding cis derivatives, by irradiation at 365 nm, under N2 with a 100-W mercury vapor discharge lamp, of the trans-ferulates. In this manner, cis-stigmasteryl ferulate, cis-gramisteryl ferulate, cis-citrostadienyl ferulate, cis-cycloeucalenyl ferulate, and cis-24-methylenecycloartanyl ferulate were synthesized. It is important to note that recently a patent has been filed concerning the preparation of steryl ferulates.24 The synthesis involves the acetylation of ferulic acid followed by esterification with a phytosterol in the presence of N,N′-dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP). Finally, deprotection of the acetate gave the desired phytosteryl ferulate.Read more
Volume 2
Tori Hudson ND, Joseph Katzinger ND, in Textbook of Natural Medicine (Fifth Edition), 2020
Gamma-Oryzanol
Gamma-oryzanol (ferulic acid) is a growth-promoting substance found in grains and isolated from rice bran oil. In the treatment of hot flashes, its primary action is to enhance pituitary function and promote endorphin release by the hypothalamus. Gamma-oryzanol was first shown to be effective in the treatment of menopausal symptoms, including hot flashes, in the early 1960s.112 Subsequent studies have further documented its effectiveness.113
In one of the earlier studies, 8 menopausal women and 13 women whose ovaries had been surgically removed were given 300 mg/day of gamma-oryzanol. At the end of the 38-day trial, more than 67% of the women had a 50% or greater reduction in menopausal symptoms.112 In a later study, the benefit of a 300-mg/day dose of gamma-oryzanol was even more effective, in that 85% of the subjects reported improvement in their menopausal symptoms.113
Gamma-oryzanol is an extremely safe natural substance. No significant side effects have been produced in experimental and clinical studies. In addition to being helpful in improving the symptoms of menopause, gamma-oryzanol has also been shown to be quite effective in lowering blood cholesterol and triglyceride levels.114
Complementary and Alternative Approaches I
Claire Wilson, … Vivian Y. Shi, in Atopic Dermatitis : Inside Out Or Outside in, 2023
Rice (starch and bran) bath
Rice bran and starch bathing is a popular medicinal treatment in Japanese folk culture. Little is known about rice’s impact on skin pathology, but several studies have proposed that its chemical constituents (e.g., γ-oryzanol) may have positive antiinflammatory, antiaging, microcirculatory, and skin barrier maintenance effects (Fujiwaki & Furusho, 1992; Islam et al., 2009). Two small studies (n = 13, 16) found evidence for the efficacy of rice starch baths (10 g/L, 15 minutes 2×/day for 4 consecutive days) on improving TEWL, reducing eczema severity, and TCS use (De Paepe, Hachem, Vanpee, Roseeuw, & Rogiers, 2002; Fujiwaki & Furusho, 1992). Of note, one patient experienced cutaneous itching and erythema after treatment and discontinued the protocol (Fujiwaki & Furusho, 1992). Given the scarcity of literature on this topic and promising results, additional, larger trials are needed to further verify the benefits of rice baths.
Development of Functional Foods (Enzyme-Treated Rice Fiber) from Rice By-products
Osamu Kanauchi, … Yvette Taché, in Wheat and Rice in Disease Prevention and Health, 2014
Rice Bran and its Physiological and Functional Properties
Dietary Fiber of Rice Bran
Using thermal processing techniques, rice bran can be stabilized to prevent the development of rancidity, and incorporated into breads and other products.5 Rice bran itself has some nutritional and physiological functions, including hypolipidemic effects.6 According to reports, full-fat rice bran reduced plasma total cholesterol or low density lipoprotein cholesterol due to the residual fat-soluble fraction (phytosterols or γ-oryzanol).6,7 The fecal bulking property of rice bran was also described as being the same as that of wheat bran in the rat.8 However, in clinical trials it was shown that rice bran was more effective than wheat bran as a means of increasing the output of stool and decreasing the fecal transit time.5,9,10 In addition, the dietary fiber fraction of rice bran was also reported to reduce the risk of coronary heart disease mortality by reducing blood pressure or improving insulin resistance.1
Protein or Amino Acid Isolated from Rice Bran
In addition to the fiber fraction of rice bran, the protein fraction or isolate is also available for use as a functional food. The nutritional and pharmaceutical potential of the protein fraction of rice bran has long been recognized; however, it was difficult to use it as a supplement or functional food for three reasons. First, the protein fraction was a composite of albumin, globulin, glutelin, and prolamin. Secondly, rice bran protein showed strong aggregation and poor solubility. Finally, rice bran has a high phytate and dietary fiber content, and these two components could bind with proteins, making the protein bodies very hard to separate from other components.11 However, application of the new technique with alkaline or phytase and xylanase utilization made the use of rice bran protein isolate possible. This isolate has an amino acid profile similar to those of casein or soybean protein isolates, except for the lysine content.11 Recently, alcalase-treated rice bran was reported to show a poor digestive rate in the gastrointestinal tract and to have an inhibitory effect on colon and hepatic cancer cell proliferation.12 Interestingly, in Japan rice bran was used for the substrate of GABA, which was produced by Lactobacillus–Saccharomyces, and GABA was utilized as a functional food for reducing the risk of hypertension or neural dysfunction.4
Fat-Soluble Fraction Including Unsaponifiables of Rice Bran
Rice bran is also an important vegetable oil source because it contains relatively high levels of oleic acid, which has hypocholesterolomic and anti-inflammatory effects13 and is recognized as the best source of phytosterols. In addition, rice bran oil contains minor components, such as γ-oryzanol and tocopherols,14,15 and considerable amounts of cycloartenol and 24-methylene cycloartanol, which have been reported to have anti-inflammatory effects or inhibitory effects on anti-human immunodeficiency virus-1 reverse transcriptase.16,17
Miscellaneous (Phytate)
Phytate is a complex form of both phosphate and inositol in rice grains. Although it forms a heterogeneous mixture with dietary minerals (zinc, iron, etc.) and can induce mineral-related deficiency, its consumption also provides protection against a variety of cancers via its antioxidant properties. Supplementation with phytase or phytase treatment can reverse the adverse effects of phytate in rice bran.18 Conversely, in the case of hypercalciuric stones, phytate is reported to be one of the most effective substances to reduce the intestinal absorption of calcium, and rice bran treatment should be effective in the prevention of recurrences of hypercalciuric stones.19Read more
Natural food science based novel approach toward prevention and treatment of obesity and type 2 diabetes: Recent studies on brown rice and γ-oryzanol
Chisayo Kozuka, … Hiroaki Masuzaki, in Obesity Research & Clinical Practice, 2013
Future perspective
Following oral administration, Orz is rapidly distributed to target tissues such as the brain and pancreas and improves fuel dyshomeostasis and dysregulation of body weight. In the hypothalamus, Orz decreases HFD-induced ER stress, leading to a shift in preference from fatty to healthy foods. Furthermore, Orz enhances GSIS and prevents ER stress-induced apoptosis in pancreatic β-cells. Orz has also been shown to decreases cholesterol absorption from the intestine [26]. As described in our recent study [34], Orz exerts a series of metabolically beneficial effects within the physiological range. Orz may help to prevent obesity and T2DM in offspring by shifting the preference from fatty foods, as well as by improving of glucose homeostasis. In this context, further studies are needed to clarify the effects of Orz on epigenetic inheritance. The results of recent studies may thus open novel avenues for investigating the molecular basis of food preference and for natural food-based therapeutics for obesity–diabetes syndrome.
Therapeutic effect of berberine on metabolic diseases: Both pharmacological data and clinical evidence
Xinmei Xu, … Gang Fan, in Biomedicine & Pharmacotherapy, 2021
4.5 Gout
BBR has a good clinical effect in the treatment of hyperuricemia and gout. Wu et al. found that the oral administration of BBR and oryzanol for 2 months considerably reduced serum UA levels in patients with hyperuricemia with an effective rate of 83 % [129]. Recently, Wang et al. investigated the efficacy of BBR combined with benzbromarone in the treatment of patients with gout. The results indicated that BBR could remarkably decrease serum UA levels and improve metabolic disorders [130]. Furthermore, BBR combined with amlodipine in the treatment of elderly patients with gout and hypertension has a substantial clinical effect and could effectively reduce blood pressure and UA levels [179,182].
A review of patent literature on the regulation of glucose metabolism by six phytocompounds in the management of diabetes mellitus and its complications
Anusree DasNandy, … Debprasad Chattopadhyay, in Journal of Integrative Medicine, 2023
2.2.3 Berberine
Researchers have filed many patent applications for antidiabetic therapies that combine berberine with other medications. Fifty-three patents were found, covering the 10 combination classes specified in this study (Table S1; Fig. 3). Different phytocompounds have been reported to be used in combination with berberine, like monacolin K, 1-deoxynojirimycin, oryzanol, ginsenoside, timosaponin B-II, stachyose, ursodeoxycholic, l-carnitine, sennoside, spirostan, silymarin and ursolic acid. One patent application showed that berberine was used in combination with Chinese medicine including kudzu vine root flavone and Phellodendron bark alkaloid. Seven patents have been found in which nutritional compounds like vitamins and fruit extracts were used in combination with berberine. Patents on berberine, taken in conjunction with the commercial diabetes drugs sitagliptin, repaglinide and metformin, are also reported [39,40]. In one patent application, researchers have tested the effects of the combination of Bifidobacterium and berberine on pre-diabetes, specifically T2D [41]. The combination of berberine derivatives with other compounds is also reported in the treatment of diabetes. Patents on the use of different combinations with various plant extracts, phytocompounds, organic compounds and nutritional supplements are reported with berberine.
Rice bran, an off-shoot to newer therapeutics in neurological disorders
Tapan Behl, … Simona Bungau, in Biomedicine & Pharmacotherapy, 2021
12 Anti-inflammatory action of rice bran
Cycloartenyl ferulate, a key element of γ-ORY, has been known to prevent dose-dependent activation of NFκB by LPS. Besides, γ-ORY and cycloartenyl ferulate have also been documented to strongly suppress the expression of genes including TNF-α, IL-1, and COX-2, iNOS implicated in inflammation [144]. These findings indicate that γ-oryzanol is considered to be helpful for inflammatory diseases. The Health, Labor, and Welfare Ministry of Japan has classified inflammatory bowel diseases such as Crohn’s disease and ulcerative colitis as intractable diseases. It is understood that oral dosing of dextran sulfate sodium to mice causes bowel inflammation that strongly matches ulcerative colitis [145]. To significantly reduce inflammation, oral administration or injection of γ-ORY is recorded and it is revealed that this result involves the inhibition activity of NFκB activation. Such findings suggest that γ-ORY is beneficial for the treatment of inflammatory bowel disease symptoms. Neuroinflammation is the central nervous system’s (CNS) normal reaction to environmental changes and homeostasis disruptions, including those triggered by CNS lesions or at the time of neurological disorders. Microglia and astrocytes are 2 major categories of cells in the CNS that are accountable for homeostasis repair [146].
For the biological defense of neurons, astrocytes are essential, and microglia are considered as the primary cells of immunity in the brain, also known as “brain macrophages”. Activated astrocytes and microglia generate a broad array of inflammatory mediators throughout neuro-inflammation, including cytokines, chemokines, ROS, and reactive nitrogen species [147]. A few of these mediators aid in triggering mechanisms that restrict and facilitate the repair of tissue damage. Even so, it can also harm brain processes when neuroinflammation grows chronic and excessive. Research shows that pro-inflammatory mediators are associated with the development of brain diseases, particularly when chronically generated. In many psychiatric and neurologic disorders, including schizophrenia, depression, PD, and AD, chronic neuroinflammation has been found and also speculated at present that peripheral inflammation, including PD, AD, depression, can cause brain diseases and postoperative cognitive impairment, via neuroinflammation initiation [133,134]. The relationship betwixt the peripheral immune network and the brain includes complex and multifactorial processes. Research findings also aided to shed some light on the possible pathways convoluted in the activation of neuroinflammation by major surgery [149]. Local inflammation of the periphery and a rise in spreaded pro-inflammatory cytokines (e.g. IL-6, TNF-α) are induced by surgical procedures [150]. Such pro-inflammatory molecules can transmit through the blood-brain barrier and influence microglial cells directly. During peripheral inflammation, elevated penetration of the blood-brain barrier has been reported. By linking with neuronal endothelial receptors or with the vagal nerve in the tissues of the periphery, proinflammatory cytokines can also cause brain immune cells indirectly [151]. Cognitive dysfunction can be improved by overt or covert activation of brain immune cells. In animal models of peripheral inflammatory activities, including lipopolysaccharide or colitis induced inflammation, have been reported to trigger neuronal inflammation (microglia activation), the interplay among peripheral inflammation and neuroinflammation has been verified [152]. The gut and intestinal microbiota also play a significant role in the relationship between the brain and peripheral tissues [153]. There are detailed analyses of these processes elsewhere. In the etiology of CNS disorders and disease advancement, neuroinflammation tends to be a critical aspect. Consequently, for developing newer therapeutic methods against these disorders, neuroinflammation could be a promising target. Since epidemiological investigations have shown that diet can influence the occurrence of brain diseases involving neuronal inflammation pathology, there is a growing curiosity in the study of particular nutrients that may be accountable for this influence and may therefore be suitable candidates for potential nutrition-relied treatments [154]. Present awareness of components of RB that tend to exhibit beneficial anti-inflammatory and therapeutic action is discussed herein. Neuroinflammation and behavior evidence also shows that FA, an important constituent obtained by the hydrolysis of γ-oryzanol of rice bran exhibits an essential role in the CNS, which may be attributable to neuroinflammation regulation [155]. FA demonstrated neuroprotective and anti-neuroinflammatory activity in a γradiation-induced neuroinflammatory model in mice by rising antioxidant enzymes (CAT, SOD) and partially decreasing rates of proinflammatory markers, including NF-κB, COX-2, iNOS, TNF-α, and IL-6 [82,141]. In some preclinical trials, an anti-depressant action of FA has been demonstrated. Screening assays with tail suspension test and forced swim test in mice for new antidepressants have shown that acute FA implementation has an antidepressant activity by modulating the serotoninergic network [157]. Besides, in the clinic for the management of depression (paroxetine, fluoxetine, and sertraline), sub effective amounts of FA have shown synergistic antidepressant actions with serotonergic drugs [158]. Other reports have shown the role of antioxidative control in antidepressant actions of FA in stress-implicated, depressive-like actions. A decrease in stress-induced antioxidant enzymes (CAT, SOD, and glutathione [GSH]) was followed by an improvement in behavioral abnormalities [159] Related antidepressant outcomes were seen in a reserpine-implicated pain and depressive-resembling behavior model in mice in which FA partially overturn behavioral abnormalities, raised and fallen nociceptive thresholds [160].
In animal models of neurodegenerative diseases, behavioral change and anti-inflammatory effects attributed to FA treatment have also been illustrated. For instance, FA attenuated behavioral abnormalities and disease-related pathology in a transgenic AD model, including the reduction of pro-inflammatory markers [161]. FA attenuated behavioral abnormalities in chemically induced PD models, reduced neuronal inflammation, and had a neuronal protective impact. collectively, this preclinical research shows that FA may have positive effects on neuroinflammation, actions associated with inflammation, and progression of the disease [162].
This portion of rice fiber may therefore be regarded as a possible candidature for upcoming clinical examination. Clinical trials with FA are, unfortunately, so far incomplete. A complete picture of antioxidant and anti-inflammatory actions of RB and different studies conducted with special reference to neurological disorders is illustrated above in Fig. 3 and below in Table 1.
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