- Oryza sativa dates back to 5000 BC. The practice of growing it is believed to have originated in China and southern and eastern Asia about 2000 BC. Rice cultivation may have simultaneously began 6500 years ago. China records cultivation 4000 years ago. (24)
- In China, the medicinal value of rice was recorded as early as 2,800 BC, used by Chinese physicians for healing purposes.
- Two major subspecies are: (1) the sticky, short-grained japonica or sinica variety, and (2) the non-sticky, long-grained indica rice variety. (34)
- A third subspecies is broad-grained, initially called javanica, now called tropical japonica. Examples are Tinawon and Unoy cultivars, grown in high-elevation rice terraces of the Cordillera Mountains in northern Luzon, Philippines. (34)
- Rice occurs in a variety of colors: white, brown, black, purple, and red.
- An isoenzyme classification (Glaszmann) sorts C. sativa into six groups: japonica, aromatic, indica, aux, rayada, and ashina. (24)
Rice is a grass species with erect,
cylindrical, hollow, jointed and striate stems, from 1 to 1.5 meters.
Leaves are flat, with long close sheaths, prominent ligule. Leaf blade is linear,
15 to 30 centimeters long, up to 2 centimeters wide, with rough and serrulate edges armed with minute forward prickles. Panicles are 20 to 30 centimeters long, at first erect, drooping and nodding as
the grains ripen. Spikelets are laxly disposed, stalked,
one-flowered, 7 to 9 millimeters long, awned or awnless. Fruit (grain) is enclosed in, but not adhering to, persistent
pales, oblong, ovoid, or oblong-ovoid, smooth, and somewhat compressed.
- Extensively cultivated
in the Philippines.
- Not a native of the Archipelago, of prehistoric introduction.
- The rice bran contains
20 percent oil and a higher percentage of protein than the polished
- Of the 7 percent proteins in rice, 0.14 is a globulin, 0.04 an
albumin, and the remainder, a protein (oryzagenin) similar to
the glutenin of wheat. soluble in dilute alkali.
- Study diethyl ether fraction of methanolic extract of NB rice bran yielded three compounds, viz., tricin and two rare flavonolignans-tricin 4'-O-(erythro-β-guaiacylglyceryl) ether and tricin 4'-O-(threo-β-guaiacylglyceryl) ether.
(see study below) (8)
- Husked rice yields carbohydrates (78.1%), some protein, minerals (sodium, potassium, magnesium, calcium, iron, sulphur, and chlorine) and fat; vitamins (thiamine and nicotinic acid) and trace elements (zinc, aluminum, nickel, iodine, fluoride). Rice bran yields 25% fatty oil. (9)
- Aqueous leaf extract yielded alkaloids, terpenoids, steroids, flavonoids, sugar, and phenolic compounds. (10)
- Rice seed yields rice bran oil, gamma oryzanol, and phytic acid.
The bran fraction is 8% of the rice kernel and consists of saturated and unsaturated fatty acids and alcohols, phytosterols, tocotrienols, tocopherols, vitamins (B 12, B1, niacin, biotin) and minerals (zinc, potassium, magnesium, phosphorus). Gamma oryzanol is a mixture of esters of sterols (campesterol, stigmasterol, ß-sitosterol) and triterpene alcohols and their ferulate esters. (14)
- Bran fraction is about 8% of the rice kernel and consists of saturated and unsaturated fatty acids and alcohols, phytosterols, tocotrienols, tocopherols, vitamins (including biotin, B12, thiamin, niacin) and minerals (including phosphorus, magnesium, potassium, zinc). (18)
- Gamma oryzanol
is a mixture of esters of sterols (campesterol, stigmasterol, ß-sitosterol) and triterpene alcohols and their ferulate esters. (18)
- Nutrient analysis
of white short-grained, cooked white rice (100g) yielded 130 calories, water 69%, protein 2.4g, carbohydrates 28.7g, fat 0.2g (satuurate 0.05g, monosaturated 0.06g, polysaturated 0.05 g, omega-3 0.01g, omega 6 0.04g, transfat 0). (22)
- Phytochemical screening of aqueous extract of leaves yielded alkaloids, carbohydrates, steroids, phenols, flavonoids, and terpenoids. (see study below) (26)
- Malted rice is peptic, carminative and tonic.
- Nutritional benefits: Excellent source of carbohydrates; good energy source; low fat, low salt, and no cholesterol; good source of vitamins and minerals, gluten-free.
roots and rhizomes.
Edibility / Nutrition
- Rice is staple food for more the 60% of the world population.
Rice is a staple article
of diet, and polished in preparation for eating.
Polished rice is deficient
in vitamin B and has been cause of beriberi.
- From the polishings is prepared an extract called tiki-tiki, a wonderful
source of vitamin B, both a preventive and cure for infantile beriberi.
- Rice bran is a healthy additive to the making of muffins, cakes, cookies,
providing both fiber and nutritive value.
- Rice wine, tapoi, is prepared from rice.
- Decoction of roots and
rhizomes for anuria.
- Lye from burned culms is considered abortive.
- Decoction and poultices of grains are emollient.
- Poultice of soft rice, applied to back and chest for coughs and bronchitis.
- Rice water used as an enema.
- Rice, boiled, drained and mashed, is made into a paste or molded into balls and applied to boils, sores, swellings, and skin blemishes.
- Sticky glutinous rice used to treat upset stomachs, heartburn, and indigestion.
- Extracts of brown rice have been used to treat warts, breast and stomach cancers. Also used for indigestion, nausea, and diarrhea.
- In Cambodia, hulls of mature plants used for treating dysentery.
- In Malaysia, boiled rice greens used as eye lotion and inflammation of inner body tissues.
- Dried powdered rice used for skin ailments.
- In India, rice water is prescribed as ointment to counteract inflamed surfaces.
- In Ayurveda, Njavara (Oryza sativa) is widely used as health food and in treatment of rheumatoid arthritis, paralysis, neurodegenerative diseases, and in rejuvenation therapy.
- Oil and furfuran: Rice oil and furfural is obtained from crude rice bran. Rice bran oil is used as edible oil, in soap and fatty acids manufacturing. Also used in cosmetics, synthetic fibers, detergents, and emulsifiers.
- Cellulose: Rice hulls are made into cellulose products, like rayon.
- Rice mill fuel by-product of carbonaceous ash is a source of sodium
silicate, soap, pigments, carbon.
- Fuel: Rice husks is used as fuel.
- Paper: Rice straw can also be a source of paper.
Used in board and paper manufacturing, packing and building materials, and as an insulator.
Also used in making compost and chemical derivatives.
- Brooms: Bundled rice straw used in the making of brooms.
- Ashes of hulls used for cleaning of discolored teeth.
- Beri-beri: From rice polishings, bran is extracted and used as an excellent source of vitamin B to prevent and cure beri-beri.
• Antianaphylactic: Study evaluated the antianaphylactic effect of a methanol extract of Oryza sativa L. in rats. Results indicated antianaphylactic activity by inhibition of histamine release of
mast cells in vivo and in vitro. (1)
• Diabetes: An investigation of indigenous
plants used as traditional phytotherapies for the control and treatment
of diabetes. There is a plenitude of folkloric hypoglycemic plants;
Oryza sativa is one of them. In the investigation, the "Antidiabetic
Flour" is obtained from 6 plants in equal amounts of 2 Kg from
each plant: the dried underground part of Daucus carrota and the seeds
of Oryza sativa, Cicer arietinum, Hordeum vulgare, Triticum aestivum
and Zea mays. In a dietary regimen for diabetes, bread from this mix
is eaten every morning with fresh cow's butter for 2 months. (2)
• Asthma: Effect of Oryza
sativa extract on the progression of airway inflammation and remodeling
in an experimental animal model of asthma: Ethanolic extract
of black rice may play a role in attenuating the progression of airway
inflammation and suggests a potential for OS in the asthma prevention
• In vitro Carbohydrate Hydrolysis / Glycemic and Insulinemic Indices: Study of Hassawi rice
showed a similar GR (glycemic index) to UBR (Uncle Ben's Rice), although with a lower insulin response. There were differences in RAG (rapidly available glucose) and SAG (slowly available glucose). Differences may be important in terms of metabolic impact and outcome on diabetes. (5)
• Processing Effects: Study evaluated effects of processing on rice. A decrease in minerals occur during milling. Mineral content is decreased in processed rice. Results suggest milling should be designed to remove the pericarp but to retain the other contents and as much aleurone layer as possible. (6)
• Antioxidant and Nutrient Analysis of Ten Cultivars: Study
evaluated ten medicinal rice cultivars from South Indian states for phytochemical content, nutrient analysis, phenols and antioxidant property. Kullakar showed the highest flavonoid content. Njavara yellow the highest phenol content, with high protein content.
• Tricin / Anti-Inflammatory: Study
of rice bran yielded three compounds, viz., tricin and two rare flavonolignans. Tricin and the threo-form of flavonolignan showed anti-inflammatory effect in carrageenan-induced paw edema experiments in rats. (see constituents above) (8)
• Antibacterial / Leaves: Study evaluated an aqueous extract of leaf of O. sativa for in-vivo antibacterial activity against some human pathogenic bacteria. Results showed enormous activity against E. coli, and moderate inhibition zones against Pseudomonas.
• Anthocyanins from Black Rice / Antimetastatic Properties: In a study for antimetastatic mechanism, results show anthocyanins show that anthocyanins can inhibit the in vitro migration and invasion of CAL 27 cancer cells. Results show anthocyanins from a species of black rice
could suppress CAL27 cell metastases by reduction of MMP-2, MMP-9, and NF-kB p65 expression through the suppression of P13K/Akt pathway and inhibition of NF-kB levels. (11)
• Anti-Inflammatory / Anti-Arthritic: Study evaluated an ethanolic extract of Oryza sativa var. Joha Rice
for in-vitro anti-inflammatory activity by HRBC membrane stabilization method and anti-arthritic activity by bovine serum protein denaturation method and albumin denaturation method. Results showed good in-vitro anti-inflammatory and anti-arthritic properties. (12)
• Lipidemic Effects: Study evaluated the lipidemic parameters in hypercholesterolemic adult male Wistar rats fed diets containing black rice variety or unrefined rice. Diet containing black rice reduced the level of plasma cholesterol, triglycerides and LDL, with an increase in HDL. (13)
• Nutrient and Antioxidant Study: Study of 10 medicinal rice cultivars from South Indian states showed a highest flavonoid content of 176 ±6.12 µg/ml, highest phenol content of 152 ±3.80 µg/ml, highest protein content of 10.92 ± 0.28%, highest carbohydrate content of 74.5 ± 2.65%, highest thiamin content 0.53 ± 0.01 mg/100g. (16)
• Modulation of Platelet Functions / Crude Rice Bran Policosanol Extract: Study investigated the antiplatelet aggregation mechanisms of crude hexane/methanolic rice bran extract in which policosanal was the targeted bioactive. Results showed dose dependent inhibition of platelet adhesion to collagen. The crude rice bran policosanol extract could inhibit in vitro platelet adhesion, aggregation, and secretion upon activation by agonists. Results suggests a scientific basis to explore alternative therapies in cardiovascular diseases related to platelet malfunction. (17)
• Antioxidant / Anti-Aging / Vanillin and Coumaric Acid: Study evaluated the antioxidant and anti-aging properties of OS extract (OSE) and its compounds, vanillin and coumaric acid. Phytochemical analysis yielded high levels of terpenoids and saponins. OSE showed lowest DPPH activity (IC50 =314.51 µg/mL) compared to vanillin (IC50=283 µg/mL) and coumaric acid (IC50=255.69 µg/mL). OSE showed the lowest anti-aging activities with the lowest collagenase, elastase, and hyaluronidase inhibitory activity (IC50= 816.78, 107.51 and 203.13 µg/mL) compared to vanillin (IC50= 16.27, 14.46 and 45.23 µg/mL) and coumaric acid (IC50= 146.89, 25.38 and 8.21 µg/mL). (18)
• Rice Bran Oil (Gamma Oryzanol) / Toxicity Study: Rice bran oil is extensively used in Asia for cooking. Approximately 7,500 tons of gamma oryzanol are processed from rice bran in Japan each year. Gamma oryzanol is widely used in the cosmetic industry. Although clinical trial data done were of poor methodology, and therefore, difficult to support suggested clinical applications, rice bran oil components may have applications in dyslipidemia, cancer, and dermatology. While contraindications have not been identified, use of its component phytic acid in renal impairment is not advised. Short term toxicity studies in rodents suggest the LD50 of rice bran oil is more than 5 g/kg. (see constituents above) (19)
• Antioxidant / Melanogenesis Stimulating Activity: Study evaluated the radical scavenging, antioxidant, and melanogenesis stimulating activities of different species of rice extracts.
Various species of rice extracts showed high antioxidant activity and the ability to stimulate melanogenesis. Results suggest potential applications in hair treatment formulation in cosmetic products. (20)
Removal of Heavy Metals from Oryza sativa Rice by Sour Lemon Peel as Biosorbent: Study evaluated the utilization of sour lemon peel as less expensive and commonly available food waste material for metal biosorption capacity to toxic heavy metal ions (nickel, cadmium, and lead) from O. sativa rice. Cooking rice by soaking rice samples by NaCl 2% and sour lemon peel at least for one hour had the greatest effect (p<0.001) in lowering the Pb and Cd levels in cooked rice. Preferentially, it reduced Cd by 96.4%, Ni 67.9%, and Pb by 90.11% when combined with rinse washing and soaking in salt for one hour. Results suggest sour lemon peel has great potential as substrates in biotechnological processes. (21)
• Traditional Rice Landraces Used
For Medical Treatment: Study identified and collected traditional rice landraces with ethnomedical applications from local communities in the Philippines. Nineteen were identified for native treatment and control of 22 community health concerns. Predominant use of plants collected were used for treatment of types of nutritional disorders (18%), digestive system disorders (18%), ill-defined symptoms (13%), viral infections (13%), and several cultural disease and disorders (11%). Grains were the most frequently used part and oral administration the preferred mode. (23)
• Health-Enhancing / Leaf Tea: Study investigated the phytochemical composition and potential health-enhancing properties of young organic jasmine rice leaf tea. Sequential extraction using solvent extracts showed phenolic acids as the dominant component of all extracts with chlorogenic acid as the major constituent. A KM acetone-based extract exhibited pronounced a-amylase and pancreatic lipase inhibitory activities. Rice leaf tea yielded volatiles (tridecane, caryophyllene and dihydroactiniolide) responsible for its attractive and unique aroma. Results suggest the young organic leaf of jasmine as potential for production of novel herbal tea that promotes good health. (25)
• Anti-Inflammatory / Acute Oral Toxicity / Leaves: Study evaluated the anti-inflammatory effect of aqueous extract of leaves of Oryza sativa. Acute oral toxicity using OECD guidelines showed an LD50 dose of 2000 mg/kg, with no lethality or profound toxic reactions at dose of 2000 mg/kg/po. Pretreatment with aqueous extract of O. sativa showed significant protection against carrageenan induced paw edema correlating with total phenolic content. (26)
• Free Radical Scavenging Potential / Bran: Study evaluated the effect of brans of selected Sri Lankan red rice varieties on physiological free radical scavenging potential using in vitro antioxidant assays. Results showed brans of all the selected red rice varieties had physiological free radical scavenging activities with varying degrees of potentials. Results suggest its potential as a functional food ingredient in the health food industry. (see study above) (27)
• Moderate Interaction with Rice Bran: Rice bran contains large amount of fiber which can decrease how much medicine the body absorbs, which can decrease effectiveness of medications. It is advised that rice bran be taken one hour after medications are taken by mouth. (28)
• Anthocyanin Pigments / Antioxidant / Anti-Inflammatory: L-MS study of black rice for anthocyanin components yielded cyanidin 3-glucoside and peonidin 3-glucoside.
A standardized extract containing the compounds showed marked antioxidant activities and free radical scavenging capacities in various in vitro model systems. Results showed black rice contain anthocyanin pigments with notable antioxidant and anti-inflammatory properties with potential for use in nutraceutical or functional food formulations. (29)
• Ethyl Iso-Allocholate / Inhibitions of Dihydropteroate Synthase in E. coli: Drug resistance is a growing medical problem. E. coli have developed resistance to most antibiotics including sulfonamides that target dihydropteroate synthase. Study identified a novel inhibitor for dihydropteroate synthase from a medicinal rice variety. Study reveals ethyl iso-allocholate and 9,12,15-octadecatrienoic acid 2,3-dihydroxypropyl ester as the best binding compounds. Results demonstrated that ethyl iso-allocholate compound isolated from "Karungkavuni" can serve as potent inhibitor for dihydropteroate synthase. (30)
• Attenuation of Hepatic Steatosis / Black Rice Supplementation: Study evaluated the effects of black rice extract (BRE) on hepatic steatosis and insulin resistance in high-fat diet-fed mice, providing a model of NAFLD. Results showed dietary supplementation with BRF improved lipid profiles and significantly enhanced mRNA expression levels of fatty acid metabolism-related genes, primarily via ß-oxidation and w-oxidation in the liver. Findings suggest BRE supplemented diet can reduce risks of hepatic steatosis, including hyperlipidemic and hyperglycemia. (31)
• White Rice Consumption and Risk of Type2 Diabetes / Meta-Analysis: Study evaluated the association between white rice consumption and risk of type 2 diabetes. Meta-analysis concludes higher consumption of white rice is associated with a significantly increased risk of type 2 diabetes, especially in Asian (Chines and Japanese) populations. (32)
• Anthocyanin in Black Rice
/ Promotion of Immune Responses in Leukemia: Study investigated whether AUPGA (Asia University-selected purpe glutinous indica rice) treatment could affect immune responses in murine leukemia cells in vivo in BALB/c mice. Results showed significant promotion of macrophage phagocytois in peripheral blood mononuclear cells (p<0.05). AUPGA treatment significantly increased natural killer cell activity from splenocytes. Treatment also promoted T cell proliferation and significantly increased decreased B cell proliferation. (33)
- Commercial cultivation.