Appraisal of Thai glutinous rice husk for health promotion products

Valorization of Rice Husk (Oryza sativa L.) as a Source of In Vitro Antiglycative and Antioxidant Agents

Rice husk is a good source of polyphenols, but it has not been efficiently utilized in food applications yet. Therefore, the aim of this work is to investigate, by in vitro assays, the polyphenolic extract (RHE) capacity of this waste to counteract the protein glycation at different stages of the reaction, correlating this activity with the antiradical properties. A microwave-assisted extraction using hydro-alcoholic solvents was applied to recover husk polyphenols. Extraction parameters were optimized by the design of the experiment. The extract with the highest polyphenolic recovery was obtained at 500 W and 90 °C, using 1:35 g of dry material/mL solvent, 80% ethanol, and a 5 min extraction time. Results highlight the ability of RHE to inhibit the formation of fructosamine in the early stage of glycation with a dose-dependent activity. Furthermore, in the middle stage of the reaction, the highest RHE tested concentration (2.5 mg/mL) almost completely inhibit the monitored advanced glycation end products (AGEs), as well as showing a good trapping ability against α-dicarbonyl intermediates. A strong positive correlation with antioxidant activity is also found. The obtained results are supported by the presence of ten polyphenols detected by RP-HPLC-DAD-ESI-MSⁿ, mainly hydroxycinnamic acids and flavonoids, already reported in the literature as antiglycative and antioxidant agents.

Comparative Evaluation of Novel Herbal Rice Husk Mouthwash with Kidodent against Streptococcus mutans: A Parallel Double-blinded Randomized Control Trial

Aim

The purpose of the study is to evaluate and compare the effectiveness of rice husk extract mouthwash (RHM) and Kidodent mouthwash (KM) for reduction in salivary Streptococcus mutans count.

Materials and methods

After approval from institutional review board and institutional informed consent, 45 children who met the inclusion criteria were divided into three groups. In group A, children received rice husk mouth wash whereas in group B placebo is specified and in group C, intervention being KM. The unstimulated saliva is collected at baseline, 7th, 10th, and 15th days and subjected to microbiological analysis. The data are statistically analyzed using one-way ANOVA and repeated measures analysis of variance (ANOVA).

Results

Rice husk mouthwash showed equivalent, significant, and effective reduction in S. mutans count similar to KM (p < 0.05).

Conclusion

The rice husk mouthwash showed potential therapeutic effect in reduction of S. mutans.

Clinical trial registry india (CTRI No) : CTRI/2020/10/028594.

How to cite this article

Havale R, Rao DG, Bemalgi N, et al. Comparative Evaluation of Novel Herbal Rice Husk Mouthwash with Kidodent against Streptococcus mutans: A Parallel Double-blinded Randomized Control Trial. Int J Clin Pediatr Dent 2022;15(3):356-361.

Comparison of β-Glucan Content in Milled Rice, Rice Husk and Rice Bran from Rice Cultivars Grown in Different Locations of Thailand and the Relationship between β-Glucan and Amylose Contents

β-glucan is a dietary fiber that is beneficial to human health, and its content varies according to its different parts, type of cereal grain, and growing environment. In this study, the β-glucan of milled rice, rice husk, and rice bran fractions, as well as the amylose content of milled rice fraction, from 38 selected rice-paddy grains from six regions of Thailand were quantitatively determined. The milled rice of the Sakon Nakhon (SN) cultivar grown in the northeast contained the highest β-glucan content (0.88 ± 0.03%), followed by the milled rice of the Jow Khao Chiangmai (JKC) cultivar (0.71 ± 0.03%) and rice bran of the Sew Mae Jan (SMJ) cultivar (0.67 ± 0.03%) grown in the north. The results reveal that the rice cultivars from each region showing variation in the β-glucan level in each fraction, which is mainly found in milled rice and rice bran, are similar to those found in other cereal grains, although low amounts are found in the husk. The amylose and β-glucan contents in the milled rice fraction showed a strong negative correlation (r = −0.805; p < 0.0001). This new information about the β-glucan content of Thai rice cultivars could be used for the development of cereal-based functional food.

Harvest Age Effect on Phytochemical Content of White and Black Glutinous Rice Cultivars

Many studies have been conducted on the bioactive compounds of rice seeds, however, there is limited information on the bioactive compounds of rice sprouts. This study focused on the age effect on the phytochemical content of white and black glutinous rice sprouts harvested between 5 and 25 days old. We assessed yield, total phenolic content, total flavonoid content, total anthocyanin content, total chlorophyll content, and proximate analysis. HPLC results identified protocatechuic acid, vanillic acid, and rutin in the sprouts of both cultivars, ranging between 0.56–1.58, 0.65–7.69, and 0.47–1.68 mg/g extract, respectively. The amount of bioactive compounds and proximate compositions in black glutinous rice were generally higher than white glutinous rice in an age-dependent manner (p < 0.05). At 5–7 days, black glutinous rice contained the highest total anthocyanin content, while white glutinous rice contained the highest total phenolic content and total flavonoid content (p < 0.05). High total chlorophyll content was initially detected in white glutinous rice at a younger age than black glutinous rice (p < 0.05), while total chlorophyll content in both cultivars was not significantly different. Our study confirms the presence of phytoconstituents in the rice sprouts of white and black glutinous rice and their potential as functional foods and for being further development as natural health products.

A full utilization of rice husk to evaluate phytochemical bioactivities and prepare cellulose nanocrystals

Rice husks (RHs) as an agro-waste generated from rice production, while its application is limited. This study was designed to introduce a full utilization of rice husks, which extracted the phytochemical at first and then produced cellulose nanocrystals (CNCs) as the use of the residue. Furthermore, the phytochemicals extracted from rice husk was identified and its biological activity, including antioxidant activity, cellular antioxidant activity (CAA) and antiproliferative activity, had been detected as well. Results showed the bound fraction of rice husk had higher antioxidant than common fruit and grain. Free fraction of rice husk deserved to have further analysis in antiproliferative activity due to its low cytotoxicity. The CNCs produced by residue was using delignification process and acid hydrolysis treatments. The chemical composition of the residue obtained after phytochemical extraction was determined. CNCs morphological investigation was performed using an optical microscope and atomic force microscopy (AFM). Our strategy is to achieve a comprehensive utilization of rice husks with both economy and environment benefits.

New Benzophenones and Xanthones from Cratoxylum sumatranum ssp. neriifolium and Their Antibacterial and Antioxidant Activities

Two new benzophenones (1 and 2) and four new xanthones (4-6 and 17) together with 24 known compounds (3, 7-16, and 18-30) were isolated from the roots and twigs of Cratoxylum sumatranum ssp. neriifolium. Their structures were elucidated by spectroscopic methods. Compounds 5 and 26 showed antibacterial activity against Micrococcus luteus, Bacillus cereus, and Staphylococcus epidermis with minimum inhibitory concentrations ranging from 4 to 8 μg/mL, whereas compounds 7, 20, and 26 displayed selective antibacterial activities against Staphylococcus aureus (8 μg/mL), Salmonella typhimurium (4 μg/mL), and Pseudomonas aeruginosa (4 μg/mL), respectively. The radical scavenging effects of some isolated compounds were investigated. Compounds 11 and 21 exhibited potent activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) with IC₅₀ values of 7.0 ± 1.0 and 6.0 ± 0.2 μM, respectively.

Strategies of functional food for cancer prevention in human beings

Functional food for prevention of chronic diseases is one of this century's key global challenges. Cancer is not only the first or second leading cause of death in China and other countries across the world, but also has diet as one of the most important modifiable risk factors. Major dietary factors now known to promote cancer development are polished grain foods and low intake of fresh vegetables, with general importance for an unhealthy lifestyle and obesity. The strategies of cancer prevention in human being are increased consumption of functional foods like whole grains (brown rice, barley, and buckwheat) and by-products, as well some vegetables (bitter melon, garlic, onions, broccoli, and cabbage) and mushrooms (boletes and Tricholoma matsutake). In addition some beverages (green tea and coffee) may be protective. Southwest China (especially Yunnan Province) is a geographical area where functional crop production is closely related to the origins of human evolution with implications for anticancer influence.

The retrogradation properties of glutinous rice and buckwheat starches as observed with FT-IR, 13C NMR and DSC

The experiment was conducted to study the retrogradation properties of glutinous rice and buckwheat starch with wavelengths of maximum absorbance, FT-IR, (13)C NMR, and DSC. The results show that the starches in retrograded glutinous rice starch and glutinous rice amylopectin could not form double helix. The IR results show that protein inhabits in glutinous rice and maize starches in a different way and appearance of C-H symmetric stretching vibration at 2852 cm(-1) in starch might be appearance of protein. Retrogradation untied the protein in glutinous amylopectin. Enthalpies of sweet potato and maize granules are higher than those of their retrograded starches. The (13)C NMR results show that retrogradation of those two starches leads to presence of β-anomers and retrogradation might decompose lipids in glutinous rice amylopectin into small molecules. Glutinous rice starch was more inclined to retrogradation than buckwheat starch. The DSC results show that the second peak temperatures for retrograded glutinous rice and buckwheat starches should be assigned to protein. The SEM results show that an obvious layer structure exists in retrograded glutinous rice amylopectin.