Evaluation of Phytochemical Contents and In Vitro Antioxidant, Anti-Inflammatory, and Anticancer Activities of Black Rice Leaf (Oryza sativa L.) Extract and Its Fractions

Steroidal compounds in Paris polyphylla:structure, biological activities, and biosynthesis

Steroidal compounds are chemical constituents found in the traditional medicinal plant Paris polyphylla, known for their significant pharmacological activities. Due to their complex structures, the biosynthetic pathways of these compounds have garnered considerable attention. In recent years, substantial progress has been made in elucidating the biosynthetic pathways of steroidal compounds from P. polyphylla, with several complete biosynthetic routes being fully characterized. The de novo synthesis of diosgenin has been successfully achieved in both Saccharomyces cerevisiae and Nicotiana benthamiana using various metabolic engineering techniques. Herein, we summarize the latest research progress regarding the structural classification, biological activities, and biosynthesis studies of steroidal compounds from P. polyphylla.

Anthocyanin-Rich Fraction from Kum Akha Black Rice Attenuates NLRP3 Inflammasome-Driven Lung Inflammation In Vitro and In Vivo

BACKGROUND/OBJECTIVES

Chronic lower respiratory tract inflammation can result from exposure to bacterial particles, leading to the activation of the NLRP3 inflammasome pathway. These effects may cause irreversible respiratory damage, contributing to persistent lung injury and chronic obstructive pulmonary disease (COPD), as observed in long COVID or bacterial pneumonia in older adults' patients. Given its profound impact, the NLRP3 inflammasome has emerged as a key therapeutic target for mitigating aberrant inflammatory responses.

METHODS

In this study, we investigated the anti-inflammatory effects of Kum Akha black rice, a functional food, on the attenuation of NLRP3 inflammasome pathway using lipopolysaccharide-induced A549 lung epithelial cells and a C57BL/6NJcl mouse model. The anthocyanin-rich fraction from Kum Akha black rice germ and bran extract (KA1-P1) was obtained using a solvent-partitioned extraction technique.

RESULTS

KA1-P1 exhibited a high anthocyanin content (74.63 ± 1.66 mg/g extract) as determined by the pH differential method. The HPLC analysis revealed cyanidin-3-O-glucoside (C3G: 45.58 ± 0.48 mg/g extract) and peonidin-3-O-glucoside (P3G: 6.92 ± 0.29 mg/g extract) as its anthocyanin's active compounds. Additionally, KA1-P1 demonstrated strong antioxidant activity, as assessed by DPPH and ABTS assays. KA1-P1 (12.5-100 μg/mL) possessed inhibitory effects on LPS + ATP-induced A549 lung cells inflammation through the significant suppressions of NLRP3, IL-6, IL-1β, and IL-18 mRNA levels and the inhibition of cytokine secretions in a dose-dependent manner (p < 0.05). Mechanistic analysis revealed that KA1-P1 downregulated key proteins in the NLRP3 inflammasome pathway (NLRP3, ASC, pro-caspase-1, and cleaved-caspase-1). Furthermore, in vivo studies demonstrated that KA1-P1 significantly diminished LPS-induced lower respiratory inflammation in C57BL/6NJcl mice, as evidenced by the reduced bronchoalveolar lavage fluid and blood levels of inflammatory cytokines (IL-6, IL-1β, and IL-18) and diminished histopathological inflammatory lung lesions.

CONCLUSIONS

Overall, our findings suggest that the anti-inflammatory properties of KA1-P1 may support its application as a functional supplement or promote the consumption of pigmented rice among the elderly to mitigate chronic lower respiratory tract inflammation mediated by the NLRP3 inflammasome pathway.

Black rice bioactive with multifunctional health promotional activities: A special reference to wound healing activity with polyhydroxybutyrate composite

Black rice (BR) extract contains several functional food bioactive components that are health-promoting. This study assessed the multifunctional bioactivities of various BR extracts (methanol, ethanol, acetone, and aqueous). These BR extracts revealed significant antioxidant and antibacterial activity against various bacterial strains. Acetone extract exhibited high cytotoxicity against gastric adenocarcinoma cells (AGS), while ethanol extract was cytotoxic against pancreatic cancer cells (PANC-1). Moreover, the acetone extract induced 33.6 % and 16.5 % apoptosis in PANC-1 and AGS cells, respectively. Acetone extract showed significant anti-inflammatory action, reducing 76 % production of nitric oxide in the RAW 264.7 (murine macrophage). Furthermore, all BR extracts inhibited PANC-1 and AGS migration and promoted RAW 264.7 migration. Field emission scanning electron microscope, Fourier-transform infrared spectroscopy, and X-ray diffraction analysis of the BR-polyhydroxybutyrate composite revealed successful deposition for BR extracts. This study highlights the potential of BR extracts to develop multifunctional activity-based strips for rapid wound healing.

Computational insights into the inhibitory mechanism of type 2 diabetes mellitus by bioactive components of Oryza sativa L. indica (black rice)

Background

Type 2 diabetes mellitus is a metabolic disease categorized by hyperglycemia, resistance to insulin, and ß-cell dysfunction. Around the globe, approximately 422 million people have diabetes, out of which 1.5 million die annually. In spite of innovative advancements in the treatment of diabetes, no biological drug has been known to successfully cure and avert its progression. Thereupon, natural drugs derived from plants are emerging as a novel therapeutic strategy to combat diseases like diabetes.

Objective

The current study aims to investigate the antidiabetic potential of natural compounds of Oryza sativa L. indica (black rice) in disease treatment.

Methods

Antioxidant activity and alpha amylase assays were performed to evaluate the therapeutic potential of the extract of Oryza sativa L. indica. Gas chromatography-mass spectrometry (GC-MS) was used for identification of constituents from the ethanol extract. ADMET profiling (absorption, distribution, metabolism, excretion, and toxicity), network pharmacology, and molecular dynamics simulation were employed in order to uncover the active ingredients and their therapeutic targets in O. sativa L. indica against type 2 diabetes mellitus.

Results

GC-MS of the plant extract provided a list of 184 compounds. Lipinski filter and toxicity parameters screened out 18 compounds. The topological parameters of the protein-protein interaction (PPI) were used to shortlist the nine key proteins (STAT3, HSP90AA1, AKT1, SRC, ESR1, MAPK1, NFKB1, EP300, and CREBBP) in the type 2 diabetes mellitus pathways. Later, molecular docking analysis and simulations showed that C14 (1H-purine-8-propanoic acid, .alpha.-amino-2, 3, 6, 7-tetrahydro-1,3,7-trimethyl-2,6-dioxo-) and C18 (cyclohexane-carboxamide, N-furfuryl) bind with AKT1 and ESR1 with a binding energy of 8.1, 6.9, 7.3, and 7.2 kcal/mol, respectively. RMSD (root-mean-square deviation) and RMSF (root-mean-square fluctuation) values for AKT1 and ESR1 have shown very little fluctuation, indicating that proteins were stabilized after ligand docking.

Conclusion

This study suggests therapeutic drug candidates against AKT1 and ESR1 to treat type 2 diabetes mellitus. However, further wet-lab analysis is required to discover the best remedy for type 2 diabetes mellitus.

Optimization of High-Pressure Processing for Microbial Inactivation in Pigmented Rice Grass Juice and Quality Impact Assessment during Refrigerated Storage

Pigmented rice grass juice (RGJ) is a good source of bioactive compounds, but fresh juice has a relatively short shelf life of only 7 days at 4 °C. The objectives of this study were to determine the optimal growth stage of pigmented rice grass, investigate the optimal condition of high-pressure processing (HPP) for bacterial inactivation in inoculated RGJ using response surface methodology (RSM), and evaluate quality changes in uninoculated HPP-treated juice during storage at 4 °C compared with heat-treated (85 °C/10 min) and untreated samples. Results revealed that the optimal growth stage of rice grass was 9 days with the highest total anthocyanin content of 158.92 mg/L. The optimal condition of HPP was determined to be 612 MPa, 11 min, and 36 °C, and inactivated Escherichia coli K12 and Listeria innocua with 6.43 and 5.02 log reductions, respectively, meeting FDA regulations. The lethality of bacteria after HPP treatment can be explained by damage to the cell membrane and the leakage of intracellular constituents such as protein and nucleic acid. During 12 weeks of storage at 4 °C, total plate counts and yeast and mold counts in uninoculated HPP-treated juice were not detected. Moreover, HPP did not significantly change phytochemical properties (p < 0.05), caused a minor impact on physicochemical properties of RGJ, and maintained the durability of juice samples during storage. Analysis of the phytochemical profile revealed that HPP treatment could preserve most of the phenolic compounds in RGJ and especially increase the contents of protocatechuic acid, 4-hydroxybenzoic acid, syringic acid, transcinnamic acid, isorhamnetin-3-o-glucoside, quercetin, and cyanidin-3-glucoside (p < 0.05). Overall, HPP is a potential pasteurization technique for microbial inactivation and nutritional preservation for rice grass juice.

The protective effect of Thai rice bran on N-acetyl-ρ-aminophen-induced hepatotoxicity in mice

Background and purpose

N-acetyl-ρ-aminophen (APAP) is a widely used medication with analgesic and antipyretic characteristics. High paracetamol doses can damage the liver. Thai-pigmented rice may treat numerous liver disorders due to its antioxidant, anti-inflammatory, and glutathione-restoring capabilities. This study aimed to evaluate the phenolic components in three Thai rice bran extracts and their antioxidant and hepatoprotective activities in an animal model.

Experimental approach

Fifty male mice were randomly assigned to the control and APAP studies. Each study was divided into 5 groups (n = 5) treated with distilled water, Hom Mali, Hang-Ngok, and Hom Nil (HN) rice compared with N-acetylcysteine with/without 60 mg/kg/day of APAP orally once a day for two weeks. Blood and liver sampling were collected for analysis.

Findings/Results

HN rice bran exhibited higher contents of total phenolic, total flavonoid, total anthocyanin, ferric-reducing antioxidant, and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activities than Hom Mali and Hang-Ngok. Anthocyanin was merely detected in HN. Following APAP administration, mice exhibited significant increases in hepatic enzymes including alanine aminotransferase (ALT) and aspartate aminotransferase (AST), pro-inflammatory cytokines (tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6)), and malondialdehyde (MDA), but lower levels of antioxidant enzymes and glutathione profiles. Amongst the three cultivars, HN rice was the only compound that decreased MDA, ALT, AST, TNF-α, and IL-6 while increasing antioxidant enzyme activity such as superoxide dismutase, catalase, and glutathione peroxidase that was very close to that of N-acetylcysteine groups.

Conclusion and implications

Given the hepatoprotective and antioxidant properties, HN has the potential to be used as a health supplement.

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.

Antioxidant Activity and Inhibitory Effects of Black Rice Leaf on the Proliferation of Human Carcinoma Cells

The leaves of black rice, well-known as postharvest agricultural waste, contain a rich source of antioxidants with multiple benefits for human health. In the present study, the ethyl acetate fraction obtained from black rice leaf was separated into five subfractions using Sephadex LH-20 column chromatography, and their antioxidant and anticancer activities were investigated. The results revealed that among all the subfractions, subfraction 5 (Sub5) showed the highest total phenolic and flavonoid values. The antioxidant activity was also superior in Sub5 (the IC₅₀ values are 3.23, 31.95, and 72.74 μg/mL, in the DPPH, ABTS, and reducing power assays, respectively) compared to the other subfractions. All subfractions, in a time-dependent manner, inhibited the proliferation of hepatoma (HepG2), breast (MCF-7), and colorectal (Caco-2) cancer cells, especially the Sub5. Thus, Sub5 was employed to conduct the cell cycle and cell apoptosis by flow cytometry. Sub5 significantly increased the accumulation of cells at the Sub-G1 phase in HepG2 cells (44.5%, at 48 h). Furthermore, it could trigger annexin V-detected apoptosis through mitochondrial and death receptor pathways accompanied by the suppression of PI3K/Akt and Erk signaling pathways. In addition, HPLC-DAD-MS/MS was conducted to characterize the bioactive constituents in the most potent antioxidant, cytotoxic, and apoptosis-inducing subfraction. Conclusively, Sub5 may have high potential as functional dietary supplements to inhibit the development of HepG2 liver cancer.