CHEMICAL INDICES, ANTIOXIDANT ACTIVITY AND ANTI-INFLAMMATORY EFFECT OF EXTRACTS OF THE MEDICINAL RICE “NJAVARA” AND STAPLE VARIETIES: A COMPARATIVE STUDY

Co-Application of Silver Nanoparticles and Symbiotic Fungus Piriformospora indica Improves Secondary Metabolite Production in Black Rice

In the current research, unique Nano-Embedded Fungus (NEF), made by the synergic association of silver nanoparticles (AgNPs) and endophytic fungus (Piriformospora indica), is studied, and the impact of NEF on black rice secondary metabolites is reported. AgNPs were synthesized by chemical reduction process using the temperature-dependent method and characterized for morphological and structural features through UV visible absorption spectroscopy, zeta potential, XRD, SEM-EDX, and FTIR spectroscopy. The NEF, prepared by optimizing the AgNPs concentration (300 ppm) in agar and broth media, showed better fungal biomass, colony diameter, spore count, and spore size than the control P. indica. Treatment with AgNPs, P. indica, and NEF resulted in growth enhancement in black rice. NEF and AgNPs stimulated the production of secondary metabolites in its leaves. The concentrations of chlorophyll, carotenoids, flavonoids, and terpenoids were increased in plants inoculated with P. indica and AgNPs. The findings of the study highlight the synergistic effect of AgNPs and the fungal symbionts in augmenting the secondary metabolites in leaves of black rice.

Investigation on Nutritional, Phytochemical, and Antioxidant Abilities of Various Traditional Rice Varieties

Rice (Oryza sativa L.) is a popular grain that is consumed by almost half of the world's population. Rice has several distinct breeds classified as traditional and ancient grains. The consumption of rice by 60% of the world's population is a staple food. Entire grain rice, often known as brown rice, is the unpolished counterpart of white rice, containing bran, germ, and endosperm. Eating whole-grain rice is linked to many health benefits; thus, scientists have focused on identifying and quantifying bioactive chemicals in this meal. The present study assessed the physio-chemical, cooking attributes, mineral contents, phytochemicals, and free radical scavenging capabilities of conventional rice cultivars using known approaches according to particle size analysis. Rice grain lengths varied between 4.10 ± 16 and 6.20 ± 007. The length and thickness ratios of rice were not substantially different (p > 0.05). Kattuyanam has the maximum protein content (9.99 ± 06%) of all the rice varieties that were physio-chemical investigated. It also has highest phenolic content and antioxidant properties compared to gallic acid equivalent (334.900 ± 61 g) (GAE)/100 g, followed by anthocyanins and flavonoids. Total phenolic content and phenolic fractions of the HPLC profile in tested landraces indicate the presence of bioactive substances derived from traditional rice cultivars and a range of phytonutrients, including phenol, revealing their healthy potentials in the present study.

Comprehensive Utilization of Thinned Unripe Fruits from Horticultural Crops

Fruit thinning is a cultivation technique that is widely applied in horticulture in order to obtain high-quality horticultural crops. This practice results in the discarding of a large number of thinned unripe fruits in orchards each year, which produces a great waste of agricultural resources and causes soil pollution that may be an important reservoir for pest and plant diseases. Current studies showed that bioactive compounds such as polyphenols, organic acids, monosaccharides and starches are present in unripe fruits. Therefore, we reviewed the bioactive components obtained from thinned unripe fruits, their revalorization for the food industry, their beneficial effects for human health and the methods for obtaining these components. We also performed a calculation of the costs and benefits of obtaining these bioactive compounds, and we proposed future research directions. This review provides a reference for the effective utilization and industrial development of thinned unripe fruits obtained from horticultural crops. Furthermore, revalorizing the waste from this cultural practice may increase the economic benefits and relieve the environmental stress.

Targeting interleukin-β by plant-derived natural products: Implications for the treatment of atherosclerotic cardiovascular disease

Inflammation is the main contributing factor to atheroma formation in atherosclerosis. Interleukin-1 beta (IL-1β) is an inflammatory mediator found in endothelial cells and resident leukocytes. Canakinumab is a selective monoclonal antibody against IL-1β which attenuates inflammation and concurrently precipitates fatal infections and sepsis. Natural products derived from medicinal plants, herbal remedy and functional foods are widely used nowadays. Experimental and clinical trial evidence supports that some natural products such as curcumin, resveratrol, and quercetin have potential effects on IL-1β suppression. In this review, we tried to document findings that used medicinal plants and plant-based natural products for treating atherosclerosis and its related diseases through the suppression of IL-1β.

Toxicological screening and evaluation of anti-allergic and anti-hyperglycemic potential of Sonneratia caseolaris (L.) Engl. fruits

Background

Sonneratia caseolaris (L.) Engl. (S. caseolaris) belonging to the Sonneratiaceae family is commonly known as Ora. It is traditionally used as an astringent, antiseptic, to treat sprains, swellings, cough and in arresting hemorrhage. The ethanolic extract of S. caseolaris (L.) Engl. fruits was investigated in the present study for its toxicity as well as anti-allergic and anti-hyperglycemic potentials.

Methods

Major phenolic compounds were identified and quantified by HPLC. Behavioral change, body weight, mortality and different blood parameters were measured to assess the toxicological effect of the extract. Anti-allergic activity was evaluated using TDI-induced allergic model mice. Oral glucose tolerance test (OGTT) and STZ-induced diabetic mice were used to evaluate the anti-hyperglycemic activity.

Results

Crude extract contained ellagic acid, vanillic acid and myrecitin (27.41, 3.06 and 7.93 mg per 100 g dry extract respectively). No major toxicity was observed in both acute and sub-acute toxicity study. Oral administration of the extract significantly ameliorated TDI-induced allergic symptoms like sneezing, scratching, swelling, redness and watery rhinorrhoea in the experimental mice. The extracts also reduced the total and differential count of leukocytes in the blood. The extract treated mice showed significant reduction in blood glucose, SGOT, SGPT, cholesterol, triglycerides, urea, creatinine and bilirubin level.

Conclusions

S. caseolaris contains bioactive phytoconstituents which may be the possible precursors to isolate and characterize the novel compounds targeting the diseases like allergy and diabetes.

Electrochemical determination of caffeic acid in antioxidant beverages samples via a facile synthesis of carbon/iron-based active electrocatalyst

An electrochemical method has described for the voltammetric determination and oxidation of caffeic acid (CA) at a glassy carbon electrode (GCE) modified carbon/iron-based active catalyst as a sensing platform. In this study, we have developed a highly sensitive electrochemical CA sensor with f-MWCNTs/α-NaFeO₂ composite, which was developed by a simple ultrasonication method. The microstructural features of the f-MWCNTs/α-NaFeO₂ composite characterized by different physicochemical and analytical techniques. Under the optimized condition, the developed sensor archive the ultra-sensitivity (44.6859 μA μM^-1cm^-2) at a lower concentration with excellent linearity (R² = 0.9943) and which shows low detection limit (LOD = 0.002 μM) and Limit of quantification (LOQ = 0.0068 μM) by using differential pulse voltammetry (DPV) technique. The suggested sensor may improve the effective and efficient platform to the determination of CA in the healthcare system.

Toxicological, anticholinesterase, antilipidemic, antidiabetic and antioxidant potentials of Grewia optiva Drummond ex Burret extracts

Background In this study, Grewia optiva Drummond ex Burret root extracts were assessed for use as a remedy for oxidative stress, diabetes mellitus and neurological disorders. Methods The antioxidative potentials of the extracts were determined using DPPH and ABTS assays, whereas their enzyme inhibitory potentials were determined against acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glucosidase and α-amylase. In the in vivo experiments, methanol extract was orally administered to mice (n = 5) at four doses of 200, 300, 400 and 500 mg kg-1 for 30 days and its effect on glucose, triglycerides, total cholesterol, etc. were investigated. Results The highest free radical scavenging activities against DPPH and ABTS radicals were recorded for the methanol and ethyl acetate extracts, and their respective IC50 values were 75 and 88 μg/mL. In addition, these two fractions were highly active in inhibiting AChE and BChE, with IC50 values of 120 and 185 μg/mL, respectively. Moderate inhibition (μg/mL) was recorded against α-glucosidase (69.02 ± 1.02 and 64.29 ± 2.41) and α-amylase (65.12 ± 2.02 and 63.29 ± 1.41) and these were comparable to the inhibitory activities exhibited by the standard, acarbose. All the extracts showed high phenolic and flavonoid contents, which correlated with their antioxidant, anticholinesterase, α-glucosidase and α-amylase activities. The phenolic compounds in the crude extract and fractions were determined using the standard HPLC method and bioactive compounds, namely, morin, ellagic acid, kaempferol-3-(p-coumaroyl-diglucoside)-7-glucoside, apigenin-7-O-rutinoside, quercetin-3-(caffeoyl-diglucoside)-7-glucoside, etc., which were detected at various retention times. Significant decrease in cholesterol, triglyceride and blood glucose levels were observed. Conclusion G. optiva is a good source of antioxidants and other phytochemicals, some of which possess anticholinesterase, anti-glucosidase, and anti-amylase activities, and can be used to treat different health conditions such as oxidative stress, neurological disorders, and diabetes mellitus.

Petroleum ether extract of Njavara rice (Oryza sativa) bran upregulates the JAK2-STAT3-mediated anti-inflammatory profile in macrophages and aortic endothelial cells promoting regression of atherosclerosis

"Njavara" (Oryza sativa L.) is a unique rice variety grown in Kerala that is reported to have significantly higher antioxidant, anti-inflammatory, chemical indices, and bioactive components compared with staple rice varieties. However, the role of NBE in reversing the atherosclerosis development remains unclear. The present study aimed to elucidate the role of NBE in promoting atherosclerotic regression. Male New Zealand white breed rabbits were divided into three groups. Group I was the control, group II was the regression control, and group III was NBE treated (100 mg/kg body mass). Serum and tissue lipids, CRP, antioxidant enzyme activities, mRNA, and protein expression of genes of RTC and mRNA expression of cytokines were studied. The current study showed that hypercholesterolemic rabbits treated with NBE decreased the serum and tissue lipids concentrations, ApoB expression, and CRP levels and enhanced the activities of antioxidant enzymes and PON1expression, JAK2, STAT3, ABCA1, and ApoA. Our results indicate that NBE attenuates proinflammatory cytokine production (IL-1β), enhanced expression and interactions of ABCA1/ApoA1 leading to JAK2/STAT3 activation in macrophages switching to an anti-inflammatory milieu in the system, and enhanced expression of IL-10 and decreased expression of ApoB, indicating that treatment with NBE facilitates plaque regression.

Mechanism of anti-inflammatory effect of tricin, a flavonoid isolated from Njavara rice bran in LPS induced hPBMCs and carrageenan induced rats

Njavara is an indigenous medicinal rice variety traditionally used in Ayurvedic system of medicine practiced in Kerala, India. Tricin is a bioflavonoid present in significantly higher levels in rice bran of Njavara. Present study attempted to identify the molecular target of tricin in TLR mediated signaling pathways by using lipopolysaccharide (LPS) induced human peripheral blood mononuclear cells (hPBMCs) and carrageenan induced paw edema in rats as experimental models. Tricin acted upstream in the activation of inflammation cascade by interfering with TLR4 activation, preferably by blocking the LPS induced activation of TLR4, MYD88 and TRIF proteins in hPBMCs. Subsequently, tricin significantly blocked the activation of downstream kinases like p38MAPK, JNK1/2 and IRF3. Thus the inhibitory effect of tricin on NF-κB and IRF3 together confirms the specific inhibition of both MYD88 dependent and TRIF dependent pathways. Tricin treatment also inhibited the pro-inflammatory effect of LPS by blocking the TLR4 signaling mediated activation of cytosolic phospholipase A2 (cPLA2), which is confirmed by specific inhibition of COX-2. Results demonstrated that in addition to NF-κB, tricin can prevent the activation of STAT proteins by significantly inhibiting the activation of both STAT1 and STAT3 via the down regulation of upstream phosphorylating enzymes like JAK1 and JAK2. The protective anti-inflammatory effect of tricin was also confirmed by in vivo experiments. Thus, this study provides strong evidence that tricin exerts its anti-inflammatory effect via a mechanism involving the TLR4/NF-κB/STAT signaling cascade.

Dietary Njavara rice bran oil reduces experimentally induced hypercholesterolaemia by regulating genes involved in lipid metabolism

The present study was carried out to evaluate the anti-atherogenic effect of Njavara rice bran oil (NjRBO) on atherosclerosis by modulating enzymes and genes involved in lipid metabolism in rats fed a high-cholesterol diet (HCD). Adult male rats (Sprague–Dawley strain, weighing 100–120 g) were divided into three groups of nine animals each. Group I served as the control, group II were fed a HCD and group III were fed a HCD and NjRBO (100 mg/kg body weight). The study duration was 60 d. Serum and tissue lipid profile, atherogenic index, enzymes of lipid metabolism, plasma C-reactive protein levels, serum paraoxonase and arylesterase activities, thiobarbituric acid-reactive substances, gene and protein expression of paraoxonase 1 (PON1), PPARα, ATP-binding cassette transporter A1 (ABCA1), apoB and apoA1 in the liver were quantified. Total cholesterol, TAG, phospholipid, NEFA, LDL-cholesterol concentrations in the serum and liver, lipogenic enzyme activities, hepatic 3-hydroxy-3-methylglutaryl-CoA reductase activity and atherogenic index were significantly increased in HCD-fed rats, but they decreased after treatment with NjRBO. HDL-cholesterol level and lecithin cholesterol acyl transferase activity were increased in the NjRBO-treated group, but decreased in the HCD-fed group. The expression levels of ABCA1, apoA1, PON1 and PPARα were found to be significantly increased in NjRBO-treated group compared with the HCD-fed group; however, the expression level of apoB was found to be higher in HCD-fed group and lower in the NjRBO-treated group. These data suggest that NjRBO possesses an anti-atherogenic property by modulating lipid metabolism and up-regulating genes involved in reverse cholesterol transport and antioxidative defence mechanism through the induction of the gene expressionPON1.

Rice antioxidants: phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ-oryzanol, and phytic acid

Epidemiological studies suggested that the low incidence of certain chronic diseases in rice-consuming regions of the world might be associated with the antioxidant compound contents of rice. The molecules with antioxidant activity contained in rice include phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ-oryzanol, and phytic acid. This review provides information on the contents of these compounds in rice using a food composition database built from compiling data from 316 papers. The database provides access to information that would have otherwise remained hidden in the literature. For example, among the four types of rice ranked by color, black rice varieties emerged as those exhibiting the highest antioxidant activities, followed by purple, red, and brown rice varieties. Furthermore, insoluble compounds appear to constitute the major fraction of phenolic acids and proanthocyanidins in rice, but not of flavonoids and anthocyanins. It is clear that to maximize the intake of antioxidant compounds, rice should be preferentially consumed in the form of bran or as whole grain. With respect to breeding, japonica rice varieties were found to be richer in antioxidant compounds compared with indica rice varieties. Overall, rice grain fractions appear to be rich sources of antioxidant compounds. However, on a whole grain basis and with the exception of γ-oryzanol and anthocyanins, the contents of antioxidants in other cereals appear to be higher than those in rice.