Effects of hydrolysis conditions on recovery of antioxidants from methanolic extracts of Nigella Sativa seeds.

Nigella sativa (NS) has health promoting beneficial properties including antioxidant activity. In this study, the impact of acid and alkaline hydrolysis conditions on phenolic (TPC), flavonoid (TFC) contents and antioxidant activity of methanolic extracts from N. sativa (NS) seeds powder is evaluated. Total phenolic and flavonoid contents were evaluated according to Folin-Ciocalteu procedure and aluminium chloride colorimetric assays, respectively. The TPC extracts varied from 67 to 73 mg/100 g NS powder, expressed as Gallic acid equivalents (GAE), while TFC concentrations varied from 96 to 113 mg rutin equivalents (RE)/100 g NS powder. Positive correlations were found between TPC and TFC in NS hydrolyzates and their1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (r2 = 0.975 and 0.978, respectively). The alkaline hydrolyzed extract (BHE) showed the highest TPC and TFC (730 µg GAE and1130 µg RE/g NS powder, respectively) as well as the highest antioxidant activity (DPPH• =167±0.133 mg TEAC /100 g dry NS, ABTS•+=112 ± 0.023 mg TEAC /100 g dry NS and FRAP=28 ± 0.159 mg GAE/100 g dry NS) compared to acid hydrolyzed (AHE) and non-hydrolyzed extracts (NHE). Non-hydrolyzed extracts showed the lowest TPC and TFC content (670 µg GAE and 960 µg RE/g NS powder, respectively) through the assays (p < 0.05). Findings of the study reveal that hydrolysis has profound effects on recovery of antioxidants from NS extracts. Overall, BHE has the highest antioxidant activity compared to AHE or NHE

Effects of germinated brown rice and its bioactive compounds on the expression of the peroxisome proliferator-activated receptor gamma gene

Dysregulated metabolism is implicated in obesity and other disease conditions like type 2 diabetes mellitus and cardiovascular diseases, which are linked to abnormalities of peroxisome proliferator-activated receptor gamma (PPARγ). PPARγ has been the focus of much research aimed at managing these diseases. Also, germinated brown rice (GBR) is known to possess antidiabetic, antiobesity and hypocholesterolemic effects. We hypothesized that GBR bioactive compounds may mediate some of the improvements in metabolic indices through PPARγ modulation. Cultured HEP-G2 cells were treated with 50 ppm and 100 ppm of extracts from GBR (GABA, ASG and oryzanol) after determination of cell viabilities using MTT assays. Results showed that all extracts upregulated the expression of the PPARγ. However, combination of all three extracts showed downregulation of the gene, suggesting that, in combination, the effects of these bioactives differ from their individual effects likely mediated through competitive inhibition of the gene. Upregulation of the gene may have therapeutic potential in diabetes mellitus and cardiovascular diseases, while its downregulation likely contributes to GBR’s antiobesity effects. These potentials are worth studying further

Thymoquinone-rich fraction nanoemulsion (TQRFNE) decreases Aβ40 and Aβ42 levels by modulating APP processing, up-regulating IDE and LRP1, and down-regulating BACE1 and RAGE in response to high fat/cholesterol diet-induced rats

Though the causes of Alzheimer’s disease (AD) are yet to be understood, much evidence has suggested that excessive amyloid-β (Aβ) accumulation due to abnormal amyloid-β precursor protein (APP) processing and Aβ metabolism are crucial processes towards AD pathogenesis. Hence, approaches aiming at APP processing and Aβ metabolism are currently being actively pursued for the management of AD. Studies suggest that high cholesterol and a high fat diet have harmful effects on cognitive function and may instigate the commencement of AD pathogenesis. Despite the neuropharmacological attributes of black cumin seed (Nigella sativa) extracts and its main active compound, thymoquinone (TQ), limited records are available in relation to AD research. Nanoemulsion (NE) is exploited as drug delivery systems due to their capacity of solubilising non-polar active compounds and is widely examined for brain targeting. Herewith, the effects of thymoquinone-rich fraction nanoemulsion (TQRFNE), thymoquinone nanoemulsion (TQNE) and their counterparts’ conventional emulsion in response to high fat/cholesterol diet (HFCD)-induced rats were investigated. Particularly, the Aβ generation; APP processing, β-secretase 1 (BACE1), γ-secretases of presenilin 1 (PSEN1) and presenilin 2 (PSEN2), Aβ degradation; insulin degrading enzyme (IDE), Aβ transportation; low density lipoprotein receptor-related protein 1 (LRP1) and receptor for advanced glycation end products (RAGE) were measured in brain tissues. TQRFNE reduced the brain Aβ fragment length 1–40 and 1–42 (Aβ40 and Aβ42) levels, which would attenuate the AD pathogenesis. This reduction could be due to the modulation of β- and γ-secretase enzyme activity, and the Aβ degradation and transportation in/out of the brain. The findings show the mechanistic actions of TQRFNE in response to high fat and high cholesterol diet associated to Aβ generation, degradation and transportation in the rat’s brain tissue

Study on the Potential Toxicity of a Thymoquinone-Rich Fraction Nanoemulsion in Sprague Dawley Rats

Toxicological studies constitute an essential part of the effort in developing an herbal medicine into a drug product. A newly developed thymoquinone-rich fraction nanoemulsion (TQRFNE) has been prepared using a high pressure homogenizer. The purpose of this study was to investigate the potential acute toxicity of this nanoemulsion in Sprague Dawley rats. The acute toxicity studies were conducted as per the OECD guidelines 425, allowing for the use of test dose limit of 20 mL TQRFNE (containing 44.5 mg TQ)/kg. TQRFNE and distilled water (DW) as a control were administered orally to both sexes of rats on Day 0 and observed for 14 days. All the animals appeared normal, and healthy throughout the study. There was no observed mortality or any signs of toxicity during the experimental period. The effects of the TQRFNE and DW groups on general behavior, body weight, food and water consumption, relative organ weight, hematology, histopathology, and clinical biochemistry were measured. All the parameters measured were unaffected as compared to the control (DW) group. The administration of 20 mL TQRFNE /kg was not toxic after an acute exposure

Development, characterization and anti-diabetic properties of thymoquinone rich fraction nanoemulsion obtained from black cumin

For thousands of years, natural products have played important roles throughout the world in preventing and treating human diseases. Black cumin (Nigella sativa L.) and its bioactive constituents, thymoquinone (TQ), have been used for various health benefits such as antidiabetic, antitumor, antihypertensive, antioxidative and antibacterial agents. Type 2 diabetes mellitus (T2DM) which accounts for over 90 % of diabetes cases is currently a major chronic disease affecting about 6 % of the global population. Therefore, discovering new therapies is vital for management of T2DM. Although TQ and thymoquinone rich fraction (TQRF) are known to be powerful antioxidants and have hypoglycemic properties, their administration in vivo remains problematic partly due to their low bioavailability. Lipid nanoemulsions from some medicinal plant oils such as TQRF or from hydrophobic bioactives such as TQ are attractive candidates for improving solubility and bioavailability of the oils and their bioactives. Therefore, the aim of the present study was to develop, characterize, and investigate antidiabetic properties of TQRF nanoemulsion (TQRFNE) and TQ nanoemulsion (TQNE). Conventional emulsions from TQRF (TQRFCE) and from TQ (TQCE) were also prepared for comparison. TQRF extracted from N. sativa using supercritical fluid extraction (SFE) contained 4.45 % TQ and was used to develop TQRFNE and TQRFCE. To develop TQNE and TQCE, Triolein (TR) was used as a carrier of commercially acquired TQ based on the concentration of TQ in TQRF. Conventional emulsions were prepared first by mixing 5 % lipid phase (TQRF or TR which contains calculated amount of TQ) with 95 % aqueous phase (2 % Tween-80, and 93 % distilled water) at room temperature using Ultra-Turrax mixer (13000 rpm / 3 min). Nanoemulsions were produced by passing the conventional emulsions through high pressure Homogenizer (800 bars and five homogenization cycles). In the characterization study, the changes in particle size, zeta potential,polydispersity index, refractive index, and chemical stability (loss of TQ during storage) of all emulsions were investigated over a period of 6 months at three different storage temperatures (4, 25, and 40 ˚C). At the end of characterization period, all nanoemulsions displayed good physical and chemical stability; there was no phase separation or any sign of instability of all nanoemulsion samples. In the antioxidant study, all emulsion samples were tested for antioxidant activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH•), 2,2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS•+), and β-carotene bleaching (BCB) assays using UV- visible spectrophotometer, and hydroxyl radical scavenging activity by electron spin resonance (ESR) spectrometer. Antioxidant activities of all nanoemulsions were slightly lower compared to conventional emulsions. In addition, acute toxicity of TQRFNE, and TQNE was studied using Sprague–Dawley rats. All the parameters measured were unaffected as compared to the negative control group (administered with distilled water). Further study was done to investigate the antidiabetic properties of the emulsions using T2DM animal model. Rats treated with TQRFNE and TQNE (10 ml/kg bw) exhibited a significant (P < 0.05) reduction in plasma total cholesterol levels (43 and 58 %), triglyceride (45 and 59 %), and fasting plasma glucose (42.1 and 54.9 %), respectively, compared to diabetic rats (DC group). However, TQRFCE and TQCE (10 ml/kg bw) also exhibited a significant (P < 0.05) reduction in plasma total cholesterol levels (56 and 69 %), triglyceride (57 and 67 %), and fasting plasma glucose (58 and 54.2 %), respectively, compared to DC group. For the liver and kidney function tests, the concentration of Alanine aminotransferase (ALT), Alkaline phosphatase (ALP), Aspartate aminotransferase (AST), Urea (URE), and Creatinine (CREA) were also measured to test any toxic effect on all tested groups. All tested parameters were also significantly lower compared to DC group. For the gene expression study, genes related to glucose metabolism (FBP1), cholesterol metabolism (LDL-R) and antioxidants (SOD1) were evaluated in this study. Treatment with TQRFNE showed antihyperglycemic,hypocholesterolemic and antioxidant effects, partly through regulation of above mentioned genes. Taken together, our finding showed that TQRFNE as a novel nanocarrier has the potential to produce better metabolic outcomes in T2DM. In addition, the findings also suggest that TQRFNE may be better than metformin in management of T2DM, and that it potentially could improve the wellbeing of diabetics through better control of metabolic indices, and likely fewer side effects

Characterization and Stability Evaluation of Thymoquinone Nanoemulsions Prepared by High-Pressure Homogenization

Despite the pharmacological properties of thymoquinone (TQ), its administration in vivo remains problematic partly due to its poor water solubility, leading to low absorptivity and bioavailability. Hence, the objective of this study is to prepare, characterize, and evaluate the stability of TQ nanoemulsion (TQNE). Conventional emulsion from TQ (TQCE) and empty nano- and conventional emulsions from Triolein (TRNE and TRCE) are also produced for comparison purposes. The oil-in-water nanoemulsions of TQ and Triolein were produced by high-pressure homogenization. Emulsions were characterized physically by droplet size, polydispersity index, zeta potential, and refractive index. The changes of these parameters in TQNE samples stored for 6 months at 4 and 25°C were not statistically significant (P<0.05). In addition, the initial particle sizes of TQNE and TRNE were 119.6 and 119.5 nm, respectively. Stability studies were also performed for the period of 6 months. At the end of the experiment, the percent of remaining TQ in TQNE at 4, 25, and 40°C was 90.6, 89.1, and 87.4 % respectively. Slower degradation of TQ indicated the chemical stability of TQ in TQNE samples. These results indicated that TQNE is stable over a period of 6 months

Characterization and Stability Evaluation of Thymoquinone Nanoemulsions Prepared by High-Pressure Homogenization

Despite the pharmacological properties of thymoquinone (TQ), its administration in vivo remains problematic partly due to its poor water solubility, leading to low absorptivity and bioavailability. Hence, the objective of this study is to prepare, characterize, and evaluate the stability of TQ nanoemulsion (TQNE). Conventional emulsion from TQ (TQCE) and empty nano-and conventional emulsions from Triolein (TRNE and TRCE) are also produced for comparison purposes. The oil-in-water nanoemulsions of TQ and Triolein were produced by high-pressure homogenization. Emulsions were characterized physically by droplet size, polydispersity index, zeta potential, and refractive index. The changes of these parameters in TQNE samples stored for 6 months at 4 and 25 ∘ C were not statistically significant ( &lt; 0.05). In addition, the initial particle sizes of TQNE and TRNE were 119.6 and 119.5 nm, respectively. Stability studies were also performed for the period of 6 months. At the end of the experiment, the percent of remaining TQ in TQNE at 4, 25, and 40 ∘ C was 90.6, 89.1, and 87.4 % respectively. Slower degradation of TQ indicated the chemical stability of TQ in TQNE samples. These results indicated that TQNE is stable over a period of 6 months

Study on the Potential Toxicity of a Thymoquinone-Rich Fraction Nanoemulsion in Sprague Dawley Tats

Toxicological studies constitute an essential part of the effort in developing an herbal medicine into a drug product. A newly developed thymoquinone-rich fraction nanoemulsion (TQRFNE) has been prepared using a high pressure homogenizer. The purpose of this study was to investigate the potential acute toxicity of this nanoemulsion in Sprague Dawley rats. The acute toxicity studies were conducted as per the OECD guidelines 425, allowing for the use of test dose limit of 20 mL TQRFNE (containing 44.5 mg TQ)/kg. TQRFNE and distilled water (DW) as a control were administered orally to both sexes of rats on Day 0 and observed for 14 days. All the animals appeared normal, and healthy throughout the study. There was no observed mortality or any signs of toxicity during the experimental period. The effects of the TQRFNE and DW groups on general behavior, body weight, food and water consumption, relative organ weight, hematology, histopathology, and clinical biochemistry were measured. All the parameters measured were unaffected as compared to the control (DW) group. The administration of 20 mL TQRFNE /kg was not toxic after an acute exposure