Comparative Evaluation of Four Extraction Methods of Antioxidant Compounds from Decatropis bicolor in Aqueous Medium Applying Response Surface Design

Antioxidant, antidiabetic, and anti-inflammatory activities of flavonoid-rich fractions of Solanum anguivi Lam. fruit: In vitro and ex vivo studies

Diabetes mellitus is a major, rapidly growing endocrine disorder in most countries. The high cost and side effects of conventional drugs for the management of this disease have shifted attention to medicinal plants. Solanum anguivi (S. anguivi) fruits has been reported to be a very good and rich source of polyphenols such as flavonoids, that can be exploited. Flavonoids are plant secondary metabolites widely found in vegetables, fruits and seeds and are known to be of medicinal significance in different range of diseases like diabetes. This study involved in vitro and ex vivo assays on the antioxidant, anti-inflammatory, and antidiabetic properties of flavonoid-rich fractions of S. anguivi fruits. Healthy male Wistar rats (n = 5) weighing 150-180 g were used for ex vivo antioxidant and antidiabetic studies, their liver was exercised for the experiment. The percentage yields of the three flavonoid-rich fractions (Fr. A, B, and C) of S. anguivi fruits obtained from the column chromatographic technique were 15.53 ± 0.75, 11.53 ± 0.80, and 10.17 ± 0.49 mg/g quercetin equivalents. The three fractions (A, B, and C) of S. anguivi fruits significantly scavenged both 2,2-diphenyl-1-picrylhydrazyl (DPPH) with fraction A having the lowest IC50 value (26.14 ± 1.06 μg/ml) compared with fraction B (37.78 ± 5.12 μg/ml) and fraction C (38.24 ± 2.40 μg/ml) when compared with ascorbic acid with the least IC50 value (15.27 ± 0.34 μg/ml). While fraction A (19.61 ± 1.19 μg/ml) scavenged nitric oxide (NO) radicals better than fraction B (22.97 ± 0.55 μg/ml) and fraction C (49.95 ± 6.18 μg/ml). Although ascorbic acid had better scavenging ability than the three fractions (17.23 ± 0.16 μg/ml). The flavonoid-rich fraction A shows better result in inhibiting α-glucosidase with IC50 value of 16.24 μg/ml compared to fraction B (128.04 μg/ml) and fraction C (143.16 μg/ml). For α-amylase, flavonoid-rich fraction A had an IC50 of 31.50 μg/ml compared to B (84.32 μg/ml) and C (145.40 μg/ml). The various controls also showed promising results with acarbose having IC50 of 3.93 μg/mL and 15.66 μg/mL respectively for α-glucosidase and α-amylase. Our findings also showed that FeSO4-induced tissue damage decreased the levels of GSH, SOD, and CAT activities while increasing the levels of MDA. In contrast, following treatment with the three flavonoid fractions of S. anguivi fruits helped to restore these parameters to near-normal levels, by significantly increasing the potential of GSH, SOD, CAT and reducing the levels of MDA which signifies that flavonoid-rich fractions of S. anguivi have great potential to address complications arising from oxidative stress. In addition, the three flavonoid-rich fractions A, B, and C of S. anguivi fruits exhibited ex vivo anti-inflammatory properties via reduced nitric oxide levels in iron-induced oxidative damage. Data obtained from this study shows that the flavonoid-rich fraction of S. anguivi possess anti-diabetic property via inhibition of α-glucosidase and α-amylase and antioxidant property via free radical scavenging. Also, comparing all the fractions, flavonoid-rich fraction A appears to be more potent compared to the fractions B and C. Further research will be needed in isolating and as well applying the fractions in real life situations in the management of diabetes.

Isolation and Identification of Indole Alkaloids from Aspergillus amstelodami BSX001 and Optimization of Ultrasound-Assisted Extraction of Neoechinulin A

This study aimed to investigate the alkaloid secondary metabolites of Aspergillus amstelodami BSX001, a fungus isolated from Anhua dark tea, and to improve the extraction yield of the active ingredients by optimizing the extraction process. The structural characterization of the compounds was investigated using mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. The antioxidant activity of echinulin-related alkaloids was evaluated by determining the total reducing power and DPPH radical scavenging capacity. The extraction process of the compound with optimum activity was optimized by a single-factor test and response surface methodology (RSM) combined with Box-Behnken design (BBD). The optimized result was validated. Finally, a new alkaloid 8-hydroxyechinulin (1), and four known alkaloids, variecolorin G (2), echinulin (3), neoechinulin A (4), and eurocristatine (5), were isolated. Echinulin-related compounds 1, 3, and 4 possessed certain antioxidant activities, with IC50 values of 0.587 mg/mL, 1.628 mg/mL, and 0.219 mg/mL, respectively, against DPPH radicals. Their total reducing power at a concentration of 0.5 mg/mL was 0.29 mmol/L, 0.17 mmol/L, and 4.25 mmol/L. The extraction process of neoechinulin A was optimized with the optimum extraction parameters of 72.76% methanol volume fraction, 25 mL/g solid-liquid ratio, and 50.8 °C soaking temperature. Under these conditions, the extraction yield of neoechinulin A was up to 1.500 mg/g.

Encapsulation of Bioactive Phytochemicals in Plant-Based Matrices and Application as Additives in Meat and Meat Products

The development of plant-based functional food ingredients has become a major focus of the modern food industry as a response to changes in consumer attitudes. In particular, many consumers are switching to a plant-based diet because of their concerns about animal-derived foods on the environment, human health, and animal welfare. There has therefore been great interest in identifying, isolating, and characterizing functional ingredients from botanical sources, especially waste streams from food and agricultural production. However, many of these functional ingredients cannot simply be incorporated into foods because of their poor solubility, stability, or activity characteristics. In this article, we begin by reviewing conventional and emerging methods of extracting plant-based bioactive agents from natural resources including ultrasound-, microwave-, pulsed electric field- and supercritical fluid-based methods. We then provide a brief overview of different methods to characterize these plant-derived ingredients, including conventional, chromatographic, spectroscopic, and mass spectrometry methods. Finally, we discuss the design of plant-based delivery systems to encapsulate, protect, and deliver these functional ingredients, including micelles, liposomes, emulsions, solid lipid nanoparticles, and microgels. The potential benefits of these plant-based delivery systems are highlighted by discussing their use for incorporating functional ingredients into traditional meat products. However, the same technologies could also be employed to introduce functional ingredients into plant-based meat analogs.