Current Bioactive Compounds - Volume 17, Issue 2, 2021

Background: A large proportion of the global production of fruits and vegetables is destined for processing by the food industry. This intense process generates tons of by-products, which may serve as sources of fiber and bioactive compounds, such as polyphenols and carotenoids. Accordingly, numerous studies have investigated the valorization of these by-products focusing on the extraction of bioactive compounds. However, the total amount of bioactive compounds ingested may not reflect the amount available for intestinal absorption, which refers to the bioaccessibility of these compounds. In addition, the interaction of bioactive compounds with dietary fiber and other nutrients may influence their bioaccessibility and may impair the understanding of the physiological effects of these by-products as prebiotic potential. Methods: The purpose of this mini-review is to summarize the main results obtained in the last five years regarding the bioaccessibility of the two major bioactive compounds of fruit and vegetable by-products, i.e., polyphenols and carotenoids, to corroborate the biopotential of this food matrix. Additionally, this review attempts to elucidate the relationship reported between the composition of these by-products and the emerging prebiotic property. Results: In general, the bioaccessibility of polyphenols and carotenoid compounds from fruit and vegetable by-products shows high variability, and it is suggested that the composition of the food matrix is one of the main factors influencing their bioaccessibility. Moreover, a promising prebiotic effect of these by-products is described. Conclusion: The brief literature review with recent studies provide relevant information that may contribute to using the fruit and vegetable by-products as a natural source of bioactive compounds and/ or functional ingredient.

Background: Nowadays, sesamol has emerged as an effective adjuvant therapeutic agent in the anticipation and therapy of various diseases. Sesamol, a natural phenolic compound is a major lignan isolated from the seeds of Sesamum indicum and sesame oil. Sesame oil is well known for its nutritional as well as their health-promoting properties. Methods: Several studies revealed that sesamol possesses significant antifungal, anti-inflammatory, antioxidant, and free radical scavenging, anticancer, neuroprotective, cardioprotective, antiaging, hepatoprotective and antidiabetic activity, etc. Results: The present review highlights the potential of sesamol as a novel medicinal agent for the treatment of numerous types of ailment. Conclusion: This review article also provides a brief idea about its uses, ethnomedicinally and commercially important analytical techniques, and its pharmacological activities.

Background: Brazil is considered a country with the highest biological biodiversity in the world and exploring underutilized food sources could diversify food production and reduce nutritional problems. Objective: This study aimed to determine the antioxidant capacity and the bioactive compounds of seven native fruits from Brazil. Methods: The samples were obtained from different cities of Brazil after confirmation of the botanical species. Carotenoids and anthocyanins were exhaustively extracted and injected into high-performance liquid chromatography. The antioxidant capacity was determined by assessing the free radical ABTS. Vitamin A activity was calculated based on retinol activity equivalent. Complex B and C vitamins were determined by high-performance liquid chromatography. Results: The main carotenoid for all species was β-carotene, and Jaracatiá showed the highest amount of β-cryptoxanthin, zeaxanthin, α- and β-carotene. Açauçara and the Butistood out among fruits analyzed with the highest antioxidant capacity (trolox equivalent). Concerning anthocyanins in Açauçara, compounds Cyanidin 3-glucoside and Cyanidin 3-rutinoside were identified. The values of all the compounds vary according to the harvest location. Jaracatiá is distinguished by the high vitamin A, C, B2, and B6 content, as well the Butiás (Praia and Serra), for B1, B2, B5 and B7. Vitamin B3 was only detected in Fisális fruits and Açahowed higher content of B5. Conclusion: Fruits included in this study were found to have considerable amounts of bioactive compounds, vitamins and antioxidant capacity, showing that they can contribute to the improvement of diet of the population.

Background: Escherichia coli especially its multiresistant strains as the common foodborne pathogens cause bloodstream infections, nosocomial pneumonia, infections of the skin and soft tissues. Therefore, the search for new effective biologically active compounds has been rapidly increasing in recent few decades. In this paper, we describe Quantitative Structure-Activity Relationships (QSAR) studies, molecular docking and in vitro antibacterial activity evaluation of a series of imidazolium-based Ionic Liquids (ILs) against E. coli spp. Methods: M2D fragment-based, classification and regression QSAR models were created using machine learning methods and types of descriptors via the OCHEM server. Biological testing of a series of synthesized imidazolium ILs with predicted activity was performed by the disc diffusion method. The most typical structures of symmetric and asymmetric ILs with high anti-E. coli activity (1e, 1h) were docked into the active site of Enoyl-Acyl Carrier Protein Reductase (ENR) in E. coli. Results: Symmetric imidazolium ILs with C8 alkyl chain length demonstrated the highest antibacterial activity in comparison to the high antibacterial potential of asymmetric ILs with C12 alkyl chain length against drug-sensitive and drug-resistant E. coli strains including hemolytic E. coli. It should be noted that symmetric ILs with C6 or C9 alkyl chain length have a slightly lower activity against certain E. coli strains. The key role in the binding of compounds (1e, 1h) in the E. coli ENR active site is associated with the NAD molecule and the amino acid residue Tyr146. Conclusion: The highly active symmetric and asymmetric imidazolium ILs can be considered as promising drug-candidates effective against E. coli spp. pathogens including multidrug-resistant strains.

Background: Pistacia lentiscus L. (Lentisk) an evergreen tree or shrub that is ubiquitous across the semi-arid areas of the Mediterranean and native to all Mediterranean islands. All parts of Lentisk, including resin, leaves, gum, fruits, and aerial parts, have been used as valuable remedies for various diseases since antiquity. Objective: This paper highlights a novel source for the isolation of pure shikimic acid from the Lentisk ethyl acetate extract, which could provide an alternative and renewable solution for shikimic acid in the future. Methods: Characterisation by melting point, elemental analysis, FTIR, HRMS, 1H-NMR, DEPT( 135)-NMR, and 13C-NMR spectroscopy confirmed the purity of shikimic acid. The antioxidant activity of Lentisk extract and shikimic acid was performed by DPPH free radical scavenging activity assay. Results: The results prove that Lentisk is an alternative and renewable source of shikimic acid. With regard to activity, the shikimic acid does not act as the lead compound in the antioxidant activity of Lentisk extract. Conclusion: Lentisk is a novel alternative and renewable source of shikimic acid.

Background: Pyropia genus is one of the most nutritionally rich marine algae which contain various bioactive compounds. Among Indian Pyropia species, Pyropia vietnamensis (P. vietnamensis), which was earlier known as Porphyra vietnamensis has recently documented with various reports. The present work is designed to evaluate the radical scavenging, nutraceutical and microbicidal properties of Pyropia vietnamensis. Methods: P. vietnamensis was collected from the coastal region of Maharashtra, namely Harihareshwar. Dried algal material was extracted with different solvents. Nutritional parameters such as fatty acids, minerals, dietary fibers, vitamins, lipids, ash content and protein were measured as per the standard protocol (WHO guidelines). Folin-Ciocalteu and aluminum chloride colorimetric procedures were used to estimate total phenolic content and total flavonoid content. Free radical scavenging activity was assessed using 2,2-diphenyl-1-picrylhydrazyl, nitric oxide and superoxide anion (O2¯) assays. Antimicrobial activity was investigated by in vitro microdilution procedure to estimate minimum inhibitory concentration and minimum bacterial concentration, against Gram-- positive bacterium (Staphylococcus aureus) and Gram-negative bacteria (Klebsiella pneumoniae, Escherichia coli, and Proteus vulgaris). Results: Nutritional analysis revealed that Pyropia vietnamensis contained a considerable amount of dietary fiber, protein, carbohydrate, methyl palmitate, magnesium, sulphur and sodium. Total phenolic content and total flavonoid content of methanolic fractions (913±21.7, 128±11.7) were more than an aqueous fraction (841±21.2, 3.7±11.1). Aqueous and ethyl acetate fractions showed significant antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (65.5±1.2 μg/mL, 68.3±1.6 μg/mL), nitric oxide (71.5±3.5 μg/mL, 52.3±1.9 μg/mL), and O2¯ (50.6±1.02 μg/mL, 62.1±1.03μg/mL) free radicals. Aqueous, methanolic and ethyl acetate fractions had the highest total antibacterial activity with minimum inhibitory concentration as 110–490 μg/mL and minimum bacterial concentration as 248–689 μg/mL against one Gram-positive and three Gram-negative microorganisms. Conclusion: Aqueous, ethyl acetate, and methanolic fractions of Pyropia vietnamensis exhibited good antimicrobial spectrum and antioxidant activity. This could be useful in preventing various oxidative stresses and pathogenic microbial strains.

Background: Marine bacteria serve as excellent sources of therapeutic enzymes, metabolites and natural products, which possess novel therapeutic properties. Increasing death rates due to cardiovascular diseases urge for cost-effective production of the fibrinolytic enzyme. Methods: In this study, marine sponge samples were screened for potent fibrinolytic producing bacteria. The primary screening was done for protease production, and clot lysis activity. The secondary screening was done for casein plasminogen activity and fibrinolytic activity. The strain which had potent fibrinolytic activity among them was further subjected to morphological, biochemical and molecular characterization. Media optimization was carried out to enhance enzyme production. The enzyme produced was subjected to purification using ammonium sulfate precipitation, gel filtration and characterized using HPLC and FTIR analysis. Results: Sponge was identified to be Desmapsamma anchorata. Thirteen bacterial isolates were isolated from the sponge sample. The 16S rRNA sequencing revealed that the potential strain had 99% similarity with Bacillus licheniformis. Amongst the isolates, most were found to be morphologically identical to the Bacillus genus. Gram’s staining and SEM analysis of the potent isolate were performed to identify the spore formation and rod-shaped morphology of the bacteria. The optimal temperature and pH for the production of the enzyme were 37°C and 8, respectively. The carbon source maltose and nitrogen sources were malt extract and yeast extract that were found to be optimal. The optimum incubation time was found to be 4 to 5 days. The crude supernatant was purified with ammonium sulfate precipitation and gel filtration chromatography. The retention time of 11.3 min and the presence of functional groups show the purity of the enzyme. The partially purified enzyme showed 96.4% clot lysis in artificial clot lysis activity. Conclusion: Although the secretion of fibrinolytic enzymes from Bacillus species is not new, based on our investigation, there are no reports regarding Bacillus licheniformis being isolated from marine sponges. However, there are reports of Bacillus licheniformis secreting fibrinolytic enzymes isolated from fermented food samples. This study identifies the marine environment as a potential source of new exploration for drug discovery.

Background: Rheum emodi has been used traditionally to treat diabetes in India. The study was designed to elucidate the effect of 75% ethanolic extract of R. emodi (rhizome) (EE-ReR) and its isolated compounds like emodin and chrysophanol on alloxan-induced diabetic rats, and to check its antidiabetic efficacy. Acute toxicological and histopathological studies were also assessed. Methods: Experimental rats were divided into six groups, with each group consisting of 6 rats. EEReR and its compounds emodin and chrysophanol were given orally for 30 days. Results: The experimental rats were sacrificed after 30 days by cervical dislocation. The renal profile and lipid parameters were determined. Histopathological changes in liver, kidney and pancreas were examined in EE-ReR treated group. EE-ReR was fed orally to diabetic rats, which resulted in a decline in the fasting blood glucose, total cholesterol, free fatty acids, creatinine, urea levels, and a rise in the insulin levels was observed almost in the normal range, in the rats which were fed with the extract. Histopathological studies of pancreas, kidney, and liver in diabetic rats revealed that the treated group of rats showed normal regeneration of islets cells. Acute toxicological studies revealed that the extract is safe up to 2000 mg/kg body weight of extract fed orally. Conclusion: These findings suggested a possible protective method to prevent damage of the internal organs by the R. emodi and its compounds like emodin and chrysophanol, and elevate insulin production during high blood glucose levels without any acute toxicological effect.

Background: The genus of Rosmarinus officinalis (Rosemary) is found in many parts of the world. Traditionally, Rosemary has been used in traditional medicine due to its therapeutic virtues and its ability to treat some diseases. Rosmarinus officinalis var. prostratus grows in the Al Kalamoon region of Syria but only a limited amount of scientific research on the medicinal uses of this plant has been done. This study focused on the medicinally active substances found in ethanolic extract of the leaves and flowers of this plant and their antidiabetic effect in alloxan-induced diabetic rats. First, an acute toxicity study was carried out to detect the optimal dose of the Rosmarinus officinalis var. prostratus extract. Then, the effect of the optimal dose of 300mg/kg was measured over 36 days. Methods: During the study, diabetic rats were treated with different doses of extract (100, 200, 300, 400, 500, and 600 mg/kg). The percentage of Fasting Blood Glucose (FBG) was measured immediately after administration of the extract and at 2h, 4h and 8h after administration. The dose of 300mg/kg was then used in the second part of the study, which involved four groups of rats: a healthy group, a diabetic group without treatment (the control group), a diabetic group treated with 300mg/kg of the extract, and a diabetic group treated by metformin (50mg/kg). The treatment continued for 36 days. Results: The results showed that the extract was rich with flavonoids, phenols and tannins. Levels of FBG and DPP-4 were significantly lower in the extract-treated group in comparison with the control group; however, the level of insulin was significantly elevated in the extract-treated group compared to the control group. This effect may be caused by two factors. First, the antioxidant effects of flavonoids that protect pancreatic beta cells from damage caused by alloxan, supports regeneration of pancreatic beta cells, and therefore insulin production. Second, the inhibition of DPP- 4 activity, which in turn leads to increased secretion of insulin. Conclusion: The ethanolic extract of Rosmarinus officinalis var. prostratus has an antidiabetic effect.