Current Bioactive Compounds - Volume 17, Issue 7, 2021

There is an emerging interest in plant polyphenols as dietary ingredients, particularly for digestive disorders and/or as antitumor agents. The plant compounds or extracts continue to be an alternative to drug use, and many studies aim to find natural substances with selective cytotoxicity on abnormal cells. Phenolic compounds, as important secondary metabolites from plants, are intensively studied as a substitute for drugs. In this review, the recent literature data from the past five years about the potential anticancer/antitumor effect of some categories of phenolics such as stilbenes and xanthones extracted from medicinal plants were surveyed. The most important results concerning the effectiveness of these active compounds as antitumor/anticancer agents, isolated compounds or as plant extracts, some bioavailability aspects and their mechanism of action in vitro and in vivo, were considered.

Background: The aim of this study is to isolate, extract and purify the antibacterial protein from Lactobacillus plantarum KY449289 and to assess its bio preservative potential. Objective: The present study was conducted to evaluate the laxative activity of Hydroethanolic Pericarp Extract of sapindus emarginatus (HESE) in animal models. Methods: Bacteriocins are antimicrobial peptides synthesized ribosomally which can be used as bio-preservative reducing the risk of chemical preservative’s effect and also replacing the thermal treatments. This study aims to isolate, purify the antibacterial protein from Lactobacillus plantarum KY449289 and to assess its bio preservative potential. In this study, twenty strains were isolated from a yogurt sample and preliminary characterization was carried out, such as morphological, biochemical, and molecular levels as a preliminary assay. Results: The characterized strains were assessed for the antibacterial activity by well diffusion assay, whereas all twenty strains were shown to have a antibacterial activity against foodborne pathogens, among which two strains VITMM04 and VITMM05 shows the highest zone of inhibition of 15 mm and 10 mm respectively against Listeria monocytogenes. The potent isolate VITMM05 solely showed a broad spectrum antibacterial activity against the pathogens. These strains were further subjected to optimization, purification, and application studies. A high increase in the inhibition zone was recorded with an optimum temperature of 35°C and its activity was found to be stable up to 85°C, optimum pH 6, and 5 mM of EDTA as an enhancer surfactant. On subjected to RP-HPLC, the purified sample showed a distinct peak at 2.192 min corresponding to the peak at 2.192 min for standard bacteriocin. Conclusion: The six-fold purified bacteriocin was effective in controlling 87% of the microbial population with 20mm zone of inhibiton against the Listeria monocytogenes and this shows the effective role of purified bacteriocin in inhibiting bacterial growth in a greater extent.

Background: The liver is one of the largest organs of the human body and the main site for intense metabolism and excretion. Liver injury or dysfunction is recognized as a serious worldwide health problem. Daphne gnidium L., a medicinal plant widely distributed in Algeria and used by populations in traditional medicine to treat hepatitis and other diseases. Objective: Protective and curative effects of aqueous extract of Daphne gnidium L. leaves were investigated against Carbon Tetrachloride (CCl4) induced hepatic damage in rats (Wistar Albino). Methods: This study was conducted on 32 Albino rats, which were divided into four groups; the first served as control. Group II animals were treated intraperitoneally with CCl4 solution (3ml/ kg). Group III animals were treated intraperitoneally with CCl4 solutions (3ml/kg) on the first day, and given aqueous Daphne extract orally at a dose level of (300 mg/kg) daily for 7 days (curative activity test). Animals of group IV were orally administered aqueous Daphne extract at a dose level of (300 mg/kg) daily, and on the seventh day treated intraperitoneally with CCl4 solution (3ml/ kg) 3 hours after the latest extract administration (preventive activity test). Results: Our results show that CCl4 significantly increases the relative liver weight, serum values of ALT, AST, ALP, GGT, and Total bilirubin, as well as the hepatic rate of oxidative stress parameters; MDA and CAT activities, and significantly decreases hepatic GSH levels compared to the control group. These results were confirmed by liver lesions observed in histological analyses. Pretreatment and curative treatment of dose 300 mg/kg of aqueous Daphne gnidium L. extract significantly reduced relative weight, serum levels of ALT, AST, ALP, GGT and Total bilirubin liver rate, CAT activity, and increases GSH level. In addition, normal liver architecture has been restored. Conclusion: The present study demonstrates the hepatoprotective and curative effects of aqueous extract Daphne gnidium leaves against CCl4-induced liver injury in rats by improving the antioxidant status in tissues (liver) and ameliorating the harmful effects induced by CCl4.

Background: Bacopa monnieri (Brahmi; family Scrophulariaceae) is a well-known plant known for its nootropic activity. Delivery of Bacosides (an active constituent) is limited at the site of action owing to the existence of the Blood-Brain Barrier (BBB). In order to take the Bacoside- Rich Extract (BRE) across BBB, formulated solid lipid nanoparticles (SLNs) were used. Objective: The objective of this work was to evaluate the pharmacokinetic and pharmacodynamic behavior (in vivo potential) of the prepared SLNs containing BRE in comparison to BRE alone for the treatment of Alzheimer’s disease. Methods: Swiss albino male mice (25-30 gm) were used for the study. The pharmacokinetic, as well as pharmacodynamic evaluation of formulated SLNs, were performed in comparison to BRE in a scopolamine-induced amnesia model. Results: BRE-loaded SLNs were found to be significantly more effective than BRE in alleviating neurodegeneration. The pharmacokinetic study revealed the improved bioavailability of prepared SLNs with the potential of sustaining the drug release in mice for an extended period of time. Conclusion: The results demonstrated that the SLNs can be considered as a potential delivery system for taking BRE across the BBB to treat Alzheimer’s disease.

Background: The current study evaluated the protective potential of quercetin against lindane induced toxicity in mice brain. For investigation, mice were allocated into four groups; the first group was the control; the second group was administered with an oral dose of lindane (25 mg/kg bw) for 4 consecutive days; the third group was exposed to quercetin (40 mg/kg bw) and to the fourth group, quercetin was administered 1 hour prior to the exposure of lindane. Objective: Two major objectives of the study were set . The first objective was to create lesions in the brain by lindane and; the second was to evaluate the neuroprotective potential of quercetin. Methods: To study oxidative responses, the levels of thiobarbituric Acid Reactive Substances (TBARS), Protein Carbonyl Content (PCC), Reduced Glutathione (GSH), Superoxide Dismutase (SOD), Catalase (CAT), and Glutathione Peroxidase (GPx) were measured in brain homogenates. Three key steps regulating enzymes of the Tricarboxylic Acid (TCA) cycle viz citrate synthase (CS), pyruvate dehydrogenase (PDH) and fumarase were also assayed. Results: Lindane treatment significantly enhanced the levels of TBARS (P<0.001),PCC (P<0.001), GPx (P<0.001), SOD (P<0.05), PDH (P<0.05) and fumarase (P<0.001) in brains of mice compared to control. Meanwhile, it alleviated GSH, CAT and CS (P<0.05) activity. Conclusion: Pretreatment with quercetin in lindane treated group not only restored previously altered biochemical parameters after lindane treatment and also significantly improved them, which suggests that quercetin is not only safe rather is neuroprotective against lindane intoxication.

Aim: The present work was aimed at finding out the anti-allergic activity of ethanol extracts of Quisqualis indica Linn. (EEQI) by in-vitro and in-vivo murine models. Background: Worldwide, the rise in the prevalence of allergic diseases has continued in the industrialized world for more than 50 years. About 0.05-2% of the population is estimated to experience anaphylaxis at some point in life. Quisqualis indica Linn in an ornamental plant that has been rarely used as a herbal medicine, however, the presence of polyphenols and flavonoids have been reported to possess anti-inflammatory, antipyretic and immunomodulatory activity, which have some pathological relevance with anaphylaxis. Objective: The objective of the present research was to investigate, scientifically explore and understand the probable anti-anaphylactic mechanism of ethanol extracts of Quisqualis indica Linn. via different preclinical models. Materials and Methods: In-vitro study was done on de-granulated mesenteric mast cells induced by compound 48/80 and in-vivo study was done by Passive Cutaneous Anaphylaxis (PCA) model. In the in-vitro study degranulated mesenteric cells were grouped into negative control (compound 48/80 treated), positive control (Disodium cromoglycate + 48/80 treated) and 3 test groups (EEQI 10 μg/ml + 48/80 treated, EEQI 50 μg/ml + 48/80 treated and EEQI 100 μg/ml + 48/80 treated). The number of degranulated mast cells was counted and compared within the different treatment groups. In the in-vivo study, the rats were first grouped into negative control (vehicle only), positive control (Disodium cromoglycate) and 2 test groups (EEQI: 100 and 200 mg/kilogram). The animals were pretreated for 12 days. On the 12th day, all the rats were immunized with serum anti-ovalbumin (obtained from an already sensitized rat) by the intradermal route. After 24 h of serum injection, Evans blue dye containing oval albumin was administered intravenously in all groups. Three days later, the rats were taken down for the severity of the anaphylactic reactions. Results: EEQI significantly attenuates mast cell degranulation and maintains cell intactness as compared to control (P < 0.001). It was set up to support the degree of anaphylaxis as compared to the control group (P < 0.001). Conclusion: The outcomes of the work revealed the preventive effect of Quisqualis indica Linn. against allergic manifestations.

Background: Currently, developing methods for the formation of nanoparticles with antimicrobial properties based on green chemistry are the research hotspots. In this research, green biosynthesis of Eriobotrya japonica extract loaded silver nanoparticles and their characterization were the main objectives to achieve. Methods: Green synthesis of E. japonica leaves extract-loaded silver nanoparticles (AgNPs) was carried out and its effect on bacterial growth was examined. The reduction of silver ions in the solution was observed using a UV-Vis spectrophotometer. The properties of AgNPs were assessed using Scanning Electron Microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and Xray Diffraction (XRD). Also, their antibacterial effects were checked against Staphylococcus aureus and Escherichia coli. Results: It was revealed that 5-50 nm sized spherical to elongated nanoparticles were synthesized that possessed comparatively better antibacterial potential against E. coli and S. aureus than the conventional extract of the E. japonica leaves. Conclusion: Green synthesis and effective utilization of Eriobotrya japonica extract loaded silver nanoparticles are a promising approach for nanoparticle production avoiding negative environmental impacts.

Introduction: Thiadiazole derivatives have been reported as a potent antimicrobial agent and the discovery of drug molecules for antimicrobial-resistant strains of Escherichia coli is still a vital challenge in the modern world. Objective: The objective of the present study is to design, synthesize and perform molecular docking studies and in-silico analysis of some novel 2-amino-1, 3, 4-thiadiazole derivatives with the aim of developing potential DNA gyrase B inhibitors. Materials and Methods: The compound 5-substituted-1, 3,4-thiadiazol-2-amine derivatives [compound 1a-1c] ; 5,6-Diphenyl- 2-{[5-(substituted)-1,3,4-thiadiazol-2-yl amino]}-2H -1,2,4-triazine- 3-thione derivatives [compound 2a-2c]; and propyl 3,4,5-trihydroxy-2,6-bis {[5-(substituted)- 1,3,4-thiadiazol-2-yl amino] benzoate derivatives [compound 3a -3c] were synthesised by temperature- controlled microwave-assisted method. The structures of the synthesized compounds were drawn in ChemSketch. Further, molecular docking and in-silico studies for the prediction of druglikeness, pharmacokinetic parameters and prediction of toxicity were carried out . The structures of the synthesized compounds were characterized by FT-IR, 1H NMR and mass spectral analysis. Results: The synthesized compounds had a better yield.The docking studies of the synthesized compounds had a better docking score with a good binding affinity towards the protein molecule. The synthesized compounds also comply with the in-silico prediction of drug-likeness, pharmacokinetic parameters and prediction of toxicity. Conclusion: The present study reveals that the 5-substituted-1, 3,4-thiadiazol-2-amine derivatives can serve as a better lead as potent DNA gyrase B inhibitor in further drug discovery.

Background: Several researches have focused on the antioxidant capacity of natural components extracted from plants. Their properties are determined by the presence of phenolic compounds that extend the shelf life of food and protect fats from autoxidation. Olive leaves, an abundant raw material, are a significant source of bioactive phenolic compounds, which can be used to enrich a widely used edible oil. Objective: The goal of this study was to improve the properties and stability of soybean oil by adding phenolic compounds extracted from the leaves of wild and cultivated olive trees. Methods: Leaf polyphenolic extracts obtained from Chemlal cultivar and wild olive were used to enrich refined soybean oil. The antioxidant activity was evaluated for the chain-breaking antioxidant effect using DPPH and FRAP assay. The oxidative stability was estimated using a rancimat apparatus. The effect of the frying conditions was studied by determining the rate of the polar fraction. Results: Total phenol contents from cultivated and wild olive leaves were important: 1047.19mg EAG /100g and 1424.59mg EAG/100g, respectively. Oil extracts enriched with Chemlal and wild olive leaves extracts at 25ppm presented 93.29% and 93.20% inhibition percent of DPPH radical, respectively. An improvement of 75 and 73% was observed for oils enriched with Chemlal and wild olive leaves respectively, for the antiradical activity against DPPH radical. The stability of the enriched oils is proportional to the concentrations of phenolic extracts and higher than that shown for the non-enriched ones. The frying test showed that the enrichment is causing a complete absence of polar compounds in the fries. Conclusion: The results of this study show the efficacy of adding polyphenols to olive leaves to increase the quality and oxidative stability of refined soybean oil.