Folin-Ciocalteu Test Research Articles

Quantitative assessment of antioxidant potential of selected homeopathic preparations in clinical practice.

Antioxidant property like radical scavenging is a primary target to elucidate the efficacy mechanism of a drug against diseases linked to oxidative stress such as cancer, metabolic disorders, rheumatoid arthritis, etc. In alternative therapies, homeopathy is one of the preferred choices by patients and clinicians due to its potential to cure chronic and complex illnesses. However, the efficacy of homeopathic preparations at high diluted potencies attracts rational criticism due to insufficient scientific knowledge supporting the mechanism of action. Therefore, an attempt was made to estimate the total phenolic content (TPC) and radical scavenging activity of clinically prescribed homeopathic drugs. With gallic acid as a reference control, mother tinctures (MTs) and different potencies of Eucalyptus globulus (EG), Syzygium jambolanum (SJ), Ruta graveolens (RG), and Thuja occidentalis (TO) were used to perform Folin-Ciocalteu test, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. The results showed TPC of MTs equivalent to µg/mL of gallic acid viz; EG (4,872.5±133.2), SJ (8,840.5±14.8), RG (985.6±39.1), and TO (341.5±19.5) with significant ABTS and DPPH radical scavenging potential. Whereas 30C and 200C potencies of each homeopathic drug showed undetectable phenolic content and insignificant radical scavenging potential compared to vehicle control, i.e.,alcohol 90% (2.0±1.5). The reported efficacy of 30C and 200C potencies of homeopathic medicines against oxidative stress-related illnesses might be due to mechanisms other than radical scavenging. Furthermore, the assays studied can be helpful in drug standardization and quality control of MTs that are used as starting material in homeopathic preparations.

A versatile untargeted metabolomics-driven technology for rapid phytochemical profiling of stem barks of Zanthoxylum species with antioxidant and antimicrobial activities

Zanthoxylum species are credited with various uses in ethnomedicine due to their rich metabolite composition. In Kenya, these include management of cancer and microbial related ailments. However, there are limited reports showing how the bioactivity of Kenyan Zanthoxylum species is linked to their phytochemical profiles. This study therefore aimed at examining the chemical variation among five Zanthoxylum species found in Kenya (Z. chalybeum, Z. gilletii, Z. holtzianum, Z. paracanthum and Z. usambarense) using metabolomics approaches and the anti-oxidant and antimicrobial activities of these species. In a Folin–Ciocalteu test, the phenolic content of the stem bark extracts of these species were 73.083–145.272 mg TAE/g, while the alkaloids (in bromothymol blue chromogenic test) and flavonoids (in aluminium chloride test) were found to be 152.39–207.19 mg ME/g, and 109.416–186.413 mg CE/g, respectively. These extracts also exerted strong antioxidant activities in the 2,2-iphenyl-1-picrylhydrazyl (DPPH) and ferric ion reducing antioxidant power assays. In a broth dilution assay, the extract of the stem bark of Z. holtzianum ability showed the highest antimicrobial activity, followed by Z. chalybeum stem bark extract. The activities were positively correlated to both flavonoids and alkaloids concentrations, while the concentration of phenolics had weak negative correlation to antimicrobial activities. A chemometric analysis of the liquid-chromatography mass spectrometry profiles led to grouping of the species into three clusters. This study illustrates the variation in the bioactivity of Zanthoxylum species based on metabolite composition and justifies the wide usage of Zanthoxylum species in Kenyan traditional medicinal practices.Graphical abstract

A Liposomal Formulation to Exploit the Bioactive Potential of an Extract from Graciano Grape Pomace.

Antioxidant compounds with health benefits can be found in food processing residues, such as grape pomace. In this study, antioxidants were identified and quantified in an extract obtained from Graciano red grape pomace via a green process. The antioxidant activity of the extract was assessed by the DPPH and FRAP tests, and the phenolic content by the Folin–Ciocalteu test. Furthermore, nanotechnologies were employed to produce a safe and effective formulation that would exploit the antioxidant potential of the extract for skin applications. Anthocyanins, flavan-3-ols and flavanols were the main constituents of the grape pomace extract. Phospholipid vesicles, namely liposomes, were prepared and characterized. Cryo-TEM images showed that the extract-loaded liposomes were predominantly spherical/elongated, small, unilamellar vesicles. Light scattering results revealed that the liposomes were small (~100 nm), homogeneously dispersed, and stable during storage. The non-toxicity of the liposomal formulation was demonstrated in vitro in skin cells, suggesting its possible safe use. These findings indicate that an extract with antioxidant properties can be obtained from food processing residues, and a liposomal formulation can be developed to exploit its bioactive value, resulting in a promising healthy product.

Studies Regarding the Antibacterial Effect of Plant Extracts Obtained from Epilobium parviflorum Schreb

The present study was carried out to develop an experimental endodontic irrigant solution based on plant extracts obtained from Epilobium parviflorum Schreb. that largely replenish the properties of the usual antiseptics used in dentistry. Background: This study investigated the phytochemical contents of plant extracts obtained from Epilobium parviflorum Schreb. and their potential antibacterial activity. Methods: Identification and quantification of biologically active compounds were made by UV field photo spectrometry, adapting the Folin-Ciocalteu test method. Antibacterial activity was tested on pathological bacterial cultures collected from tooth with endodontic infections using a modified Kirby-Bauer diffuse metric method. Results: Polyphenols and flavonoids were present in all plant extracts; the hydroalcoholic extract had the highest amount of polyphenols—17.44 pyrogallol equivalent (Eq Pir)/mL and flavonoids—3.13 quercetin equivalent (Eq Qr)/mL. Plant extracts had antibacterial activity among the tested bacterial species with the following inhibition diameter: White Staphylococcus (16.5 mm), Streptococcus mitis (25 mm), Streptococcus sanguis (27 mm), Enterococcus faecalis (10 mm). Conclusions: All plant extracts contain polyphenols and flavonoids; the antibacterial activity was in direct ratio with the amount of the bioactive compounds.

Determination of volatiles, antioxidant activity, and polyphenol content in the postharvest waste of Ocimum basilicum L

The treatment of postharvest wastes is an integral part of the food value chain. Therefore, Ocimum basilicum L. residues were dried in an oven and a microwave. Volatiles were extracted using hydrodistillation, headspace solid-phase microextraction (HS-SPME) and then analyzed by Gas Chromatography-Mass Spectrometry (GC–MS). Thirty volatiles were identified in raw material, with β-linalool, methyleugenol, methylcinnamate, and estragole predominating. Meanwhile, 24 and 18 volatiles were detected in the oven- and microwave-dried samples, with a significant decrease of methyleugenol content. The highest radical scavenging ability and total phenolic content were achieved for microwaved wastes using photochemiluminescence, DPPH, and Folin-Ciocalteu test. Moreover, 8 phenolic acids and 9 flavonoids were identified in the LC-MS/MS analysis, with significant contents of rosmarinic acid and luteolin (1042.45 and 11.68 µg/g of dry matter, respectively) in the microwaved basil. This experiment pointed out that microwaved basil wastes could be re-used in the food, pharmacy and/or cosmetic industries.

Phytochemical characterization, antioxidant potential and antimicrobial activity of Averrhoa carambola L. (Oxalidaceae) against multiresistant pathogens

The objective of this work was to perform the phytochemical characterization, to determine total phenols, antioxidant (AAO%) and antimicrobial potential of the ethanolic extracts of carambola. The phytochemical study was carried out through a qualitative analysis of the chemical constituents and quantitative determination of the phenol content By the Folin-Ciocalteu test. Qualitative and quantitative antioxidant tests were performed using the DPPH method (2,2 diphenyl-1-picryl-hydrazila) and iron reduction (FRAP). The minimum inhibitory concentration (MIC) was determined by microdilution in 96-well plates. The presence of pyrogallic tannins, steroids and saponins has been identified. The highest total phenol content, quantified in the samples, was found in the stem bark (0.0866 mgEAG/g) and in the fruit (0.0734 mgEAG/g). In the antioxidant evaluation, the extracts of the green fruit bagasse (AAO% 71.9%,) and stem bark at 50 μg/mL (AAO% 94%) with CE50 23.7 μg/mL. Leaf extracts, stem bark, ripe fruit bagasse and green fruit bagasse presented MICs of 100 μg/mL against multiresistant pathogenic bacteria and fungi.

Influence of solvents on polyphenol content and antioxidant activity of fig leaf extracts obtained by maceration and ultrasonic extraction

In this paper, the polyphenol content and antioxidant activity of fig leaf extracts were analyzed. Extraction was performed with methanol, ethanol, acetone and their aqueous mixtures (50:50 v/v). Extractions were performed with stirring at 300 rpm on a vibromix and ultrasonic bath for 15 minutes. The polyphenol content was determined spectrophotometrically using the Folin-Ciocalteu test. Antioxidant capacity was tested using the FRAP and DPPH methods. The results showed a significant effect of extraction of bioactive components using an organic solvent:water mixture in relation to the organic solvent itself. Ultrasonic extraction proved to be a more efficient technique compared to mixing at 300 rpm. Â

Antioxidant Effects of Pinus eldarica Extracts Against Cisplatin-induced Cytotoxicity in Human Hepatoma (HepG2) Cell Line

Background: Cisplatin has cytotoxic effects through free radical generation. Reports indicate that various members of Pinaceae family may have antioxidant properties. In this study we investigated the cytoprotective effects of needle volatile oil and bark extract of Pinus eldarica in Hepatoma G2 (HepG2) cell line. Methods: Using the maceration technique, we obtained the ethanolic extract of Pinus eldarica’s bark (BHAEPE). Folin-ciocalteu reagent was used to determine the total phenolic content of BHAEPE. The Needle’s Volatile Oil of Pinus eldarica (NVOPE) was obtained by Clevenger hydrodistillation method. The main components of NVOPE were identified by Gas Chromatography and Mass Spectrophotometry (GC-MS). We used DPPH assay to investigate the antioxidant activity of both NVOPE and BHAEPE. Also, MTT assay was performed to test the protective effects of both BHAEPE and NVOPE against cisplatin. Results: Folin-ciocalteu test demonstrated that each gram of BHAEPE was equivalent to 371±6 mg of gallic acid. Also, GC-MS identified germacrene D as the main component of NVOPE. BHAEPE had more antioxidant capacity compared to NVOPE. When incubated solely with cells, neither BHAEPE nor NVOPE represented cytotoxicity on. Furthermore, BHAEPE demonstrated mitogenic effects on higher doses (50, 75 and 100 μg/ml). However, both NVOPE and lower doses of BHAEPE (10, 20 μg/ml) could not protect the cells against cisplatin’s cytotoxicity, but higher doses of BHAEPE provided cytoprotective effects. Conclusion: The antioxidant properties of both NVOPE and lower doses of BHAEPE did not adequately protect HepG2 cells against the cisplatin’s cytotoxicity. However, BHAEPE at high concentrations demonstrated cytoprotective effects.

Analytical Methods Used in Determining Antioxidant Activity: A Review.

The study of antioxidants and their implications in various fields, from food engineering to medicine and pharmacy, is of major interest to the scientific community. The present paper is a critical presentation of the most important tests used to determine the antioxidant activity, detection mechanism, applicability, advantages and disadvantages of these methods. Out of the tests based on the transfer of a hydrogen atom, the following were presented: the Oxygen Radical Absorption Capacity (ORAC) test, the Hydroxyl Radical Antioxidant Capacity (HORAC) test, the Total Peroxyl Radical Trapping Antioxidant Parameter (TRAP) test, and the Total Oxyradical Scavenging Capacity (TOSC) test. The tests based on the transfer of one electron include the Cupric Reducing Antioxidant Power (CUPRAC) test, the Ferric Reducing Antioxidant Power (FRAP) test, the Folin–Ciocalteu test. Mixed tests, including the transfer of both a hydrogen atom and an electron, include the 2,2′-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) test, and the [2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl] (DPPH) test. All these assays are based on chemical reactions and assessing the kinetics or reaching the equilibrium state relies on spectrophotometry, presupposing the occurrence of characteristic colours or the discolouration of the solutions to be analysed, which are processes monitored by specific wavelength adsorption. These assays were successfully applied in antioxidant analysis or the determination of the antioxidant capacity of complex samples. As a complementary method in such studies, one may use methods based on electrochemical (bio)sensors, requiring stages of calibration and validation. The use of chemical methods together with electrochemical methods may result in clarification of the operating mechanisms and kinetics of the processes involving several antioxidants.

In vitro and in vivo evaluation of pharmacological potential of Begonia barbata Wall

BackgroundBegonia barbata Wall is an important medicinal plant in Bangladesh used to treat several human diseases. The intention of the existing work was to determine in vitro and in vivo pharmacological properties of petroleum-ether, dichloromethane, and ethyl acetate soluble fractions of methanol extract of B. barbata whole plant (MEBB). The total phenolic content (TPC) was determined by Folin-Ciocalteu test while antioxidant activity assay was performed by DPPH radical quenching process. Tail immersion and acetic acid-induced writhing methods were utilized to evaluate analgesic effect in albino mice. To evaluate the hypoglycemic potential, glucose tolerance test is used. Castor oil-induced diarrhea method is utilized to figure out the anti-diarrheal action in mice. Thiopental-sodium-induced sleeping time test was exploited for the appraisal of CNS antidepressant action.ResultsAntioxidant activities of the test materials followed the order: dichloromethane fraction (DCMF) > ethyl acetate fraction (EAF) > petroleum-ether fraction (PEF). The EAF yielded maximum amount of phenolic compounds (12.47 mg of GAE/g of sample). The DMF was most effective in terms of thrombolytic activity while the EAF protected the membrane integrity of erythrocyte by 63.47% inhibition of hemolysis induced by heat. Among all fractions, the PEF (400 mg/kg body weight) demonstrated highest analgesic activity in both tail immersion test (maximum elongations as 262.053%) and acetic acid-induced writhing method (66.02% writhing inhibition). During anti-diarrheal test, the plant samples significantly diminished the frequency of diarrheal episodes in mice. Similarly, the plant samples decreased the sleeping duration induced by thiopental sodium.ConclusionThe above outcome exposed that B. barbata possesses significant pharmacological potential, which validates its use in Bangladesh folk medicinal practices.

Antioxidant Potential and the Effects of the Aqueous Extract of Spondias cytherea Fruit Pulp on B16-F10 Melanoma Cell Cycle

Consumption of diets rich in fruits and vegetables bring substantial health benefits. Spondias cytherea is a plant belonging to the family of Anacardiaceae, the fruits are highly consumed in Cameroon and commonly known as “kassimango”. In this work, the antioxidant and cytotoxic activities of the aqueous extract of Spondias cytherea pulp was investigated. The antioxidant capacity was evaluated by DPPH (2,2-diphenyl-1-picryl-hydrazyl) ferric reducing antioxidant power (FRAP) and metal chelating power assays. The Total phenolic and flavonoid contents were determined by Folin-ciocalteu test and aluminum chloride colorimetric test respectively. Selenium, and Zinc contents were evaluated. The effect of S. cytherea fruit aqueous extract on cell cycle of B16-F10 skin cancer cells was investigated using propidium iodide staining. The results revealed that the extract was efficient in reducing Fe3+ into Fe2+ and its ion chelating power increased with the extract concentration. The IC50 value for DPPH radical was found to be 96.28 µg/ mL. Total phenolic and flavonoid contents of Spondias cytherea fruits were 649.45 ± 0.71 mg GAE/100 g and 86.69 ± 0.02 mg CE/100 g of dry matter respectively. As far as the tested minerals are concerned, S. cytherea fruit presented 4.48 mg/100 g of zinc and 0.86 µg/100 g of selenium. It was observed that S. cytherea fruit aqueous extract inhibit the proliferation of B16-F10 cancer cells by inducing the cell cycle arrest at Sub G0 phase (apoptotic phase), G0/G1 (proliferation phase) and G2/M phase (mitosis phase). These results indicated that Spondias cytherea fruit have antioxidant and can be used in the management of cancer pending on further researches.

HPLC Fingerprint Analysis with the Antioxidant and Cytotoxic Activities of Selected Lichens Combined with the Chemometric Calculations.

The aim of this study was to evaluate the ability of multivariate techniques to predict antioxidant and cytotoxic activity of the selected lichens from the chromatographic data. A simple and reproducible HPLC-DAD technique has been used to obtain the chromatographic fingerprint profiles. Reversed phase high performance liquid chromatography (RP-HPLC) linear gradient system with methanol, water and phosphoric acid (V) (pH 2.3) as the mobile phase was used (50 min). Principal Component Analysis (PCA) has been applied to the evaluation of the phytochemical similarity between studied samples, especially between the same species collected in various places of Poland (Cetraria islandica (L.) Ach., CI, Cladina mitis Sandst., CM, Hypogymnia physodes (L.) Nyl., HP). The ability to scavenge free radicals was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods and the total phenolic content was determined by Folin-Ciocalteu (F-C) test. In the case of DPPH % of inhibition was higher for selected species (Pseudevernia furfuracea (L.) Zopf, H. physodes in comparison to the literature data. The FRAP test showed that the H. physodes extract had higher ability to scavenge free radical in comparison to Cladonia furcata (Huds.) Schrader and Evernia prunastri (L.) Ach., whereas P. furfuracea extract showed higher ability than C. islandica. The high content of phenolics in P. furfuracea and H. physodes confirms their high antioxidant activity. The cytotoxic activity of studied extracts was tested by cell culture method using the human HL-60 / MX2 acute CKL-22 (CRL-2257) promyelocytic leukemia tumor cell line. The lowest values of IC50 [µg∙mL−1] were obtained for: H. physodes (HP1)—99.4; C. digitate—122.6; H. physodes (HP)—136.5, C. subulata—142.6; C. mitis—180.2.

A Pilot Study of a Natural Food Supplement as New Possible Therapeutic Approach in Chronic Kidney Disease Patients.

The identification of natural bioactive compounds, able to counteract the abnormal increase of oxidative stress and inflammatory status in chronic degenerative non-communicable diseases is useful for the clinical management of these conditions. We tested an oral food supplement (OFS), chemically characterized and evaluated for in vitro and in vivo activity. Vitamin C, analyzed by High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD), was 0.19 mg/g in rosehip dry extract and 15.74 mg/capsule in the OFS. The identification of polyphenols was performed by HPLC-DAD; the total antioxidant capacity was assessed by Folin–Ciocalteu test. Total polyphenols were 14.73 mg/g gallic acid equivalents (GAE) for rosehip extract and 1.93 mg/g GAE for OFS. A total of 21 chronic kidney disease (CKD) patients and 10 healthy volunteers were recruited. The evaluation of routine laboratory and inflammatory parameters, erythrocyte glutathione transferase (e-GST), human oxidized serum albumin (HSAox), and assessment of body composition were performed at two different times, at baseline and after 5 weeks of OFS assumption. In the study, we highlighted a significant decrease of traditional inflammatory biomarkers (such as C-reactive protein, erythrocyte sedimentation rate, platelet to lymphocyte ratio) and other laboratory parameters like e-GST, azotaemia, and albuminuria after OFS treatment in CKD patients. Moreover, we demonstrated a lipid profile improvement in CKD patients after OFS supplementation.

Evaluation of the Microbial Quality and Total Phenolic Content of a Local Smoked Cheese

The increasing of the organic foods consumption to prevent the loss of cultural and social traditions that have survived for centuries, requires a proper assessment of the safety and quality of these products. The purpose of this study was the microbiological analysis of smoked cheese and non-smoked cheese, in order to assess the antimicrobial effect of smoke, as well as the determination of water-soluble phenolic compounds. The microbiological analyzes that were performed are: total number of aerobic mesophilic germs, coliform bacteria, coagulase-positive staphylococci, total number of yeasts and molds. The Folin–Ciocalteu test was chosen to measure total phenolic content of smoked cheese extracts. Microbial activity is reduced in smoked cheese types compared to non-smoked. The registered values were below the maximum admissible limits in the case of the total aerobic germs and shown coliform absence and inhibation in the growth of coagulase-positive staphylococci. Yeast and molds have been also inhibited through the smoking process. The total content of phenols varied from one assortment to another, with higher values in traditionally smoked cheese. The study shows that the microbiological quality of the cheese is greatly influenced by the hygienic conditions of processing and storage.

Comparative Study of Total Phenolic Content and Total Flavonoid Content Extraction from Guava Juices by Progressive Freeze Concentration and Evaporation

The guava fruit is rich with high valuable nutrients that have health-promoting features. It has been used over the centuries across various cultures in the world. Nowadays, people enjoy a simpler way to ensure a healthy diet by consuming supplements and juices. Guava juice was concentrated through progressive freeze concentration (PFC) or evaporation techniques. Total phenolic (TPC) content and total flavonoid content (TFC) were determined after these processes. TPC was analysed by folin-ciocalteu test and TFC was determined through Dowd method. Temperature and stirring rate were manipulated during the process. It was observed that TPC and TFC were higher for PFC than evaporation techniques, with TPC value of 8.1050 mg gallic acid equivalent (GAE)/g guava and TFC value of 0.8296 mg Quercetin/g guava, respectively. It was observed that the increase of temperature will enhance the TPC extraction due to higher mass transfer for extraction but reduce the TFC extraction due to the conversion of flavonoids into monomers.

Antioxidant activities, total phenol an flavonoid contents of two Teucrium polium subspecies extracts

The soxhlet extracts of two subspecies from Moroccan Teucrium polium were examined for their antioxidant activities, total polyphenol and total flavonoids contents. The Antioxidant activities was evaluated in vitro spectrophotometrically using four methods, such as ABTS + · , 1,1-diphenyl-2-picrylhydrzyl (DPPH · ), ferric reducing antioxidant power and phosphomolybdenum assay. Total polyphenol and flavonoid contents were measured using Folin-Ciocalteu test and aluminum chloride colorimetric method, respectively. The total phenol contents, flavonoids contents and antioxidant activities of T. polium subsp. polium extracts were higher than T. polium subsp. aurum . The phenols contents ranged from 112.27 to 4.38 mg GA E/ g dry extract. The total flavonoids varied between 174.57 and 40.42 mg RE/ g dry weight. The extract showed significant scavenging activity of ABTS + · and DPPH · , with IC 50 values ranging from 0.38 to 5 mg/ml and from 0.23 to 4.02 mg/ml, respectively. Moreover all extracts showed a good ferric reducing antioxidant power with EC 50 values varying between 0.19 and 3.94 mg/ml. The total antioxidant capacity assay revealed that the water extract of T. polium subsp. aurum had a high activity with a value of 220 mg VitCE/g dry weight. The ethyl acetate extract has a weak antioxidant activity in the four tests. These results shows that Moroccan T. polium subspecies are a rich source of phenols and natural antioxidant compounds, which can be used as a natural food preservative.

Effects of natural antioxidants on the oxidative stability of waste cooking oil biodiesel

The present study investigates the effect of natural antioxidants such as turmeric, cinnamon, black pepper, Red bell pepper, watermelon seed on the oxidation stability of Waste Cooking Oil biodiesel. The antioxidant capability of the selected antioxidants has been evaluated employing DPPH (2, 2-diphenyl-1-picrylhydrazyl) scavenging activity. The maximum percentage scavenging effect at 2500 ppm for the turmeric, cinnamon, black pepper, red bell pepper, and watermelon seed was found to be 92, 85, 88, 89 and 80 respectively. The presence of OH, RCOOH and phenolic compounds responsible for antioxidant activity was recorded by respective wave number by Fourier Transform Infrared Spectroscopy (FTIR). The phenolic content present in the natural antioxidant extracts was determined in terms of Gallic Acid Equivalent (GAE) using the Folin-Ciocalteu Test. The maximum value of GAE was recorded as 236.28 mg/g for Turmeric and minimum value as 101.14 mg/g for watermelon seed respectively. The antioxidant characteristics were evaluated through determination of oxidation stability of Waste Cooking Oil biodiesel and its antioxidant blends in terms of the stability period. It was observed that stability time increased with addition of antioxidants and found to be maximum for Turmeric extract as 18.61 h when compared to WCO biodiesel as 1.72 h.

Analysis of Heavy Metal Content in Conventional and Herbal Toothpastes Available at Maltese Pharmacies

Although toothpastes are considered as topical cosmetics that are not normally ingested, it is evident that they may contribute to the introduction of heavy metals and xenobiotics through buccal and gastrointestinal absorption. The purpose of this study was to determine the potential presence of metals and polyphenols in conventional, children’s and herbal toothpastes. Metal analysis was conducted by using the Microwave Plasma-Atomic Emission Spectrometer and the total polyphenolic content was determined by using the Folin–Ciocalteu test. Results showed that cadmium and mercury were absent in all toothpastes while zinc and tin exhibited high values. This was because the latter two metals are incorporated as part of the ingredients. In the case of polyphenols, the highest value was obtained in one of the samples from the children’s toothpaste category while the lowest value was obtained from the conventional toothpaste category. Lead and nickel were two other metals that fell outside the limits for EU and US standards. Most of these limits are usually applicable to topical cosmetic products or food products. However, these may not adequately cover oral hygiene products, such as toothpastes.

Total Phenolic Content and Antioxidant and Antibacterial Activities of Pereskia bleo.

Different solvent extracts of Pereskia bleo leaves were evaluated for total phenolic content (TPC) and antioxidant activities based on the Folin–Ciocalteu test and DPPH scavenging activities. The antibacterial activities against four bacteria, namely, Gram-positive bacteria: Streptococcus pyogenes ATCC 19615 (SP) and Staphylococcus aureus ATCC 29737 (SA) and Gram-negative bacteria: Escherichia coli ATCC 10536 (EC) and Pseudomonas aeruginosa ATCC 9027 (PA), were also performed based on the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. The findings demonstrated that both the methanolic and chloroform extracts displayed strong activities against SA, SP, EC, and PA while the hexane extract demonstrated the weakest activities towards all the four bacteria. The methanolic extract also exhibited higher TPC and possessed higher antioxidant activity with the IC50 value 33.83 µg/mL compared to the chloroform and hexane extracts. As such, the methanolic extract has a higher ability to scavenge free radical compared to other extracts. Due to the interesting result, activities are shown by the methanolic and chloroform crude extracts of P. bleo; hence, the study has been extended to the isolation of bioactive compounds to uncover its great potential as a natural source for antibacterial and antioxidant agents.

The Role of Acetylcholine Esterase in Resistance Mechanism of Plutella xylostella to Emamektin Benzoate

One of the resistance mechanism of P. xylostellato emamektin benzoate is target insensitivity which is acetylcholine esterase that responsible for resistance occurrence. The objective of this study was to determine the role of acetylcholinesterase in the resistance mechanism of P. xylostella population to emamektin benzoate. For enzyme activity analysis, larvae homogenate of the third instar of P. xylostella was prepared. The number of insects required for each scour is 1 for each field population. The protein content in P. xylostella homogenate was measured by the Folin-Ciocalteu test. Non-specific esterase activity with an absorption rate was read using ELISA reader tool with λ = 450 nm. The inhibition level of acetylcholinesterase activity by emamectin benzoate in the tested population was 36.84%. The highest inhibition occurs in Puasan (Ngablak) population. The result shows that a α-naphthyl acetate substrate was used so that it was recorded as non-specific esterase activity and did not exhibit esterase activity which specifically describes emamectin benzoate. Non-specific esterase enzyme activity of either α or β-naphthyl acetate substances to benzoic emamectin in the tested population most of the population was still susceptible. On α-naphthyl acetate substrate, the highest absorbance value found in susceptible population to benzoate emamectin (0.773), while the lowest found in Babrik (Ngablak) population (0.083).