RESUMO
Although several studies have already been carried out in investigating the general profile of the gut mycobiome across several countries, there has yet to be an officially established baseline of a healthy human gut mycobiome, to the best of our knowledge. Microbial composition within the gastrointestinal tract differ across individuals worldwide, and most human gut fungi studies concentrate specifically on individuals from developed countries or diseased cohorts. The present study is the first culture-dependent community study assessing the prevalence and diversity of gut fungi among different ethnic groups from South East Asia. Samples were obtained from a multi-ethnic semi-rural community from Segamat in southern Malaysia. Faecal samples were screened for culturable fungi and questionnaire data analysis was performed. Culturable fungi were present in 45% of the participants' stool samples. Ethnicity had an impact on fungal prevalence and density in stool samples. The prevalence of resistance to fluconazole, itraconazole, voriconazole and 5-fluorocytosine, from the Segamat community, were 14%, 14%, 11% and 7% respectively. It was found that Jakun individuals had lower levels of antifungal resistance irrespective of the drug tested, and male participants had more fluconazole resistant yeast in their stool samples. Two novel point mutations were identified in the ERG11 gene from one azole resistant Candida glabrata, suggesting a possible cause of the occurrence of antifungal resistant isolates in the participant's faecal sample.
Assuntos
Antifúngicos/farmacologia , DNA Espaçador Ribossômico/genética , Fezes/microbiologia , Fungos/classificação , Fungos/crescimento & desenvolvimento , Adolescente , Adulto , Sistema Enzimático do Citocromo P-450/genética , DNA Fúngico/genética , Farmacorresistência Fúngica Múltipla , Feminino , Proteínas Fúngicas/genética , Fungos/efeitos dos fármacos , Fungos/isolamento & purificação , Microbioma Gastrointestinal , Humanos , Malásia/etnologia , Masculino , Pessoa de Meia-Idade , Técnicas de Tipagem Micológica , Filogenia , Mutação Puntual , Prevalência , População Rural , Adulto JovemRESUMO
A Gram-negative, filamentous aerobic bacterium designated as strain Mgbs1T was isolated on 12 April 2017 from the subsurface soil and leaf litter substrate at the base of a Koompassia malaccensis tree in a tropical peat swamp forest in the northern regions of the state of Selangor, Malaysia (3° 39' 04.7' N 101° 17' 43.7'' E). Phylogenetic analyses based on the full 16S rRNA sequence revealed that strain Mgbs1T belongs to the genus Chitinophaga with the greatest sequence similarity to Chitinophaga terrae KP01T (97.65â%), Chitinophaga jiangningensis DSM27406T (97.58â%), and Chitinophaga dinghuensis DHOC24T (97.17â%). The major fatty acids of strain Mgbs1T (>10â%) are iso-C15â:â0, C16â:â1 ω5c and iso-C17â:â0 3-OH while the predominant respiratory quinone is menaquinone-7. Strain Mgbs1T has a complete genome size of 8.03 Mb, with a G+C content of 48.5 mol%. The DNA-DNA hybridization (DDH) score between strain Mgbs1T and C. jiangningensis DSM27406T was 15.9â%, while in silico DDH values of strain Mgbs1T against C. dinghuensis DHOC24T and C. terrae KP01T were 20.0 and 19.10% respectively. Concurrently, Average Nucleotide Identity (ANI) scores between strain Mgbs1T against all three reference strains are 73.2â%. Based on the phenotypic, chemotaxonomic, and phylogenetic consensus, strain Mgbs1T represents a novel species of the genus Chitinophaga, for which the name Chitinophaga extrema sp. nov. is proposed (=DSM 108835T=JCM 33276T).
Assuntos
Gammaproteobacteria/classificação , Filogenia , Microbiologia do Solo , Áreas Alagadas , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Florestas , Gammaproteobacteria/isolamento & purificação , Malásia , Hibridização de Ácido Nucleico , Folhas de Planta , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMO
The decoction and infusion of Rhoeo spathacea (Swartz) Stearn leaves have been recognized as a functional food particularly in South America, but has not yet gained international popularity as a beverage. The primary aim of this study was to establish the viability of R. spathacea aqueous leaf extracts as a beverage, in terms of its antioxidant activity and antibacterial activity. The antioxidant contents of aqueous and methanol leaf extracts were evaluated by the total phenolic content (TPC) and total flavonoid content (TFC) assays. The antioxidant activities measured were DPPH radical scavenging activity (FRS), ferric reducing power (FRP) and ferrous ion chelating (FIC) activity. The aqueous leaf extracts in the forms of decoction and infusion, were found to have comparable TPC and antioxidant activity with other herbal teas previously reported by our research group. Both decoction and infusion also exhibited antibacterial activity against six species of Gram positive and four species of Gram negative bacteria, notably methicillin-resistant Staphylococcus aureus and Neisseria gonorrhoeae. A total of four different known phenolic compounds were identified by HPLC and MS, three of which have not been previously reported to be found in this plant. Both the decoction and infusion of the leaves R. spathacea have potential to be popularized into a common beverage.
RESUMO
Geraniin, an ellagitannin, has shown a potent blood pressure-lowering effect in vivo. Therefore, this study aims to further characterize the ability of geraniin to attenuate hypertensive vascular dysfunction, a key feature of cardiovascular disease (CVD) development. Hypertension was induced in male Sprague-Dawley rats through feeding a high-fat diet (HFD) for eight weeks, followed by oral administration of 25 mg/kg/day geraniin for four weeks. The parameters of vascular dysfunction such as the structure and function of blood vessels as well as the vascular oxidative stress and inflammation were evaluated. The outcomes of geraniin-treated rats were compared with those of untreated rats on either a normal diet (ND) or HFD and with HFD-fed rats treated with captopril (40 mg/kg/day). We found that geraniin supplementation effectively ameliorated HFD-induced hypertension and abnormal remodelling of the thoracic aorta by suppressing excessive vascular superoxide (O2-) radical generation and overexpression of pro-inflammatory mediators in the circulating leukocytes. Furthermore, compared to the ND-fed rats, geraniin also independently promoted the significant enlargement of the thoracic aortic lumen for blood pressure reduction. Notably, the vascular benefits of geraniin were comparable to that of captopril. Collectively, these data suggest that geraniin can mitigate hypertensive vascular remodelling caused by overnutrition, which potentially abrogates the further development of CVDs.
Assuntos
Antioxidantes , Hipertensão , Ratos , Masculino , Animais , Antioxidantes/metabolismo , Taninos Hidrolisáveis/farmacologia , Taninos Hidrolisáveis/uso terapêutico , Ratos Sprague-Dawley , Captopril , Remodelação Vascular , Hipertensão/tratamento farmacológico , Hipertensão/etiologia , Obesidade/tratamento farmacológico , Dieta Hiperlipídica/efeitos adversos , Estresse Oxidativo , Modelos Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêuticoRESUMO
Isatis indigotica Fortune is a biennial Chinese woad of the Cruciferae family. It is primarily cultivated in China, where it was a staple in indigo dye manufacture till the end of the 17th century. Today, I. indigotica is used primarily as a therapeutic herb in traditional Chinese medicine (TCM). The medicinal use of the plant is separated into its leaves (Da-Qing-Ye) and roots (Ban-Lan-Gen), whereas its aerial components can be processed into a dried bluish-spruce powder (Qing-Dai), following dehydration for long-term preservation. Over the past several decades, I. indigotica has been generally utilized for its heat-clearing effects and bodily detoxification in TCM, attributed to the presence of several classes of bioactive compounds, including organic acids, alkaloids, terpenoids, and flavonoids, as well as lignans, anthraquinones, glucosides, glucosinolates, sphingolipids, tetrapyrroles, and polysaccharides. This paper aims to delineate I. indigotica from its closely-related species (Isatis tinctoria and Isatis glauca) while highlighting the ethnomedicinal uses of I. indigotica from the perspectives of modern and traditional medicine. A systematic search of PubMed, Embase, PMC, Web of Science, and Google Scholar databases was done for articles on all aspects of the plant, emphasizing those analyzing the bioactivity of constituents of the plant. The various key bioactive compounds of I. indigotica that have been found to exhibit anti-inflammatory, antimicrobial, anticancer, and anti-allergic properties, along with the protective effects against neuronal injury and bone fracture, will be discussed. Collectively, the review hopes to draw attention to the therapeutic potential of I. indigotica not only as a TCM, but also as a potential source of bioactive compounds for disease management and treatment.
Assuntos
Alcaloides , Isatis , Humanos , Medicina Tradicional Chinesa , Folhas de Planta , Raízes de PlantasRESUMO
The full plethora of environmental bacteria is often poorly represented in vitro as the majority remain difficult, if not impossible, to culture under standard laboratory settings. These bacteria often require native conditions for the formation of cell masses that collectively have higher chances of survival. With that, a 3D-printed version of the isolation chip (iChip) was used to cultivate bacteria from a tropical peat swamp in situ prior to growth and maintenance in vitro. Briefly, plates made from either acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), or epoxy resin were tested in terms of their usability and durability under acidic conditions similar to those of peat matter. The epoxy resin plates were then found to be most optimal for the sampling conditions. Peat soil samples were collected from the base of a Koompassia malaccensis tree and reconstituted in molten 10% (wt/vol) tryptone soy agar (TSA) prior to inoculation. The iChips were subsequently assembled and buried in the site of origin. As a comparison, bacteria from the same soil sample were cultivated directly on TSA and incubated at 28 °C for two weeks. Thereafter, agar plugs from the iChip were transferred to TSA plates to allow microcolonies within each plug to grow. Each pure isolate from both cultivation approaches that grew was then pooled and extracted for total DNA prior to 16S rRNA gene amplification and sequencing via Illumina MiSeq. Taxonomic abundance comparison revealed that the bacterial taxa at the level of order were significantly different between the two approaches, particularly in the orders, Burkholderiales, Xanthomonodales, Enterobacteriales, and Actinomycetales (differences of 12.0, 7.1, 8.0, and 4.2%, respectively). This indicated that the 3D-printed iChips present a possible low-cost tool for the isolation of bacterial genera that may not be able to grow on media directly in vitro.
Assuntos
Bactérias , Impressão Tridimensional , Ágar , Meios de Cultura , RNA Ribossômico 16S/genéticaRESUMO
In the past decade, researchers have focused on the emergence of drug resistance in fungal pathogens such as Candida albicans, also considered as pathobionts that occur harmlessly in the human body but could potentially be triggered to cause diseases. The increasing rate of antifungal resistance in commensal gut fungi is alarming and should be further investigated. Here, we report seven novel MLST (Multi Locus Sequence Typing) genotypes of multi-drug resistant C. albicans isolates obtained from participants of a community study in Segamat, a district in the state of Johor, Malaysia. A total of eight C. albicans were isolated from four individuals, which were found to express high resistance against fluconazole, itraconazole, voriconazole and 5-fluorocytosine antifungals. MLST was performed to assess the clonal relatedness of these drug resistant isolates among themselves and against other strains isolated from other geographical regions. The novel MLST C. albicans sequence types suggest significant genetic changes compared to previous genotypes.
Assuntos
Candida albicans , Farmacorresistência Fúngica , Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/genética , Candida albicans/isolamento & purificação , Candidíase/microbiologia , Farmacorresistência Fúngica/efeitos dos fármacos , Farmacorresistência Fúngica/genética , Resistência a Múltiplos Medicamentos/genética , Humanos , Malásia , Testes de Sensibilidade Microbiana , Tipagem de Sequências MultilocusRESUMO
Widely used throughout the world as traditional medicine for treating a variety of diseases ranging from cancer to microbial infections, members of the Tradescantia genus show promise as sources of desirable bioactive compounds. The bioactivity of several noteworthy species has been well-documented in scientific literature, but with nearly seventy-five species, there remains much to explore in this genus. This review aims to discuss all the bioactivity-related studies of Tradescantia plants and the compounds discovered, including their anticancer, antimicrobial, antioxidant, and antidiabetic activities. Gaps in knowledge will also be identified for future research opportunities.
Assuntos
Plantas Medicinais/química , Tradescantia/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/farmacologia , Medicina TradicionalRESUMO
OBJECTIVES: Metabolic syndrome (MetS), a multiplex risk factor for cardiovascular disease and type 2 diabetes, is increasingly prevalent worldwide. Ellagitannin geraniin, a polyphenol found in the rind of rambutan (Nephelium lappaceum), has demonstrated therapeutic effects against metabolism dysfunction. The aim of this study was to characterize the metabolic effects and possible mechanism of geraniin in rats with MetS induced by a high-fat diet (HFD). METHODS: MetS was induced in Sprague Dawley rats on an HFD, followed by a daily oral gavage of geraniin (25 mg/kg) for 4 wk. The outcomes of geraniin-treated rats were compared with those of untreated rats on either a control diet or an HFD and with rats with MetS treated with metformin on a daily basis (200 mg/kg). RESULTS: The supplementation of geraniin ameliorated multiple metabolic abnormalities caused by HFD, including hypertension, impaired glucose and lipid metabolism, ectopic fat deposition in the visceral fat and liver, and disturbed antioxidant mechanism and inflammatory response. The benefits conferred by geraniin were comparable to metformin. Transcriptomic analysis revealed a profound influence of geraniin on the hepatic expression profiles. The lipid and steroid metabolic processes that were aberrantly activated by HFD were suppressed by geraniin. Based on the differential transcriptomes, geraniin also exerted a significant modulatory effect on the expression of mitochondrial genes, potentially influencing the mitochondrial activity and leading to the observed beneficial effects. CONCLUSION: Geraniin supplementation mitigated metabolic anomalies of MetS in rats, making it an attractive drug candidate for further investigation.
Assuntos
Diabetes Mellitus Tipo 2 , Síndrome Metabólica , Animais , Dieta Hiperlipídica/efeitos adversos , Glucosídeos , Taninos Hidrolisáveis/farmacologia , Fígado , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/etiologia , Ratos , Ratos Sprague-DawleyRESUMO
Species of fungi belonging to the order Mucorales can be found everywhere in the environment. Gilbertella persicaria, which belongs to this order, have often been isolated from fruits and in water systems. However, there has been no report of isolation of this fungus from human samples. During a gut mycobiome study, from the Segamat community, Gilbertella persicaria was isolated from a human fecal sample and was characterized through a series of morphological assessment, biochemical tests, and molecular techniques. The isolate produced a white velvety surface that turned grayish after 24 h. Although no biofilm production was observed, the results indicated that the isolate could form calcium oxalate crystals, produced urease, and was resistant to low pH. The isolate was sensitive to amphotericin but resistant to voriconazole and itraconazole. The features of this fungus that could help in its survival in the human gut are also discussed.
Assuntos
Fezes/microbiologia , Microbioma Gastrointestinal , Mucorales/isolamento & purificação , Adolescente , Antibacterianos/farmacologia , Biofilmes/crescimento & desenvolvimento , Oxalato de Cálcio/metabolismo , Portador Sadio/microbiologia , Genoma Fúngico , Humanos , Concentração de Íons de Hidrogênio , Masculino , Urease/biossínteseRESUMO
The present study aimed to outline the physiological and metabolic disparity between chow- and purified ingredient-based high-fat diets and their efficacy in the induction of metabolic syndrome (MetS). Male, 3-week-old Sprague Dawley rats were randomly assigned to chow-based control diet, chow-based high-fat diet, purified control diet, and purified high-fat diet for 12 weeks. Physical and biochemical changes were documented. Chow-based diets, irrespective of the lipid content, resulted in significantly lower weight gain and organ weight compared to purified ingredient-based diets. Circulating insulin, total proteins, albumin, and certain lipid components like the triglycerides, total cholesterol, and high-density lipoprotein-cholesterol were also lower in the chow-based diet groups. Both chow- and purified high-fat diets induced central obesity, hypertension, and hyperglycaemia, but the latter was associated with earlier onset of the metabolic aberrations and additionally, dyslipidaemia. In conclusion, purified high-fat diet is a better diet for MetS induction in rats. PRACTICAL APPLICATIONS: Modeling metabolic syndrome is commonly accomplished with the use of chow- or purified ingredient diets enriched with carbohydrates and/or lipids, but the differences and associated drawbacks are unclear. This study highlights that chow- or modified chow-based diets have a tendency to introduce unwanted metabolic changes which are inconsistent with the progression of metabolic syndrome. Thus, the use of these diets in metabolic disease study should be avoided. On the other hand, purified high-fat diet which can effectively induce the features of metabolic syndrome is highly recommended.
Assuntos
Ração Animal/análise , Dieta Hiperlipídica/efeitos adversos , Gorduras na Dieta/análise , Síndrome Metabólica/etiologia , Animais , Colesterol/sangue , Gorduras na Dieta/metabolismo , Modelos Animais de Doenças , Humanos , Insulina/sangue , Masculino , Síndrome Metabólica/metabolismo , Ratos , Ratos Sprague-Dawley , Triglicerídeos/sangueRESUMO
Ursolic acid (UA) is a pentacyclic triterpene of the ursane type. As a common chemical constituent among species of the family Lamiaceae, UA possesses a broad spectrum of pharmacological properties. This overview focuses on the anticancer properties of UA against breast cancer (BC) and colorectal cancer (CRC) that are most common among women and men, respectively. In vitro studies have shown that UA inhibited the growth of BC and CRC cell lines through various molecular targets and signaling pathways. There are several in vivo studies on the cytotoxic activity of UA against BC and CRC. UA also inhibits the growth of other types of cancer. Studies on structural modifications of UA have shown that the -OH groups at C3 and at C28 are critical factors influencing the cytotoxic activity of UA and its derivatives. Some needs for future research are suggested. Sources of information were from ScienceDirect, Google Scholar and PubMed.
Assuntos
Antineoplásicos/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Neoplasias Colorretais/tratamento farmacológico , Medicamentos de Ervas Chinesas/administração & dosagem , Triterpenos/administração & dosagem , Animais , Antineoplásicos/efeitos adversos , Neoplasias da Mama/fisiopatologia , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/fisiopatologia , Medicamentos de Ervas Chinesas/efeitos adversos , Medicamentos de Ervas Chinesas/química , Feminino , Humanos , Masculino , Triterpenos/efeitos adversos , Triterpenos/química , Ácido UrsólicoRESUMO
In the biomedical field, there is growing interest in using human stem cell-derived neurons as in vitro models for pharmacological and toxicological screening of bioactive compounds extracted from natural products. Lignosus rhinocerus (Tiger Milk Mushroom) is used by indigenous communities in Malaysia as a traditional medicine to treat various diseases. The sclerotium of L. rhinocerus has been reported to have medicinal properties, including various bioactivities such as neuritogenic, anti-inflammatory, and anticancer effects. This study aims to investigate the neuroprotective activities of L. rhinocerus sclerotial extracts. Human embryonic stem cell (hESC)-derived neural lineages exposed to the synthetic glucocorticoid, dexamethasone (DEX), were used as the in vitro models. Excess glucocorticoids have been shown to adversely affect fetal brain development and impair differentiation of neural progenitor cells. Screening of different L. rhinocerus sclerotial extracts and DEX on the hESC-derived neural lineages was conducted using cell viability and neurite outgrowth assays. The neuroprotective effects of L. rhinocerus sclerotial extracts against DEX were further evaluated using apoptosis assays and Western blot analysis. Hot aqueous and methanol extracts of L. rhinocerus sclerotium promoted neurite outgrowth of hESC-derived neural stem cells (NSCs) with negligible cytotoxicity. Treatment with DEX decreased viability of NSCs by inducing apoptosis. Coincubation of L. rhinocerus methanol extract with DEX attenuated the DEX-induced apoptosis and reduction in phospho-Akt (pAkt) level in NSCs. These results suggest the involvement of Akt signaling in the neuroprotection of L. rhinocerus methanol extract against DEX-induced apoptosis in NSCs. Methanol extract of L. rhinocerus sclerotium exhibited potential neuroprotective activities against DEX-induced toxicity in hESC-derived NSCs. This study thus validates the use of human stem cell-derived neural lineages as potential in vitro models for screening of natural products with neuroprotective properties.
Assuntos
Células-Tronco Embrionárias Humanas , Neuroproteção , Fármacos Neuroprotetores/farmacologia , Polyporaceae/metabolismo , Animais , Anexina A5 , Anexinas/análise , Apoptose/efeitos dos fármacos , Proteínas de Arabidopsis , Produtos Biológicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dexametasona/efeitos adversos , Humanos , Malásia , Medicina TradicionalRESUMO
The present study aimed to examine the effects of the types of high-calorie diets (high-fat and high-fat-high-sucrose diets) and two different developmental stages (post-weaning and young adult) on the induction of metabolic syndrome. Male, post-weaning and adult (3- and 8-week old, respectively) Sprague Dawley rats were given control, high-fat (60% kcal), and high-fat-high-sucrose (60% kcal fatâ¯+â¯30% sucrose water) diets for eight weeks (n = 6 to 7 per group). Physical, biochemical, and transcriptional changes as well as liver histology were noted. Post-weaning rats had higher weight gain, abdominal fat mass, fasting glucose, high density lipoprotein cholesterol, faster hypertension onset, but lower circulating advanced glycation end products compared to adult rats. This is accompanied by upregulation of peroxisome proliferator-activated receptor (PPAR) α and γ in the liver and receptor for advanced glycation end products (RAGE) in the visceral adipose tissue. Post-weaning rats on high-fat diet manifested all phenotypes of metabolic syndrome and increased hepatic steatosis, which are linked to increased hepatic and adipocyte PPARγ expression. Adult rats on high-fat-high-sucrose diet merely became obese and hypertensive within the same treatment duration. Thus, it is more effective and less time-consuming to induce metabolic syndrome in male post-weaning rats with high-fat diet compared to young adult rats. As male rats were selectively included into the study, the results may not be generalisable to all post-weaning rats and further investigation on female rats is required.
RESUMO
The clinical value of tocotrienols is increasingly appreciated because of the unique therapeutic effects that are not shared by tocopherols. However, their effect on metabolic syndrome is not well-established. This study aimed to investigate the effects of a tocotrienol-rich fraction (TRF) from palm oil in high-fat-diet-treated rats. Male, post-weaning Sprague Dawley rats were provided high-fat (60% kcal) diet for eight weeks followed by a TRF (60 mg/kg) treatment for another four weeks. Physical, metabolic, and histological changes were compared to those on control and high-fat diets respectively. High-fat feeding for eight weeks induced all hallmarks of metabolic syndrome. The TRF reversed systolic and diastolic hypertension, hypercholesterolemia, hepatic steatosis, impaired antioxidant defense, and myeloperoxidase hyperactivity triggered by the high-fat diet. It also conferred an inhibitory effect on protein glycation to reduce glycated hemoglobin A1c and advanced glycation end products (AGE). This was accompanied by the suppression of the receptor for advanced glycation end product (RAGE) expression in the liver. The treatment effects on visceral adiposity, glycemic control, triglyceride level, as well as peroxisome proliferator-activated receptor α and γ expression were negligible. To conclude, treatment with a TRF exhibited protective effects on the cardiovascular and liver health in addition to the amelioration of plasma redox imbalance and AGE-RAGE activation. Further investigation as a therapy for metabolic syndrome is therefore worthwhile.
Assuntos
Dieta Hiperlipídica/efeitos adversos , Produtos Finais de Glicação Avançada/metabolismo , Hipertensão/induzido quimicamente , Receptor para Produtos Finais de Glicação Avançada/metabolismo , Tocotrienóis/farmacologia , Adiposidade , Animais , Composição Corporal , Ingestão de Alimentos , Ingestão de Energia , Teste de Tolerância a Glucose , Humanos , Masculino , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Aumento de PesoRESUMO
Natural product research is an active branch of science, driven by the increased value placed on individual health and well-being. Many naturally-occurring phytochemicals in plants, fruits and vegetables have been reported to exhibit antioxidant and antibacterial activity; often touted as being beneficial for human health. In vitro screening is a common practice in many research laboratories as a means of rapidly assessing these properties. However, the methods used by many are not necessarily optimal; a result of poor standardization, redundant assays and/or outdated methodology. This review primarily aims to give a better understanding in the selection of in vitro assays, with emphasis placed on some common assays such as the total phenolic content assay, free radical scavenging activity, disc-diffusion and broth microdilution. This includes a discussion on the reasons for choosing a particular assay, its strengths and weaknesses, ways to improve the accuracy of results and alternative assays.
Assuntos
Antibacterianos/farmacologia , Antioxidantes/farmacologia , Extratos Vegetais/farmacologia , Sequestradores de Radicais Livres/farmacologia , Humanos , Técnicas In Vitro , Fenóis/análise , Extratos Vegetais/análiseRESUMO
BACKGROUND: For generations, the rhizomes of Drynaria ferns have been used as traditional medicine in Asia. Despite this, the bioactivities of Drynaria rhizomes and leaves have rarely been studied scientifically. METHODS: This study evaluates the antioxidant properties of the methanolic extracts of the fertile fronds and rhizomes from three species in this genus: Drynaria quercifolia, Drynaria rigidula and Drynaria sparsisora. The phenolic and flavonoid contents of the samples were respectively quantified with the total phenolic content (TPC) and total flavonoid content (TFC) assays, while the antioxidant activities were determined via measuring the DPPH radical scavenging activity (FRS), ferric reducing power (FRP), ferrous ion chelating (FIC) activity and lipid peroxidation inhibition (LPI). The tyrosinase inhibition activity of all three species was also reported. RESULTS: The fertile fronds of D. quercifolia were found to exhibit the highest overall TPC (2939 ± 469 mg GAE/100 g) and antioxidant activity amongst all the samples, and the fertile fronds of D. quercifolia and D. rigidula exhibited superior TPC and FRP compared to their rhizomes, despite only the latter being widely used in traditional medicine. The fronds of D. quercifolia had high tyrosinase inhibition activity (56.6 ± 5.0 %), but most of the Drynaria extracts showed unexpected tyrosinase enhancement instead, particularly for D. sparsisora's fronds. CONCLUSION: The high bioactivity of the fertile fronds in the fern species indicate that there is value in further research on the fronds of ferns which are commonly used mostly, or only, for their rhizomes.
Assuntos
Antioxidantes/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Polypodiaceae/metabolismo , Rizoma/metabolismo , Flavonoides/metabolismo , Peroxidação de Lipídeos , Fenóis/metabolismo , Extratos Vegetais/metabolismo , Polypodiaceae/classificação , Especificidade da EspécieRESUMO
Commelinaceae is a family of herbaceous flowering plants with many species used in ethnobotany, particularly in South America. However, thus far reports of their bioactivity are few and far between. The primary aim of this study was to quantify the antioxidant and antibacterial activity of five Commelinaceae methanolic leaf extracts. The antioxidant content was evaluated by the total phenolic content (TPC), total tannin content (TTC), and total flavonoid content (TFC) assays. The antioxidant activities measured were DPPH free radical scavenging (FRS), ferric reducing power (FRP), and ferrous ion chelating (FIC); of the five plants, the methanolic leaf extract of Tradescantia zebrina showed the highest antioxidant content and activity, and exhibited antibacterial activity against six species of Gram-positive and two species of Gram-negative bacteria in a range of 5-10 mg/mL based on the broth microdilution method.