Comparison of antioxidant, antimicrobial activities and chemical profiles of three coffee (Coffea arabica L.) pulp aqueous extracts

AbstractBackgroundThis study explored the bioactivities and nutrient compositions of coffee (Coffea Arabica L.) pulp which was prepared in three different ways [Coffee Pulp Extracts (CPE) 1–3].MethodsThe coffee pulp was prepared in three different ways by distinct selecting and freezing processes. The nutritional values, polyphenol contents, antioxidant activity, and antibacterial properties of the coffee pulp as well as the characterization of the active ingredients by liquid chromatography-electrospray ionization-quadrupole-time-of-flight mass spectrometry (LC-ESI-Q-TOF-MS) were evaluated.ResultsThe chemical profiles of three aqueous extracts were compared and characterized using LC-ESI-QTOF-MS. They showed slightly different nutrient compositions. The total phenolic content was highest in CPE1, and decreased in the following order: CPE1>CPE2 > CPE3. Among the CPEs tested, CPE1 showed the most potent antioxidant activity with IC50 18μg/mL and 82μg/mL by 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and 1,1-diphenyl-2-picryl-hydrazyl assay, respectively. Chlorogenic acid and caffeine were the most prominent in CPE1 and it contained more compounds than the others. Moreover, CPE1 demonstrated antibacterial activity against both gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) and gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli).ConclusionThese findings indicated that CPE1 has powerful nutrients with antioxidant and antibacterial properties—the potency of which is impacted by the preparation process

Chemical Profiles and In Vitro Cholinesterase Inhibitory Activities of the Flower Extracts of Cassia spectabilis

Background. Cassia spectabilis is a flowering plant containing various metabolites that provide potential for pharmacological activities. The current study aimed to investigate the ethanolic and water extracts of C. spectabilis as cholinesterase inhibitor as one of the target treatments for Alzheimer’s disease. The chemical composition of the extracts was also studied to determine which components are responsible for the bioactivity. Methods. The cholinesterase inhibitory activity assay was carried out by the modified Ellman’s method against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). LC-MS/MS analysis was carried out to investigate the chemical profiles of the extracts, followed by a molecular networking study by GNPS. Results. Both extracts showed inhibition against AChE and BChE in a dose-dependent manner, with the higher potency exhibited by the ethanolic extract with IC50 values of 7.88 and 3.78 μg/mL. The chemical analysis and molecular networking study of the flower extracts revealed similarity between the ethanolic and water extracts. Piperidine alkaloids were identified in both extracts, while the sphingolipid compounds were found in the ethanolic extract. Conclusion. The water and ethanolic extracts of C. spectabilis flowers displayed potency for Alzheimer’s disease treatment. The presence of piperidine alkaloids in the extract may be responsible for the cholinesterase inhibitory activity. The higher potency of the ethanolic extract compared to the water extract is possibly due to the higher amount of piperidine alkaloids in the ethanolic extract. Further study is needed to quantify the concentration of alkaloids in the extracts

Development of On-Line High Performance Liquid Chromatography (HPLC)-Biochemical Detection Methods as Tools in the Identification of Bioactives

Biochemical detection (BCD) methods are commonly used to screen plant extracts for specific biological activities in batch assays. Traditionally, bioactives in the most active extracts were identified through time-consuming bio-assay guided fractionation until single active compounds could be isolated. Not only are isolation procedures often tedious, but they could also lead to artifact formation. On-line coupling of BCD assays to high performance liquid chromatography (HPLC) is gaining ground as a high resolution screening technique to overcome problems associated with pre-isolation by measuring the effects of compounds post-column directly after separation. To date, several on-line HPLC-BCD assays, applied to whole plant extracts and mixtures, have been published. In this review the focus will fall on enzyme-based, receptor-based and antioxidant assays

Chemical profiles of three varieties of germinated rice based on LC-MS and their antioxidant activity

In this study,chemical profiles in different germinated rice extracts (GREs) using different solvent extraction ratio were investigated.Three varieties of germinated rice (GR), including germinated white rice(GWR), germinated black rice (GBR) and germinated red rice(GRR) were extracted using 70and 100% ethanol(v/v). Both extracts were characterized for their chemical profiles using liquid chromatography-electrospray ionization−quadrupole−time−of−flight mass spectrometry (LC−ESI−Q−TOF−MS). The content of γ−aminobutyric acid (GABA), total phenolic content (TPC), and antioxidant activities were also determined. The chemical profiles of GREs are composed of organic acids, amino acids, vitamins, flavonoids,and phenolic compounds. The GABA content of all rice varieties presented the same pattern in both ethanolic extracts. The TPC of GRE extracted by 70% ethanol (v/v) showed significant higher amount than that in the 100%v/vethanolic extract(p<0.05). The highest TPC was obtained from GBR, followed by GRR and GWR, respectively(p<0.05). The antioxidant activity from three assays, including DPPH, ABTS, and FRAP showed higher activities in the 100% v/vethanolic extracts than their 70% v/v counterparts(p<0.05). The phenolic content showed a low positive Pearson correlation with antioxidant activities, however,the strong positive Pearson’s correlation coefficients were observed among these activities (r= 0.846-0.935). The results suggested that the GR was composed of potential bioactive compounds such as GABA and other phytochemical contents possessing high antioxidant bioactivity which can be used as functional food or as part of nutraceutical products

Phytoconstituents, antioxidant, and cholinesterase inhibitory activities of the leaves and stem extracts of Artocarpus sericicarpus

The study aimed to investigate the antioxidant and cholinesterase inhibitory activities of the leaves and stems of Artocarpus sericicarpus and to analyse the phenolic compounds in the extracts. The modified Ellman’s method was used to determine the cholinesterase inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. The antioxidant properties were evaluated using DPPH and ABTS methods. The total phenolic content (TPC) was measured by spectrometric assay, and compound identification was carried out by LC-MS/MS analysis. The results showed that the leaf and stem extracts of A. sericicarpus exerted significant inhibitory effects against AChE and BChE, as well as antioxidant activities. The stem ethanolic extract exhibited the highest potency against AChE and BChE with IC50 values of 5.81 and 11.46 µg/mL, respectively. The leaf and stem ethanolic extracts gave higher antioxidant activities and TPC compared to the water-based extracts. The LC-MS/MS analysis indicated the presence of phenolic compounds, such as flavones, flavonols, flavanones, prenylated chalcones, and xanthones in the extracts

Effect of drying methods and solvent extraction on the phenolic compounds of Gynura pseudochina (L.) DC. leaf extracts and their anti-psoriatic property

Gynura pseudochina (L.) DC. is a local herb that has been used as an anti-inflammatory agent. To study the utilization of plant phenolics for psoriatic treatment, the effects of the drying process, solvent extraction process and age of the leaves on the total phenolic content (TPC), total flavonoid content (TFC), crude extract and anti-oxidant activity were evaluated. The phenolic composition in the plant extracts was investigated. The most efficient process was applied to obtain a suitable extract for in vitro studies. HaCaT cells subjected to non-TNF-α and TNF-α stimulation were utilized to evaluate the cytotoxicity and anti-RelA, anti-RelB and anti-IL-8 properties of the extracts. The results showed that freeze drying and microwave drying preserved high levels of TPC, TFC and anti-oxidant activity. The HPLC results indicated that 50% (v/v) methanol demonstrated a good efficiency for recovering phenolic compounds, specifically chlorogenic acid (CGA), caffeic acid (CA), p-coumaric acid (PCA) and rutin (RUT). CA content was increased with microwave drying. Microwave drying and mixed-aged leaves were utilized for further studies. Ethanol was used instead of methanol because the former is a safer solvent for health product application. The LC–MS/MS results revealed that 25% (v/v) and 99.9% (v/v) ethanol extracts of mixed-ages leaves dried using a microwave (MLM) contained phenolic acids, flavonoids, a xanthone derivative, a phenylpropanoid, a phenolic glycoside compound and a glycerol-phospholipid. The MLM extract additionally contained pyrrolizidine alkaloids (PAs) at a low concentration. Co-extraction with 25% and 50% (v/v) ethanol of the MLM extract (EMLM) was performed for recovering each phenolic compound. EMLM extracts and their marker compounds (CGA, CA, RUT and PCA) were not toxic to HaCaT cells subjected to non-TNF-α and TNF-α stimulation, except for CA. The EMLM extracts and certain concentrations of the marker compounds could inhibit the RelB canonical pathway and IL-8 production. All results support the possible application of G. pseudochina leaf extracts for psoriasis alleviation

Metabolite profiles of red and white rice aqueous extracts derived at different temperatures and their relationship with biological propertiesas determined using 1H-NMR-based metabolomics analysis

Consumption of pigmented rice has continued to increase in recent years, due in part to its potential health promoting properties, especially protection against chronic diseases. Chemical extracts of red rice have demonstrated strong ability to scavenge free radicals, however little is yet known about water extracts of red rice. The antioxidant activity, α-glucosidase inhibition, nitric oxide inhibition, and metabolic profiling of this cultivar’s water extracts have yet to be investigated. In this study, red rice and white rice were extracted using ultrasound-assisted hydrothermal extraction at three different temperatures. The total phenolic content (TPC) as well as the DPPH radical scavenging, α-glucosidase inhibitory, and nitric oxide (NO) inhibitory activities of each extract were determined. NMR analysis was performed to find out the metabolite profiles of the extracts. Correlations between the metabolites and the biological activities of the rice extracts were then investigated using metabolomics analysis. Results show that the red rice aqueous extracts had a higher TPC than the white rice extracts. The highest extraction temperature led to a decrease in the TPC. However, the extraction temperature did not affect the radical scavenging, α-glucosidase inhibitory, or NO inhibitory activities of the red rice extracts. The PCA results indicated extract discrimination by extraction temperature. The PLS score plot exhibited the potentials of red rice aqueous extracts on the α-glucosidase and NO inhibitory activities. The 1H-NMR-based metabolomics analysis shows that red rice aqueous extract possesses beneficial properties which can make it useful as an ingredient for functional foods or other products