The aim of the study was to isolate digestive enzymes inhibitors from Mimosa pudica through a bioassay-guided fractionation approach. Repeated silica gel and sephadex LH 20 column chromatographies of bioactive fractions afforded stigmasterol, quercetin and avicularin as digestive enzymes inhibitors whose IC50 values as compared to acarbose (351.02 ± 1.46 μg mL-1) were found to be as 91.08 ± 1.54, 75.16 ± 0.92 and 481.7 ± 0.703 μg mL-1, respectively. In conclusion, M. pudica could be a good and safe source of digestive enzymes inhibitors for the management of diabetes in future.
Diabetes is a common metabolic disease indicated by unusually high plasma glucose level that can lead to major complications such as diabetic neuropathy, retinopathy, and cardiovascular diseases. One of the effective therapeutic managements of the disease is to reduce postprandial hyperglycemia through inhibition of α-glucosidase, a carbohydrate-hydrolyzing enzyme to retard overall glucose absorption. In recent years, a plenty of research works have been conducted looking for novel and effective α-glucosidase inhibitors (AGIs) from natural sources as alternatives for the synthetic AGI due to their unpleasant side effects. Plants and herbs are rich with secondary metabolites that have massive pharmaceutical potential. Besides, studies showed that phytochemicals such as flavonoids, alkaloids, terpenoids, anthocyanins, glycosides, and phenolic compounds possess significant inhibitory activity against α-glucosidase enzyme. Malaysia is a tropical country that is rich with medicinal herbs. In this review, we focus on eight Malaysian plants with the potential as AGI to develop a potential functional food or lead compounds against diabetes.
We investigate induction of apoptosis by xanthohumol on Ca Ski cervical cancer cell line. Xanthohumol is a prenylated chalcone naturally found in hop plants, previously reported to be an effective anticancer agent in various cancer cell lines. The present study showed that xanthohumol was effective to inhibit proliferation of Ca Ski cells based on IC50 values using sulforhodamine B (SRB) assay. Furthermore, cellular and nuclear morphological changes were observed in the cells using phase contrast microscopy and Hoechst/PI fluorescent staining. In addition, 48-hour long treatment with xanthohumol triggered externalization of phosphatidylserine, changes in mitochondrial membrane potential, and DNA fragmentation in the cells. Additionally, xanthohumol mediated S phase arrest in cell cycle analysis and increased activities of caspase-3, caspase-8, and caspase-9. On the other hand, Western blot analysis showed that the expression levels of cleaved PARP, p53, and AIF increased, while Bcl-2 and XIAP decreased in a dose-dependent manner. Taken together, these findings indicate that xanthohumol-induced cell death might involve intrinsic and extrinsic apoptotic pathways, as well as downregulation of XIAP, upregulation of p53 proteins, and S phase cell cycle arrest in Ca Ski cervical cancer cells. This work suggests that xanthohumol is a potent chemotherapeutic candidate for cervical cancer.
Introduction: The use of crude herbs for well-being as well as curation and prevention of ailments is evident globally, including Malaysia. To understand the effectiveness and reliability, the presence of phytochemical compounds as the factor influencing the use of crude herbs shall be determined. This study was conducted to screen the presence of phytochemical compounds in the local crude herbs consumed by patients with chronic diseases. This is part of
a larger study, where a cross-sectional study was conducted and reported elsewhere. Methods: In total, 15 types of crude herbs were reported by the patients with chronic diseases attending government health clinic at Kampar, Perak. The herbs were extracted using hot and standard cold methods respectively. Results: All the 15 crude herbs’ hot and cold extracts revealed the presence of eight phytochemical compounds, namely, phenols, quinones, tannins, terpenoids, saponins, flavonoids, glycosides, and alkaloids at varying intensity. Saponins, alkaloids, and glycosides were present in all the crude herbs extracts. However, terpenoids, tannins, and phenols were absent in Orthosiphon stamineus, Clinacanthus nutans, and Pandanus amaryllifolius extracts respectively. However, the cold extracts exhibited a higher intensity of phytochemicals compared to hot extracts. The present study confirms the presence of
phytochemicals in the local crude herbs consumed by patients with chronic diseases. The screened phytochemicals are bioactive compounds that possess medicinal properties that may trigger the patients to treat their diseases’ underlying conditions. However, the use of prescribed medicine, particularly among aging patients must be taken into account while consuming crude herbs. Conclusion: The findings of this study indicate that structured-evidence based crude herbs use interventions for patients with chronic diseases is warranted.
The emergence of antimicrobial resistance due to the widespread and inappropriate use of antibiotics has now become the global health challenge. Flavonoids have long been reported to be a potent antimicrobial agent against a wide range of pathogenic microorganisms in vitro. Therefore, new antibiotics development based on flavonoid structures could be a potential strategy to fight against antibiotic-resistant infections. This research aims to screen the potency of flavonoids of the genus Erythrina as an inhibitor of bacterial ATPase DNA gyrase B. From the 378 flavonoids being screened, 49 flavonoids show potential as an inhibitor of ATPase DNA gyrase B due to their lower binding affinity compared to the inhibitor and ATP. Further screening for their toxicity, we identified 6 flavonoids from these 49 flavonoids, which are predicted to have low toxicity. Among these flavonoids, erystagallin B (334) is predicted to have the best pharmacokinetic properties, and therefore, could be further developed as new antibacterial agent.
Orthosiphon stamineus Benth. (Lambiaceae) is an important traditional plant for the treatment of hypertension. Previous studies have demonstrated that the sinensetin content in O. stamineus is correlated with its vasorelaxant activity. However, there is still very little information regarding the vasorelaxant effect of sinensetin due to a lack of scientific studies. Therefore, the present study was designed to investigate the underlying mechanism of action of sinensetin in vasorelaxation using an in vitro precontraction aortic ring assay. The changes in the tension of the aortic ring preparations were recorded using a force-displacement transducer and the PowerLab system. The mechanisms of the vasorelaxant effect of sinensetin were determined in the presence of antagonists. Sinensetin caused relaxation of the aortic ring precontracted with PE in the presence and absence of the endothelium and with potassium chloride in endothelium-intact aortic rings. In the presence of Nω-nitro-L-arginine methyl ester (nitric oxide synthase inhibitor), methylene blue (cyclic guanosine monophosphate lowering agent), ODQ (selective soluble guanylate cyclase inhibitor), indomethacin (a nonselective cyclooxygenase inhibitor), tetraethylammonium (nonselective calcium activator K+ channel blocker), 4-aminopyridine (voltage-dependent K+ channel blocker), barium chloride (inwardly rectifying Kir channel blocker), glibenclamide (nonspecific ATP-sensitive K+ channel blocker), atropine (muscarinic receptor blocker), or propranolol (β-adrenergic receptor blocker), the relaxation stimulated by sinensetin was significantly reduced. Sinensetin was also active in reducing Ca2+ release from the sarcoplasmic reticulum (via IP3R) and in blocking calcium channels (VOCC). The present study demonstrates the vasorelaxant effect of sinensetin, which involves the NO/sGC/cGMP and indomethacin pathways, calcium and potassium channels, and muscarinic and beta-adrenergic receptors.
The effects of different drying methods (freeze drying, vacuum oven drying, and shade drying) on the phytochemical constituents associated with the antioxidant activities of Z. officinale var. rubrum Theilade were evaluated to determine the optimal drying process for these rhizomes. Total flavonoid content (TFC), total phenolic content (TPC), and polyphenol oxidase (PPO) activity were measured using the spectrophotometric method. Individual phenolic acids and flavonoids, 6- and 8-gingerol and shogaol were identified by ultra-high performance liquid chromatography method. Ferric reducing antioxidant potential (FRAP) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays were used for the evaluation of antioxidant activities. The highest reduction in moisture content was observed after freeze drying (82.97%), followed by vacuum oven drying (80.43%) and shade drying (72.65%). The highest TPC, TFC, and 6- and 8-shogaol contents were observed in samples dried by the vacuum oven drying method compared to other drying methods. The highest content of 6- and 8-gingerol was observed after freeze drying, followed by vacuum oven drying and shade drying methods. Fresh samples had the highest PPO activity and lowest content of flavonoid and phenolic acid compounds compared to dried samples. Rhizomes dried by the vacuum oven drying method represent the highest DPPH (52.9%) and FRAP activities (566.5 μM of Fe (II)/g DM), followed by freeze drying (48.3% and 527.1 μM of Fe (II)/g DM, respectively) and shade drying methods (37.64% and 471.8 μM of Fe (II)/g DM, respectively) with IC50 values of 27.2, 29.1, and 34.8 μg/mL, respectively. Negative and significant correlations were observed between PPO and antioxidant activity of rhizomes. Vacuum oven dried rhizomes can be utilized as an ingredient for the development of value-added food products as they contain high contents of phytochemicals with valuable antioxidant potential.
The present work sought to investigate the nutritional composition and phytochemical properties of red pitaya (Hylocereus polyrhizus) juices from Malaysia and Australia and to determine the optimum ethanol concentration (in the range of 0 – 100% ethanol) for the extraction of phenolic, flavonoid and betacyanin contents. The predominant macronutrient in red pitaya juice was carbohydrate while potassium and vitamin A were the major mineral and vitamin content. Red pitaya juice from Malaysia achieved optimal total phenolic content at 20% of ethanol (20 mL ethanol in 100 mL water, v/v); total flavonoid content at 60% (v/v); and betacyanin content at 0% (v/v). Red pitaya juice from Australia achieved the maximum total phenolic content at 60% (v/v); total flavonoid content at 20% (v/v); and betacyanin content at 80% (v/v). Nutritional composition and the phytochemical properties of red pitaya in Malaysia and Australia were significantly different suggested the role of environmental factors like soil and climate on the phytochemical properties of red pitaya.
Garcinia is a plant under the family of Clusiaceae that is commonly used as a flavouring agent. Various phytochemicals including flavonoids and organic acid have been identified in this plant. Among all types of organic acids, hydroxycitric acid or more specifically (-)-hydroxycitric acid has been identified as a potential supplement for weight management and as antiobesity agent. Various in vivo studies have contributed to the understanding of the anti-obesity effects of Garcinia/hydroxycitric acid via regulation of serotonin level and glucose uptake. Besides, it also helps to enhance fat oxidation while reducing de novo lipogenesis. However, results from clinical studies showed both negative and positive antiobesity effects of Garcinia/hydroxycitric acid. This review was prepared to summarise the update of chemical constituents, significance of in vivo/clinical anti-obesity effects, and the importance of the current market potential of Garcinia/hydroxycitric acid.
This study documents for the first time the phytochemical composition and biological activities of Tambourissa peltata Baker, an endemic plant from Mauritius. Phytochemical extraction was performed using ethyl acetate, methanol and distilled water as solvents. The phytochemical composition was determined through HPLC-MS and other standard assays. The DPPH, ABTS, FRAP, CUPRAC and phosphomolybdenum assays were employed for the determination of the antioxidant potential, whereas cell viability assays were used to determine the cytotoxicity. The highest phenolic and phenolic acid contents were obtained in the aqueous extract (179.91 ± 0.67 gallic acid equivalents/g and 55.74 ± 1.43 caffeic acid equivalents/g). The highest quantity of flavonoids was obtained in the ethyl acetate extract (28.97 ± 0.46 rutin equivalents/g). The methanolic extract was the highest source of flavonols (33.71 ± 0.13 mg catechin equivalents/g). A total of 34 phytochemicals were identified, mainly proanthocyanidins and flavonoid glycosides. The highest antioxidant activity in DPPH (973.40 ± 5.65 mg TE (Trolox equivalents)/g), ABTS (2030.37 ± 40.83 mg TE/g), FRAP (1461.39 ± 5.95 mg TE/g), CUPRAC (1940.99 ± 20.95 mg TE/g) and phosphomolybdenum (8.37 ± 0.23 mmol TE/g) assays was recorded for the aqueous extract. The ethyl acetate extract was the most active metal chelator. The highest acetylcholinesterase inhibitor was the methanolic extract, whereas the ethyl acetate extract was the most active against BChE. The tyrosinase enzyme was most inhibited by the methanolic extract. Alpha-amylase and glucosidase were most inhibited by the aqueous extract. The methanolic extract was capable of inducing cell cytotoxicity to the human colorectal carcinoma without damaging normal cells. T. peltata warrants further attention from the scientific community given its multifaceted biological properties.
The identification of plant metabolites is very important for the understanding of plant physiology including plant growth, development and defense mechanism, particularly for herbal medicinal plants. The metabolite profile could possibly be used for future drug discovery since the pharmacological activities of the indigenous herbs have been proven for centuries. An untargeted mass spectrometric approach was used to identify metabolites from the leaves and stems of Impatiens balsamina using LC-DAD-MS/MS. The putative compounds are mostly from the groups of phenolic, organic and amino acids which are essential for plant growth and as intermediates for other compounds. Alanine appeared to be the main amino acid in the plant because many alanine derived metabolites were detected. There are also several secondary metabolites from the groups of benzopyrones, benzofuranones, naphthoquinones, alkaloids and flavonoids. The widely reported bioactive components such as kaempferol, quercetin and their glycosylated, lawsone and its derivatives were detected in this study. The results also revealed that aqueous methanol could extract flavonoids better than water, and mostly, flavonoids were detected from the leaf samples. The score plots of component analysis show that there is a minor variance in the metabolite profiles of water and aqueous methanolic extracts with 21.5 and 30.5% of the total variance for the first principal component at the positive and negative ion modes, respectively.
Morin (3,5,7,2',4'-pentahydroxyflavone) is a yellow coloured natural flavonoid found in plants of the Moraceae family. This favonoid is easily sources from readily available fruits, vegetables and eve certain beverages. Among the sources that was identified, it is clear that morin is most abundantly found in almond, old fustic, Indian guava, and Osage orange. Multiple studies have suggested that morin has multiple therapeutic actions and possess potential to be a functional potent drug. Previous studies demonstrated that morin is capable of resolving deoxycorticosterone acetate-salt-induced hypertension and possess strong vasorelaxant properties. However, the exact mechanisms remains unknown. Therefore, this study is designed to investigate the in vitro mechanism of morin-induced vasorelaxant effects. The underlying mechanisms of morin's vasorelaxant activities were evaluated on thoracic aortic rings isolated from Sprague-Dawley rats. Results from the study demonstrated morin causing vasodilatory reaction in phenylephrine and potassium chloride pre-contracted endothelium-intact aortic rings with the effect being significantly affected in endothelium-denuded aortic rings. Pre-incubation of the aortic rings with ODQ (selective cGMP-independent sGC inhibitor), indomethacin (nonselective COX inhibitor), L-NAME (endothelial nitric oxide inhibitor), propranolol (β2-adrenegic receptors blocker), and atropine (muscarinic receptors blocker) significantly reduced the vasorelaxant effect of morin. It was also found to be able to reduce the intracellular calcium level by blocking VOCC and calcium intake from the extracellular environment and the intracellular release of calcium from the sarcoplasmic reticulum. The present study showed that the vasorelaxant effect of morin potentially involves the NO/sGC, muscarinic receptors, β2-adrenegic receptors, and calcium channels.
Staphylococci are facultative anaerobes, perfectly spherical un-encapsulated cocci, with a diameter not exceeding 1 micrometer in diameter. Staphylococcus aureus are generally harmless and remain confined to the skin unless they burrow deep into the body, causing life-threatening infections in bones, joints, bloodstream, heart valves and lungs. Among the 20 medically important staphylococci species, Staphylococcus aureus is one of the emerging human pathogens. Streptomycin had its highest potency against Staphylococcus infections despite the likelihood of getting a resistant type of staphylococcus strains. Methicillin-resistant S. aureus (MRSA) is the persister type of Staphylococcus aureus and was evolved after decades of antibiotic misuse. Inadequate penetration of the antibiotic is one of the principal factors related to success/failure of the therapy. The active drug needs to reach the bacteria at concentrations necessary to kill or suppress the pathogen's growth. In turn the effectiveness of the treatment relied on the physical properties of Staphylococcus aureus. Thus understanding the cell integrity, shape and roughness is crucial to the overall influence of the therapeutic agent on S. aureus of different origins. Hence our experiments were designed to clarify ultrastructural changes of S. aureus treated with streptomycin (synthetic compound) in comparison to artonin E (natural compound). In addition to the standard in vitro microbial techniques, we used transmission electron microscopy to study the disrupted cell architecture under antibacterial regimen and we correlate this with scanning electron microscopy (SEM) to compare results of both techniques.
This study aimed to determine the total phenolic content, DPPH scavenging, α-glucosidase, and nitric oxide (NO) inhibition of Gynura procumbens and Cleome gynandra extracts obtained with five different ethanolic concentrations. The findings showed that the 100% ethanolic extract of G. procumbens had the highest phenolic content and the lowest IC50 values for DPPH scavenging and NO inhibition activity compared to the properties of the other extracts. For C. gynandra, the 20% and 100% ethanolic extracts had comparably high total phenolic contents, and the latter possessed the lowest IC50 value in the NO inhibition assay. In addition, the 20% ethanolic extract of C. gynandra had the lowest IC50 value in the DPPH scavenging assay. However, none of the extracts from either herb had the ability to inhibit α-glucosidase enzyme. Pearson correlation analysis indicated a strong relationship between the phenolic content and DPPH scavenging activity in both herb extracts. A moderately strong relationship was also observed between the phenolic content and NO inhibition in G. procumbens extracts and not in C. gynandra extracts. The UHPLC-ESI-Orbitrap-MS revealed major phenolics from the groups of hydroxycinnamic acids, hydroxybenzoic acids, and flavonoid derivatives from both herbs, which could be the key contributors to their bioactivities. Among the identified metabolites, 24 metabolites were tentatively assigned for the first time from both species of studied herbs. These two herbs could be recommended as prospective natural products with valuable medicinal properties.
Honey is a good source of several important chemical compounds and antioxidants and is harvested throughout the year. However, no study has determined how their contents change over the years. The aim of the present research was to investigate the changes in the phenolics, flavonoids and antioxidant properties, as well as other physicochemical properties, of Malaysian acacia honey collected during different months during a two year period. The DPPH (1,1-diphenyl-2-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) methods were used to determine the total antioxidant activity of the honey samples. Generally, honey samples collected in the beginning and the middle of the year tended to have higher sugar content, which may be attributed to its high acidic nature and low moisture content. There was a gradual increase in the phenolic content of the acacia honey samples collected between September 2010 and December 2010. The honey sample collected at the beginning of the year (January) showed the highest color intensity and was dark amber in color. It also contained the highest concentration of phenolic compounds (341.67 ± 2.94 mg(gallic acid)/kg), the highest flavonoid content (113.06 ± 6.18 mg(catechin)/kg) and the highest percentage of DPPH inhibition and the highest FRAP value, confirming its high antioxidant potential. There was a positive correlation between DPPH and total phenolic content, suggesting that phenolic compounds are the strongest contributing factor to the radical scavenging activity of Malaysian acacia honeys. Overall, our results indicated that there were significant seasonal variations in the antioxidant potentials of honey over the two year period and the time of honey collection affects its physicochemical properties. Therefore, acacia honey from Malaysia should ideally be collected during the dry season, particularly in the months of January, May and June.
Baeckea frutescens or locally known as Cucur atap is used as antibacterial, antidysentery, antipyretic and diuretic agent. In Malaysia and Indonesia, they are used as an ingredient of the traditional medicine given to mothers during confinement. A three-steps infra-red (IR) macro-fingerprinting method combining conventional IR spectra, and the secondary derivative spectra with two dimensional infrared correlation spectroscopy (2D-IR) have been proved to be effective methods to examine a complicated mixture such as herbal medicines. This study investigated the feasibility of employing multi-steps IR spectroscopy in order to study the main constituents of B. frutescens and its different extracts (extracted by chloroform, ethyl acetate, methanol and aqueous in turn). The findings indicated that FT-IR and 2D-IR can provide many holistic variation rules of chemical constituents. The structural information of the samples indicated that B. frutescens and its extracts contain a large amount of flavonoids, since some characteristic absorption peaks of flavonoids, such as ∼1600cm(-1), ∼1500cm(-1), ∼1450cm(-1), and ∼1270cm(-1) can be observed. The macroscopical fingerprint characters of FT-IR and 2D-IR spectra can not only provide the information of main chemical constituents in medicinal materials and their different extracts, but also compare the components differences among the similar samples. In conclusion, the multi-steps IR macro-fingerprint method is rapid, effective, visual and accurate for pharmaceutical research.
Tualang honey (TH) is rich in flavonoids and phenolic acids and has significant anticancer activity against breast cancer cells comparable to the effect of tamoxifen (TAM), in vitro. The current study evaluated the effects of TH when used in combination with TAM on MCF-7 and MDA-MB-231 cells. We observed that TH promoted the anticancer activity of TAM in both the estrogen receptor-(ER-)responsive and ER-nonresponsive human breast cancer cell lines. Flow cytometric analyses indicated accelerated apoptosis especially in MDA-MB-231 cells and with the involvement of caspase-3/7, -8 and -9 activation as shown by fluorescence microscopy. Depolarization of the mitochondrial membrane was also increased in both cell lines when TH was used in combination with TAM compared to TAM treatment alone. TH may therefore be a potential adjuvant to be used with TAM for reducing the dose of TAM, hence, reducing TAM-induced adverse effects.
Many chronic diseases are associated with increased oxidative stress caused by an imbalance between free-radical production and the antioxidant level. Antioxidants, which are abundant in natural honey, are free-radical scavengers that either reduce the formation of or neutralize free radicals. The composition and source of honey greatly dictates its biochemical properties. We performed a comparative analysis of the total phenolic content and antioxidant potential of common commercially available honeys along with Malaysian tualang honey. In vitro biochemical analysis of the phenolic content by the Folin-Ciocalteau method revealed a significantly elevated phenolic content (83.96 ± 4.53 mg gallic acid equivalents per 100 g) in tualang honey. In addition, the antioxidant capacity (53.06 ± 0.41 mg ascorbic acid equivalents per gram) of tualang honey was greater, as assessed by the phosphomolybdenum method, 2,2-diphenyl-1-picryl-hydrazyl assay, and ferric reducing/antioxidant power assay. Peroxynitrite and superoxide radical scavenging activity was determined by spectrophotometric analysis in different honey types. Our data suggest that the elevated free-radical scavenging and antioxidant activity observed in tualang honey is due to the increased level of phenolic compounds. In addition to its antibacterial, anticarcinogenic, and anti-inflammatory properties, our study highlights the favorable antioxidant properties of tualang honey, which may be important to human nutrition and health.