Antioxidant and cytotoxic flavonoids from the flowers of Melastoma malabathricum L

A sustainable and efficient strategy for bioconverting naringin to L-rhamnose, 2R-naringenin, and kaempferol

The development of a sustainable and efficient bioconversion strategy is crucial for the full-component utilization of naringin. In this study, an engineering Pichia pastoris co-culture system was developed to produce L-rhamnose and 2S/2R-naringenin. By optimizing transformation conditions, the co-culture system could completely convert naringin while fully consuming glucose. The production of 2S/2R-naringenin reached 59.5 mM with a molar conversion of 99.2%, and L-rhamnose reached 59.1 mM with a molar conversion of 98.5%. In addition, an engineering Escherichia coli co-culture system was developed to produce 2R-naringenin and kaempferol from 2S/2R-naringenin. Maximal kaempferol production reached 1050 mg/L with a corresponding molar conversion of 99.0%, and 996 mg/L 2R-naringenin was accumulated. Finally, a total of 17.4 g 2R-naringenin, 18.0 g kaempferol, and 26.1 g L-rhamnose were prepared from 100 g naringin. Thus, this study provides a novel strategy for the production of value-added compounds from naringin with an environmentally safe process.

Phytoecdysteroids from Dioscorea dumetorum (Kunth) Pax. and their antioxidant and antidiabetic activities

Diabetes is a significant global health challenge, affecting circa 540 million adults worldwide. Dioscorea dumetorum, a Nigerian folkloric antidiabetic plant is severely understudied in terms of its bioactive phytochemical constituents. Antidiabetic guided isolation of the tubers and peels of D. dumetorum afforded three phytoecdysteroids bearing a cis-fused A/B ring junction including two new ones: 24-hydroxymuristerone A (1) and 24-hydroxykaladasterone (2), alongside the known muristerone A (3). Additionally, 2,2',7,7'-tetramethoxy-[1,1'-biphenanthrene]-4,4',6,6'-tetraol (4), batatasin I (5), and dihydroresveratrol (6) were isolated. Structural elucidation relied on spectroscopic, spectrometric methods, and comparison with existing literature. The ethyl acetate extracts of both the tubers and peels of D. dumetorum exhibited the highest phenolic content, correlating with potent antioxidant activity. Compounds 4 (IC50 = 0.10 mg/mL) and 6 (IC50 = 0.22 mg/mL) demonstrated superior inhibitory effects against α-glucosidase compared to acarbose (IC50 = 0.63 mg/mL). In contrast, compounds 3, 4, and 5 showed reduced α-amylase inhibition, with IC50 values of 2.58, 3.78, and 1.12 mg/mL, respectively, compared to acarbose (IC50 = 0.42 mg/mL). These observed bioactivities validate the traditional use of D. dumetorum and contribute valuable phytochemical data to the scientific literature of the species.

Euonymus alatus Twig Extract Protects against Scopolamine-Induced Changes in Brain and Brain-Derived Cells via Cholinergic and BDNF Pathways

In the current study, the therapeutic and preventive effects of Euonymus alatus (EA) twig extract were investigated in a mouse model of cognitive deficit and B35 cells. Twig extract 1 was extracted with 70% ethanol and later twig extract 2 was extracted through liquid-liquid extraction with 70% ethanol and hexane. EA twig 2 (300 mg/kg) along with the standard drug donepezil (5 mg/kg) were orally administered to the mice for 34 days. Scopolamine was given intraperitoneally for 7 days. Administration of EA twig extract 2 significantly improved the passive avoidance test (PAT) in mice. EA twigs extract also restored the scopolamine-reduced brain-derived neurotrophic factor (BDNF)/extracellular regulated kinase (ERK)/cyclic AMP responsive element binding protein (CREB) signaling in B35 cells and the mouse hippocampus. In addition, EA twig extract significantly inhibited the acetylcholine esterase (AChE) activity in B35 cells in a dose-dependent manner. Chromatography and ESI MS analysis of EA twig extract revealed the presence of flavonoids; epicatechin, taxifolin, aromadendrin, and naringenin with catechin being the most abundant. These flavonoids exerted protective effects alone and had the possibility of synergistic effects in combination. Our work unmasks the ameliorating effect of EA twig extract 2 on scopolamine-associated cognitive impairments through the restoration of cholinergic systems and the BDNF/ERK/CREB pathway.

Structural Characterization and Assessment of Anti-Inflammatory Activities of Polyphenols and Depsidone Derivatives from Melastoma malabathricum subsp. normale

The roots of Melastoma malabathricum subsp. normale (D. Don) Karst. Mey have been used in traditional ethnic medicine systems in China to treat inflammation-triggered ailments, such as trauma, toothache, and fever. Therefore, the aim of this study is to screen for compounds with anti-inflammatory activity in the title plant. The extract of M. malabathricum subsp. normale roots was separated using various chromatographic methods, such as silica gel, ODS C18, MCI gel, and Sephadex LH-20 column chromatography, as well as semi-preparative HPLC. One new complex tannin, named whiskey tannin D (1), and an undescribed tetracyclic depsidone derivative, named guanxidone B (2), along with nine known polyphenols (2–10) and three known depsidone derivatives (12–14) were obtained from this plant. The structures of all compounds were elucidated by extensive NMR and CD experiments in conjunction with HR-ESI-MS data. All these compounds were isolated from this plant for the first time. Moreover, compounds 1–4, 8, and 10–14 were obtained for the first time from the genus Melastoma, and compounds 1, 2, and 11–14 have not been reported from the family Melastomataceae. This is the first report of complex tannin and depsidone derivatives from M. malabathricum subsp. normale, indicating their chemotaxonomic significance to this plant. Compounds 1–12 were investigated for their anti-inflammatory activities on the production of the nitric oxide (NO) in lipopolysaccharide (LPS)-stimulated RAW264.7 cells, and compounds 1, 11, and 12 showed anti-inflammatory activities with IC₅₀ values of 6.46 ± 0.23 µM, 8.02 ± 0.35 µM, and 9.82 ± 0.43 µM, respectively. The structure–activity relationship showed that the catechin at glucose C-1 in ellagitannin was the key to its anti-inflammatory activity, while CH₃O- at C-16 of aromatic ring A in depsidone derivatives had little effect on its anti-inflammatory activity. The study of structure–activity relationships is helpful to quickly discover new anti-inflammatory drugs. The successful isolation and structure identification of these compounds, especially complex tannin 1, not only provide materials for the screening of anti-inflammatory compounds, but also provide a basis for the study of chemical taxonomy of the genus Melastoma.

Rhamnusalaternus Plant: Extraction of Bioactive Fractions and Evaluation of Their Pharmacological and Phytochemical Properties

Rhamnus alaternus, is a wild-growing shrub, belonging to the Rhamnaceae family. Widely distributed in the Mediterranean basin, R. alaternus is used in the usual medicine in numerous countries, mostly Tunisia, Algeria, Morocco, Spain, France, Italy, and Croatia. A large number of disorders-including dermatological complications, diabetes, hepatitis, and goiter problems-can be treated by the various parts of R. alaternus (i.e., roots, bark, berries, and leaves). Several bioactive compounds were isolated from R. alaternus, including flavonoids, anthocyanins, and anthraquinones, and showed several effects such as antioxidant, antihyperlipidemic, antigenotoxic, antimutagenic, antimicrobial, and antiproliferative. This review summarizes the updated information concerning the botanical description, distribution, extraction processes applied on R. alaternus, and its ethnopharmacology, toxicity, phytochemistry, and pharmacological effects.

A new xanthone dimer and cytotoxicity from the stem bark of Calophyllum canum

A phytochemical investigation of the stem bark of Calophyllum canum resulted in the isolation of a new xanthone dimer identified as biscaloxanthone (1), together with four compounds; trapezifoliaxanthone (2), trapezifolixanthone A (3), taraxerone (4) and taraxerol (5). The structures of these compounds were determined via spectroscopic methods of IR, UV, MS and NMR (1D and 2D). The cytotoxicity of compounds 1-3 were screened against A549, MCF-7, C33A and 3T3L1 cell lines, wherein weak cytotoxic activities were observed (IC₅₀ > 50 μm).

A review of the traditional uses, phytochemistry and biological activities of the Melastoma genus

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Melastoma consists of approximately 100 species distributed widely in tropical and subtropical countries, and Melastoma species are often used for medicinal purposes, such as treatment for bleeding, diarrhea, diabetes, and gynecological tumors by local people, mostly in Southeast Asian countries.

AIM OF THE REVIEW

The present review summarizes the traditional uses, phytochemistry and pharmacology of species belonging to Melastoma to suggest further research strategies and to facilitate the exploitation of the therapeutic potential of Melastoma species for the treatment of human disorders.

MATERIALS AND METHODS

Information related to the traditional uses, phytochemistry and pharmacological activities was systematically collected by searching for the word "Melastoma" in electronic databases, including SciFinder, Web of Science, PubMed, and Google Scholar, from Apr. 1968 until Dec. 2019.

RESULTS

A systematic literature survey revealed that Melastoma spp. are widely distributed in southern Asia to northern Oceania and the Pacific Islands and are traditionally used to treat bleeding, diarrhea, swelling, and gynecological tumors. Approximately 142 compounds, including flavonoids, tannins, phenylpropanoids, organic acids, terpenoids, and steroids, have been reported from Melastoma spp. Different extracts have been evaluated for their pharmacological activities, including anti-inflammatory, hemostatic, anticoagulant, cytotoxic, antibacterial, antioxidant, hepatoprotective, gastroprotective and hypoglycemic activities.

CONCLUSIONS

Melastoma spp. are popularly used in Southeast Asian countries as effective herbs and are rich in flavonoids, tannins and organic acids with valuable medicinal properties. However, additional studies of the chemical constituents and the mechanism-based pharmacological activities of many members of Melastoma are still needed for developing new plant-derived drugs. In addition, studies on the clinical safety and efficacy of Melastoma are also needed.

Isolation of flavonoids from Musa acuminata Colla (Simili radjah, ABB) and the in vitro inhibitory effects of its leaf and fruit fractions on free radicals, acetylcholinesterase, 15-lipoxygenase, and carbohydrate hydrolyzing enzymes

Musa species are used traditionally for the management of many diseases. The study evaluated and compared anticholinesterase, anti-inflammatory, antioxidant, and antidiabetic activities of Musa acuminata (Simili radjah, ABB) fruits and leaves fractions and characterized the bioactive compounds using HPTLC-HRMS and NMR. Leaf fractions gave the higher biological activities than the fruit. Ethyl acetate fraction of the leaf had the highest total phenolic content (911.9 ± 1.7 mg GAE/g) and highest 2,2-diphenyl-1-picrylhydrazyl (DPPH^· ) scavenging activity (IC_50, 9.0 ± 0.4 µg/ml). It also gave the most effective inhibition of acetylcholinesterase (IC_50, 404.4 ± 8.0 µg/ml) and α-glucosidase (IC_50, 4.9 ± 1.6 µg/ml), but a moderate α-amylase inhibition (IC_50, 444.3 ± 4.0 µg/ml). The anti-inflammatory activity of n-butanol (IC_50, 34.1 ± 2.6 µg/ml) and ethyl acetate fractions (IC₅₀ , 43.1 ± 11.3 µg/ml) of the leaf were higher than the positive control, quercetin (IC₅₀ , 54.8 ± 17.1 µg/ml). Kaempferol-3-O-rutinoside and quercetin-3-O-rutinoside (rutin) were identified as the bioactive compounds with antioxidant and antidiabetic activities from the ethyl acetate fraction of M. acuminata leaf. PRACTICAL APPLICATIONS: All parts of Musa acuminata are known to be useful ethnomedicinally even as food. The leaves are mostly used to serve food and used for wrapping purposes. However, this study concluded that M. acuminata leaf is rich in bioactive flavonoids such as kaempferol-3-O-rutinoside and rutin, with relatively high antioxidative, antidiabetic, and anti-inflammatory activities. Therefore, aside the fact that the leaves can serve as potential drug leads for pharmaceutical industries, it can also be embraced in the food sector to produce supplements and/or nutraceuticals in the management of Alzheimer's, diabetes and other inflammatory diseases.

Effect-directed profiling and identification of bioactive metabolites from field, in vitro-grown and acclimatized Musa spp. accessions using high-performance thin-layer chromatography-mass spectrometry

Bananas and plantains (Musa spp.) are used as nutritious foods, and at the same time, are a source of phytoconstituents for the pharmaceutical industry. As biological activities of especially the pulp and peel of Musa spp. have been documented, this study investigated the variation in the secondary metabolite profiles of the leaves from field, in vitro-grown and acclimatized accessions. The genetic fidelity of the diverse accessions was assessed using diversity array technology sequencing. It showed that the in vitro-grown accessions were true-to-type with the field samples. The antioxidant and anticholinesterase activities of the samples from different culture systems (field and in vitro) were evaluated by UV-spectrophotometry and compared to high-performance thin-layer chromatography-effect-directed analysis (HPTLC-EDA). The latter was applied for the first time for effect-directed profiling of the polar and medium polar sample components via different biochemical and biological assays. Compound zones showed acetyl-/butylrylcholinesterase inhibition (zones 1-4), α-/β-glucosidase inhibition (zones 1 and 2) as well as antioxidative (zones 1-3) and antimicrobial (zone 4) activities. Structures were preliminary assigned by HPTLC-HRMS. The HPTLC was effective for bioactivity-guided characterization of the bioactive constituents in Musa spp. accessions. Accumulation of useful metabolites, especially compounds with antioxidant and anticholinesterase properties, was higher in samples from in vitro system. This validated the use of plant tissue culturing as an alternative method for large scale production of plant material and supply of bioactive constituents.

α-Glucosidase Inhibitory Activity of Phenolic Rich Extracts Obtained from the Seeds of Melastoma saigonense (Kuntze) Merr

The aim of this study was to perform a phytochemical analysis of Melastoma saigonense seed extracts and to determine their α-glucosidase inhibitory activity. The extracts from seeds of M. saigonense indicated that the total phenolic content was in the range between 233.46 and 967.22 mg GAE/g DE, whereas the flavonoids content was in the range between 359.96 and 850.84 mg QE/g DE. The present study of antidiabetic inhibitory activity by in vitro α-glucosidase revealed that the crude extracts using ethyl acetate (EA), butanol (BU) and final aqueous residue extracts (AQ) exhibited a strong α-glucosidase inhibitory effect (IC50 4.42-11.95 μg/mL). The ethyl acetate and butanol extracts of seeds of Melastoma saigonense (Kuntze) Merr. were further fractionated by silica gel column chromatography into four fractions (EAF1−EAF4) and five fractions (BUF1−BUF5), respectively and their bioactivities were investigated. The nine fractions exhibited significant α-glucosidase inhibitory activity (p < 0.05) with an IC50 between 3.42-34.77 μg/mL which is less than the IC50 for standard acarbose (IC50 = 507.26 μg/mL). Among all the fractions, BUF1 and EAF1 exhibited high inhibitory activity against α-glucosidase with BUF1 showing the highest inhibitory activity (IC50 = 3.42 μg/mL). The dominant phenolic acids were sinapic, gallic, ferrulic, syringic, gallic and caffeic acids and the prominent flavonoids were myricetin and quercetin. These findings suggest that the seeds of M. saigonense have potential as a source of antidiabetic agent (s).

In Vitro Anti-Inflammatory and In Vivo Antiarthritic Activities of Aqueous and Ethanolic Extracts of Dissotis thollonii Cogn. (Melastomataceae) in Rats

Dissotis thollonii Cogn. (Melastomataceae) is a tropical plant widely used in traditional Cameroonian medicine to relieve and treat many pathologies. It is widespread in the western region where it is used to treat typhoid fever, gastrointestinal disorders, and inflammatory diseases. The purpose of this study is to scientifically demonstrate the anti-inflammatory and antiarthritic properties of the aqueous and ethanolic extracts of the leaves of Dissotis thollonii. The anti-inflammatory properties were evaluated in vitro by inhibition tests for cyclooxygenase, 5-lipoxygenase, protein denaturation, extracellular ROS production, and cell proliferation; while antiarthritic properties were evaluated in vivo in rats using the zymosan A-induced monoarthritis test and the CFA-induced polyarthritis model. This study shows that aqueous and ethanolic extracts at a concentration of 1000 μg/ml inhibit the activity of cyclooxygenase (47.07% and 63.36%) and 5-lipoxygenase (66.79% and 77.7%) and protein denaturation (42.51% and 44.44%). Similarly, both extracts inhibited extracellular ROS production (IC₅₀ = 5.74 μg/ml and 2.96 μg/ml for polymorphonuclear leukocytes, 7.47 μg/ml and 3.28 μg ml for peritoneal macrophages of mouse) and cell proliferation (IC₅₀ = 16.89 μg/ml and 3.29 μg/ml). At a dose of 500 mg/kg, aqueous and ethanolic extracts significantly reduce edema induced by zymosan A (69.30% and 81.80%) and CFA (71.85% and 79.03%). At the same dose, both extracts decreased sensitivity to mechanical hyperalgesia with 69.00% and 70.35% inhibition, respectively. Systemic and histological analyzes show that both extracts maintain the studied parameters very close to normal and greatly restored the normal architecture of the joint in animals. Dissotis thollonii would therefore be a very promising source for the treatment of inflammatory diseases.

De novo Assembly and Characterization of the Floral Transcriptomes of Two Varieties of Melastoma malabathricum

Melastoma malabathricum is an important medicinal and landscape plant that is globally distributed in temperate and subtropical regions. However, available genomic information for the entire Melastomataceae family is notably limited. In view of the application potential of floral parts in secondary metabolite extraction, we characterized for the first time the floral transcriptomes of two key M. malabathricum varieties, purple variety and white variety. Our transcriptome assembly generated 52,498 and 49,380 unigenes with an N50 of 1,906 and 1,929 bases for the purple and white varieties, respectively. Comparative analysis of two transcriptomes demonstrated that they are highly similar but also highlighted genes that are presumably lineage specific, which explains the phenotypes of each variety. Additionally, a shared transcriptional signature across the floral developmental stages was identified in both M. malabathricum varieties; this signature included pathways related to secondary metabolite synthesis, plant hormone signaling and production, energy homeostasis and nutrient assimilation pathways, and cellular proliferation. The expression levels of flavonoid accumulation and candidate flavonoid biosynthesis-related genes in M. malabathricum flower development stages validated the transcriptome findings. The transcriptome data presented in this study will serve as a valuable resource for future work on the exploitation of M. malabathricum and other related species. The gene expression dynamics during flower development will facilitate the discovery of lineage-specific genes associated with phenotypic characteristics and will elucidate the mechanism of the ontogeny of individual flower types.

Analysis of quercetin and kaempferol levels in various phase of flowers Melastoma malabathricum L

Melastoma malabathricum L. flowers are part of a plant that contains quercetin and kaempferol. Quercetin and kaempferol are useful for their antioxidant and anticancer properties. The flowering phase affects levels of quercetin and kaempferol. There are four phases of flower blooming: 1st bud phase (K1), 2nd bud phase (K2), 3rd bud phase (K3), and flower bloom (M). It remains to be determined which phase of Melastoma malabathricum L. flowering shows the highest levels of quercetin and kaempferol. Quercetin and kaempferol levels were measured using HPLC MS/MS. The measured quercetin levels of K1, K2, K3, and M phases, respectively, were: 19.47 μg/g, 17.78 μg/g, 31.2 μg/g, and 94.32 μg/g. Levels of kaempferol during K1, K2, K3, and M, respectively, were: 140.99 μg/g, 57.28 μg/g, 95.32 μg/g, and 349.37 μg/g.

Novel Weed-Extracted Silver Nanoparticles and Their Antibacterial Appraisal against a Rare Bacterium from River and Sewage Treatment Plan

This is the first investigation to demonstrate the use of biochemical contents present within Cyperus rotundus, Eleusin indica, Euphorbia hirta, Melastoma malabathricum, Clidemia hirta and Pachyrhizus erosus extracts for the reduction of silver ion to silver nanoparticles (AgNPs) form. In addition, the antibacterial capability of the synthesized AgNPs and plant extracts alone against a rare bacterium, Chromobacterium haemolyticum (C. haemolyticum), was examined. Moreover, ultraviolet-visible spectroscopy (UV-vis), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX) and inductively coupled plasma atomic emission spectroscopy (ICPOES) of the synthesized AgNPs were characterized. The smallest AgNPs can be produced when Cyperus rotundus extracts were utilized. In addition, this study has found that the synthesis efficiencies using all plant extracts are in the range of 72% to 91% with the highest percentage achieved when Eleusin indica extract was employed. All synthesized AgNPs have antibacterial capability against all examined bacteria depending on their size and bacteria types. Interestingly, Melastoma malabathricum and Clidemia hirta extracts have demonstrated an antibacterial ability against C. haemolyticum.

Antioxidant and acetylcholinesterase inhibitory activities of leaf extract and fractions of Albizia adianthifolia (Schumach) W.F. Wright

BACKGROUND

This study was conducted to determine the antioxidant and acetylcholinesterase inhibitory activities of the leaf extract and different fractions of Albizia adianthifolia (Schumach.) W. Wright, and also to identify and quantify some phenolic compounds in the extract.

METHODS

The antioxidant and acetylcholinesterase inhibitory activities of the methanol extract (CME), ethyl acetate (EAF), chloroform (CHF), and n-hexane (NHF) fractions of A. adianthifolia leaves were subjected to in vitro chemical analyses.

RESULTS

Phytochemical screening revealed important classes of secondary metabolites. All extracts showed good antioxidant and acetylcholinesterase inhibitory activities. The EAF and CHF gave the highest total phenolic contents of 18.02±0.14 and 18.43±0.95 mg gallic acid equivalent per gram of extract, respectively. The polar extracts gave the highest activity in both assays with lower IC50 values. In the 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging activity assay, the IC50 values of CME, EAF, CHF, and NHF were 77.74±0.84, 55.76±2.30, 58.47±0.72, and 232.24±2.70 µg/mL, respectively, while in the acetylcholinesterase inhibitory assay, the IC50 values of CME, EAF, CHF, and NHF were 11.80±0.88, 10.04±1.67, 17.44±1.74, and 124.38±1.51 µg/mL, respectively.

CONCLUSIONS

The results of this study suggest that the leaf of A. adianthifolia could serve as a potential candidate for future search of antioxidant and acetylcholinesterase inhibitors for the management of neurodegenerative disorders such as Alzheimer's disease.

Cytotoxic Activity of Compounds from Styrax obassia

Cancer is a major public health burden in both developed and developing countries. Plant-derived compounds have played an important role in the development of useful anti-cancer agents. The current study was designed to evaluate the cytotoxic activity of chemical compounds from the stem bark of Styrax obassia. Seven known compounds (1–7) were isolated and identified. Compound 2 exhibited cytotoxic activity against the breast cancer cell line MCF-7 with an IC50 of 27.9 μM, followed by the human cervical cancer cell line Hela with an IC50 of 23.3 μM, and the human promyelocytic leukemia cell line HL-60 with an IC50 of 47.8 μM. Compound 7 exhibited cytotoxicity against Hela cells with an IC50 of 16.8 μM, followed by MCF-7 cells with an IC50 of 53.5 μM. This is the first study to investigate the significant anti-tumor properties of isolated compounds from the stem bark of S. obassia.

Mass spectrometry and potentiometry studies of Al(iii)–naringin complexes

Here we have studied the complexation of naringin with Al(iii) under physiological conditions (i.e., at 37 °C and in 0.16 mol L⁻¹NaCl).

Cholinesterase inhibitory activity and chemical constituents of Stenochlaena palustris fronds at two different stages of maturity

Stenochlaena palustris fronds are popular as a vegetable in Southeast Asia. The objectives of this study were to evaluate the anticholinesterase properties and phytochemical profiles of the young and mature fronds of this plant. Both types of fronds were found to have selective inhibitory effect against butyrylcholinesterase compared with acetylcholinesterase. However, different sets of compounds were responsible for their activity. In young fronds, an antibutyrylcholinesterase effect was observed in the hexane extract, which was comprised of a variety of aliphatic hydrocarbons, fatty acids, and phytosterols. In the mature fronds, inhibitory activity was observed in the methanol extract, which contained a series of kaempferol glycosides. Our results provided novel information concerning the ability of S. palustris to inhibit cholinesterase and its phytochemical profile. Further research to investigate the potential use of this plant against Alzheimer’s disease is warranted, however, young and mature fronds should be distinguished due to their phytochemical differences.

Bioassay-guided fractionation of Melastoma malabathricum Linn. leaf solid phase extraction fraction and its anticoagulant activity

The aims of this study were to examine the bioactive component(s) responsible for the anticoagulant activity of M. malabathricum Linn. leaf hot water crude extract via bioassay-guided fractionation and to evaluate the effect of bioactive component(s) on the intrinsic blood coagulation pathway. The active anticoagulant fraction of F3 was subjected to a series of chromatographic separation and spectroscopic analyses. Furthermore, the effect of the bioactive component(s) on the intrinsic blood coagulation pathway was studied through immediate and time incubation mixing studies. Through Activated Partial Thromboplastin Time (APTT) assay-guided fractionation, Subfraction B was considered the most potent anticoagulant fraction. Characterisation of Subfraction B indicated that anticoagulant activity could partly be due to the presence of cinnamic acid and a cinnamic acid derivative. APTT assays for both the immediate and time incubation mixing were corrected back into normal clotting time range (35.4–56.3 s). In conclusion, cinnamic acid and cinnamic acid derivative from Subfraction B were the first such compounds to be discovered from M. malabathricum Linn. leaf hot water crude extract that possess anticoagulant activity. This active anticoagulant Subfraction B prolonged blood clotting time by causing factor(s) deficiency in the intrinsic blood coagulation pathway.

Cytotoxic Activities against Breast Cancer Cells of Local Justicia gendarussa Crude Extracts

Justicia gendarussa methanolic leaf extracts from five different locations in the Southern region of Peninsular Malaysia and two flavonoids, kaempferol and naringenin, were tested for cytotoxic activity. Kaempferol and naringenin were two flavonoids detected in leaf extracts using gas chromatography-flame ionization detection (GC-FID). The results indicated that highest concentrations of kaempferol and naringenin were detected in leaves extracted from Mersing with 1591.80 mg/kg and 444.35 mg/kg, respectively. Positive correlations were observed between kaempferol and naringenin concentrations in all leaf extracts analysed with the Pearson method. The effects of kaempferol and naringenin from leaf extracts were examined on breast cancer cell lines (MDA-MB-231 and MDA-MB-468) using MTT assay. Leaf extract from Mersing showed high cytotoxicity against MDA-MB-468 and MDA-MB-231 with IC₅₀ values of 23 μg/mL and 40 μg/mL, respectively, compared to other leaf extracts. Kaempferol possessed high cytotoxicity against MDA-MB-468 and MDA-MB-231 with IC₅₀ values of 23 μg/mL and 34 μg/mL, respectively. These findings suggest that the presence of kaempferol in Mersing leaf extract contributed to high cytotoxicity of both MDA-MB-231 and MDA-MB-468 cancer cell lines.

Effects of Flower and Fruit Extracts of Melastoma malabathricum Linn. on Growth of Pathogenic Bacteria: Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium

Melastoma malabathricum Linn. is a shrub that comes with beautiful pink or purple flowers and has berries-like fruits rich in anthocyanins. This study was carried out with the aim to evaluate the inhibitory activities of different concentrations of the M. malabathricum Linn. flower and fruit crude extracts against Listeria monocytogenes IMR L55, Staphylococcus aureus IMR S244, Escherichia coli IMR E30, and Salmonella typhimurium IMR S100 using the disc diffusion method. The lowest concentrations of the extracts producing inhibition zones against the test microorganisms were used to determine their minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). In addition, the growth of Listeria monocytogenes IMR L55 and Staphylococcus aureus IMR S244 grown in medium supplemented with the respective extracts at different temperatures (4°C, 25°C, and 37°C) and pHs (4, 6, 7, and 8) was determined.

Estimation of total phenol and in vitro antioxidant activity of Albizia procera leaves

BACKGROUND

Research on natural products has gained a wide popularity due to the potential of discovering active compounds. The antioxidant properties contained in plants have been proposed as one of the mechanisms for the observed beneficial effect. Therefore, the present study investigated the antioxidant activity and total phenolic contents of various solvent extracts of Albizia procera leaves.

METHODS

Antioxidant activity of the methanol extract and its derived fractions petroleum ether (APP), carbon tetrachloride (APC), dichloromethane (APD), ethyl acetate (APE), and residual aqueous fraction (APA) of the leaves of Albizia procera was performed by in vitro chemical analyses. Total phenolic content of the APM and other five fractions were also determined. APM and its derived fractions were also subjected to preliminary phytochemical screening test for various constituents.

RESULTS

Phytochemical screening revealed the presence of saponins, steroids, tannins, glycosides and flavonoids in the extracts. Amongst the extracts, APE showed the highest total phenolic content (449.18 ± 18.41mg of gallic acid equivalent/g of extract). In DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging test, the IC(50) value of APM, APP, APC, APD, APE and APA was 43.43, 63.60, 166.18, 41.15, 11.79, and 63.06 μg/mL, respectively. Therefore, among the APM and its derived fractions, APE showed the highest antioxidant activity which is comparable to that of standard ascorbic acid (AA) (IC(50) 10.12 μg/mL). The total antioxidant capacity was found to be varied in different fractions. The reducing activity on ferrous ion was ranked as APE > APD > APM > APA > APC.

CONCLUSION

The above evidences suggest that APE of A. procera leaf is a potential source of natural antioxidant and can be used to prevent diseases associated with free radicals.

A survey of folk remedies for gastrointestinal tract diseases from Thailand's three southern border provinces

ETHNOPHARMACOLOGICAL RELEVANCE

Gastrointestinal tract diseases commonly occur in Thailand. However, surveying for finding out traditional drugs has never been done.

AIM OF STUDY

To quantify and categorize the folk medicinal remedies that are used for healing the gastrointestinal tract by the traditional healers living in Thailand's three southern border provinces.

MATERIALS AND METHODS

The Pattani, Yala and Narathiwat provinces were selected. Semi-structured interviews of nine healers were conducted to collect information that included the remedy names, herbal ingredients, plant parts used, preparation, properties and treatment methods. The data were then further analyzed.

RESULT

The results revealed that 39 multi-species remedies and 36 single-species remedies were used to treat gastrointestinal disorders. A total of 103 plant species and 5 other materia medica were used as therapeutics. Most of the plants used were of the Zingiberaceae, Fabaceae and Euphorbiaceae families. Furthermore, it was found that although most of the healers used different remedies for a particular disease, some of the ingredients might have been similar. For example, Caesalpinia bonduc (L.) Roxb. was an ingredient used for parasitic disease remedies, and Senna alata (L.) Roxb. was used for constipation remedies.

CONCLUSION

A review of the literature revealed 57 plant species and 2 other materia medica that have already been tested for their biological activities, whereas 46 plant species and 3 materia medica have never been tested. Consequently, research should be performed to confirm the pharmacological properties of folk remedies.

In vitro antioxidant and antiproliferative potential of medicinal plants used in traditional Indian medicine to treat cancer

OBJECTIVE

The goal of this study was to evaluate the antioxidant and antiproliferative activities of 10 traditional medicinal plants, Asclepias curassavica, Ophiorrhiza mungos Linn., Cynodon dactylon (L.) Pers, Costus speciosus (J. Koenig.) Smith Costaceae, Achyranthes aspera L., Amaranthus tristis Roxb., Blepharis maderaspatensis L., Merremia emerginata Hall.f., Aegle marmelos Corr., and Tabernaemontana heyneana Wall., used in the traditional Indian system of medicine as a cure for cancer. The present study focuses on the anticancer potential of traditional medicinal plants to induce apoptosis in cancer cell lines.

METHODS

Plants were sequentially extracted with hexane, ethyl acetate, and methanol. The extract was concentrated to yield the crude extract, which was tested for antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl, nitric oxide and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assays on four cancer cell lines and a normal cell line. The anticancer potential of cytotoxic extracts was determined by the Annexin-fluorescein isothiocyanate-conjugated assay in human colon adenocarcinoma cell lines (COLO 320 DM).

RESULTS

All the tested extracts showed significant antioxidant and antiproliferative activities in a concentration- and time-dependant manner in the following descending order: A. curassavica > C. dactylon > C. speciosus root > A. tristis > M. emarginata > O. mungos > T. Heyneana > B. maderaspatensis > A. marmelos > A. aspera.

CONCLUSION

The results of the present study support the need of further studies to isolate potential anticancer drug with cancer cell-specific cytotoxicity. Additionally, the study supports the anticancer property of medicinal plants used in the traditional Indian medicine system and further evaluation of the selected medicinal plants for an effective anticancer drug with minimal side effects.

Melastoma malabathricum (L.) Smith Ethnomedicinal Uses, Chemical Constituents, and Pharmacological Properties: A Review

Melastoma malabathricum L. (Melastomataceae) is one of the 22 species found in the Southeast Asian region, including Malaysia. Considered as native to tropical and temperate Asia and the Pacific Islands, this commonly found small shrub has gained herbal status in the Malay folklore belief as well as the Indian, Chinese, and Indonesian folk medicines. Ethnopharmacologically, the leaves, shoots, barks, seeds, and roots of M. malabathricum have been used to treat diarrhoea, dysentery, hemorrhoids, cuts and wounds, toothache, and stomachache. Scientific findings also revealed the wide pharmacological actions of various parts of M. malabthricum, such as antinociceptive, anti-inflammatory, wound healing, antidiarrheal, cytotoxic, and antioxidant activities. Various types of phytochemical constituents have also been isolated and identifed from different parts of M. malabathricum. Thus, the aim of the present review is to present comprehensive information on ethnomedicinal uses, phytochemical constituents, and pharmacological activities of M. malabathricum.