Plant natural compounds have great potential as alternative medicines for preventing and treating diseases. Melicope lunu-ankenda is one Melicope species (family Rutaceae), which is widely used in traditional medicine, consumed as a salad and a food seasoning. Consumption of different parts of this plant has been reported to exert different biological activities such as antioxidant and anti-inflammatory qualities, resulting in a protective effect against several health disorders including neurodegenerative diseases. Various secondary metabolites such as phenolic acid derivatives, flavonoids, coumarins and alkaloids, isolated from the M. lunu-ankenda plant, were demonstrated to have neuroprotective activities and also exert many other beneficial biological effects. A number of studies have revealed different neuroprotective mechanisms for these secondary metabolites. This review summarizes the most significant and recent studies for neuroprotective activity of M. lunu-ankenda major secondary metabolites in neurodegenerative diseases.
Neurodegenerative diseases (NDDs) are chronic conditions that have drawn robust interest from the scientific community. Phytotherapeutic agents are becoming an important source of chemicals for the treatment and management of NDDs. Various secondary metabolites have been isolated from Melicope lunu-ankenda plant leaves, including phenolic acid derivatives. However, their neuroprotective activity remains unclear. Thus, the aim of this study is to elucidate the in vitro neuroprotective activity of 7-geranyloxycinnamic acid isolated from Melicope lunu-ankenda leaves. The neuroprotective activity was evaluated in differentiated human neuroblastoma (SH-SY5Y) cells by monitoring cell viability using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Moreover, the potential to impair apoptosis in differentiated cells was investigated employing the Annexin V-FITC assay, acridine orange and propidium iodide (AO/PI) staining, and fluorescence microscopy. Morphological assessment and ultrastructural analysis were performed using scanning and transmission electron microscopy to evaluate the effect of 7-geranyloxycinnamic acid on surface morphology and internal features of the differentiated cells. Pre-treatment of neuronal cells with 7-geranyloxycinnamic acid significantly protected the differentiated SH-SY5Y cells against H2O2-induced apoptosis. Cytoskeleton and cytoplasmic inclusion were similarly protected by the 7-geranyloxycinnamic acid treatment. The present findings demonstrate the neuroprotective potential of 7-geranyloxycinnamic acid against H2O2-induced neurotoxicity in neuronal cells, which is an established hallmark of neuronal disorders.
An alkaloid from Maclurodendron porteri has been isolated and characterized. Extraction process was conducted by acid-base extraction method followed by column chromatography. The structure was established by nuclear magnetic resonance spectroscopy and mass spectrometry. The compound was identified as haplophytin B which occurs commonly in the Rutaceae family. However, this is the first time this alkaloid was isolated and reported from the species. The compound showed no inhibition against Staphylococus aureus, Pseudomonas aeruginosa, Bacillus cereus and Escherichia coli and no cytotoxic activity against H199 and A549 cell lines.
The genus Acronychia (Rutaceae) comprise 44 species, most of which are represented by shrubs and small trees, distributed in a wide geographical area of South-Eastern Asia comprising China, India, Malaysia, Indonesia, Australia, and the islands of the western Pacific Ocean. Most of the species of the genus Acronychia have been used for centuries as natural remedies in the ethnomedical traditions of indigenous populations as anti-microbial, anti-fungal, anti-spasmodic, stomachic, anti-pyretic, and anti-haemorragic agent. Moreover fruits and aerial parts are used as food in salads and condiments, while the essential oil obtained from flowers and leaves has been employed in cosmetics production. Phytochemicals isolated from Acronychia spp. include acetophenones, quinoline and acridone alkaloids, flavonoids, cinnamic acids, lignans, coumarins, steroids, and triterpenes. The reported biological activities of the above mentioned natural compounds refer to anti-plasmodial, anti-cancer, anti-oxidant, anti-inflammatory, anti-fungal, and neuroprotective effects. The aim of this review is to examine in detail from a phytochemical and pharmacologically point of view what is reported in the current literature about the properties of phytopreparations or individual active principles obtained from plants belonging to the Acronychia genus.
Fifteen prenylated or geranylated flavanones and flavanonols were isolated from the leaf extracts of different Glycosmis species collected in Thailand and Malaysia. All structures were elucidated by spectroscopic methods, especially 1D and 2D NMR. Six compounds were described for the first time and two were only known so far as synthetic products. The chemotaxonomic significance of flavanoid accumulation within the genus Glycosmis is highlighted.
A new coumarin, 8,4''-dihydroxy-3'',4''-dihydrocapnolactone-2',3'-diol (1) and two known triterpenes, 5(6)-gluten-3-one (2) and 5(6)-gluten-3alpha-ol (3) were isolated from the leaves of Micromelum minutum (Rutaceae) collected from Sepilok, Sabah, Malaysia and their structures were characterized by spectroscopic methods.
In a continuation of our study of the Rutaceae, detailed chemical investigation on Micromelum minutum (Rutaceae) collected from Sepilok, Sabah, Malaysia gave four new coumarins. The structures of the coumarins have been fully characterised by spectroscopic methods as 3",4"-dihydrocapnolactone 1, 2',3'-epoxyisocapnolactone 2, 8-hydroxyisocapnolactone-2',3'-diol 3 and 8-hydroxy-3",4"-dihydrocapnolactone-2',3'-diol 4.
Quorum sensing regulates bacterial virulence determinants, therefore making it an interesting target to attenuate pathogens. In this work, we screened edible, endemic plants in Malaysia for anti-quorum sensing properties. Extracts from Melicope lunu-ankenda (Gaertn.) T. G. Hartley, a Malay garden salad, inhibited response of Chromobacterium violaceum CV026 to N-hexanoylhomoserine lactone, thus interfering with violacein production; reduced bioluminescence expression of E. coli [pSB401], disrupted pyocyanin synthesis, swarming motility and expression of lecA::lux of Pseudomonas aeruginosa PAO1. Although the chemical nature of the anti-QS compounds from M. lunu-ankenda is currently unknown, this study proves that endemic Malaysian plants could serve as leads in the search for anti-quorum sensing compounds.
During our phytochemical investigation of Haplophyllum villosum (Rutaceae), a perennial herb from Iran, a new 4,8-diaryl-3,7-dioxobicyclo-(3,3,0)-octane type lignan, eudesmin A (1), together with four known compounds--eudesmin (2), haplamine (3), umbelliferone (4) and scopoletin (5)--were isolated from aerial parts of the plant. The structures of the compounds were elucidated using NMR spectral analysis (¹H-NMR, ¹³C-NMR, HSQC, COSY and HMBC) as well as UV, IR and MS spectra and comparison with previously reported data.
Antibiotics which once a boon in medicine and saved millions of lives are now facing an ever-growing menace of antibacterial resistance, which desperately needs new antibacterial drugs which are innovative in chemistry and mode of action. For many years, the world has turned to natural plants with antibacterial properties to combat antibiotic resistance. On that basis, we aimed to identify plants with antibacterial and antibiotic potentiating properties. Seventeen different extracts of 3 plants namely Burkillanthus malaccensis, Diospyros hasseltii and Cleisthanthus bracteosus were tested against multi-drug resistant Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Methicillinresistant Staphylococcus aureus (MRSA) and methicillin-susceptible Staphylococcus aureus (MSSA). Antibacterial activity of hexane, methanol and chloroform extracts of bark, seed, fruit, flesh and leaves from these plants were tested using, disk diffusion assay, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. Antibiotic potentiating capabilities were tested using time-kill assay. B. malaccensis fruit chloroform extract showed the biggest zone of inhibition against MRSA (13.00±0.0 mm) but C. bracteosus bark methanol extract showed the biggest inhibition zone against MSSA (15.33±0.6 mm). Interestingly, bark methanol extract of C. bracteosus was active against MRSA (8.7±0.6 mm), MSSA (7.7±0.6 mm) (Gram-positive) and A. baumannii (7.7±0.6 mm) (Gram-negative). Overall, the leaf methanol and bark methanol extract of C. bracteosus warrants further investigation such as compound isolation and mechanism of action for validating its therapeutic use as antibiotic potentiator importantly against MRSA and A. baumannii.