Psychotria malayana Jack has traditionally been used to treat diabetes. Despite its potential, the scientific proof in relation to this plant is still lacking. Thus, the present study aimed to investigate the α-glucosidase inhibitors in P.malayana leaf extracts using a metabolomics approach and to elucidate the ligand–protein interactions through in silico techniques. The plant leaves were extracted with methanol and water at five various ratios (100, 75, 50, 25 and 0% v/v; water–methanol). Each extract was tested for α-glucosidase inhibition, followed by analysis using liquid chromatography tandem to mass spectrometry. The data were further subjected to multivariate data analysis by means of an orthogonal partial least square in order to correlate the chemical profile and the bioactivity. The loading plots revealed that the m/z signals correspond to the activity of α-glucosidase inhibitors, which led to the identification of three putative bioactive compounds, namely 5′-hydroxymethyl-1′-(1, 2, 3, 9-tetrahydro-pyrrolo (2, 1-b) quinazolin-1-yl)-heptan-1′-one (1), α-terpinyl-β-glucoside (2), and machaeridiol-A (3). Molecular docking of the identified inhibitors was performed using Auto Dock Vina software against the crystal structure of Saccharomyces cerevisiae isomaltase (Protein Data Bank code: 3A4A). Four hydrogen bonds were detected in the docked complex, involving several residues, namely ASP352, ARG213, ARG442, GLU277, GLN279, HIE280, and GLU411. Compound 1, 2, and 3 showed binding affinity values of −8.3, −7.6, and −10.0 kcal/mol, respectively, which indicate the good binding ability of the compounds towards the enzyme when compared to that of quercetin, a known α-glucosidase inhibitor. The three identified compounds that showed potential binding affinity towards the enzymatic protein in molecular docking interactions could be the bioactive compounds associated with the traditional use of this plant.

The plant Psychotria malayana Jack belongs to the Rubiaceae family and is known in Malaysia as “meroyan sakat/salung”. A rapid analytical technique to facilitate the evaluation of the P. malayana leaves’ quality has not been well-established yet. This work aimed therefore to develop a validated analytical technique in order to predict the alpha-glucosidase inhibitory action (AGI) of P. malayana leaves, applying a Fourier Transform Infrared Spectroscopy (FTIR) fingerprint and utilizing an orthogonal partial least square (OPLS). The dried leaf extracts were prepared by sonication of different ratios of methanol-water solvent (0, 25, 50, 75, and 100% v/v) prior to the assessment of alpha-glucosidase inhibition (AGI) and the following infrared spectroscopy. The correlation between the biological activity and the spectral data was evaluated using multivariate data analysis (MVDA). The 100% methanol extract possessed the highest inhibitory activity against the alpha-glucosidase (IC50 2.83 ± 0.32 μg/mL). Different bioactive functional groups, including hydroxyl (O-H), alkenyl (C=C), methylene (C-H), carbonyl (C=O), and secondary amine (N-H) groups, were detected by the multivariate analysis. These functional groups actively induced the alpha-glucosidase inhibition effect. This finding demonstrated the spectrum profile of the FTIR for the natural herb P. malayana Jack, further confirming its medicinal value. The developed validated model can be used to predict the AGI of P. malayana, which will be useful as a tool in the plant’s quality control.

Objective: The aim of this study was to investigate physical characteristics of nanostructured lipid carriers (NLCs) mixture of alpha tocopheryl acetate, cetyl palmitate, Tween 80 and propylene glycol using high shear homogenization technique on NLC preparation to predict the optimum ratio of alpha tocopheryl acetate-cetyl palmitate to produce good characteristics of NLC loaded coenzyme, higher % EE, good penetration, controlled release, and stable.Methods: Lipid characterizations were conducted by diffraction scanning calorimetry, X-ray diffraction, and Fourier transforms infrared spectrophotometry. Coenzyme Q10 concentration was measured by spectrophotometer at 275 nm. NLC characteristics based on their morphology was determined using transmission electron microscope, particle size, and its polydispersity index which were measured with Delsa Nano™ particle size analyzer. Percentage of coenzyme Q10 entrapped in NLC was determined by dialysis bag method. Coenzyme Q10 release profile was measured using with Franz cell for 12 hrs. The penetration depth of NLC coenzyme Q10 in abdominal skin of Wistar rat was determined with fluorescence microscopy using rhodamine B as marker. NLC physical stability based on minimum of particle size variation, pH and viscosity during 90 days storage. Results:The result showed that formula with ratio of cetyl palmitate-alpha tocopheryl acetate 70:30 (% w/w) produce good characteristics of NLC loaded coenzyme, higher % EE, good penetration, controlled release, and stable in 90 days storage. Conclusion:The coenzyme Q10 NLC system with cetyl palmitate and alpha tocopherol acetate as lipid matrixare characterized by small particle size, low crystallinity, spherical morphology of particle and high coenzyme Q10 entrapment efficiency. Crystal modification led to the formation of a more amorphous thereby increasing the drug entrapment

Introduction: Research related to alternative medicine from natural ingredients that can relieve the effects of inflammation is important, especially to reduce the unwanted side effects of antiinflammatory drugs. Cinnamomum burmannii (Nees & T. Nees) Blume is a native Indonesian species which contains essential oils and reported for its anti-inflammatory effect. Therefore, this research was conducted to determine the metabolite profile and anti-inflammatory effect of essential oil from the bark of C. burmannii (CBO) from Lombok Timur Regency. Methods: The metabolite profile of CBO was determined using Gas Chromatography-Mass Spectra (GC-MS). The anti-inflammatory test was conducted used male Wistar rats. A total of 30 male rats were divided into 5 groups, each group consisting of 6 rats. Rats were injected with carrageenan 1%/100µl/paw which had previously been given oral CBO at a dose of 30, 60, 90 mg/kg BW. Paw swelling was measured at 1, 2, 3, 4 and 5 hours after injection. The volume of edema was measured and the animals were sacrificed. The left leg was cut and preserved as material for Hematoxylin Eosin (HE) and Immunohistochemistry (IHC) preparations. The variables taken were the percentage of inhibition edema, the number of inflammatory cells by HE and the amount of TNF-α by IHC staining. Results: The results showed that there was a difference between negative control and positive control in the number of inflammatory cells and TNF-α observed in rat's paw edema. The number was less in the positive control. Likewise, when administering CBO (60 mg/kg BW and 90 mg/kg BW) the number of inflammatory cells and TNF-α was lower than the negative control. Conclusion: It can be concluded that CBO from Lombok Timur can be used as a natural anti-inflammatory agent.

Psychotria malayana Jack leaf, known in Indonesia as “daun salung”, is traditionally used for the treatment of diabetes and other diseases. Despite its potential, the phytochemical study related to its anti-diabetic activity is still lacking. Thus, this study aimed to identify putative inhibitors of α-glucosidase, a prominent enzyme contributing to diabetes type 2 in P. malayana leaf extract using gas chromatography-mass spectrometry (GC-MS)- and nuclear magnetic resonance (NMR)-based metabolomics, and to investigate the molecular interaction between those inhibitors and the enzyme through in silico approach. Twenty samples were extracted with different solvent ratios of methanol–water (0, 25, 50, 75, and 100% v/v). All extracts were tested on the alpha-glucosidase inhibition (AGI) assay and analyzed using GC-MS and NMR. Multivariate data analysis through a partial least square (PLS) and orthogonal partial square (OPLS) models were developed in order to correlate the metabolite profile and the bioactivity leading to the annotation of the putative bioactive compounds in the plant extracts. A total of ten putative bioactive compounds were identified and some of them reported in this plant for the first time, namely 1,3,5-benzenetriol (1); palmitic acid (2); cholesta-7,9(11)-diene-3-ol (3); 1-monopalmitin (4); β-tocopherol (5); α-tocopherol (6); 24-epicampesterol (7); stigmast-5-ene (8); 4-hydroxyphenylpyruvic acid (10); and glutamine (11). For the evaluation of the potential binding modes between the inhibitors and protein, the in silico study via molecular docking was performed where the crystal structure of Saccharomyces cerevisiae isomaltase (PDB code: 3A4A) was used. Ten amino acid residues, namely ASP352, HIE351, GLN182, ARG442, ASH215, SER311, ARG213, GLH277, GLN279, and PRO312 established hydrogen bond in the docked complex, as well as hydrophobic interaction of other amino acid residues with the putative compounds. The α-glucosidase inhibitors showed moderate to high binding affinities (−5.5 to −9.4 kcal/mol) towards the active site of the enzymatic protein, where compounds 3, 5, and 8 showed higher binding affinity compared to both quercetin and control ligand.