The α-glucosidase inhibitory activity of avicularin and 4-O-methyl gallic acid isolated from Syzygium myrtifolium leaves.

Diabetes Mellitus is the main cause of death on a global scale. In 2019, there were 463 million people with diabetes, and WHO predicts that by 2030, there will be 578 million. As an antidiabetic agent, α-glucosidase inhibitors are one of the methods employed to reduce the prevalence of diabetes. Diabetes is traditionally treated with Syzygium as a primary material, medicine, fruit, ornamental plant, and source of carpentry. This investigation aimed to examine the inhibitory effect of seven species of Syzygium against α-glucosidase enzyme using an in vitro assay and isolate active substances and ascertain their concentrations in each sample. As a solvent, ethanol was used in maceration to extract the substance. Afterward, the extract underwent a series of fractionation techniques, including liquid-liquid extraction, vacuum liquid chromatography, column chromatography, and preparative Thin Layer Chromatography (TLC) for purification and isolation. The compound's structures were elucidated using TLC, UV-Visible spectrophotometry, and nuclear magnetic resonance (NMR) spectroscopy. Based on concentrations of 100 and 200 µg/mL, Syzygium myrtifolium exhibited the most significant inhibitory effect, followed by other species of Syzygium. The proportion of ethyl acetate had the strongest activity (IC50 0.40 ± 0.02 µg/mL) contrasted to positive control acarbose (IC50 55.39 ± 0.67 g/mL) and quercitrin (IC50 6.47 ± 0.40 µg/mL). Avicularin and 4-O-methyl gallic acid were discovered in the ethyl acetate fraction of Syzygium myrtifolium with IC50 values of 17.05 ± 0.75 µg/mL and 25.19 ± 0.21 µg/mL, respectively. As α-glucosidase inhibitory, the results of this study indicate Syzygium myrtifolium can be used as a dietary supplement to manage hyperglycemia.

UHPLC-Q-Orbitrap HR-MS-Based Metabolomics for Profiling the Sida rhombifolia Metabolites with Different Plant Organs and Cultivation Ages.

Plant organs and cultivation ages can result in different compositions and concentration levels of plant metabolites. The metabolite profile of plants can be determined using liquid chromatography. This study determined the metabolite profiles of leaves, stems, and roots of Sida rhombifolia at different cultivation ages at 3, 4, and 5 months post-planting (MPP) using liquid chromatography-mass spectrometry/mass spectrometry (LC/MS/MS). The results identified that 41 metabolites in S. rhombifolia extract for all plant organs and cultivation ages. We successfully identified approximately 36 (leaves), 22 (stems), and 18 (roots) compounds in all extract. Using principal component analysis (PCA) with peak area as the variable, we clustered all sample extracts based on plant organs and cultivation ages. As a result of PCA, S. rhombifolia extracts were grouped according to plant organs and cultivation ages. In conclusion, a clear difference in the composition and concentration levels of metabolites was observed in the leaves, stems, and roots of S. rhombifolia harvested at 3-, 4-, and 5-MPP.

Potential Antioxidative Activity of Waste Product of Purple Sweet Potato (Ipomoea batatas Lam.).

<b>Background and Objective:</b> Antioxidants are substances that can deactivate free radicals. Phenol and flavonoid are antioxidant compounds widely found in plants, including purple sweet potato (<i>Ipomoea batatas</i> L.). This research aimed to investigate three purple sweet potato-based organs' antioxidative activity and flavonoid contents. <b>Materials and Methods:</b> Antioxidative activities, total phenolic content and total flavonoid content were performed by UV-visible spectrophotometry. Pearson's method analyzed the correlation of TPC and TFC with antioxidative activities and the correlation between two antioxidative testing methods. <b>Results:</b> Antioxidative activity of three organs purple sweet potato using DPPH method showed values varied from 6.572-290.894 mg AAE g¹ and using CUPRAC method varied from 25.169-621.254 mg AAE g¹. The highest TPC was found in ethanolic leaves extract (20.885 g GAE 100 g¹), while the highest TFC was found in ethyl acetate leaves extract (10.048 g QE 100 g¹). <b>Conclusion:</b> DPPH and CUPRAC tests revealed that purple sweet potato leaves, stem and tuber extracts were potent antioxidants. The potential antioxidative activity was found in the waste product of purple sweet potatoes (leaves and stem). Phenol and flavonoid compounds had contributors to antioxidative activity. DPPH and CUPRAC methods gave linear results for most of the antioxidative activity in three organs of purple sweet potato. Ethanol stem extract contained luteolin 7-O-glucoside, rutin, quercetin, kaempferol and apigenin. Rutin had the highest content, which was 0.399%.

Peperomia pellucida extracts stimulates bone healing in alveolar socket following tooth extraction.

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In Vitro Alpha-Glucosidase Inhibitory Activity and the Isolation of Luteolin from the Flower of Gymnanthemum amygdalinum (Delile) Sch. Bip ex Walp.

Diabetes mellitus is a major health issue that has posed a significant challenge over the years. Gymnanthemum amygdalinum is a well-known plant that can be potentially used to treat this disease. Therefore, this study aimed to evaluate the inhibitory effect of its root, stem bark, leaves, and flower extracts on alpha-glucosidase using an in vitro inhibition assay to isolate the bioactive compounds and determine their levels in the samples. The air-dried plant parts were extracted by maceration using methanol. The results showed that the flower extract had the greatest inhibitory effect (IC50 47.29 ± 1.12 µg/mL), followed by the leaves, roots, and stem bark. The methanolic flower extract was further fractionated with different solvents, and the ethyl acetate fraction showed the strongest activity (IC50 19.24 ± 0.12 µg/mL). Meanwhile, acarbose was used as a positive control (IC50 73.36 ± 3.05 µg/mL). Characterization based on UV, 1H-, and 13C-NMR established that the ethyl acetate fraction yielded two flavonoid compounds, namely, luteolin and 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-3-methoxy-4H-chromen-4-on, which had IC50 values of 6.53 ± 0.16 µg/mL and 39.95 ± 1.59 µg/mL, respectively. The luteolin levels in the crude drug, methanolic extract, and ethyl acetate fraction were 3.4 ± 0.2 mg (0.3%), 32.4 ± 0.8 mg (3.2%), and 68.9 ± 3.4 mg (6.9%) per 1 g samples, respectively. These results indicated that the G. amygdalinum flower extract exerted potent inhibitory alpha-glucosidase activity.

Antihypertensive Activity of Combination of Anredera cordifolia (Ten.) V. Steenis and Sonchus arvensis L. Leaves on Epinephrine Induced Male Wistar Rat.

In Indonesia, hypertension is a condition that can lead to death through stroke and TB. Herbs have traditionally been used in Indonesia as an alternative medicine for lowering blood pressure. The leaves of Anredera cordifolia and Sonchus arvensis have been investigated for their antihypertensive potential. Based on the number of treatments, rats were randomized into groups. Each group consists of five rats. The test animals were grouping as follows: the positive control group (hypertension induction without treatment), A. cordifolia 50 mg/kg b.w. group, A. cordifolia 100 mg/kg b.w., S. arvensis 50 mg/kg b.w, S. arvensis 100 mg/kg b.w., A. cordifolia 25 mg/kg b.w + S. arvensis 25 mg/kg b.w, A. cordifolia 50 mg/kg b.w + S. arvensis 50 mg/kg b.w, and atenolol 4.5 mg/kg b.w. The rats were given 0.25 mg/kg b.w. of epinephrine intraperitoneally. The initial, after induction, and final blood pressure of the animals were measured using the CODA® noninvasive blood pressure device. All animal test groups at T60 showed a significant difference in systolic and diastolic blood pressures to initial blood pressure (T0), P < 0.05. The combination of A. cordifolia 50 mg/kg b.w and S. arvensis 50 mg/kg b.w showed the highest percent inhibition of systolic and diastolic blood pressure. The combination of A. cordifolia and S. arvensis 50-50 mg/kg b.w showed the best effect of lowering systolic and diastolic blood pressure on the pathway of inhibiting adrenergic receptors.

Molecular modeling for potential cathepsin L inhibitor identification as new anti-photoaging agents from tropical medicinal plants.

Ultraviolet exposure can cause photoaging toward the human skin which is begun by the inflammation on the exposure area, also resulting in activation of a degradative enzyme cathepsin L. This enzyme is one of the interesting novel therapeutic targets for antiaging agents. Three plants, named Kleinhovia hospita, Aleurites moluccana, and Centella asiatica, are well-known in the tropical region as anti-inflammatory herbs. The aims of this study were to predict the antiaging activity of the 31 compounds from these plants via inhibition of cathepsin L. All compounds were minimized their energies and then used in molecular docking. After that, molecular dynamics (MD) simulation was employed for the 5 candidate ligands and the positive control; schinol. Interaction analysis results of the pre-MD and post-MD simulation structures were obtained. Furthermore, a toxicity test was performed using ADMET Predictor 7.1. Based on the molecular docking and the MD simulation results, kleinhospitine A, ß-amyrin, and castiliferol exhibited lower binding free energy than schinol (-27.0925, -28.6813, -26.0037 kcal/mol) and also had interactions with the S´ region binding site. The toxicity test indicated that ß-amyrin is the most potential candidate since it exhibited the lowest binding energy and the high safety level.

Isolation and Characterization of Phenylpropanoid and Lignan Compounds from Peperomia pellucida [L.] Kunth with Estrogenic Activities.

Extracts of Peperomia pellucida [L.] Kunth have previously been demonstrated to have in vivo estrogenic-like effects, thereby functioning as an anti-osteoporotic agent. However, the compounds responsible for these effects have not yet been determined. Therefore, the aim of this study is to isolate and elucidate potential compounds with estrogenic activity. The structures of the isolated compounds were identified using 1D 1H and 13C-NMR and confirmed by 2D FT-NMR. The estrogenic activity was evaluated using the E-SCREEN assay, and a molecular docking study was performed to predict the binding affinity of the isolated compounds to estrogen receptors. In this experiment, we successfully isolated three phenylpropanoids and two lignan derivatives, namely, 6-allyl-5-methoxy-1,3-benzodioxol-4-ol (1), pachypostaudin B (2), pellucidin A (3), dillapiole (4), and apiol (5). Among these compounds, the isolation of 1 and 2 from P. pellucida is reported for the first time in this study. Activity assays clearly showed that the ethyl acetate extract and its fractions, subfractions, and isolated compounds exerted estrogenic activity. Methanol fraction of the ethyl acetate extract produced the highest estrogenic activity, while 1 and 2 had partial agonist activity. Some compounds (derivates of dillapiole and pellucidin A) also had, in addition, anti-estrogenic activity. In the docking study, the estrogenic activities of 1-5 appeared to be mediated by a classical ligand-dependent mechanism as suggested by the binding interaction between the compounds and estrogen receptors; binding occurred on Arg 394 and His 524 of the alpha receptor and Arg 346 and His 475 of the beta receptor. In summary, we reveal that P. pellucida is a promising anti-osteoporotic agent due to its estrogenic activity, and the compounds responsible for this activity were found to be lignan and phenylpropanoid derivatives. The presence of other compounds in either the extract or fraction may contribute to a synergistic effect, as suggested by the higher estrogenic activity of the methanol fraction. Hence, we suggest further research on the osteoporotic activity and safety of the identified compounds, especially regarding their effects on estrogen-responsive organs.

Isolation of 5,7-Dihydroxy, 6,8-Dimethyl Flavanone from Syzygium aqueum with Its Antioxidant and Xanthine Oxidase Inhibitor Activities.

BACKGROUND: Syzygium aqueum Burm.f. Alston (water apple) belonging to Myrtaceae family was originated from tropical areas. It was traditionally used as a medicinal plant. OBJECTIVE: The objective of the study was to isolate the active compound from the methanolic extract of S. aqueum leaves. METHODS: Extraction was done using continuous extraction with methanol as a solvent. The extract was then fractionated using liquid-liquid extraction, vacuum liquid chromatography, and radial chromatography. Recrystallization was done for purification. The structure of the compound was determined by Ultraviolet-Visible and (1D and 2D) nuclear magnetic resonance (NMR) spectrometer. RESULTS: The isolate showed maximum wavelengths at 347 (band I) and 296 (band II) nm. After addition of NaOH and CH3 COONa, the maximum wavelengths of band II moved to 340 and 339 nm, respectively. There was no change in wavelengths after addition CH3 COONa/H3 BO3 and AlCl3. The 1H-NMR spectrum showed 16 protons, whereas 13C-NMR spectrum showed 15 carbons. Based on those data, the isolate was determined as 5,7-dihydroxy-6,8-dimethyl flavanone (demethoxymatteucinol). At a concentration of 100 and 50 µg/mL, it could inhibit 25.13% of xanthine oxidase (XO) activity and scavenge 11.87% of diphenyl-picrylhydrazyl, respectively. CONCLUSION: Demethoxymatteucinol was isolated for the first time from S. aqueum and it had mild antioxidant and XO inhibitory activities. SUMMARY: One flavonoid compound, which 5,7-dihydroxy 6,8-dimethyl flavanone (demethoxymatteucinol), was isolated from the methanol extract of Syzygium aqueum. It had mild antioxidant and xanthine oxidase inhibitory activities. Abbreviations Used: CH3 COONa/H3 BO3: Natrium acetate/Boric acid; DPPH: Diphenyl-picrylhydrazyl, NMR: Nuclear Magnetic Resonance; ABTS: 2,2'-azinobis (3-ethyl-benzothiazline-6-sulfonic acid); AEAC: Ascorbic Acid Equivalent Antioxidant Capacity; UV-Vis: Ultraviolet-Visible; XO: Xanthine Oxidase; HSQC: Heteronuclear Single Quantum Coherence; HMBC: (Heteronuclear Multiple Bond Correlation).