Biologically Active Compounds from the Genus Uncaria (Rubiaceae)

Malondialdehyde and TNF-α lowering effects of purified gambier (Uncaria gambir Roxb.) in diabetic rats

BACKGROUND

Malondialdehyde (MDA) is one of a dominat marker in oxidative stress condition, and when inflammation occurred tumor necrosis factor- α (TNF-α) played a significant influence in the propagation this process. Purified gambier (Uncaria gambier Roxb.) contained 90% catechin which is proven to have antioxidant activity and may prevent unwanted inflammatory responses during diabetic state.

OBJECTIVE

The objective of this research was to assess how purified gambier affected plasma MDA and TNF- α levels in alloxan-induced diabetic rats.

MATERIAL AND METHODS

In this study, 35 rats were used. Alloxan 120 mg/kg BW intraperitoneal injection was administered to induce diabetes conditions in rats. All animals were divided into 5 groups, diabetic control group treated with vehicle, positive control group treated with glibenclamide dose 0.45 mg/kg BW), and treatment groups treated with purified gambier dose of 2.5; 5 and 10 mg/kg BW. All animals were treated respectively for 14 days. Plasma MDA and TNF- α levels were measured on day 3, and 14.

RESULTS

Two-way ANOVA was applied to analyze all of the data, these findings suggested that purified gambier has antioxidant-related anti-inflammation actions. possesses blood sugar-lowering activity (p<0.05). The plasma MDA and TNF- α level of treatment group were significantly reduced (p<0.05) compared to diabetes control group.

CONCLUSION

These results depicted that at doses of 2.5-10 mg/kg BW, purified gambier has antioxidant-associated anti-inflammation effects when given for 14 days on diabetic rat model by reducing plasma levels MDA and TNF-α.

Antifungal Constituents of Piper crocatum and Their Activities as Ergosterol Biosynthesis Inhibitors Discovered via In Silico Study Using ADMET and Drug-Likeness Analysis

Along with the increasing resistance of Candida spp. to some antibiotics, it is necessary to find new antifungal drugs, one of which is from the medicinal plant Red Betel (Piper crocatum). The purpose of this research is to isolate antifungal constituents from P. crocatum and evaluate their activities as ergosterol biosynthesis inhibitors via an in silico study of ADMET and drug-likeness analysis. Two new active compounds 1 and 2 and a known compound 3 were isolated, and their structures were determined using spectroscopic methods, while their bioactivities were evaluated via in vitro and in silico studies, respectively. Antifungal compound 3 was the most active compared to 1 and 2 with zone inhibition values of 14.5, 11.9, and 13.0 mm, respectively, at a concentration of 10% w/v, together with MIC/MFC at 0.31/1.2% w/v. Further in silico study demonstrated that compound 3 had a stronger ΔG than the positive control and compounds 1 and 2 with -11.14, -12.78, -12.00, and -6.89 Kcal/mol against ERG1, ERG2, ERG11, and ERG24, respectively, and also that 3 had the best Ki with 6.8 × 10-3, 4 × 10-4, 1.6 × 10-3, and 8.88 μM. On the other hand, an ADMET analysis of 1-3 met five parameters, while 1 had one violation of Ro5. Based on the research data, the promising antifungal constituents of P. crocatum allow P. crocatum to be proposed as a new antifungal candidate to treat and cure infections due to C. albicans.

The Potential of 24-Propylcholestrol as Antibacterial Oral Bacteria of Enterococcus faecalis ATCC 29212 and Inhibitor Biofilms Formation: in vitro and in silico Study

Introduction

Uncontrolled biofilm can cause several diseases such as dental caries, gingivitis, and periodontitis. Dental caries is a disease caused by the accumulation of plaque-containing pathogenic bacteria, including Enterococcus faecalis. These bacteria infect the root canals of teeth and colonize to form biofilms. Biofilm inhibition is carried out by interfering with cell wall formation metabolism. MurA enzyme has a role in peptidoglycan biosynthesis of cell walls. Enterococcal surface protein (Esp) is the main contributor of E. faecalis to form biofilms. In addition, inhibition of biofilms by interfering with the quorum sensing (QS) system, suppressing gelatinase virulence factors by blocking autoinducers gelatinase biosynthesis-activating pheromone (GBAP).

Purpose

Knowing the potential of Piper betel Linn. compounds as antibacterial in vitro and antibiofilm agents against E. faecalis in silico.

Patients and Methods

The compounds were purified by a bioactivity-guided chromatographic method. Antibacterial activity was tested by disc diffusion method, in vitro studies. In silico study, compound P. betel L. was used as the test ligand and compared with positive control fosfomycin, ambuic acid, quercetin, and taxifolin. The proteins used MurA, Esp, GBAP, and gelatinase were docking with the Autodock Vina PyRx 0.8 followed by the PYMOL program and visualized with the Discovery Studio 2020 program.

Results

An antibacterial compound was identified 24-propylcholesterol which can inhibit the activity of E. faecalis ATCC 29212 with MIC value of 78.1 µg/mL and MBC value of 156.3 µg/mL. Molecular docking results showed the binding affinity of 24-propylcholesterol with MurA, ESP, GBAP, and gelatinase enzymes was -7.6, -8.7, -5.3, and -7.9 kcal/mol.

Conclusion

24-propylcholesterol has potential as an antibacterial against E. faecalis and as an antibiofilm through in silico inhibition of QS. However, further research is needed in vitro and in vivo to determine the effectiveness of these compounds as antibacterial and antibiofilm.

Nanoparticulate System for the Transdermal Delivery of Catechin as an Antihypercholesterol: In Vitro and In Vivo Evaluations

Gambir (Uncaria Gambir, Roxb.) contains catechins that is often empirically used to treat various diseases. Catechins can reduce cholesterol levels by inhibiting coenzyme HMG-CoA reductase that plays a role in cholesterol metabolism. Research has been carried out covering the optimization of transethosomal catechins, the formulation of Transethosomal Catechin Gel (TCG) and Non-Transethosomal Catechin Gel (NTCG), which were then tested for catechin permeation from these gel preparations in vitro using Franz’s diffusion cell with PTFE membranes. The anti-hypercholesterol activity test was carried out with Simvastatin orally as a positive control using 25 male Wistar rats (Rattus norvegicus). The catechin transetosomes have a size of 176.1 ± 5.8 nm, Zeta potential −11.6 ± 5.28, and Entrapment Efficacy of 96.77% ± 0.05. The result of cumulative catechins that permeated from TCG and NTCG were and 172.454 ± 5.287 and 112.741 ± 2.241 μg respectively. Permeation test graphs showed similar permeation and flux profiles. TCG can reduce total cholesterol and LDL (Low Density Lipoprotein) values in rats by 39.77% and 51.52% respectively during 14 days of use.

Celastrol and Rhynchophylline in the mitigation of simulated muscle atrophy under in vitro

Muscular atrophy (MA) is a disease of various origins, i.e., genetic or the most common, caused by mechanical injury. So far, there is no universal therapeutic model because this disease is often progressive with numerous manifested symptoms. Moreover, there is no safe and low-risk therapy dedicated to muscle atrophy. For this reason, our research focuses on finding an alternative method using natural compounds to treat MA. This study proposes implementing natural substances such as celastrol and Rhynchophylline on the cellular level, using a simulated and controlled atrophy process. Methods: Celastrol and Rhynchophylline were used as natural compounds against simulated atrophy in C2C12 cells. Skeletal muscle C2C12 cells were stimulated for the differentiation process. Atrophic conditions were obtained by the exposure to the low concertation of doxorubicin and validated by FoxO3 and MAFbx. The protective and regenerative effect of drugs on cell proliferation was determined by the MTT assay and MT-CO1, VDAC1, and prohibitin expression. Results: The obtained results revealed that both natural substances reduced atrophic symptoms. Rhynchophylline and celastrol attenuated atrophic cells in the viability studies, morphology analysis by diameter measurements, modulated prohibitin VDAC, and MT-CO1 expression. Conclusions: The obtained results revealed that celastrol and Rhynchophylline could be effectively used as a supportive treatment in atrophy-related disorders. Thus, natural drugs seem promising for muscle regeneration.

Blood pressure and blood sugar-lowering effects of purified gambir on diabetic hypertensive Wistar Kyoto rats

OBJECTIVES

Antioxidants protect people from diabetes and its cardiovascular complication. Purified gambir (Uncaria gambir Roxb.) is a potential medicinal plant for treating this condition based on the antioxidant activity of its catechin compound. This study tries to reveal the potential activity of purified gambir as a blood pressure-lowering drug while lowering blood glucose in diabetic hypertensive rats induced by oral NaCl-Prednisone and Alloxan.

METHODS

Rats were induced by oral NaCl 0.8% and Prednisone 5 mg/kg BW for 14 days to obtain hypertensive condition. Alloxan 125 mg/kg BW was given intra peritoneal injection on the 8th day to obtain diabetic hypertensive condition. The animal was divided into five groups, normal control group treated with vehicle, treatment groups were treated with purified gambir at dose of 2.5; 5 and 10 mg/kg BW respectively, while the positive control group were treated with a combination of captopril-glibenclamide at dose of 2.25 and 0.45 mg/kg BW. All animals were treated orally for 14 days. Fasting blood glucose and cardiovascular parameters (SBP, DBP, MAP, HR, BF and BV) were measured on days 1, 3, 7, and 14. NO level were measured on day 0 and day 14. Data were analyzed using two-way ANOVA followed by Duncan Multiple Range Test.

RESULTS

The purified gambir has blood pressure and blood sugar-lowering activity (p<0.05). The NO levels of the treatment group also increased significantly (p<0.05).

CONCLUSIONS

This study indicated that purified gambir could be an alternative medicine to manage blood glucose and blood pressure in the diabetic hypertensive model.

Bio-Mechanism of Catechin as Pheromone Signal Inhibitor: Prediction of Antibacterial Agent Action Mode by In Vitro and In Silico Study

The utilization of medicinal plants has long been explored for the discovery of antibacterial agents and the most effective mechanisms or new targets that can prevent and control the spread of antibiotic resistance. One kind of bacterial cell wall inhibition is the inactivation of the MurA enzyme that contributes to the formation of peptidoglycan. Another approach is to interfere with the cell–cell communication of bacteria called the Quorum sensing (QS) system. The blocking of auto-inducer such as gelatinase biosynthesis-activating pheromone (GBAP) can also suppress the virulence factors of gelatinase and serine protease. This research, in particular, aims to analyze lead compounds as antibacterial and anti-QS agents from Gambir (Uncaria gambir Roxburgh) through protein inhibition by in silico study. Antibacterial agents were isolated by bioactivity-guided isolation using a combination of chromatographic methods, and their chemical structures were determined by spectroscopic analysis methods. The in vitro antibacterial activity was evaluated by disc diffusion methods to determine inhibitory values. Meanwhile, in the in silico analysis, the compound of Uncaria gambir was used as ligand and compared with fosfomycin, ambuic acid, quercetin, and taxifolin as the standard ligand. These ligands were attached to MurA, GBAP, gelatinase, and serine proteases using Autodock Vina in PyRx 0.8 followed by PYMOL for combining the ligand conformation and proteins. plus programs to explore the complex, and visualized by Discovery Studio 2020 Client program. The antibacterial agent was identified as catechin that showed inhibitory activity against Enterococcus faecalis ATCC 29212 with inhibition zones of 11.70 mm at 10%, together with MIC and MBC values of 0.63 and 1.25 μg/mL, respectively. In the in silico study, the molecular interaction of catechin with MurA, GBAP, and gelatinase proteins showed good binding energy compared with two positive controls, namely fosfomycin and ambuic acid. It is better to use catechin–MurA (−8.5 Kcal/mol) and catechin–gelatinase (−7.8 Kcal/mol), as they have binding energies which are not marginally different from quercetin and taxifolin. On the other hand, the binding energy of serine protease is lower than quercetin, taxifolin, and ambuic acid. Based on the data, catechin has potency as an antibacterial through the inhibition of GBAP proteins, gelatinase, and serine protease that play a role in the QS system. This is the first discovery of the potential of catechin as an alternative antibacterial agent with an effective mechanism to prevent and control oral disease affected by antibiotic resistance.

Evaluation of extraction methods for pharmacologically active compounds from anticonvulsant traditional Chinese medicines: Gou Teng, Tian Ma, Jiang Can using DART-TOF-MS

Chinese herbal medicines (CHMs) are classified as dietary supplements. Interactions with western medications, the presence of contaminants or adulterants, or a mis-labeled or mis-used CHM may lead to toxicological emergencies that can be undetected in death investigations. Laboratories must be able to efficiently analyze cases in which CHMs are suspected. Five extractions were evaluated for their ability to extract pharmacologically active compounds from herbal matrices: water, ethanol, microwave-assisted (MAE), ethanol : chloroform, and acid-wash. Anticonvulsive and other pharmacologically active compounds in Gou Teng, Tian Ma, and Jiang Can purchased from Beijing, China and New York were compared in the powder and the extracts using Direct Analysis in Real Time-Mass Spectrometry (DART-MS). Approximately 0.25 g of macerated herb was used per extraction. The water and ethanol extractions were simple liquid extractions. For the MAE, powdered herb was soaked in 65% ethanol, microwaved, and concentrated. The ethanol : chloroform extraction involved soaking in 1 : 1 ethanol : chloroform, sonication, and concentration. In the acid-wash extraction, powdered herb was soaked in acetic acid, followed by addition of sodium hydroxide, hexane extraction, and reconstitution in ethyl acetate. The powdered herbs and extracts were analyzed using a Jeol JMS T100LC AccuTOF DART-MS in positive and negative mode. Of the evaluated methods, no single extraction worked for all active compounds from the three CHMs. The MAE extract contained the most pharmacologically active compounds, while the acid-wash contained the least for the three products. Gou Teng purchased from different sources did exhibit a difference in pharmacologically active compounds, potentially from different species.

Recent research progress of Uncaria spp. based on alkaloids: phytochemistry, pharmacology and structural chemistry

Medicinal plants are well-known in affording clinically useful agents, with rich medicinal values by combining with disease targets through various mechanisms. Plant secondary metabolites as lead compounds lay the foundation for the discovery and development of new drugs in disease treatment. Genus Uncaria from Rubiaceae family is a significant plant source of active alkaloids, with anti-hypertensive, sedative, anti-Alzheimer's disease, anti-drug addiction and anti-inflammatory effects. This review summarizes and discuss the research progress of Uncaria based on alkaloids in the past 15 years, mainly in the past 5 years, including biosynthesis, phytochemistry, pharmacology and structural chemistry. Among, focusing on representative compounds rhynchophylline and isorhynchophylline, the pharmacological activities surrounding the central nervous system and cardiovascular system are described in detail. On the basis of case studies, this article provides a brief overview of the synthesis and analogues of representative compounds types. In summary, this review provides an early basis for further searching for new targets and activities, discussing the mechanisms of pharmacological activity and studying the structure-activity relationships of active molecules.