Methyl gallate: Review of pharmacological activity

In silico docking, ADMET profiling, and bio-accessibility experimentation on Breynia retusa phytocompounds and in vitro validation for anti-proliferative potencies against ovarian carcinoma

This study aimed to assess the medicinal properties of Breynia retusa, a plant rich in phytocompounds predominantly used as an ethnomedicinal agent in Western Ghats, which appeared to be promising for therapeutic use, especially in the treatment of ovarian cancer. Herein, its cytotoxic potential on ovarian cancer cell lines SKOV-3, neurotoxicity, antioxidant activity, and molecular docking was determined to aid in explaining the mechanisms of interactions with proteins related to ovarian cancer. B . retusa methanolic extract demonstrated exuberant antioxidant activity, with 81.91% scavenging ability of DPPH radicals and efficient reduction of phosphomolybdenum (22.98 mg ascorbic acid equivalents antioxidant capacity/g extract). The extract proved to be an important anti-inflammatory agent through membrane stabilization inhibition of 83%. The cytotoxicity study against the SKOV-3 cell line indicated an IC50 value of 34.01 µg/mL and a very negligible neurotoxicity in SH-SY5Y cell lines. The GC-MS and HPLC profiling indicated many anticancer compounds in the extract such as secalciferol, methyl gallate, ricinoleic acid, gallic acid, and naringenin. The docking study showed significant interactions of secalciferol molecules with the key ovarian cancer proteins, which include IGF1 (-6.758 kcal/mol) and c-ERBB2 (-4.281 kcal/mol). Fatty acid derivatives and methyl gallate showed efficient dock scores (< -5.0 kcal/mol) with antioxidant (catalase and superoxide dismutase) enzymes and inflammatory cytokines (IL-6 and COX-1), respectively, as evidences of antioxidant and anti-inflammatory potentials. The bio-accessibility of phenolics and their antioxidant activity ranged above 90%, indicating the promising bioavailability of phytochemicals expected in vivo. Hence the current study emphasizes the anticancer potential of B. retusa phytocompounds that appeared to interact very strongly with ovarian cancer targets and confirms the dose-dependent cytotoxic and antioxidant activities of B. retusa methanolic extract.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-025-04276-8.

Establishment of an efficacy-oriented quality grading framework for herbal medicines: Phyllanthus emblica as an example

ETHNOPHARMACOLOGICAL RELEVANCE

Quality control is a powerful method for ensuring the effectiveness and safety of herbal medicines. Phyllanthus emblica L. fruit (PE) has been extensively used in both Ayurvedic and traditional Chinese medicine. However, the current Indian and Chinese pharmacopeias set a minimum concentration threshold of gallic acid to identify qualified PE samples, without providing a clear framework to distinguish superior-quality PE samples.

AIM OF THE STUDY

To establish an efficacy-oriented quality grading framework for herbal medicines, using PE, a medicinal plant known for its hepatoprotective activity, as an example.

METHODS

First, a mouse model of alcohol-induced liver injury was developed to evaluate the hepatoprotective effects of PE. Second, a combined strategy of serum pharmacochemistry, network pharmacology, metabolomics and experimental validation was employed to identify key quality markers (Q-markers) linked to the hepatoprotective effects of PE. Finally, PE samples from different sources were collected to assess their hepatoprotective activities and Q-marker concentrations. A discriminant analysis model was then developed to classify PE samples into different quality grades by using Q-marker concentration as the predictive factor and hepatoprotective activity as the evaluation criterion.

RESULTS

PE significantly alleviated liver damage, as evidenced by a reduction in pathological abnormalities and serum aminotransferase levels. Six hepatoprotective Q-markers in PE were identified and verified, including gallic acid, methyl gallate, corilagin, chebulagic acid, ellagic acid and quercitrin. Significant variability in Q-marker concentrations and hepatoprotective effects was observed among different sources of PF samples, and a discriminant analysis model accurately classified PE samples into distinct quality grades.

CONCLUSIONS

This study successfully established an efficacy-oriented quality grading framework for PE, providing a methodological approach for the quality classification of herbal medicines.

Bioactivity and biomedical applications of pomegranate peel extract: a comprehensive review

Pomegranate peel is a by-product generated during the processing of pomegranate (Punica granatum L.) fruit, accounting for approximately 50% of the total mass of the fruit. Although pomegranate peel is usually regarded as waste, it is rich in various bioactive metabolites such as polyphenols, tannins, and flavonoids, demonstrating significant medicinal and nutritional value. In recent years, Pomegranate peel extract (PPE) has shown broad application prospects in the biomedical field due to its multiple effects, including antioxidant, anti-inflammatory, antibacterial, anti-apoptotic properties, and promotion of cell regeneration. This review consolidates the major bioactive metabolites of PPE and explores its applications in biomedical materials, including nanodrug carriers, hydrogels, and tissue engineering scaffolds. By synthesizing the existing literature, we delve into the potential value of PPE in biomedicine, the challenges currently encountered, and the future directions for research. The aim of this review is to provide a scientific basis for optimizing the utilization of PPE and to facilitate its broader application in the biomedical field.

Quercus infectoria galls mitigates colitis in mice through alleviating mucosal barrier impairment and suppressing inflammatory factors

ETHNOPHARMACOLOGICAL RELEVANCE

Xipayi Kuijie'an herbal enema preparation, a traditional Uyghur medicinal preparation derived from Quercus infectoria galls (QIG), has been clinically employed at Xinjiang Uyghur Medical Hospital for ulcerative colitis (UC) management. Despite its well-documented therapeutic efficacy, the precise mechanisms underlying its pharmacological actions remain poorly understood.

AIM OF STUDY

This study aimed to elucidate the therapeutic mechanisms of QIG against UC through an integrated approach combining network pharmacology analysis with experimental validation.

MATERIALS AND METHODS

An integrated approach combining network pharmacology analysis and molecular docking simulations was employed to identify bioactive compounds and their corresponding molecular targets. The effects of QIG on dextran sodium sulfate (DSS) induced colitis were systematically investigated, including disease activity index (DAI), colon length, histopathological observations, as well as the determination of colonic mucosal barrier permeability and biochemical indicators.

RESULTS

QIG significantly improved DAI and CMDI scores, reduced colonic shortening, decreased colonic mucosal barrier permeability, reduce the release of pro-inflammatory factors and mitigated histopathological changes.

CONCLUSION

This study demonstrates the efficacy of an integrated approach combining network pharmacology with experimental validation as a robust strategy for elucidating the therapeutic mechanisms of traditional medicines, as exemplified by the systematic investigation of QIG's anti-ulcerative colitis properties.

Flavonoids of Euphorbia hirta inhibit inflammatory mechanisms via Nrf2 and NF-κB pathways

Euphorbia hirta has anti-inflammatory effects in traditional medicine, but its anti-inflammatory mechanism has not been explored at the cellular and molecular levels. To unravel these mechanisms, the main active components in the 65 and 95% ethanol extracts of Euphorbia hirta were first identified by UPLC-Q-TOF/MS. Subsequently, potential anti-inflammatory targets and signaling pathways were predicted using network pharmacology and experimentally validated using RT-PCR and flow cytometry in a lipopolysaccharide (LPS)-induced inflammation model of RAW264.7 cells. The results revealed flavonoids as the key active components. Network pharmacology uncovered 71 potential anti-inflammation targets, with a protein-protein interaction (PPI) network highlighting 8 cores targets, including IL-6, TNF, NFκB and Nrf2 et al. Furthermore, Euphorbia hirta exerts anti-inflammation effects through modulation of Nrf2 and NF-κB signaling pathways. Specifically, the 65% ethanol extract of Euphorbia hirta (EE65) and quercitrin (HPG) exerted anti-inflammatory activity by inhibiting the expression of inflammatory genes associated with the NF-κB signaling pathway, whereas baicalein (HCS) suppressed cellular inflammation by promoting Nrf2-mediated antioxidant gene expression and enhancing apoptosis of inflammatory cells. The results of the study suggest that Euphorbia hirta has potential for the development of anti-inflammatory drugs.

Anti-inflammatory effects of Rhus javanica ethanol extract for pulmonary and colonic disorders

BACKGROUND

Rhus javanica is a traditional medicinal herb widespread in East Asia, including Korea, China, and Japan. Valued for its antidiarrheal, bactericidal, and anti-inflammatory properties, it epitomizes the synergy of traditional wisdom and natural benefits.

PURPOSE

This study aimed to investigate the anti-inflammatory properties of Rhus javanica ethanol extract (Rj-EE) in both in vitro and in vivo models, elucidate the underlying mechanisms, and provide a theoretical foundation for its potential use as a natural therapeutic option for clinical colitis and lung diseases.

STUDY DESIGN

RAW264.7 cells, peritoneal macrophages, HEK293T cells, and mouse models of acute lung injury and acute ulcerative colitis were used to evaluate the anti-inflammatory activity of Rj-EE.

METHODS

In this study, the phytochemical constituents of Rj-EE were identified by GC-MS and LC-MS. Inflammatory targets were sourced from GeneCards and Swiss Target Prediction databases. Gene ontology and KEGG analyses revealed Rj-EE's anti-inflammatory mechanisms. Nitric oxide (NO) production and cell viability were assessed with Griess and MTT assays, respectively. Inflammatory cytokines were measured by RT-PCR, transcription factor activity by luciferase assays, and protein expression through Western blotting. Overexpression and CETSA assays were conducted in HEK293T cells. In vivo model animals with lipopolysaccharide-induced acute lung injury and dextran sulfate sodium-induced acute ulcerative colitis were treated with Rj-EE and then assessed by RT-PCR, hematoxylin and eosin (H&E), cytokine analysis via an enzyme-linked immunosorbent assay, and Western blotting.

RESULTS

KEGG analysis identified the NF-κB pathway as key to Rj-EE's anti-inflammatory effects, with Src as a central target. Molecular docking showed strong binding between Rj-EE's active components and key genes. In vitro, Rj-EE reduced NO production and inflammatory mRNA markers, and inhibited MyD88- and TRIF-induced NF-κB and AP-1 activity. It also targeted Src and Syk. In vivo, Rj-EE alleviated colitis and lung injury.

CONCLUSION

Overall, Our findings lay a foundation for further research into Rj-EE's molecular anti-inflammatory mechanisms and suggest that Rhus javanica could be explored as a potential anti-inflammatory agent targeting Src and Syk for conditions like lung injury and colitis.

Antibacterial, antioxidant, cytotoxicity, and phytochemical screening of Moringa oleifera leaves

Bacterial resistance to antibiotics remains a significant clinical challenge, contributing to persistently high rates of morbidity and mortality. Achieving treatment success is increasingly difficult, necessitating the evaluation of new antibiotics and complementary approaches, including source control and alternative therapies. This study aimed to investigate the antibacterial, antioxidant, cytotoxic, and phytochemical properties of Moringa oleifera leaf extract using high-performance liquid chromatography (HPLC), and to evaluate the pharmacokinetic properties of its major compound. The extract demonstrated strong antibacterial activity against standard strains and foodborne bacterial species. It also showed significant antioxidant potential, supported by the presence of high concentrations of phenolic and flavonoid compounds. HPLC analysis identified multiple bioactive compounds, with quercetin as the predominant component. The cytotoxicity study confirmed the safety of the extract at low and moderate concentrations, and ADMET analysis indicated favorable pharmacokinetic characteristics of quercetin. In conclusion, Moringa oleifera exhibits promising potential for medical and food industry applications due to its significant antibacterial and antioxidant activities, combined with a strong safety profile and rich phytochemical content.

Electrospun Cellulose Acetate/Poly(Vinyl Alcohol) Nanofibers Loaded with Methyl Gallate and Gallic Acid for Anti-Staphylococcus aureus Applications

Methyl gallate (MG) and gallic acid (GA) are natural compounds with potent activity against methicillin-resistant Staphylococcus aureus (MRSA), a significant global health concern. In this study, MG and GA were incorporated into cellulose acetate (CA) blended with poly(vinyl alcohol) (PVA) to create electrospun nanofibers aimed at combating both methicillin-susceptible S. aureus (MSSA) and MRSA. Key electrospinning parameters-DC voltage, injection flow rate, and syringe tip-collector distance-were optimized, with the best conditions being a 1.5 mL/h flow rate, 30 cm distance, and 20 kV voltage. The resulting nanofiber mats were characterized by SEM, FTIR, DSC, tensile strength testing, contact angle measurement, swelling behavior, and release profiling. Antibacterial properties were assessed using the agar diffusion test. The obtained nanofibers had diameters ranging from 879.33 to 906.13 nm. Among the samples, MG-GA-CA/PVA exhibited the highest tensile strength, good flexibility, and improved stiffness, which was related to enhanced thermal stability and chemical interactions as shown by DSC and FTIR analyses. This formulation also displayed excellent hydrophilicity, swelling properties, and a consistent release profile over 8 to 24 h. Furthermore, MG-GA-CA/PVA showed superior antibacterial activity against both MSSA and MRSA, suggesting its potential as a strong, flexible, and effective anti-S. aureus material.

Therapy Targeted to the NLRP3 Inflammasome in Chronic Kidney Disease

Background

The NLRP3 inflammasome is a cytoplasmic polymeric protein complex composed of the cytoplasmic sensor NLRP3, the apoptosis-related spot-like protein ASC, and the inflammatory protease caspase-1. NLRP3 activates and releases IL-1β through classical pathways, and IL-18 mediates inflammation and activates gasdermin-D protein to induce cellular pyroptosis. Numerous studies have also emphasized the non-classical pathway activated by the NLRP3 inflammasome in chronic kidney disease (CKD) and the inflammasome-independent function of NLRP3.

Summary

The NLRP3-targeting inflammasome and its associated pathways have thus been widely studied in models of CKD treatment, but no drug that targets NLRP3 has thus far been approved for the treatment of CKD.

Key Messages

We herein reviewed the current interventional methods for targeting the NLRP3 inflammasome in various CKD models, analyzed their underlying mechanisms of action, classified and compared them, and discussed the advantages and follow-up directions of various interventional methods. This review therefore provides novel ideas and a reference for the development of targeted NLRP3-inflammasome therapy in CKD.

Phytochemical Screening Using LC-MS to Study Antioxidant and Toxicity Potential of Methanolic Extracts of Atraphaxis pyrifolia Bunge

Atraphaxis pyrifolia, a native medicinal plant of Central Asia, has a long history of traditional medicinal use; however, scientific research on its phytochemical and biological properties remains scarce. This paper aims to elucidate its chemical profile and assess its pharmacological potential through a comprehensive investigation of the phytochemical composition of stems and leaves using Liquid Chromatography-Mass Spectrometry (LC-MS), in conjunction with the assessment of its antioxidant (DPPH and ABTS) and cytotoxicity test on Artemia salina. Predominantly, glycosylated flavonoids were detected in stems and leaves extracts, notably including 8-Acetoxy-3',4',5,5'-tetrahydroxy-7-methoxy-3-α-L-rhamno-pyranosyloxyflavone, pyrifolin, and dehydroxypyrifolin. While the latter compound is exclusive to A. pyrifolia, the former compounds serve as shared chemical markers with other Atraphaxis species. The methanolic extracts of A. pyrifolia leaves exhibited significant antioxidant capacity without toxicity against Artemia salina. This study contributes to current research through providing valuable insights into the chemical diversity and potential medicinal properties of this plant species.

Paeonia genus: a systematic review of active ingredients, pharmacological effects and mechanisms, and clinical applications for the treatment of cancer

The main active constituents of plants of the Paeonia genus are known to have antitumor activity. Hundreds of compounds with a wide range of pharmacological activities, including monoterpene glycosides, flavonoids, tannins, stilbenes, triterpenoids, steroids, and phenolic compounds have been isolated. Among them, monoterpenes and their glycosides, flavonoids, phenolic acids, and other constituents have been shown to have good therapeutic effects on various cancers, with the main mechanisms including the induction of apoptosis; the inhibition of tumor cell proliferation, migration, and invasion; and the modulation of immunity. In this study, many citations related to the traditional uses, phytochemical constituents, antitumor effects, and clinical applications of the Paeonia genus were retrieved from popular and widely used databases such as Web of Science, Science Direct, Google Scholar, and PubMed using different search strings. A systematic review of the antitumor constituents of the Paeonia genus and their therapeutic effects on various cancers was conducted and the mechanisms of action and pathways of these phytochemicals were summarised to provide a further basis for antitumor research.

Potential anti-HIV and antitrypanosomal components revealed in Sorindeia nitidula via LC-ESI-QTOF-MS/MS

Sorindeia nitidula (Anacardiaceae) is used by traditional practitioners to treat influenza illnesses with cephalgia and febrile aches. However, the potential active ingredients for its remarkable antioxidant, anti-HIV and antitrypanosomal activities remain unexplored. The present study aims to evaluate the antioxidant, anti-HIV and antitrypanosomal activities of the ethyl acetate extract of S. nitidula (SN) in order to screen out the bioactive compounds and to analyze their possible mechanisms of action. Overall, 21 phenolic compounds were annotated, by using the MS and MS/MS information provided by the QTOF-MS. In vitro assays on the extract revealed potent antioxidant (IC50 = 0.0129 ± 0.0001 mg/mL), anti-HIV (IC50 = 1.736 ± 0.036 µM), antitrypanosomal (IC50 = 1.040 ± 0.010 µM) activities. Furthermore, SN did not present cytotoxic effect on HeLa cancer cell lines. The integrated strategy based on LC-ESI-QTOF-MS/MS provided a powerful tool and a multidimensional perspective for further exploration of active ingredients in S. nitidula responsible for the antioxidant, anti-HIV and antitrypanosomal activities.

Gallic Acid Attenuates Sepsis-Induced Liver Injury through C/EBPβ-Dependent MAPK Signaling Pathway

SCOPE

Liver injury is a major complication associated with sepsis. Together with others, the study has shown that gallic acid (GA) exerts anti-inflammatory and antioxidant effects in vivo. However, the role of GA in sepsis-mediated hepatic impairment and the underlying mechanisms remains to be elucidated.

METHODS AND RESULTS

C57BL/6J mice are pretreated with saline or GA and subjected to sham or cecal ligation and puncture (CLP). The pathological alterations are assessed by hematoxylin and eosin staining as well as immunohistochemical staining. RNA sequencing is employed to analyze hepatic transcriptome modifications. The study finds that GA supplementation significantly ameliorates CLP-induced mortality, liver dysfunction, and inflammation. RNA sequencing reveals that 1324 genes are markedly differentially regulated in livers of saline- or GA-treated sham or CLP mice. Gene ontology analysis demonstrates that the differentially expressed genes regulated by GA are predominantly correlated with the immune system process, oxidation-reduction process, and inflammatory response. Furthermore, mitogen-activated protein kinase (MAPK) signaling is localized in the center of the GA-mediated pathway network. Notably, activation of MAPK by C16-PAF significantly blocks GA-mediated protective effects on hepatic injury, inflammation, as well as CCAAT/enhancer-binding protein-β (C/EBPβ) dependent extracellular signal-regulated kinase 1/2 (ERK1/2) and nuclear factor-κB (NF-κB) signaling.

CONCLUSION

Therefore, this study indicates that GA may offer a promising therapeutic opportunity for sepsis-associated liver injury.

Polyphenol Compound 18a Modulates UCP1-Dependent Thermogenesis to Counteract Obesity

Recent studies increasingly suggest that targeting brown/beige adipose tissues to enhance energy expenditure offers a novel therapeutic approach for treating metabolic diseases. Brown/beige adipocytes exhibit elevated expression of uncoupling protein 1 (UCP1), which is a thermogenic protein that efficiently converts energy into heat, particularly in response to cold stimulation. Polyphenols possess potential anti-obesity properties, but their pharmacological effects are limited by their bioavailability and distribution within tissue. This study discovered 18a, a polyphenol compound with a favorable distribution within adipose tissues, which transcriptionally activates UCP1, thereby promoting thermogenesis and enhancing mitochondrial respiration in brown adipocytes. Furthermore, in vivo studies demonstrated that 18a prevents high-fat-diet-induced weight gain and improves insulin sensitivity. Our research provides strong mechanistic evidence that UCP1 is a complex mediator of 18a-induced thermogenesis, which is a critical process in obesity mitigation. Brown adipose thermogenesis is triggered by 18a via the AMPK-PGC-1α pathway. As a result, our research highlights a thermogenic controlled polyphenol compound 18a and clarifies its underlying mechanisms, thus offering a potential strategy for the thermogenic targeting of adipose tissue to reduce the incidence of obesity and its related metabolic problems.

Phytochemical Analysis, Biological Activities, and Molecular Docking Studies of Root Extracts from Paeonia Species in Serbia

Without being aware of their chemical composition, many cultures have used herbaceous peony roots for medicinal purposes. Modern phytopreparations intended for use in human therapy require specific knowledge about the chemistry of peony roots and their biological activities. In this study, ethanol-water extracts were prepared by maceration and microwave- and ultrasound-assisted extractions (MAE and UAE, respectively) in order to obtain bioactive molecules from the roots of Paeonia tenuifolia L., Paeonia peregrina Mill., and Paeonia officinalis L. wild growing in Serbia. Chemical characterization; polyphenol and flavonoid content; antioxidant, multianti-enzymatic, and antibacterial activities of extracts; and in vitro gastrointestinal digestion (GID) of hot water extracts were performed. The strongest anti-cholinesterase activity was observed in PT extracts. The highest anti-ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical potential was observed in PP extracts, whereas against DPPH (2,2-diphenyl-1-picrylhydrazyl radicals), the best results were achieved with PO extracts. Regarding antibacterial activity, extracts were strongly potent against Bacillus cereus. A molecular docking simulation was conducted to gather insights into the binding affinity and interactions of polyphenols and other Paeonia-specific molecules in the active sites of tested enzymes. In vitro GID of Paeonia teas showed a different recovery and behavior of the individual bioactives, with an increased recovery of methyl gallate and digallate and a decreased recovery of paeoniflorin and its derivatives. PT (Gulenovci) and PP (Pirot) extracts obtained by UAE and M were more efficient in the majority of the bioactivity assays. This study represents an initial step toward the possible application of Paeonia root extracts in pharmacy, medicine, and food technologies.

Exploring Four Atraphaxis Species: Traditional Medicinal Uses, Phytochemistry, and Pharmacological Activities

Atraphaxis is a genus of flowering plants in the family Polygonaceae, with approximately 60 species. Species of Atraphaxis are much-branched woody plants, forming shrubs or shrubby tufts, primarily inhabiting arid zones across the temperate steppe and desert regions of Central Asia, America, and Australia. Atraphaxis species have been used by diverse groups of people all over the world for the treatment of various diseases. However, their biologically active compounds with therapeutic properties have not been investigated well. Studying the biologically active components of Atraphaxis laetevirens, Atraphaxis frutescens, Atraphaxis spinosa L., and Atraphaxis pyrifolia is crucial for several reasons. Firstly, it can unveil the therapeutic potential of these plants, aiding in the development of novel medicines or natural remedies for various health conditions. Understanding their bioactive compounds enables scientists to explore their pharmacological properties, potentially leading to the discovery of new drugs or treatments. Additionally, investigating these components contributes to preserving traditional knowledge and validating the historical uses of these plants in ethnomedicine, thus supporting their conservation and sustainable utilization. These herbs have been used as an anti-inflammatory and hypertension remedies since the dawn of time. Moreover, they have been used to treat a variety of gastrointestinal disorders and problems related to skin in traditional Kazakh medicine. Hence, the genus Atraphaxis can be considered as a potential medicinal plant source that is very rich in biologically active compounds that may exhibit great pharmacological properties, such as antioxidant, antibacterial, antiulcer, hypoglycemic, wound healing, neuroprotective, antidiabetic, and so on. This study aims to provide a collection of publications on the species of Atraphaxis, along with a critical review of the literature data. This review will constitute support for further investigations on the pharmacological activity of these medicinal plant species.

Assessing the Potential of Gallic Acid and Methyl Gallate to Enhance the Efficacy of β-Lactam Antibiotics against Methicillin-Resistant Staphylococcus aureus by Targeting β-Lactamase: In Silico and In Vitro Studies

Methicillin-resistant Staphylococcus aureus (MRSA), a global health concern, has prompted research into antibiotic adjuvants as a potential solution. Although our group previously reported the enhancing effects of gallic acid (GA) and methyl gallate (MG) on penicillin G activity against MRSA, the synergistic potential with other β-lactam antibiotics and the underlying mechanism have not been fully explored. Therefore, this study primarily aimed to investigate the antibacterial synergism with β-lactam antibiotics through disc diffusion, checkerboard, and time-kill assays. The β-lactamase inhibition was also examined through both molecular modeling and in vitro experiments. Additionally, bacterial morphology changes were studied using a scanning electron microscopy (SEM). The results revealed that both GA and MG exhibited anti-MRSA activity and showed indifferent effects when combined with β-lactam antibiotics against methicillin susceptible S. aureus (MSSA). Interestingly, MG demonstrated synergism with only the β-lactamase-unstable antibiotics against MRSA with the lowest fractional inhibitory concentration (FIC) indexes of ≤3.75. However, GA and MG exhibited weak β-lactamase inhibition. Furthermore, GA, MG, and the combination with ampicillin induced the morphological changes in MRSA, suggesting a possible mechanism affecting the cell membrane. These findings suggest that MG could potentially serve as an adjunct to β-lactam antibiotics to combat MRSA infections.