Anti-Infective Agents - Volume 23, Issue 2, 2025

Antiviral compounds from plant origin have been the focus of researchers throughout the world for a long time as the potential alternative to classical antiviral therapies. The search for antiviral phytochemicals comes into the limelight amidst the recent COVID-19 pandemic. This tremendous surge in the hunt for effective and alternative treatment from the plant source is mainly due to the toxicity and inadequate responses of synthetic antiviral drugs to resistant viral strains.

A comprehensive literature survey on the antiviral activity of bioactive compounds from the genus Clerodendrum was conducted using known and widely acknowledged scientific databases.

This in-depth review is prepared to shed light on the promising effect of the bioactive phytochemicals isolated from different Clerodendrum spp. against some of the most pathogenically relevant viruses such as Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS-CoV-2), Human Immunodeficiency Virus (HIV), Influenza Virus, Hepatitis C Virus (HCV), Herpes Simplex Virus (HSV), Japanese Encephalitis Virus (JEV), Dengue Virus (DENV), and Chikungunya Virus (CHIKV). Bioactive compounds such as ursolic acid, sugiol, and quercetin are reported to prevent virus-host cell adhesion. Harpagide is found to reduce intracellular Ca²⁺ and mitochondrial stress in infected cells, preventing viral infection. Researchers reported the efficacy of β-sitosterol in inhibiting immune responses via RIG-I signalling and IFN production. Rengyolone is found to mitigate viral infection by preventing acute inflammation. Betulinic acid, tricin, and oleanolic acid are found to prevent IAV and HIV replication. Evidence has also suggested the possible action of kaempferol, acacetin and apigenin to inhibit mRNA and protein production in virus-infected cells.

Future research should be oriented towards the isolation and quantitation of these bioactive compounds from Clerodendrum spp., along with their efficacy both in vitro and in vivo prior to their clinical applications in combating a variety of viral infections.

The active ingredient in medicinal herbs has a considerable therapeutic impact. Historically, medicinal plants have been critical in helping people recover from unfavorable microbial infection-related illnesses. Therefore, we can use these plants as raw materials to make antibiotics.

To summarize, several traditional herbs have antibacterial properties, and their use as a therapy option offers a successful treatment approach.

A detailed study of literature was started by looking through many data sets from the Herbalist Library and well-known scientific databases like the Cochrane Library, PubMed, ScienceDirect, Web of Science, and Google Scholar. Literature focusing on herbs having antibiotic potential, specifically in the English language, from the years 1980 to 2023 was considered to be included in this review.

In this review article, all the natural herbal antibiotics are summarised with their pharmacological effects as well as the active components responsible for their biological role. The current analysis provides thorough information on many medicinal plants examined over the last few decades in order to investigate possible herbal antibiotics for future treatment.

Hydatidosis is an infectious disease that occurs in the larval stage of Echinococcus granulosus. Benzimidazoles are the only official and approved drugs for treatment, but their effectiveness varies among patients. Therefore, safe discoveries are needed for new and safe herbal medicines and supplements to improve the treatment of this disease. The current research was carried out to investigate the chemical composition of the plant essential oil and its protoscolicidal effects on hydatid cyst protoscolex in laboratory conditions.

Gas chromatography/mass spectrometry (GC/MS) analysis was performed to identify the chemical composition of the essential oil EO(s). Hydatid cyst protoscoleces were collected from infected sheep's liver and then treated with concentrations of EO(s) (0.625, 1.25, 2.5, 5 and 10 mg/mL) for 3, 5, 10, 15, and 30 minutes in laboratory conditions. Then, using eosin dye, the viability of protoscolexes was examined.

According to GC/MS analyses, the main components of the EO(s) were β-Pinene (27.01%), (+)-3-Carene (24.87%), α-Pinene (18.34%), and Sabinene (17.69%), respectively. The killing effects of 5 and 10 minutes of exposure to 2.5 mg/ml of this essential oil were 100% lethal. Statistical results showed that the best time was 5 minutes, with a concentration of 5 mg/mL as the lowest concentration and the shortest incubation time (P<0.05).

Our findings show the strong protoscolide effects of P. ferulacea plant essential oil in vitro. However, more studies are needed to assess the safety and efficacy of this plant as a promising anti-inflammatory agent in vivo and clinical studies.

Mosquitoes significantly threaten public health, transmitting dangerous diseases to humans and animals. Conventional insecticide spraying, while common, has limitations in effectively controlling vector-borne diseases. Many chemical pesticides harm humans and animals, and some persist in the environment and cause toxic effects. Recently, there has been renewed interest in plant-based products due to concerns about insecticide resistance, cross-resistance, potential toxicity associated with synthetic options, and rising costs. Therefore, this study aimed to screen the Plectranthus amboinicus and Hyptis suaveolens phytochemicals targeting the odorant binding proteins (OBPs) of Aedes aegypti and Aedes albopictus.

In this study, we conducted molecular docking analyses using specific plant-derived compounds from H. suaveolens and P. amboinicus.

We focused on the interaction of these compounds with OBPs from dengue and chikungunya vectors (Aedes aegypti and Aedes albopictus). The selected phytochemical compounds exhibited strong binding with the OBP of both Ae. aegypti and Ae. albopictus. Tetrahydrofuran-2-carboxylic acid, Carvacryl acetate, and Brallobarbital showed high binding affinity and significant interaction with Ae. aegypti. Tetrahydrofuran-2-carboxylic acid and 3-Methyl-4-isopropylphenol also demonstrated substantial binding affinity and effective interaction with Ae. albopictus OBP.

These findings suggest that the identified compounds can potentially disrupt the attraction of mosquitoes to humans, thus reducing human-vector contact. They may offer a promising alternative for developing natural and efficient mosquito repellents, surpassing currently used synthetic options like N, N-diethyl-meta-toluamide, and other conventional repellents.

The increasing use of synthetic antimicrobials and antioxidants is a concern for human health.

The main objective of this study was to examine the chemical composition of the Essential oil extracted from Salvia argentea and its hydrosol extract while evaluating their antioxidant and antimicrobial effects in vitro.

The Essential oil was obtained by hydrodistillation, while the hydrosol extract was obtained by the liquid-liquid extraction method. The volatile compounds of the Essential oil and hydrosol extract were analysed by gas chromatography (GC/FID) and gas chromatography coupled with mass spectrometry (GC/MS). Antioxidant activities were evaluated using two methods: free radical scavenging activity (DPPH) and iron reduction antioxidant power (FRAP), with BHT used as a positive control. The antimicrobial activity of the Essential oil and hydrosol extract was evaluated using the agar disc diffusion method.

According to the GC/FID and GC/MS analysis, the Essential oil of S. argentea consisted mainly of germacrene D-4-ol (26.3%), epi-α-muurolol (19.2%), and epi-α-cadinol (10.2%). In contrast, the hydrosol extract consisted of oxygenated compounds, including (E)-phytol (23.5%), 14-hydroxy-δ-cadine (17.5%), caryophyllene oxide (11.5%), piperitone (13.5%), and piperitone oxide (11.5%). The Essential oil and hydrosol extract showed positive antioxidant activity with both tests. It should be noted that the hydrosol extract showed the best performance, with an IC50 of 8.3 g/L with the DPPH and an IC50 of 12.3 g/L with the FRAP test compared to the BHT. The Essential oil revealed antimicrobial activity with strong inhibition against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Bacillus subtilis compared to Gentamicin.

The results showed that Essential oil and hydrosol extract have promising antimicrobial and antioxidant properties. These findings provide encouraging prospects for their potential use in the pharmaceutical or cosmetic sectors.

The development of antimicrobial resistance and reduced discovery and commercialization of newer antibiotics point to the need for the discovery of novel antibacterial agents. Schiff bases are reported to possess a broad range of pharmacological activities, which also include antibacterial activity. With this background, novel Schiff bases were synthesized.

The present study aimed to synthesize novel Schiff bases of 2-phenoxy-1-phenyl-ethanone with aryl amines and evaluate their antibacterial activity.

The desired Schiff bases were synthesized by condensing various aryl amines with 2-bromo-1-phenylethanone and characterized by physicochemical and spectral methods. The antibacterial activity of the synthesized Schiff bases was determined by the cup diffusion method. Molecular docking with Staphylococcus aureus tyrosyl-t-RNA synthetase (Protein Data Bank ID: 1JIJ) was performed using Autodock. Molecular dynamics simulation studies were performed using GROMACS. ADME analysis and drug-likeliness of the synthesized compounds were predicted using SwissADME. Protein-ligand interactions were studied using BIOVIA Discovery Studio Visualizer.

Out of the synthesized compounds, two compounds, sb_04 and sb_05, exhibited fair antibacterial activity. The compounds sb_04 and sb_05 exhibited better binding energy values than the original ligand of the target enzyme and comparable binding energy with ampicillin. The Autodock program estimated the binding free energy and inhibition constant values of compound sb_05 as -9.18 kcal/mol and 187.33 nM and for the compound sb_04 as -8.82 kcal/mol and 341.59 nM, respectively. The RMSD values of the compound sb_04 were stable throughout the duration of the simulation; however, the compound sb_05 showed lesser stability in the docked complex. Interestingly, the compound sb_05 (-182.754 kJ/mol) exhibited stable interaction with a lower value of total interaction energy than sb_04 (-136.304 kJ/mol). The synthesized Schiff bases showed no violation of Lipinski’s rule of five and a bioavailability score in the range of 55% to 85%.

The synthesized Schiff bases present a scaffold for the development of novel antibacterial agents, in particular the compounds sb_04 and sb_05.

Betula utilis, commonly known as the Himalayan Birch or Bhojpatra, has been used for centuries in Traditional Chinese Medicine (TCM) for its diverse pharmacological and phytochemical properties. This overview delves into the rich history and therapeutic applications of Betula utilis from a TCM perspective. It discusses its role in promoting health and addressing various ailments, drawing on the wisdom of traditional Chinese herbal medicine. Furthermore, this abstract provides insights into the phytochemical constituents of Betula utilis, shedding light on the active compounds responsible for its medicinal benefits.

Information regarding the different species within the Betula genus was gathered through electronic searches utilizing platforms, such as Pubmed, SciFinder, Scirus, Google Scholar, JCCC@INSTIRC, and Web of Science. Additionally, a library search was conducted to locate articles published in peer-reviewed journals.

The bark of Betula utilis finds extensive usage in both Ayurveda and the Chinese system of medicine, where it is employed to address a range of health issues and medical conditions. These include applications in wound healing, skin sanitation, bronchitis, seizures, leprosy, blood disorders, and ear-related ailments. Moreover, the plant and its active components are frequently utilized for their anti-inflammatory, liver-protective, antimicrobial, and anti-tumor properties. This comprehensive review aims to provide a thorough examination of the available literature concerning the pharmacological and chemical characteristics of Betula utilis.

To perform in-silico screening of the natural phytoconstituents against COVID-19 main protease.

COVID-19 is an atypical virus that is universal around the globe. WHO (World Health Organization) has also affirmed the emergency public health concerns regarding COVID-19. As COVID-19 spreads globally within a shorter duration, there is a great demand for effective therapy with minimal side effects.

To perform SP and XP docking of the naturally obtained ligand Quercetin (flavonoid) based on HTVS.

To identify the effectiveness of natural phytoconstituents for COVID-19 main protease virus.

In the present study, natural ligands were used for performing the virtual screening, which was obtained from Prestwick Phytochemical Library by applying hierarchal screening. Several docking protocols, such as SP and XP, are used to screen the best natural hit compounds. The three best-hit compounds and hydroxychloroquine were further studied for SAR analysis. Moreover, the ADME study by QikProp and the identification of biological sources were carried out by Duke's Phytochemical and Ethnobotanical Databases.

The results suggest that Quercetin showed good binding affinity towards 6LU7 (-56.689 kcal/mol), which could be an effective natural phytoconstituent for COVID-19.

Based on HTVS, SP, and XP docking, the naturally obtained ligand Quercetin (a flavonoid) can be used in place of Hydroxychloroquine against COVID-19's main protease virus. This scientific exploration will help to identify the effective natural compound for the COVID-19 main protease virus.

Considering the emergence of antibiotic resistance in enterococci and the possibility of transmission of resistant strains to humans, their spread in natural reservoirs is of particular importance. The food chain is known as a source of enterococci that is resistant to antimicrobial agents, and these bacteria are present in foods of animal origin, such as meat and milk. Hence, the purpose of this study was to investigate the frequency of aminoglycoside- and vancomycin-resistant genes in Enterococcus spp isolates isolated from chicken meat in Qom City, Iran.

After collecting and culturing 200 chicken meat samples from September 2021 to August 2022, enterococci were isolated and identified using biochemical and microbial standard tests. Antibiotic sensitivity and resistance of the isolates, aph(2”)1c ، aph(2”)1b ، aph(2”)1d ، ant(3') ، aph(3')IIIa ، ant(4')1a، ant(6') و aac(6'), vanA and vanB genes were determined.

From 200 chicken meat samples, 40(40%) isolates of Enterococcus faecalis and 60 (60%) isolates of Enterococcus faecium were isolated. Resistance to gentamicin, tobramycin, amikacin, neomycin, tetracycline, chloramphenicol, vancomycin, and ampicillin were 33, 30, 33, 20, 69, 38, 28, and 45, respectively. Frequency of aph(2”)1c, aph(2”)1b, aph(2”)1d, ant(3'), aph(3')IIIa, ant(4')1a, ant(6') and aac (6'), vanA and vanB were reported to be 13%, 2%, 3%, 45%, 20%, 7%, 19%, 21%, 7%, and 6%, respectively.

To reduce the infection with this organism and to prevent and control its spread and mortality, investigating the epidemiology and determining the frequency of resistance to aminoglycosides are important.