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Background: β-lactam antibiotics are a class of broad-spectrum antibiotics consisting of all antibiotic agents that contain a β-lactam ring in their molecular structures. β-lactam antibiotics are only known to be isolated from fungi (e.g. Acremonium chrysogenum, Penicillium chrysogenum and Aspergillus nidulans) and bacteria (e.g. Streptomyces clavuligerus). We have shown that botanical extracts prepared from Larrea tridentata have strong antimicrobial activity against several bacteria, including members of Staphylococcus and Streptococcus genera., Methods: Through resistance studies, inhibitor assays, and ELISA testing, we demonstrated L. tridentata extracts may contain a β-lactam type antibiotic activity., Results: Based on the estimated β-lactam concentration within the extract, the antimicrobial activity of the L. tridentata extract was approximately 2000-8000-fold greater against Staphylococcus as compared to other β-lactams, penicillin or ampicillin. In the L. tridentata extract, this increased activity was found to be associated with the likely presence of a cofactor leading to increased potentiation of the β-lactam activity. This potentiation activity was also observed to enhance the activity of exogenously added natural penicillin antibiotics., Conclusions: Although constituents were not isolated in this study, the results obtained strongly support the presence of β-lactam type antibiotic activity and antibiotic potentiation activity present in ethanolic extracts prepared from L. tridentata.

Herpes simplex virus type-1 (HSV-1), one of the most widely spread human viruses in the Herpesviridae family, causes herpes labialis (cold sores) and keratitis (inflammation of the cornea). Conventional treatment for HSV-1 infection includes pharmaceutical drugs, such as acyclovir and docosonal, which are efficacious but maintain the potential for the development of viral drug resistance. Extracts from the carnivorous pitcher plant, Sarracenia purpurea, have previously been shown to inhibit the replication of HSV-1. In this study, we demonstrate that S. purpurea extracts can inhibit the replication of HSV-1 by two distinct mechanisms of action. These extracts directly inhibit extracellular virions or viral attachment to the human host cell as well as inhibiting the expression of viral immediate-early, early and late genes when added at various times post-infection. This botanical has previously been shown to inhibit the replication of poxviruses through the inhibition of early viral gene transcription. These results support a broader anti-viral activity of S. purpurea extracts against both pox and herpes viruses.

Staphylococcus aureus is an opportunistic pathogen. Over- and improper-use of pharmaceuticals against S. aureus has led to the development of antibiotic resistance, including methicillin-resistant S. aureus (MRSA). This study examined the efficacy of botanical extracts as an alternative form of treatment to S. aureus and MRSA, including penicillin/methicillin-resistant S. aureus (Pen R ), and multidrug resistant S. aureus (MDR). Initial screening of botanicals was done via a minimum inhibitory concentration procedure. In addition, a temporal growth curve was performed in order to quantify the growth of the bacteria in the presence of the extracts. Results demonstrated 13 botanicals that had varying activities against S. aureus, Pen R , and MDR. These botanicals were separated into mild, moderate, and highly efficacious based on the concentration needed to inhibit bacterial growth. These results propose a comparison of botanical-derived antimicrobial extracts that may be utilized against S. aureus and different antibiotic resistant strains of MRSA., (© 2018 John Wiley & Sons, Ltd.)

Background: Resurgences of Staphylococcus aureus infection continue globally, with antibiotic resistance increasing dramatically, making these infections more difficult to treat. S. aureus epidemics impose public health threats, and economic burdens on health care costs worldwide, presenting challenges modern medicine struggles to control., Objective: In order to answer today's call for effective treatments against S. aureus, we evaluated and compared various botanical extracts that have historically been suggested as useful for their antimicrobial properties against S. aureus., Design: Briefly, S. aureus cultures were treated with selected botanical extracts and the minimum inhibitory concentration (MIC) determined. In addition, to obtain more quantitative measures on bacterial growth, 24-hour growth studies were done to examine the temporal activity and stability of various botanicals on bacterial replication., Results: The antimicrobial activity observed for the botanical extracts used in this comparative evaluation of efficacy included both bacteriostatic and bacteriocidal activity against S. aureus. Highly effective botanicals including Salvia officinalis, Eucalyptus globulus, Coleus forskohlii, Coptis chinensis, Turnera diffusa, and Larrea tridentata exhibited MIC values ranging from 60 to 300 μg/mL and a 10(6)-fold reduction in bacterial replication. Arctostaphylos uva-ursi and Allium sativum were slightly less effective, exhibiting MIC values ranging from 90 to 400 μg/mL and a 10(5)-fold reduction, while Anemopsis californica gave MIC value of 360 μg/mL and a 10(4)-fold reduction in bacterial replication. Many botanicals, especially at lower doses, had an initial inhibitory effect followed by a recovery in bacterial replication. Such botanicals included E. globulus, C. chinensis, T. diffusa, A. californica, and Berberis vulgaris., Conclusions: Our data demonstrate that S. officinalis, E. globulus, C. forskohlii, A. uva-ursi, C. chinensis, T. diffusa, A. californica, A. sativum, and L. tridentata all show promising direct antimicrobial activity against S. aureus. For many of these botanicals, strong bacteriocidal activity was observed at higher concentrations, but even at lower concentrations, bacteriostatic activity was evident. Other botanicals including B. vulgaris, Baptisia tinctoria, and Glycyrrhiza glabra showed moderate activity against S. aureus, while Schisandra chinensis, Echinacea angustifolia, and Polygonum multiflorum were shown to be ineffective.