Several reports have suggested that the viable but non-culturable (VBNC) state is a resistant form of bacterial cells that allows them to remain in a dormant form in the environment. Nevertheless, studies on the resistance of VBNC bacterial cells to ecological factors are limited, mainly because techniques that allow this type of evaluation are lacking. Differential scanning calorimetry (DSC) has been used to study the thermal resistance of culturable bacteria but has never been used to study VBNC cells. In this work, the heat resistance of Escherichia coli cells in the VBNC state was studied using the DSC technique. The VBNC state was induced in E. coli ATCC 25922 by suspending bacterial cells in artificial sea water, followed by storage at 3 ± 2°C for 110 days. Periodically, the behaviour of E. coli cells was monitored by plate counts, direct viable counts and DSC. The entire bacterial population entered the VBNC state after 110 days of storage. The results obtained with DSC suggest that the VBNC state does not confer thermal resistance to E. coli cells in the temperature range analysed here.
Cancer includes a group of more than 100 different types of diseases characterized by the accelerated and disorderly growth of abnormal cells. Cancer is a major worldwide public health problem. According to the International Agency for Research on Cancer (IARC), cancer increased to 18.1 million new cases and 9.6 million cancer deaths in 2018 (1). Historically, natural products have been used since ancient times and in folklore for treatment of many diseases (2). Traditional medicine is known the sum total of the knowledge, skills, and practices based on the theories and experiences indigenous to different cultures used in the maintenance of health and for the prevention, diagnosis, improvement, and/or treatment of illness (3). Plants have comprised the basis of traditional medicine systems and their use by the peoples of many cultures has been widely documented. The World Health Organization has estimated that approximately 80% of the worldís inhabitants mainly employ traditional medicine for their primary healthcare (4). Currently, the use of medicinal plants to treat and prevent various types of cancer has experienced a breakthrough. Along with the cancer treatment ranging from surgery and radiation to chemotherapy or immunotherapy, millions of people seek additional options such as complementary and alternative medicine. In traditional Mexican folk medicine, Solanum rostratum has been used for years to treat kidney disorders, stomachache, and digestive disorders and with the use of the infusion of the leaves as a purgative. A tea prepared with the plantís flowers is rec
El Aloe vera (Aloe barbadensis Miller), de nombre común Sábila o Sávila, es la especie de Aloe más utilizada en el mundo en la medicina tradicional, como antibacteriano, en cicatrización de heridas, como antioxidante, además de tener una acción en los mecanismos de inmunidad. Se conocen aproximadamente 75 compuestos activos, donde destacan fenoles como cromonas (aloesina) y antraquinonas (barbaloína, isobarbaloína y aloemodina), así como polisacáridos, generado el interés de estudiar su actividad biológica en la industria para la aplicación de estos compuestos en productos cosméticos, farmacéuticos y alimentos, teniendo cuidado en la manipulación para evitar la pérdida de las propiedades naturales de la planta. En el presente trabajo se obtuvieron dos extractos, acuoso y etanólico, mediante maceración, comparados con un extracto obtenido comercialmente, a los tres extractos se les aplicaron pruebas químicas preliminares y posteriormente, se analizaron los espectros de IR obtenidos, observando principalmente señales de compuestos polihidroxilados con bandas correspondientes de OH entre 3000 y 3700 cm-1. Posteriormente se evaluó el efecto del proceso de extracción usado comercialmente sobre la estabilidad de los compuestos activos, aplicando técnicas de conservación como la microencapsulación, por lo que de la misma forma el extracto comercial fue microencapsulado con maltodextrina y analizado con microscopia electrónica de barrido, pruebas químicas e IR, con el fin de comparar los compuestos activos presentes en este, con los extraídos en el laboratorio.
Microcystis aeruginosa is one of the main harmful bloom-forming cyanobacteria species worldwide. Plant extracts are considered an appropriate practice to obtain effective, economical and sustainable algaecides. For the first time, the effects of Argemone mexicana, Bougainvillea spectabilis, Larrea tridentata and Tradescantia zebrina on the growth of M. aeruginosa in solid and liquid media were investigated by measuring cell density, Chl-a concentration, malondialdehyde (MDA), proteins and nucleotides. Total polyphenol content was quantified to reveal the nature of inhibition. The results in solid medium showed that the methanolic extract of L. tridentata had the greatest effect, showing an inhibition zone of 28.67±0.58 mm. In liquid medium, the methanolic extract of L. tridentata again showed the greatest effects on the cell density of M. aeruginosa (93.80%, p<0.0001), followed by B. spectabilis (87.66%, p<0.0001) and A. mexicana with (87.11%, p<0.001), with EC50 = 13.63, 20.27 and 24.47 mg/L, respectively. L. tridentata also showed a decrease of Chl-a of 91.51% (P<0.0001), MDA increased 6.42 times, and proteins and nucleotides 2.09 and 2.12 times in relation to the control, respectively. L. tridentata showed the highest total polyphenol content, 363.51 mgGAEq/gDE. These results indicate that the decrease in photosynthetic capacity and lipid peroxidation are the most probable mechanisms of action of this species against M. aeruginosa.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.