New combination approaches to combat methicillin-resistant Staphylococcus aureus (MRSA)

Abstract

The herbal products proved to be more promising antimicrobials even though their antimicrobial activity is milder than commercially available antibiotics. Moreover, herbal drugs may act synergistically with antibiotics to kill microbes. In this study, we aimed to enhance the activity of penicillin against MRSA through combination with the active saponin fraction isolated from the Zygophyllum album plant. Three different types of metabolites (saponins, sterols, and phenolics) have been extracted from Zygophyllum album with ethanol and purified using different chromatographic techniques. The antibacterial activity of crude extract and the separated metabolites were checked against MRSA isolates, Saponin fraction (ZA-S) was only the active one followed by the crude extract. Therefore, the compounds in this fraction were identified using ultra-high-performance liquid chromatography connected to quadrupole time-of-flight mass spectrometry (UHPLC/QTOF-MS) operated in positive and negative ionization modes. UHPLC/QTOF-MS revealed the presence of major six ursane-type tritepenoidal saponins (Quinovic acid, Quinovic acid 3β-O-β-D-quinovopyranoside, Zygophylloside C, Zygophylloside G, Zygophylloside K and Ursolic acid), in addition to Oleanolic acid. Interaction studies between saponin fraction and penicillin against MRSA were performed through the checkerboard method and time-kill assay. According to checkerboard results, only three combinations showed a fractional inhibitory concentration index less than 0.5 at concentrations of (62.5 + 312.5, 62.5 + 156.25, and 62.5 + 78.125 of penicillin and ZA-S, respectively). Time kill assay results showed that the highest reduction in log10 colony-forming unit (CFU)/ml of initial inoculum of MRSA after 24 h occurred by 3.7 at concentrations of 62.5 + 312.5 (µg/µg)/ml of penicillin and ZA-S, respectively. Thus, the combination between saponin fraction of Zygophyllum album and penicillin with these concentrations could be a potential agent against MRSA that can serve as possible model for new antibacterial drug.

In Vitro and In Silico Cytotoxic and Antibacterial Activities of a Diterpene from Cousinia alata Schrenk

“…e cytotoxic activity of the isolated compounds was determined using the brine shrimp (Artemia salina) lethality test. e results showed that, among the isolated compounds, grindelic acid (1) and penduletin (5) were able to inhibit the crustaceans in all tested concentrations (10.0, 5.0, and 1.0 mg ml −1 ) while grindelic acid (1) had the highest activity comparing with other isolated compounds. e average activity was showed by retusine (2) and 5, 7, 3′-trihydroxy-3, 4′-dimethoxyflavone (7); these compounds were active at 10-5 mg ml −1 and inactive at 1 mg ml −1 .…”

“…e global increase in antibiotic resistance causes an increase in medical costs and mortality rates, especially with some severe bacterial infections such as pneumonia, tuberculosis, gonorrhea, and salmonellosis [4]. Natural products can be considered as the main source of antimicrobial and anticancer compounds [5]. e activity of natural products either originated from plants [5][6][7], marines [8,9] or fungi [10][11][12][13][14] is owned to a diversity of secondary metabolites that belong to various chemical classes such as flavonoids [15][16][17], saponins [6,18], pyrones [19], isochromenes [20], and alkaloids [21].…”

“…Natural products can be considered as the main source of antimicrobial and anticancer compounds [5]. e activity of natural products either originated from plants [5][6][7], marines [8,9] or fungi [10][11][12][13][14] is owned to a diversity of secondary metabolites that belong to various chemical classes such as flavonoids [15][16][17], saponins [6,18], pyrones [19], isochromenes [20], and alkaloids [21].…”

Isolation and In Silico Anti-COVID-19 Main Protease (Mpro) Activities of Flavonoids and a Sesquiterpene Lactone from Artemisia sublessingiana

“…Natural secondary metabolites are a significant source for anti-infective agents since dawn of history. ese metabolites are found in many sources in nature such as plants [14,15], marines [16,17], and microbes [18][19][20], and they could be assorted following their chemical structure into countless classes such as saponins [21,22], diterpenes [23], pyrones [24], isochromenes [25], flavonoids [26,27], and alkaloids [28].…”

Isolation, Crystal Structure, and In Silico Aromatase Inhibition Activity of Ergosta-5, 22-dien-3β-ol from the Fungus Gyromitra esculenta

“…Natural products are the key source that humankind relied on to treat diseases and maintain good health [1,2]. e effective secondary metabolites that are responsible for natural products' activity could be derived from plants [3,4] or marines [5,6]. Furthermore, fungi represent an unlimited origin of bioactive metabolites [7][8][9][10][11][12][13].…”