Exploring and targeting potential druggable antimicrobial resistance targets ArgS, SecY, and MurA in Staphylococcus sciuri with TCM inhibitors through a subtractive genomics strategy.

Staphylococcus sciuri (also currently Mammaliicoccus sciuri) are anaerobic facultative and non-motile bacteria that cause significant human pathogenesis such as endocarditis, wound infections, peritonitis, UTI, and septic shock. Methicillin-resistant S. sciuri (MRSS) strains also infects animals that include healthy broilers, cattle, dogs, and pigs. The emergence of MRSS strains thereby poses a serious health threat and thrives the scientific community towards novel treatment options. Herein, we investigated the druggable genome of S. sciuri by employing subtractive genomics that resulted in seven genes/proteins where only three of them were predicted as final targets. Further mining the literature showed that the ArgS (WP_058610923), SecY (WP_058611897), and MurA (WP_058612677) are involved in the multi-drug resistance phenomenon. After constructing and verifying the 3D protein homology models, a screening process was carried out using a library of Traditional Chinese Medicine compounds (consisting of 36,043 compounds). The molecular docking and simulation studies revealed the physicochemical stability parameters of the docked TCM inhibitors in the druggable cavities of each protein target by identifying their druggability potential and maximum hydrogen bonding interactions. The simulated receptor-ligand complexes showed the conformational changes and stability index of the secondary structure elements. The root mean square deviation (RMSD) graph showed fluctuations due to structural changes in the helix-coil-helix and beta-turn-beta changes at specific points where the pattern of the RMSD and root mean square fluctuation (RMSF) (< 1.0 Å) support any major domain shifts within the structural framework of the protein-ligand complex and placement of ligand was well complemented within the binding site. The ß-factor values demonstrated instability at few points while the radius of gyration for structural compactness as a time function for the 100-ns simulation of protein-ligand complexes showed favorable average values and denoted the stability of all complexes. It is assumed that such findings might facilitate researchers to robustly discover and develop effective therapeutics against S. sciuri alongside other enteric infections.

Morinda citrifolia Linn. fruit extract mitigates heroin seeking behavior in mice.

Methanolic extract of Morinda citrifolia unripe fruit (MMC) was tested against heroin addiction using a mouse modified runway model of drug­seeking. Habituation sessions were carried out for 10 min/d for 3 days. On day 0, the total run time of each mouse was noted (the start box to goal box) during the preconditioning test. This was followed by the conditioning session (30 min), in which the animals were conditioned with escalating doses of heroin hydrochloride (5, 10, 20, 40 and 40 mg/kg) for 5 days upon entry into the goal box. On day 6, the run time of each mouse, from start to goal box, was recorded during the post conditioning test. Extinction trials were performed for the next 5 days, in which no drug/saline was injected upon goal box entry. On day 13, a priming dose of heroin (8 mg/kg) was given to reinstate drug seeking in the mice. MMC given as oral doses (1, 3 and 5 g/kg) dose­dependently prolonged the run time to reach the goal box, indicating MMC attenuated heroin reinforcement. Moreover, MMC (5 g/kg) was found to reverse the heroin­seeking on extinction trial 1 and 2. MMC was also found to reverse heroin­induced reinstatement in mice. This study demonstrates that MMC attenuated heroin seeking at different phases of drug self­administration in a mouse modified runway model.

Methanolic Extract of Morinda citrifolia L. (Noni) Unripe Fruit Attenuates Ethanol-Induced Conditioned Place Preferences in Mice.

Phytotherapy is an emerging field successfully utilized to treat various chronic diseases including alcohol dependence. In the present study, we examined the effect of the standardized methanolic extract of Morinda citrifolia Linn. unripe fruit (MMC), on compulsive ethanol-seeking behavior using the mouse conditioned place preference (CPP) test. CPP was established by injections of ethanol (2 g/kg, i.p.) in a 12-day conditioning schedule in mice. The effect of MMC and the reference drug, acamprosate (ACAM), on the reinforcing properties of ethanol in mice was studied by the oral administration of MMC (1, 3, and 5 g/kg) and ACAM (300 mg/kg) 60 min prior to the final CPP test postconditioning. Furthermore, CPPs weakened with repeated testing in the absence of ethanol over the next 12 days (extinction), during which the treatment groups received MMC (1, 3, and 5 g/kg, p.o.) or ACAM (300 mg/kg, p.o.). Finally, a priming injection of a low dose of ethanol (0.4 g/kg, i.p.) in the home cage (Reinstatement) was sufficient to reinstate CPPs, an effect that was challenged by the administration of MMC or ACAM. MMC (3 and 5 g/kg, p.o.) and ACAM (300 mg/kg, p.o.) significantly reversed the establishment of ethanol-induced CPPs and effectively facilitated the extinction of ethanol CPP. In light of these findings, it has been suggested that M. citrifolia unripe fruit could be utilized for novel drug development to combat alcohol dependence.