Potential Fatty Acid as Antibacterial Agent Against Oral Bacteria of Streptococcus mutans and Streptococcus sanguinis from Basil (Ocimum americanum): In vitro and In silico Studies

Ocimum Species: A Review on Chemical Constituents and Antibacterial Activity

Infection by bacteria is one of the main problems in health. The use of commercial antibiotics is still one of the treatments to overcome these problems. However, high levels of consumption lead to antibiotic resistance. Several types of antibiotics have been reported to experience resistance. One solution that can be given is the use of natural antibacterial products. There have been many studies reporting the potential antibacterial activity of the Ocimum plant. Ocimum is known to be one of the medicinal plants that have been used traditionally by local people. This plant contains components of secondary metabolites such as phenolics, flavonoids, steroids, terpenoids, and alkaloids. Therefore, in this paper, we will discuss five types of Ocimum species, namely O. americanum, O. basilicum, O. gratissimum, O. campechianum, and O. sanctum. The five species are known to contain many chemical constituents and have good antibacterial activity against several pathogenic bacteria.

Ingestional Toxicity of Radiation-Dependent Metabolites of the Host Plant for the Pale Grass Blue Butterfly: A Mechanism of Field Effects of Radioactive Pollution in Fukushima

Biological effects of the Fukushima nuclear accident have been reported in various organisms, including the pale grass blue butterfly Zizeeria maha and its host plant Oxalis corniculata. This plant upregulates various secondary metabolites in response to low-dose radiation exposure, which may contribute to the high mortality and abnormality rates of the butterfly in Fukushima. However, this field effect hypothesis has not been experimentally tested. Here, using an artificial diet for larvae, we examined the ingestional toxicity of three radiation-dependent plant metabolites annotated in a previous metabolomic study: lauric acid (a saturated fatty acid), alfuzosin (an adrenergic receptor antagonist), and ikarugamycin (an antibiotic likely from endophytic bacteria). Ingestion of lauric acid or alfuzosin caused a significant decrease in the pupation, eclosion (survival), and normality rates, indicating toxicity of these compounds. Lauric acid made the egg-larval days significantly longer, indicating larval growth retardation. In contrast, ikarugamycin caused a significant increase in the pupation and eclosion rates, probably due to the protection of the diet from fungi and bacteria. These results suggest that at least some of the radiation-dependent plant metabolites, such as lauric acid, contribute to the deleterious effects of radioactive pollution on the butterfly in Fukushima, providing experimental evidence for the field effect hypothesis.

Predominance of non-Streptococcus mutans bacteria in dental biofilm and its relation to caries progression

This study aims to assess differences in biofilm bacterial composition between patients with low and high caries. Patients without a medical problem and with no history of antibiotic use, mouth wash or fluoride application in the previous 3 months were recruited. Caries was recorded at cavitation level; score was calculated by a national mean (dmft of 4.8 and DMFT of 2.7). Pooled biofilm samples were collected from mesial, distal, buccal, lingual, and occlusal surfaces. Based on caries experience, individuals were classified into low and high caries and both groups were compared regarding bacteria identified using 16S rRNA gene sequencing, and molecular phylogenetic analysis of the isolates was performed. A total of twenty seven randomly selected samples with low (n = 13) and high (n = 14) caries. Identification of oral bacteria was performed using 16S rRNA sequence, Rothia mucilaginosa and R. aeria were identified in low caries individuals, while R. dentocariosa was detected in high caries individuals. Two Streptococcus spp. were identified only in low caries S. salivarius and S. gordonii whereas S. sanguinis, S. mitis, S. sinensis, S. rubneri, S. vestibularis, S. cristatus and S. massiliensis were identified only in individuals with high caries. This study revealed the absence of R. mucilaginosa in the high caries subjects and its coexistence with the low caries subjects. Streptococcus mutans was insignificant contributor of caries among samples, while, Streptococcus sanguinis was the main constituent of high caries Saudi patients.

Effectiveness and Anticancer Activity of a Novel Phenolic Compound from Garcinia porrecta Against the MCF-7 Breast Cancer Cell Line in vitro and in silico

Background

Cancer is a leading cause of death worldwide, with breast cancer being the most common invasive cancer type in women. Several therapeutic strategies have been explored to reduce the mortality rates of breast cancer. Chemotherapy is the most commonly used systemic treatment, but associated with numerous side-effects. Development of anticancer agents with high efficacy and minimal negative effects is therefore an important focus of research. Natural materials provide an excellent source of bioactive compounds. For instance, Garcinia porrecta from the Clusiaceae family has multiple pharmacological activities, including antioxidant, anti-inflammatory, antibacterial, antiviral, anti-HIV, antidepressant, and anticancer properties.

Purpose

The main objective of this study was to investigate the potential anticancer effects of compounds extracted from the bark of G. porrecta.

Materials and Methods

Our experiments were divided into three steps: (1) chromatographic isolation of compounds using various separation techniques, such as extraction, separation and purification, (2) characterization via infrared (IR), nuclear magnetic resonance (NMR) and mass spectroscopy, and (3) evaluation of anticancer activity in vitro (MTT assay) and in silico (via analysis of molecular docking against caspase-9, tumor necrosis factor alpha (TNF-α), estrogen receptor alpha (ER-α), and human epidermal growth factor receptor 2 (HER-2)).

Results

Depsidone (1) and benzophenone (2) from the ethyl acetate extract of bark of G. porrecta were identified as bioactive components. Examination of the activities of these compounds against MCF-7 cells revealed an IC₅₀ value of 119.3 µg/mL for benzophenone, whereas IC₅₀ for depsidone could not be estimated. Benzophenone activity was lower than that of the positive control doxorubicin (6.9 µg/mL). Depsidone showed the highest binding affinity for HER-2 (−9.2 kcal.mol-1) and benzophenone for ER-α (−8.0 kcal.mol-1).

Conclusion

Benzophenone displays potency as an anticancer agent through blocking ER-α.

Prediction Mechanism of Nevadensin as Antibacterial Agent against S. sanguinis: In vitro and In silico Studies

BACKGROUND

Streptococcus sanguinis can contribute to tooth demineralization, which can lead to dental caries. Antibiotics used indefinitely to treat dental caries can lead to bacterial resistance. Discovering new antibacterial agents from natural products like Ocimum basilicum will help combat antibiotic resistance. In silico analysis (molecular docking) can help determine the lead compound by studying the molecular interaction between the drug and the target receptor (MurA enzyme and DNA gyrase). It is a potential candidate for antibacterial drug development.

OBJECTIVE

The research objective is to isolate the secondary metabolite of O. basilicum extract that has activity against S. sanguinis through in vitro and in silico analysis.

METHODS

n-Hexane extract of O. basilicum was purified by combining column chromatography with bioactivity-guided. The in vitro antibacterial activity against S. sanguinis was determined using the disc diffusion and microdilution method, while molecular docking simulation of nevadensin (1) with MurA enzyme and DNA gyrase was performed used PyRx 0.8 program.

RESULTS

Nevadensin from O. basilicum was successfully isolated and characterized by spectroscopic methods. This compound showed antibacterial activity against S. sanguinis with MIC and MBC values of 3750 and 15000 μg/mL, respectively. In silico analysis showed that the binding affinity to MurA was -8.5 Kcal/mol, and the binding affinity to DNA gyrase was -6.7 Kcal/mol. The binding of nevadensin-MurA is greater than fosfomycin-MurA. Otherwise, Nevadensin-DNA gyrase has a weaker binding affinity than fluoroquinolone-DNA gyrase and chlorhexidine-DNA gyrase.

CONCLUSION

Nevadensin showed potential as a new natural antibacterial agent by inhibiting the MurA enzyme rather than DNA gyrase.

Insect Derived Lauric Acid as Promising Alternative Strategy to Antibiotics in the Antimicrobial Resistance Scenario

Antibiotic misuse is greatly contributing to an increase in antimicrobial resistance (AMR) in humans and animals. Natural and synthetic alternative strategies are being investigated in human and veterinary medicine, but little attention is paid to the antimicrobial effects of edible lipids, such as medium-chain fatty acids (MCFAs) and monoglycerides. Among MCFAs, lauric acid (LA) and its monoglyceride derivative, glycerol monolaurate (GML), exhibit the strongest antimicrobial activity. Coconut and palm kernel oils are considered the main sources of LA. On the other hand, some edible insects (e.g., Hermetia illucens) are gaining interest as novel feed ingredients, due to the high amount of LA they contain as well as their numerous bioactive components, which provide many additional benefits to animal health. Although the beneficial effect of both MCFAs and LA is gradually being recognized, their high content within insects and, consequently, their possible role as antimicrobials, has not been well-reported. This mini review focuses on the anti-infective effects of the insect-derived MCFAs LA and its derivatives. We emphasize the potential of insect lipids, compared to the other vegetable sources, in the current global scenario where a sustainable and circular economy is required. Finally, we critically discuss the use and the benefits of edible insects such as favorable options as feed and food from the perspective of animal and human nutrition.