Synthesis of silver nanoparticles using gum Arabic: Evaluation of its inhibitory action on Streptococcus mutans causing dental caries and endocarditis.

BACKGROUND: Streptococcus mutans are an oral pathogen that causes dental caries, endocarditis, and systemic dysfunctions, an alternative antibacterial solution from silver nanoparticles (AgNPs) are investigated. METHODS: AgNPs were synthesized using the ethnobotanical product gum Arabic. It influenced the nanoparticles with medicinal value through their role as capping, stabilizing, or surface-attached components. The biophysical characteristics of the synthesized AgNPs were studied using UV-vis spectrum, XRD, EDAX, SEM, and TEM tools. The AgNPs were spherical with the average size less than 10 nm. By using the well diffusion and microdilution techniques, the impact of synthesized AgNPs was tested against S. mutans isolates. RESULTS: The smaller the size, the greater the antibacterial and antiviral potential the particles exhibit. The biophysical characteristics of AgNPs the presence of phenols, alcohols, amides, sulfoxide, flavanoids, terpenoids and steroids. The AgNPs exhibited a good antibacterial action against the oral pathogen S. mutans. The synthesized NPs at a dose level of 200 µg/mL exhibited an inhibition zone with 18.30 ± 0.5 nm diameter. The synthesised nanoparticles inhibited the genes responsible for biofilm formation of S. mutans over host tooth and gums (gtfB, gtfc, gtfD) and virulent protective factors (comDE, brpA and smu 360) and survival promoter genes (gyrA and spaP, gbpB). CONCLUSION: The potent antibiotic action over S. mutans seen with the synthesized NPs, paves the way for the development of novel dental care products. Also, the small-sized NPs promote its applicability in COVID-19 pandemic containment.

Potential Role of Acacia Senegal (Gum Arabic) as Immunomodulatory Agent among newly diagnosed COVID 19 Patients: A structured summary of a protocol for a randomised, controlled, clinical trial.

OBJECTIVES: To investigate the potential efficacy of Acacia Senegal extract Gum Arabic (GA) supplementation as immunomodulatory and anti-inflammatory dietary intervention among newly diagnosed COVID 19 Sudanese patients. To study the effect of GA on the level of cytokines, TNFα, IL8, IL6 IL10, CRP and the viral load. Secondary outcomes will be the effect of GA oral intake on mortality rate and days of hospital admission. TRIAL DESIGN: Quadruple blind, randomized placebo-controlled clinical trial Phase II & III. Prospective, two-arm, parallel-group, randomised (1:1 allocation ratio) superiority trial of oral GA among seropositive COVID-19 patients. PARTICIPANTS: Inclusion criteria: COVID-19 infected (newly diagnosed) as proved by real-time PCR within 72 hours of PCR. Age 8-90 years Both genders Exclusion criteria: Intubated patients on parenteral treatment Allergy to Gum Arabic The study will be conducted in COVID Isolation Centres and Soba University Hospital Khartoum State Sudan. INTERVENTION AND COMPARATOR: Experimental: Intervention Group This arm will receive 100% natural Gum Arabic provided in a powder form in 30-grams-dose once daily for four weeks Placebo Comparator: Control group: This group will be provided with pectin powder provided as one-gram-dose once daily for four weeks Both GA and placebo will be in addition to standard care treatment based on local clinical guidelines. MAIN OUTCOMES: Mean change from baseline score of Immune Response to end of the trial. Changes of the level of Tumor Necrosis Factor (TNFα), interleukin IL8, IL6, and IL10 from the baseline values (Four weeks from the start of randomization). Mortality rate: The percentage of deaths among COVID 19 patients received Gum Arabic compared to placebo (Four weeks from the start of randomization]). RANDOMISATION: Randomization (1:1 allocation ratio) and will be conducted using a sequence of computer-generated random numbers by an independent individual. Each participating centre will be assigned a special code generated by the computer. The randomization will be kept by the PI and a research assistant. BLINDING (MASKING): Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) NUMBERS TO BE RANDOMISED (SAMPLE SIZE): 110 eligible patients will be randomly assigned to either GA (n=55) or placebo (n=55) groups. TRIAL STATUS: Protocol Version no 2, 30th June 2020. Recruitment will start on 15th September 2020. The intended completion date is 15th January 2021. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04381871 . Date of trial registration: 11 May 2020. FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.