An Eight-Week In Vivo Study on the Clinical Signs of Systemic Toxicity and Bone Regenerative Performance of Composites Containing Beta Tricalcium Phosphate, Hydrogel and Melatonin in Adult New Zealand Rabbit (Oryctolagus cuniculus)

@#Introduction: Melatonin (MEL) loaded alginate-chitosan/beta-tricalcium phosphate (Alg-CH/β-TCP) composite hydrogel has been formulated as a scaffold for bone regeneration. MEL in the scaffold was anticipated to accelerate bone regeneration. The objective of this study is to observe signs of systemic toxicity and physical changes on surface defected bone for bone regenerative performance of the composite. Methods: The proximal-medial metaphyseal cortex of the left tibia of New Zealand white rabbit was the surgical site of the defect. A total of nine rabbits were randomly allocated to three groups; Group I; implanted with MEL loaded Alg-CH/β-TCP, Group II; Alg-CH/β-TCP and Group III defects were sham control. The rabbits were daily observed to determine systemic toxicity effects by composites. The physical changes to implanted site were observed using digital x-ray radiography and computerized tomography at weeks 0, 2, 4, 6 and 8 of post-implantation. Results: There were no clinical signs of systemic toxicity for all groups of rabbits. Digital radiography did not show adverse effects to the bone. Computerized tomography showed reduction in the area size and depth volume of the implantation site, but accelerated regeneration within the 8 weeks was not significantly different (P<0.05) between the groups. Conclusion: Overall, the study suggests that Alg-CH/β-TCP composite scaffolds with and without the addition of MEL are compatible to bone. The composite scaffolds reduced the area size and depth volume of the implanted site within the 8-week duration. However, no remarkable difference in the accelerated reduction of area size and depth volume was observed.

Citrus aurontifolia and Cymbopogan flexuosus against Staphylococcus aureus and Escherichia coli

Abstract@#Introduction: Good hand hygiene is an important measure to avoid the transmission of infectious agents in the hospital and in the community. This study aimed to investigate the antimicrobial effects of Citrus aurantifolia (key lime) juice and the aqueous extract of Cymbopogan flexuosus leaves on the growth of Staphylocuccus aureus and Escherichia coli. Methods: Antimicrobial activity was quantitatively evaluated by spectrophotometry and viable cell count versus bacterial growth time. The efficacy of the plant extracts and the commercial hand wash product was also compared by measuring the number of bacterial colonies before and after using C. aurantifolia juice and commercial hand wash product. Results: In the kinetic growth study, C. aurantifolia juice and the aqueous extracts of C. flexuosus leaves effectively eliminated S. aureus and E. coli. C. aurantifolia juice also efficiently removed most of the microorganisms on the volunteers’ hand, indicating a significant finding in human trial compared to in vitro study. The percentage of microorganisms left after hand washing with C. aurantifolia juice was significantly reduced to 91.72 %, which was comparable with that of the commercial hand wash product (82.87 %). Conclusion: This study showed that these plant materials are promising alternatives for antibacterial agents in hand wash products. Further studies should be conducted on the use of C. aurantifolia juice as hand sanitiser given its antibacterial activities against endemic microbes