Bibu John KariyilVIDYAVARSHA S. J.2023-04-032023-04-032022-04-02https://krishikosh.egranth.ac.in/handle/1/5810196044Submitted in partial fulfilment of the requirement for the degree of Master of Veterinary Science in Veterinary Pharmacology and ToxicologyWound healing is a multidimensional process that involves four overlapping phases, including hemostasis, inflammation, proliferation, and remodelling, to restore damaged or wounded tissue. Wound infections impede wound healing and lead to chronicity. Staphylococcus aureus is the most common bacteria causing wound infections. Due to the haphazard use of antibiotics in humans and animals, methicillin-resistant S. aureus (MRSA) has developed resistance to practically all commercially available antibacterial drugs. Hence, the present study is envisaged to assess the wound healing activity of andrographolide and hordenine on infected wounds. The study was designed to evaluate the antibacterial activity and wound healing activity of andrographolide and hordenine. Kirby-Bauer agar disc diffusion method and modified resazurin microtiter plate assay were used to determine the antibacterial activity. MTT and scratch assays were used to evaluate the cell viability and cell migration of L929 mouse skin fibroblast cells. Angiogenesis activity was determined by chorioallantoic membrane (CAM) assay. In vivo MRSA infected excision wound healing study on male Wistar rats was conducted to evaluate the wound healing potential of andrographolide and hordenine. Both andrographolide and hordenine did not show any zone of inhibition against MRSA and S. aureus. While hordenine showed MIC of 1000 µg/mL against MRSA and S. aureus. An increase in the per cent mean cell viability in a concentration dependent manner from 10 to 100 µg/mL was observed. Among the treatment groups, andrographolide treated cells showed highly significant (P<0.001) per cent mean cell viability. Andrographolide and hordenine treated L929 cells reduced the cellular gap significantly (P<0.001) at day 3. Among the two treatments, the reduction in cellular gap was significant (P=0.002) for hordenine treated L929 cells. Andrographolide treatment increased the primary and secondary blood vessels significantly (P<0.001) than the hordenine treatment. Andrographolide and hordenine treatments significantly (P≤0.001) increased the number of tertiary and quaternary blood vessels. Andrographolide and hordenine showed significant (P=0.017, P=0.003 respectively) reduction in the per cent reduction in wound from day 6 onwards. The per cent reduction in wound was comparable for both the treatments on day 15. Significant (P<0.001) increase in hydroxyproline content in hordenine treated group was observed than the andrographolide treated group. The hexosamine content in both the andrographolide and hordenine treated groups were comparable. On histopathological examination, fibroblast proliferation, angiogenesis, collagen formation were confirmed. Andrographolide and hordenine accelerated wound healing by proliferation and migration of fibroblasts, and angiogenesis. Hence andrographolide and hordenine could be incorporated into the treatment of MRSA infected wound. The antibacterial activity of hordenine could be utilised against S. aureus and MRSA. Furthermore, the study could be extended to exploit the mechanism of antibacterial and wound healing properties of andrographolide and hordenine.EnglishThesis