Celery (Apium graveolens) as a potential antibacterial agent and its effect on cytokeratin-17 and other healing promoters in skin wounds infected with methicillin-resistant Staphylococcus aureus

Abstract

Background and aim: Antimicrobial resistance is a global problem caused by extensive utilization of antibiotics that promote gene resistant among bacteria, including Staphylococcus aureus. This study aimed to analyze the potential effects of celery (Apium graveolens) extract as an antioxidant and antimicrobial agent against methicillin-resistant S. aureus (MRSA), in vitro and in vivo.

Materials and methods: Celery was extracted and tested against a MRSA isolate in vitro. The minimum inhibitory concentration (MIC) against MRSA for the celery extract (CE) was determined to be 0.1% and it was formulated into a cream. A total of 30 female Sprague Dawley rats were divided into five groups: Group 1, negative control; Group 2, positive control; Group 3, treated with 0.05% CE cream; Group 4, 0.1% CE cream; and Group 5, 0.2% CE cream. All animals in the groups were exposed to a full-thickness skin biopsy on the dorsal portion, and they were infected with 30 µL of 10⁵ colony-forming units of the MRSA isolate. The treatment was administered twice a day for 7 days. The skin samples were collected on days 3 and 7 after the treatment. The skin tissue was examined histologically using hematoxylin and eosin, Gram staining, and immunohistochemistry against cytokeratin (CK)-17.

Results: Results showed that 0.2% of CE cream was the best treatment for wounds infected with MRSA. CE (0.2%) cream increased skin reepithelialization, fibroblast proliferation, and CK-17 expression; it also decreased the percentage of wound area, inflammatory cell infiltration, and bacterial colonization in skin wound tissue compared to the other treatments (p≤0.05).

Conclusion: This study demonstrated that celery could be utilized as an alternative herbal therapy against MRSA-associated skin infections.

Keywords: antimicrobial; celery; cytokeratin-17; methicillin-resistant Staphylococcus aureus; wound healing.

Figure-1

Percentage of wound area. The gross lesion of skin wound infected with methicillin-resistant Staphylococcus aureus on the rat’s back (arrow) with the measurement indicator as follows: d1 = diameter 1 and d2 = diameter 2 (a); a trend of percentage of wound area from each group (b).

Figure-2

The score of inflammatory cells infiltration of skin wound infected with methicillin-resistant Staphylococcus aureus. The neutrophils that massively infiltrated on the wound tissue (arrow) (a); a trend of inflammation’s score from each group (b). H&E staining, 400× (a).

Figure-3

The epidermal thickness of skin wound infected with methicillin-resistant Staphylococcus aureus. The measured epidermis during morphometry (arrow) (a); a trend of epidermal thickness from each group (b). H&E staining, 400× (a).

Figure-4

The score of fibroblast proliferation of skin wound infected with methicillin-resistant Staphylococcus aureus. The fibroblast that proliferated on the wound tissue (arrow) (a); a trend of fibroblast’s score from each group (b). H&E staining, 400× (a).

Figure-5

The percentage of bacterial colonization of skin wound infected with methicillin-resistant Staphylococcus aureus. The bacterial colonizations were indicated with blue color (arrow) (a); a trend of bacterial colonization from each group (b). Gram staining, 400× (a).

Figure-6

The percentage of cytokeratin (CK)-17 expression on skin wound infected with methicillin-resistant Staphylococcus aureus. The high density of CK-17 expression (arrow) is shown by brown color in the suprabasal keratinocytes of wound tissue (A); a trend of CK-17 expression from each group (b). Immunohistochemistry antibody anti-CK-17, diaminobenzidine, 400× (a).