Acute Phase Response and Neutrophils？:？Lymphocyte Ratio in Response to Astaxanthin in Staphylococcal Mice Mastitis Model

The purpose of the study was to determine the immunotherapeutic effect of astaxanthin (AX) on total clinical score (TCS), C-reactive protein (CRP), and neutrophil？:？lymphocyte ratio in mice mastitis model challenged with pathogenic Staphylococcus aureus. Twenty-four lactating mice were divided in 4 equal groups: group I mice served as normal healthy control, group II, positive control, were challenged with pathogenic S. aureus, group III mice were challenged and treated with AX, and group IV were treated with amoxicillin plus sulbactum. The TCS was higher in postchallenged mice; however it was significantly higher in group II untreated mice as compared to group III and group IV mice. The neutrophil was higher and lymphocyte count was lower in group II mice at 120 hrs post challenge (PC). The CRP was positive in all the challenged group at 24 hrs PC, but it remained positive till 120 hrs PC in group II. The parameters are related to enhancement of the mammary defense and reduction of inflammation. Hence AX may be used alone or as an adjunct therapy with antibiotic for amelioration of mastitis. Development of such therapy may be useful to reduce the antibiotic burden in management of intramammary infection. 1. Introduction Bovine mastitis is the inflammation of the mammary gland frequently resulting from Staphylococcus aureus colonization in the mammary parenchyma causing high economic losses despite intensive research and preventive measures [1]. In vitro antibacterial sensitivity of commonly used antibioticswas demonstrated by several researchers for S. aureus isolates [2]; however the pathogen remains difficult to eradicate with the available antibiotics. Failure in treatment could be due to nonavailability or weak penetration of the antibiotics as the organism survives intracellularly. The greatest demerits of antibiotic treatment are the development of multiple drug resistant bacterial strains and residues in the milk which possess human health hazard. World Health Organization [3] emphasizes need of judicial use of antimicrobials to combat antimicrobial resistance and also to encourage the development of novel preventive and therapeutic aids. Hence search is going on globally for an alternative to antibiotic, or to reduce its dose and duration for therapy. Astaxanthin (AX) is a xanthophyll carotenoid, predominantly of marine origin and naturally obtained from the chlorophyte algae Haematococcus pluvialis [4]. Astaxanthin is a highly potent antioxidant apart from it, it anti-inflammatory, immunomodulatory and antibacterial activities [5–8].