Berberine and Cyperus rotundus extract nanoformulations protect the rats against Staphylococcus-induced mastitis via antioxidant and anti-inflammatory activities: role of MAPK signaling

Berberine (BER) and Cyperus rotundus rhizomes extract (CRE) are phytochemicals characterized by broad-spectrum pharmacological activity that could tackle the side effects of conventional mastitis therapies, however, they undergo a modest bioavailability. In the current study, nanoformulations of BER and CRE chitosan hydrogel (BER/CH-NPs, CRE/CH-NPs) were investigated for their antibacterial, antioxidant, anti-inflammatory and anti-apoptotic effects against S. aureus-induced mastitis in a rat model. The experiment was conducted on 80 early lactating female albino rats allocated into 6 groups; control, mastitis, BER/CH-NPs (1 and 0.5 mg), CRE/CH-NPs (0.5 and 0.25 mg), BER/CH-NPs + CRE/CH-NPs (0.5 + 0.25 and 0.25 + 0.125 mg). The nanoparticles were given by oral gavage once every other day from day 2 to day 12 after parturition. On the 13^th day, intra-mammary inoculation with 100 µl of S. aureus suspension containing 2.1 × 10⁸ CFU/ml in all groups except the control group. The results expressed the effect of BER/CH-NPs and CRE/CH-NPs on mammary gland tissue including significantly diminished viable bacterial load as well as attenuated the levels of MPO, MDA, caspase-3 with elevating Nrf2 level, and modulating glutathione redox. Also, the nanoformulations resulted in attenuation of the mRNA expression of TLR2, NOD2, Keap-1 and MAPK signaling pathway additional to the immune reactivity of NF-κB P65 and p-ERK as well as the preservation of the regular alveolar architecture. The supplementation of the berberine and Cyperus rotundus extract nanoformulations could be a prospective protective approach against Staphylococcal mastitis via their antibacterial, antioxidant, antiapoptotic, anti-inflammatory and modulation of MAPK signaling pathway.