In vivo Antistaphylococcal Activity Evaluation of Ocimum gratissimum Linn. (Lamiaceae) Ophthalmic Ointment

The goal of this study is to evaluate the antistaphylococcal potential of ophthalmic ointment obtained from the leaves of Ocimum gratissimum. Cutaneous and ocular tolerances of methanolic extract of O. gratissimum leaves were evaluated according to the Organisation for Economic Co-operation and Development (OECD) 404 and 405 Guidelines. Gentamicin ophthalmic ointment 0.3 % was used as antibiotic reference. In vivo antibacterial activity evaluation of the phytomedicine was carried out in rabbits infected by S. aureus CIP 4.83. During 15 days, three groups of 6 animals were treated as follows: the excipient (vaseline + liquid paraffin), gentamicin ointment and Ocimum gratissimum ophthalmic ointment (OGO). 0, 5% Good cutaneous and ocular tolerances of methanolic extract were observed. The microbial contamination control carried out on the 5th and 240th days showed that the prepared formulation is consistent with the preparation of cleanliness standards for topical application to the European Pharmacopoeia. The subconjunctival injection of S. aureus suspension caused mucopurulent acute keratoconjunctivitis with edema, and sometimes eyelid erythema. It is therefore on these ocular observations that therapeutic efficacy of the phytomedicine was evaluated. The treated rabbits without anti-infective agent have developed leucoma, eyelids swelling and conjunctiva hyperemia. Only one panophthalmitis case was observed. From the 1st to 5th days, we observed significant and gradual regression on ocular damages in animals treated with gentamicin. On the 15th day, the eye became normal; the rabbits showed no lesion on cornea. The batch treated with OGO is experiencing a similar trend. The in vivo therapeutic activity of the OGO was similar to that of gentamicin.