ABSTRACT
Nigeria is geographically located North of the equator and is therefore known for having tropical climate and a mean annual temperature of 26.9⁰C. As a result, Nigerians are prone to high exposure to ultraviolet radiation from the sun which can result to a lot of dermatological conditions. Nigerians who are concerned about their skin often resort to using synthetic sunscreens and skin care products which can irritate the skin and cause allergic reactions hence the need for natural products In traditional medicine, Ocimum gratissimum L. is a herbaceous aromatic plant of the Lamiaceae family, popularly known as Clove basil. It has found useful role as an analgesic, anti-inflammatory, anthelminthic, antidiarrheal, anti-mutagenic, sedative, and also has antimicrobial activities. Therefore, this study is aimed at investigating physical parameters such as the specific gravity and refractive index of Ocimum gratissimum L., phytochemical constituents, antioxidant activities and Sun Protection Factor (SPF) of the essential oil of Ocimum gratissimum L. The Specific gravity and refractive index of Ocimum gratissimum L. essential oil was found to be 0.9025g/ml and 1.4959 respectively. Phytochemical screening of Ocimum gratissimum L. aqueous extract revealed the presence of alkaloids, saponins, phenolics, tannins, flavonoids, terpenoids, carbohydrate, reducing sugar and proteins. Five major compounds identified by GC-MS analysis were gamma-Terpinene (16.21%), thymol (15.44%), o-cymene (11.16%), bicyclo[3.1.0]hex-2- ene, 2-methyl-5-(1-methylethyl)- (5.42%) and beta.-Myrcene (4.73%). The SPF at 0.01%, 0.001% and 0.0001% were found to be 1.8663, 1.8053, 1.6287 respectively. In conclusion, the essential oil of Ocimum gratissimum L. possessed antioxidant and sun protection activities. Future studies will be carried out to characterise the chemical constituents.
