A comparative study of the phytochemical and anti-microbial properties of leaves of Loranthus micranthus harvested from six host trees, namely, Irvingia gabonensis, Pentaclethra macrophylla, Kola acuminata, Baphia nitida, Persea americana and Azadirachta indica, was carried out using standard methods. The result showed marked variations in phytochemical constituents and anti-microbial activities of the extracts from the different host trees, both kind and in degree. The extracts from K. acuminata, P. americana and to lesser extent, I. gabonensis showed marked broad-spectrum activities against bacteria and fungi. When compared with standard antibiotics (amoxycillin and ketoconazole) as controls, some of the extracts were found to be significantly more active than the control. The extract from P. americana exhibited significant anti-pseudomonal activity (P < 0.01) when compared to amoxycillin while the extracts from I. gabonensis, P. macrophylla and A. indica all showed significant activity (P<0.05) against Staph. aureus when compared to amoxycillin. Alkaloids were found to be most abundant in K acuminata; P. americana and I. gabonensis The preponderance of alkaloids in the extracts from K. acuminata, P. americana and I. gabonensis as compared to the extract from the other host plants could be suggestive of a relationship between alkaloidal content and the antimicrobial activity. Hence, during the preparation of Pharmaceutical /herbal formulation for the treatment of non- specific infections, mistletoe may be preferentially sourced from K. acuminata and P. americana.
Keywords: Mistletoe, host-tree variation, antimicrobial activity, phytochemical contents, Loranthus micranthus, comparative study.
Bio-Research Vol.2(1) 2004: 18-23