~1~ International Journal of Herbal Medicine 2014; 2 (3): 01-04 ISSN 2321-2187 IJHM 2014; 2 (3): 01-04 Received: 12-09-2014 Accepted: 01-10-2014 Samuel N. Osei-Djarbeng Department of Pharmaceutical Sciences, Kumasi Polytechnic, P. O. Box 854, Kumasi, Ghana. Jacob Amonoo-Neizer Department of Pharmaceutical Sciences, Kumasi Polytechnic, P. O. Box 854, Kumasi, Ghana. Portia Boadi Department of Pharmaceutical Sciences, Kumasi Polytechnic, P. O. Box 854, Kumasi, Ghana Priscilla N.A. Opoku Department of Horticulture, Faculty of Agriculture, College of Agriculture and Natural Resources, KNUST, Kumasi- Ghana. Samuel Osei-Asante Department of Pharmaceutical Sciences, Kumasi Polytechnic, P. O. Box 854, Kumasi, Ghana. Correspondence: Samuel N. Osei-Djarbeng Department of Pharmaceutical Sciences, Kumasi Polytechnic, P. O. Box 854, Kumasi, Ghana Comparative antimicrobial activities of different solvent extracts and a refreshing drink (Sobolo) made from Hibiscus sabdariffa Linn. Samuel N. Osei-Djarbeng, Jacob Amonoo-Neizer, Portia Boadi, Priscilla N.A. Opoku, Samuel Osei-Asante. Abstract The calyx of Hibiscus sabdariffa is used in making refreshing drinks in many parts of Africa including Ghana. The aim of the current study is to find out if a refreshing drink prepared from the calyx (known as sobolo) has antimicrobial activity and also to compare the antimicrobial activities of different solvent extracts of the calyx; using the agar well diffusion and the micro-broth dilution methods. Sobolo showed the greatest antimicrobial activity with average diameter of zone of inhibition in the range 12–19 mm against the microbes employed in the study. The polar extracts exhibited the greatest antimicrobial activity with MICs of 125–250 µg/ml against the bacteria, and 1000 µg/ml against the fungi. The medium polar solvent extract showed average activity and the non-polar one, the least activity. The study has shown that sobolo has antimicrobial activity, and that polar solvents are more effective in the extraction of the antimicrobial principles in the plant. Keywords: Sobolo, Hibiscus sabdariffa, refreshing drink, antimicrobial activity. 1. Introduction In many developing countries greater number of the population employ folk medicine for the treatment of diseases and infections of common occurrence [1] . Many traditional healers have claimed that medicinal plants are more effective, cheaper and more organic than modern medicine. It is believed that inhabitants of rural communities where plants are the main source of medication, and those who take in a lot of vegetables, fruits, seeds, plant juices and other products from plants have a reduced risk of getting infectious diseases from resistant pathogens. This is probably due to the fact that these plants and/or their products contain numerous compounds that may have antimicrobial activities; perhaps acting as prophylaxis for those who use these plants. It is possible that many medicinal plants used as condiments, spices or for culinary and other purposes may still exert their medicinal activities when used for these non-medicinal purposes. One such plant worth investigating is Hibiscus sabdariffa. H. sabdariffa Linn belongs to the plant family Malvacaea, the same family to which popular plants such as Cola nitida (cola) and Theobroma cacao (cocoa) belong. The genus Hibiscus has more than forty species; the species sabdariffa being one of the most common ones, perhaps because of its numerous therapeutic claims in many parts of the world. H. sabdariffa is an important annual or perennial erect, mostly branched, shrub that is grown successfully in tropical and sub-tropical climates [2] . It takes about five months from planting to harvesting. The plant is widely cultivated for commercial purposes in the Tropical and Sub-tropical regions for its fibre and edible calyx; the most important part being the fleshy calyx (sepals) that surrounds the fruit (capsules). Additionally, it is grown for culinary and ornamental purposes in much of the tropical world. The plant is known by different names in different parts of the world. These include roselle, razelle, sorrel (red sorrel, Jamaican sorrel, Indian sorrel, Guinea sorrel) sour-sour, and Queensland jelly plant [3] . According to Kays [4] the Japanese call it rohzelu; and the Hindus, lal-ambari, patwa or laalambaar; it is also called sabdriqa or lalambari in Urdu. The Yorubas of southwestern Nigeria call it 'Isakpa' [5] . Roselle (H. sabdariffa) has many traditional and medicinal uses around the world. In Chinese traditional medicine and also in Senegal it is used in the management of hypertension, as well