Research paper Antimicrobial and anthelmintic potential of root and leaf extracts of Gazania krebsiana Less. subsp. serrulata (DC.) Roessler: An in vitro assessment Bongani Donnycath Tshabalala, Kazeem Adekunle Alayande, Saheed Sabiu, Anofi Omotayo Tom Ashafa* Phytomedicine and Phytopharmacology Research Group, Department of Plant Sciences, University of the Free State, QwaQwa Campus, Phuthaditjhaba 9866, South Africa A R T I C L E I N F O Article history: Received 6 July 2015 Received in revised form 17 March 2016 Accepted 17 March 2016 Keywords: Antimicrobial activity Anthelmintic activity Intestinal parasitic infections Phytochemical screening Gazania krebsiana A B S T R A C T Introduction: Phytotherapy has found relevance in the management and treatment of diseases in South Africa, particularly among the rural dwellers. In the present study, root and leaf extracts of Gazania krebsiana were investigated for antimicrobial and anthelmintic activities. Methods: G. krebsiana’s antimicrobial activity was evaluated against human pathogenic bacteria and fungi using agar well dilution method, while its anthelmintic activity was tested against gastrointestinal nematodes of sheep using egg hatchability and larvae mortality assays. Results: The extracts elicited varied degrees of antimicrobial activity with the ethanol extract showing the lowest minimum inhibitory concentrations (MICs) of 0.16–0.63 mg/mL. The activity of the water extract appeared to be the least with MICs ranging from 10 to 20 mg/mL on most of the isolates. At 10 mg/mL, both the ethanol and acetone root extracts of G. krebsiana caused 100% egg hatch inhibition, and competed well with Tramisol J . Similarly, except for ethanol extract, other leaf extracts displayed commendable and concentration-dependent anthelmintic activity of nearly 100% (90.70–93.70%) inhibitions and a corresponding 100% parasite mortality after 72 h exposure period at 10 mg/mL dose. Conclusion: The observed effects could be adduced to the presence of active principles as revealed by the phytochemical analysis of the extracts. There is a need for in vivo studies to complement the present findings, the data so far presented have validated and lent scientific support to the applications of G. krebsiana as a vermifuge and antimicrobial agent by the Basotho people of the eastern Free State of South Africa. ã 2016 Elsevier GmbH. All rights reserved. 1. Introduction Microbial and helmintic infections are one of the leading causes of morbidity and mortality in the world. It has been estimated that microbial species comprise about 60% of the Earth’s biomass. This, together with the fact that their genetic, metabolic and physiolog- ical diversity is extraordinary, makes them a major threat to the health and development of populations across the world [1]. Similarly, helminths as parasites are also a public health menace and have significantly contributed to the prevalence of anaemia, pneumonia, and malnutrition in tropical countries like South Africa [2,3]. Their impact on livestock may also be devastating as that could result in considerable economic losses in domestic animals [4]. More worrisome is the widespread antibiotic/ anthelmintic resistance, the emergence of new pathogens in addition to the resurgence of old ones, and the lack of effective new therapeutics that has exacerbated the complications of these infections. In fact, the risk of residue, availability and high cost of anthelmintics especially to low income farmers in developing countries, have led to the notion that sustainable helminth control with synthetic anthelmintics alone might be a mere dream. Thus, the need to discover and develop new antimicrobial agents and seek alternative strategies against gastrointestinal nematodes is critical to improving the health status and economic standard of mankind. Medicinal plants represent an alternative and a rich source of antimicrobial and anthelmintic agents. They are used therapeuti- cally in many quarters of the world and are a source of many pharmacologically potent and efficacious drugs [5]. In South Africa, traditional system of medicine is an integral part of culture and * Corresponding author. E-mail address: ashafaaot@ufs.ac.za (A.O.T. Ashafa). http://dx.doi.org/10.1016/j.eujim.2016.03.011 1876-3820/ã 2016 Elsevier GmbH. All rights reserved. European Journal of Integrative Medicine 8 (2016) 533–539 Contents lists available at ScienceDirect European Journal of Integrative Medicine journa l home page : www.e lsevier.com/eujim