JOURNAL OF COMPLEMENTARY MEDICINE RESEARCH, 2018 VOL 7, NO. 2, PAGES 161–170 eJManager 10.5455/jcmr.20171205011734 ORIGINAL RESEARCH Open Access Antitrypanosomal, antiplasmodial, and antibacterial activities of extracts from selected Diospyros and Annonaceae species Robert Christopher1,2,3, Quintino A. Mgani1, Stephen S. Nyandoro1, Amanda L. Rousseau2, Sandy F. van Vuuren3, Michelle Isaacs4, Heinrich C. Hoppe4 1Chemistry Department, College of Natural and Applied Sciences, University of Dar es Salaam, Dar es Salaam, Tanzania 2Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg, South Africa 3Department of Pharmacy and Pharmacology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa 4Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa ABSTRACT ARTICLE HISTORY Aim: To screen methanol extracts from root bark, leaves, and stem bark of selected plant Received December 05, 2017 species from the genus Diospyros and some Annonaceae species for antitrypanosomal, Accepted March 14, 2018 antiplasmodial, and antibacterial activities against selected test organisms. Published March 27, 2018 Methods: Antitrypanosomal and antiplasmodial assays of methanol extracts from KEYWORDS selected plant species were carried out in single concentration screens and in dose-re- sponse for active extracts. The minimum inhibitory concentration (MIC) values of Antitrypanosomal; selected plant extracts against selected bacterial strains were determined by microplate antiplasmodial; antibacterial dilution method in sterile 96-well microtiter plates. Results: In the dose-response antitrypanosomal assay, the most potent extracts tested exhibited activities against Trypanosoma brucei brucei (Lister 427 strain) with IC50 val- ues ranging from 1.28 to 7.85 μg/ml, with methanol extract of Diospyros verrucosa stem bark being the most active with IC50 value of 1.28 μg/ml. In the dose-response antiplasmodial assay, three extracts exhibited activities against Plasmodium falciparum (strain 3D7) with IC50 values ranging from 4.55 to 24.22 μg/ml, with methanol extract of Diospyros capricornuta root bark being the most potent with IC50 value of 4.55 μg/ml. In the antibacterial assay, the investigated extracts exhibited a wide range of activities against Staphylococcus aureus [American Type Culture Collection (ATCC) strain 25923], Bacillus cereus (ATCC strain 11775), and Escherichia coli (ATCC strain 8740) with MIC val- ues ranging from 0.00125 to 0.00625 mg/ml (more active), 0.125 to 0.500 mg/ml (mod- erately active), and 1.00 to 8.00 mg/ml (less active) while some extracts were inactive at the highest concentration tested of 16.00 mg/ml. Conclusions: Methanol extracts obtained from root bark, leaves, and stem bark of selected plant species from the genus Diospyros and some Annonaceae species that showed good activities in antitrypanosomal, antiplasmodial, and antibacterial assays corroborate reported literature about the traditional medicinal uses of the members of genus Diospyros and some Annonaceae species. Introduction malaria, and bacterial diseases are among the infec- Infectious diseases are the leading causes of death tious diseases with the highest epidemics [2]. worldwide. About 14.9 million annual human HAT, commonly known as sleeping sickness is a deaths worldwide are caused by infectious diseases disease caused by two subspecies of extracellular [1]. According to the World Health Organization protozoan parasites, namely Trypanosoma brucei (WHO), human African trypanosomiasis (HAT), gambiense and T. b. rhodesiense. The four drugs Contact Robert Christopher [email protected] Chemistry Department, College of Natural and Applied Sciences, University of Dar es Salaam, Dar es Salaam, Tanzania. © EJManager. This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License (http:// creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted, noncommercial use, distribution and reproduction in any medium, provided the work is properly cited. Robert Christopher, Quintino A. Mgani, Stephen S. Nyandoro, Amanda L. Rousseau, Sandy F. van Vuuren, Michelle Isaacs, Heinrich C. Hoppe currently available for the treatment of human with the Gram-negative bacterium, Escherichia coli African sleeping sickness are pentamidine, sur- which result in three clinical syndromes (namely diarrheal disease, urinary tract infections, and another drug, that was introduced in the market meningitis) is also resistant to available chemother- inamin, the melarsoprol,1960s for the and treatment eflornithine. of Chagas Nifurtimox, disease apies [9,10]. Thus, the development of antibacterial (human American trypanosomiasis), is restricted active plant extracts that can be used for the discov- to treatment of HAT in combination with other try- ery of antibacterial drugs is also necessary. panocidal drugs for patients who do not respond to Medicinal plants provide a reliable source of bio- - logically active compounds; and thus, a search for nithine combination therapy used for the treatment extracts that are active against parasitic protozo- oflate late stage stage medicines HAT, caused [3]. In by 2009, T. b. nifurtimox–eflorgambiense infec- ans such as trypanosomes and plasmodia as well tions, was included on the WHO essential medicines as pathogenic bacteria could aid the discovery of list. Despite the advancement in HAT treatment, the drugs. The genus Diospyros is known for various currently available drugs are unsatisfactory for var- traditional medicinal uses including for the treat- ious reasons including unacceptable toxicity, poor ment of HAT, malaria, headache, diarrhea, dysen- drug resistance [4]. This inspires the need to carry [11–18]. According to interviewed natives during outefficacy, ethnopharmacological undesirable route investigationsof administration, towards and tery, stomach ache, andDiospyros inflammatory natalensis conditions is used as a herbal remedy for the treatment of fever and may be investigated for the development of new internalthe field body excursion, pain [19]. Plant species in the fam- antitrypanosomalidentification of possible pharmaceuticals. active plant extracts that ily Annonaceae are also known for their uses as Malaria is a disease caused by infection of red traditional medicines for the treatment of various blood cells with protozoan parasites of the genus diseases. Greenwayodendron suaveolens is used as Plasmodium inoculated into the human host by a herbal remedy for the treatment of malaria and the blood-feeding female Anopheles mosquitoes. helminthiasis [20,21]. The genus Uvariodendron Treatment of malaria is also affected by drug resis- is used as a traditional medicine for the treatment tance. If different drugs with different mechanisms of resistance are used together, the emergence and root of Uvaria tanzaniae is used as a herbal remedy spread of resistance can be limited [5]. As a result, forof skin the controlinflammation of fever and [23]. liver In this disorders work, therefore,[22]. The combination therapy is used to reduce the develop- we report the in vitro antitrypanosomal, antiplas- ment of drug resistance, and most countries with P. modial, and antibacterial activities of extracts from falciparum malaria have adopted artemisinin-based selected Diospyros and some Annonaceae species. - tions. ACTs have been estimated to reduce malaria Materials and Methods mortalitycombination in children therapies aged (ACTs) 1–23 as months first-line by 99% medica and in children aged 24–59 months by 97% [6]. Despite Collection of plant materials the use of combination therapy, Plasmodium falci- The root bark, leaves, and stem bark of Diospyros parum species selected for the study were collected in countries in the Greater Mekong sub-region. Drug Tanzania as follows: D. bussei Gurke in June 2014 at resistance resistance has been to ACTsdocumented has been for detected all classes in five of Koloha-Kwakihande, Mkange village in Bagamoyo antimalarial chemotherapies and is a major threat district. GPS location: S 06°03'24.0", E 038°36'21.6”; to malaria control efforts [5]. Thus, the discovery elevation 196 m. Diospyros natalensis (Harv.) of antiplasmodial active plant extracts for poten- Brenan in May 2014 at Manolo Forest Reserve in tial drug development is important to increase the Lushoto District. GPS location: S 04°39'02.3", E number of alternative medicines available. 038°12'36.0". Diospyros squarrosa Klotzsch in May The Gram-positive bacterium Staphylococcus 2014 at Madala, Tuliani Village in Handeni District. aureus GPS location: S 05°40'18.7", E 038°05'20.4"; eleva- intestinal infections, and pneumonia. The emer- tion 595 m. Diospyros verrucosa Hiern in June 2014 gence of is strainsthe causative of S. aureus agent resistantof skin inflammations, to some anti- at Gongo Village in Bagamoyo District. GPS loca- biotics such as methicillin has been documented tion: S 06°09'57.8", E 038°37'33.1"; elevation 302 [7,8]. Bacillus cereus, a Gram-positive bacterium m. D. capricornuta F. White in June 2014 at Pugu that causes two types of gastrointestinal diseases forest reserve in Kisarawe District. GPS location: (the diarrheal and the emetic syndromes) together S 06°53'28.4", E 039° 05'56.3"; elevation 269 m. 162 J Complement Med Res • 2018 • Vol 7 • Issue 2 Antitrypanosomal, antiplasmodial, and antibacterial activities Diospyros kabuyeana F. White in June 2014 at Pugu The root