Uganda has one of the fastest growing populations in the world with a fertility rate of 6.7 and an annual population growth rate of 3.2%. This is due in part   to   low contraceptive use as a result of lack of access to safe and affordable contraceptives (UDHS 2011). The capacity to address the  world incidence   of unintended pregnancy and abortions lies in the ability to discover an alternative effective, safe and affordable contraceptive (WHO). The current contraceptive methods are associated with serious adverse effects such as: thromboembolic events, hepatic tumors, breast cancers, cardiovascular diseases, uterine cervical cancer, breakthrough bleeding, spotting, amenorrhea, diabetes mellitus, gall bladder disease, continuous change in healthy body metabolism (that is, causes migraine headaches, weight increase, moodiness, and loss of libido), hypertension, depression, abortion (Kahlenborn, 2006; Giannitrapani, 2006) which are inconveniencing and less satisfactory probing in adherence and acceptability problems. Despite plants are extremely exploited in traditional healing systems, only in some cases their therapeutic potential in human has been substantiated (Rad et al., 2013; Sharifi-Rad et al., 2013, 2014a, b). Screenings for anti-fertility activity of potential medicinal plants provided alternative safe and affordable contraceptive (Farnsworth, 1975). There are several plants that have been known to possess contraceptive activity (Mukund et al., 2012). Asparagus africanus Lam and Annona senegalensis Pers, locally known as “Ogwaro” and “Obwolo” respectively are some of the traditionally used anti-fertility plants in Abim, Uganda. However, there were no reports on both ethno botanical and pharmacological profile of these plants. A. africanus Lam (Liliaceae) is an erect armed herb that grows up to 5 ft high. The plant is widely distributed in tropical Africa. In traditional medicine, the plant is used for the treatment of headache, backache, stomach pain and as an aid in childbirth (Msonthi and Magombo, 1983), heamaturia, heamorrhoids (Desta, 1993), malaria, lishmaniansis, bilharziasis, syphilis and gonorrhoea (Oketch-Rabah et al., 1992). The root extract is applied externally for the relief of pain, rheumatism and chronic gout (Watt and Breyer-Brandurijk, 1962). It is also used as a diuretic, for sore throat and otitis (Oliver, 1960). Three steroidal saponins have been isolated from the roots of A. africanus (Debella et al., 1999). A. senegalensis takes the form of a small tree, growing between two and six meters tall. Occasionally, it may become as tall as 11 m. The plant is widely distributed in tropical Africa. It is among medicinal plants that have been documented to possess antibacterial effects (Muanza et al., 1994). It is also used in the treatment of wounds and infectious diseases such as diarrhea (Suleiman et al., 2008), periodontal and other oral infections (More et al., 2008). Furthermore, the anticonvulsant, sedative and muscle relaxant (Okoye et al., 2010) as well as anti-inflammatory (Okoye et al., 2011) effects of the root bark extract and fractions of A. senegalensis have been reported. This study was carried out to determine the antifertility activity of the crude extract of A. africanus Lam and A. senegalensis Pers root combination, with particular emphasis on phytochemical   screening,  determining  the toxicity profile and evaluating the anti-fertility effects using experimental models in rats.

Study site

The study was carried out in the Pharmaceutical Chemistry Laboratory, Biochemistry Laboratory and Animal Research Facility of Mbarara University of Science and Technology.

Study design

This was an experimental short term prospective research study.

Plant collection and extract preparation

The roots of A. africanus Lam and A. senegalensis Pers were collected from Abim district, North Eastern Uganda in January 2014. The plants were identified by a botanist at the Department of Plant Biology, the Herbarium section at Makerere University, Kampala main campus and authenticated and assigned the voucher numbers by a botanist at the Department of Plant Biology, Faculty of Science, Mbarara University of Science and Technology (Oscar P’Okello Okidi 001 and 002, respectively). The roots of the plants were washed and shade dried at room temperature for a period of 21 days, crushed using mortar and pestle to reduce the size and then blended using a blender to powder of which 400 g of the combined plant material in the ratio of 1:1 was cold macerated in distilled water for 24 h, filtered with filter paper (Whatman No.1) and the solvent evaporated using an oven at 65°C for 4 days resulting in the recovery of a brownish dark solid.

Experimental animals

Cyclic virgin female Sprague Dawley rats, 3 months old (200±10 g) were used for the acute toxicity testing and anti-fertility activity while the male rats were used for mating in the anti-fertility assay. All animals were housed in standard cages with uniform conditions of lighting (12 h dark: 12 h light cycle) and at room temperature. Animals were fed on pellet and tap water. Animals were handled in this study as per the National Institute of Health guidelines (1978) for the care and use of laboratory animals.

Phytochemical screening

Identification of the chemical constituents of the aqueous roots bark extract of A. africanus Lam and A. senegalensis Pers combination was carried out as per the method described by Trease and Evans (2009).

Determination of oral median lethal dose (LD₅₀)

The acute toxicity (LD₅₀) was determined in female rats by the method of Lorke (1983) using the oral route. The test was performed in one phase. Animals in the three different groups received oral administration of one of 5000, 8000, and 12,800 mg/kg (n=3) and observed for 24 h for mortality (number of deaths) and general behavior. The rats were further observed for fourteen more days for delayed toxicities and deaths.