Browsing by Author "Mabiki, Faith P"

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Epifriedelanol is the key Compound to antibacterial Effects of extracts of synadenium glaucescens (pax) against Medically important bacteria
(Frontiers, 2023) Msengwa, Zaituni; Rwegoshora, Frank; David, Credo; Mwesongo, James; Mafuru, Magesa; Mabiki, Faith P; Mwang’onde, Beda J; Mtambo, Madundo M; Kusiluka, Lughano J. M; Mdegela, Robinson H; Olsen, John E
Introduction: Synadenium glaucescens has been used for the treatment of bacterial infections in many parts of the world. We investigated the antibacterial and cytotoxicity activities of secondary metabolites of this plant. Methods: Hexane, dichloromethane, methanol, and water were used as extraction solvents. The extract of the root bark was fractionated with ethyl acetate and methanol. The isolation of compounds from root barks, leaves and stem wood extracts were carried out using column chromatography. Antibacterial activities were characterized based on growth curves, killing curves and MIC determinations. Haemolytic effect towards sheep red blood cells (RBCs) was analysed with spectrophotometer at the wavelength of 540nm. Results and Discussion: Extracts from whole root and root bark showed strong activity against Staphylococcus aureus, and Streptococci and Enterococci species, and moderate to weak activity against Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella species, Shigella sonnei and Yersinia enterocolitica. Staphylococcus aureus was the most susceptible, and E. coli and Klebsiella pneumonia were the least susceptible ones. Likewise, extracts, fractions, sub-fractions and epifriedelanol demonstrated bacteriostatic activity against S. aureus. The haemolytic activity of the extracts, fractions, sub-fractions and epifriedelanol was significantly low compared to the positive control, hydrogen peroxide. But extract from leaves showed high haemolytic effects at the concentrations of 500 mg/mL and 1000 mg/mL. Thus, extracts of S. glaucescens have antibacterial activity against several Gram-positive bacteria including Methicillin Resistant S. aureus with low haemolytic activity. At high concentrations, the extracts from leaves have toxicity risk. More studies for the active compounds are required for biological testing.
Fungicidal effects of commiphora swynnertonii (burrt.) and synadenium Glaucescens (pax.) against tomato fusarium wilt disease
(Elservier, 2023) Madege, Richard R; Babu, Saidi; Mabiki, Faith P; Mtui, Hosea; Kudra, Abdul
Tomato fusarium wilt disease is an important soil-borne disease caused by Fusarium oxysporum f. sp. Lycopersici (FoL) worldwide. The disease causes yield losses of about 90% worldwide. This study aimed to evaluate the extracts of C. swynnertonii (resins) and S. glaucescens (latex, fresh and dry leaves) for their efficacy against FoL. In the laboratory, a 4 × 4 factorial experiment in a Complete Randomized Design (CRD) was carried out to evaluate resins, latex, fresh, and dry leaves each in four concentrations (0.01 g/ml, 0.05 g/ml, 0.1 g/ml and 0.15 g/ml). The negative and positive controls were Sterile Distilled Water (SDW) and a Linkmil 72 WP (Mancozeb 64% + Metalaxyl 8%) respectively. In a screenhouse, resins, latex, and fresh and dry leaves, each at 0.15 g/ml were applied on pre-inoculated tomato plants to manage TFW disease. The experiment was laid out in a Randomized Complete Block Design (RCBD) with four replications. The negative and positive controls were the untreated soil and soil treated with Linkmil 72 WP respectively. The differences between extracts in the in- hibition of radial mycelial growth of the pathogen were highly significant (p = 0.000). The efficacy of the plant extracts against in vitro growth of FoL was significantly dependent on the application dose. The inhibition of mycelial growth caused by latex and dry leaves was higher than that of Linkmil 72 WP (23.58%) and SDW (0%) by 41% and 65% respectively. Findings show that there was a TFW disease reduction of 72.92% 68.75% and 56.25% in plants treated with dry leaves, the latex of S. glaucescens, and resin of C. swynnertonii in that order. Plant extracts had significant effects (p = 0.000) on plant growth. The plants treated with dried leaf powder attained the highest height, the number of branches/plant, leaves/plant, and leaf area of 85.85 cm, 19.25,99.5 and 59.39 respectively. The findings benchmark the fungicidal potential of C. swynnertonii and S. glaucescens.
In vitro antibacterial potential of extracts of sterculia Africana, acacia sieberiana, and cassia abbreviata ssp. abbreviata used by yellow baboons (papio cynocephalus) for possible self-medication in Mikumi national park, Tanzania
(Hindawi, 2018) Kirabo, Irene; Mabiki, Faith P; Mdegela, Robinson H; Obbo, Christopher J. D
In the animals in general and nonhuman primates in particular self-medication has been widely reported; however, little is still known about the pharmacological activity of the extracts present in their daily diet. The in vitro antibacterial activity of the stem, root bark, and leaf extracts of three selected plants on which yellow baboons feed in an unusual manner in Mikumi National Park, Tanzania, was evaluated. Crude plant extracts were tested against Gram positive and Gram negative bacteria of medical and veterinary importance employing a modified agar well diffusion method and Minimum Inhibitory Concentration (MIC) technique. The lowest MIC value for Gram positive strains was 0.31 mg/ml demonstrated by Cassia abbreviata ssp. abbreviata against Staphylococcus aureus (ATCC 25923). The highest susceptibility to the ethanol plant extracts was exhibited by Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus, examples of microbes that affect both human and nonhuman primates. These findings demonstrate that the plant extracts from Sterculia africana, Acacia sieberiana, and Cassia abbreviata ssp. abbreviata have antibacterial activity and may be used as feed for their prophylactic benefits. Remarkably, the lowest MIC of 0.16 mg/ml was only 16-fold weaker than Gentamicin, a standard drug.
Isolation and cytotoxicity evaluation of long chain bioactive compounds from commiphora swynnertonii (Burtt)
(Journal of Scientific and Innovative Research, 2022) Mabiki, Faith P; Machumi, Francis; Chacha, Musa
Commiphora swynnertonii (Burtt) is a medicinal plant with diverse traditional uses in Tanzania. However, there is limited information on isolation and cytotoxicity properties of bioactive compounds responsible for its pharmacological activities. Hence, this study attempted to isolate and assess toxicity properties of bioactive compounds from its leaves, stem barks and whole root. Isolation of bioactive compounds was done by column chromatography method. There structures were deduced with the aid of NMR and GC-MS data and comparison with spectral data available in the literatures. Cytotoxicity evaluation was done by brine shrimp lethality test (BSLT) method. Chromatographic separation led to isolation of Hexacosane (1), Ethyl octadecanoate (2) and Octacosanol (3) from the leaves; Ethyl pentadecanoate (4) and Hexacosanoic acid (5) from the stem barks and Ethyl tetradecanoate (6), Methyl pentadecanoate (7) and Ethyl hexadecanoate (8) from the whole root. BSLT evaluation revealed that all compounds were non-toxic to brine shrimp larvae (LC 50 >100 μg/ml). This study reports the isolation of these compounds for the first time from this plant, moreover, their presence demonstrates the usefulness of C. swynnertonii as a good source of pharmacological active reported compounds which authenticate its diverse uses in traditional medicine. Furthermore, the revealed non-toxic effect of these compounds shows safety and possibly its traditional use has no cytotoxicity effect. Yet, further studies on toxicity of these compounds are recommended.
Scientific evidence for policy making: a missing link in higher learning institutions in Tanzania
(2022) Nyanda, Suzana S; Massawe, Fatihiya A; Mabiki, Faith P
Higher learning institutions are well known for their capacity to produce scientific evidence that can guide development initiatives in developing countries. Despite this acknowledgment, transferring research findings into policy and practice has remained to be a long-time challenge in Tanzania. An action research was conducted to assess the use of research findings generated from higher learning institutions in decision making. Specifically, the study aimed at establishing the level of awareness on the concept of scientific evidence for decision making among researchers; assessing the capacity of researchers in disseminating research findings to policymakers and examining the coordination of higher learning institutions in contributing to evidence informed decision making (EIDM). A survey was conducted on a total of 29 researchers from 9 higher learning institutions and 7 key informants from selected ministries and regulatory authorities. Descriptive statistics and content analysis were used for data analysis. Findings indicate that higher learning institutions are academic oriented as such the research findings generated are not synthesized, and not repackaged and presented in a user-friendly language for easy uptake by policymakers and implementers. Limited awareness of EIDM among researchers; and weak coordinated efforts for evidence generated from higher learning institutions to influence policy change were also reported. The study suggests capacity building among researchers on research findings synthesis and dissemination for EIDM. This will be coupled with the establishment of a research findings synthesis unit to facilitate the contribution of higher learning institutions in EIDM for the country’s socio-economic transformation.