Browsing by Author "Chacha, Musa"

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    Antimicrobial activities of Tephrosia vogelii against selected pathogenic fungi and bacteria strains
    (2019-12-19) Mlozi, Stephano H.; Mmongoyo, Juma A.; Chacha, Musa
    Candida albicans and Cryptococcus neoformans are dangerous pathogens causing fungal dis eases. C. albicans and C. neoformans developed resistance to fungicides such as fluconazole. Similarly, pathogenic bacteria Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Salmonella typhi have become resistant to antibiotcs such as methicillin. Thus, searching for alternative antimicrobial agents is inevitable. Tephrosia vogelii used traditionally for manage ment of fungal and bacterial diseases is potential source of antimicrobial agents. It is in this vein that, antimicrobial activities of leaf and root extracts of T. vogelii were evaluated against C. albicans (ATCC 90028), C. neoformans (clinical isolate), S. aureus (ATCC25923), E. coli (ATCC29953), K. pneumoniae (ATCC 700603) and S. typhi (NCTC 8385). A two-fold serial dilution method using the sterilised 96 wells of polystyrene microlitre plates used to determine the minimum inhibitory concentration (MIC) of extracts. Hexane and dichloromethane extracts exhibited the lowest activity against fungi strains with MICs >10 mg/mL. Root and leaf methanolic extracts exhibited activity at MICs of 5 and 1.25 mg/mL, respectively, against both tested fungi. Dichloromethane and methanolic extracts exhibited antibacterial activity with MICs ranging from 2.5 - 10 mg/mL and 0.625 - 5 mg/mL, respectively. Antimicrobial activities of the extracts of T. vogelii revealed potentiality of bioactives against fungal and bacterial diseases.
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    Antimicrobial activities of Tephrosia vogelii against selected pathogenic fungi and bacteria strains
    (2020) Mlozi, Stephano Hanolo; Mmongoyo, Juma, A; Chacha, Musa
    Candida albicans and Cryptococcus neoformans are dangerous pathogens causing fungal diseases. C. albicans and C. neoformans developed resistance to fungicides such as fluconazole. Similarly, pathogenic bacteria Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Salmonella typhi have become resistant to antibiotcs such as methicillin. Thus, searching for alternative antimicrobial agents is inevitable. Tephrosia vogelii used traditionally for management of fungal and bacterial diseases is potential source of antimicrobial agents. It is in this vein that, antimicrobial activities of leaf and root extracts of T. vogelii were evaluated against C. albicans (ATCC 90028), C. neoformans (clinical isolate), S. aureus (ATCC25923), E. coli (ATCC29953), K. pneumoniae (ATCC 700603) and S. typhi (NCTC 8385). A two-fold serial dilution method using the sterilised 96 wells of polystyrene microlitre plates used to determine the minimum inhibitory concentration (MIC) of extracts. Hexane and dichloromethane extracts exhibited the lowest activity against fungi strains with MICs >10 mg/mL. Root and leaf methanolic extracts exhibited activity at MICs of 5 and 1.25 mg/mL, respectively, against both tested fungi. Dichloromethane and methanolic extracts exhibited antibacterial activity with MICs ranging from 2.5 - 10 mg/mL and 0.625 - 5 mg/mL, respectively. Antimicrobial activities of the extracts of T. vogelii revealed potentiality of bioactives against fungal and bacterial diseases.
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    Antimicrobial and Cytotoxicity Activity of Clausena Anisata, Acokanthera Shemperii and Olea Europaea Growing in Tanzania
    (2016) Makirita, Winisia E.; Chauka, Leonard J.; Chacha, Musa
    Aims: To evaluate antimicrobial and cytotoxicity activities of Clausena anisata, Acokanthera shemperii and Olea europaea against seven Gram negative bacteria and fungal species. Study Design: Bioassay of antimicrobial assay was done using 96-well micro-dilution method. Place and Duration of Study: School of Life Science and Bioengineering, Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania, from April 2014 to June 2014. Methodology: 96-well micro dilution method was used in antimicrobial assay. Extracts were loaded in the wells of the first row, followed by serial dilution and 50 µl of the bacterial suspensions (0.5 MacFarland standard turbidity) were added in each well. The first concentration which showed no bacterial growth was considered as minimum inhibition concentration. Method developed by Meyer et al 1982 was adopted in cytotoxicity activities. Results: All extracts indicated antibacterial activity on at least three to five of the tested seven bacteria and two fungi species with MIC value ranging 0.7812 - 12.5 mg/mL. The highest activity was demonstrated by Olea europaea leaf methanolic, Acokanthera shemperii stem bark and Clausena anisata twigs ethyl acetate extracts with MIC value of 0.7812 mg/mL against Pseudomonas aeruginosa while the same MIC value was exhibited by Olea europaea stem bark methanol against Proteus mirabilis. However the Olea europaea root methanolic extract inhibited the growth of Pseudomonas aeruginosa and Salmonella kisarawe with MIC value of 0.7812 mg/mL. Olea europaea leaf methanolic and stem bark methanolic which demonstrated high antimicrobial activity were non toxic against brine shrimp larvae with LC50 value of 369.8272 and 226.1566 µg/mL, while Clausena anisata twigs ethyl acetate, Acokanthera shemperii stem bark ethyl acetate and Olea europaea root methanolic extracts were toxic with LC50 value of 6.21276, 67.4179 and 92.3089 µg/mL respectively. Conclusion: This study has unveiled antimicrobial and cytotoxicity properties of Clausena anisata, Acokanthera shemperii and Olea europaea.
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    The in vivo toxicity evaluation of leaf and root methanolic extracts of Tephrosia vogelii Hook.f using animal model
    (2020-11-10) Mlozi, Stephano H.; Mmongoyo, Juma A.; Chacha, Musa
    Background: Traditionally, herbal medicines are commonly used to cure several diseases since immemorial of human life. Nevertheless, the safety of some traditionally used medicinal plants is uncertain. Since Tephrosia vogelii Hook.f is a traditionally used medicinal plant, the effects of its extracts were evaluated on lethality (LD50) and sub acute toxicity in this study. Methods: Phytochemistry screening and an in vivo toxicity evaluation of leaf and root methanolic extracts of T. vogelii using laboratory albino rats were conducted. Methanolic extracts of doses 600, 1200, 2000 and 5000 mg/kg body weights were administered single dose in rats to observe deaths within 72 h in order to determine the LD50. Methanolic extracts doses of 600, 1200 and 2000 mg/kg body weights were consecutively administered for 14 days in order to evaluate sub-acute toxicity. Results: Tannins, steroids, terpenoids, flavonoids and saponins were identified in the phytochemical screening. The LD50 experiments revealed zero deaths of rats for the administered doses, 600 to 5000 mg/kg body weight. Histopathological examination of liver and kidney for sub-acute toxicity test showed safety at all doses except root methanolic extracts dose of 2000 mg/kg which exhibited necrosis and vacuolation of liver cells on the 14th day. Nonetheless, hepatic necrosis and hepatic vacuolation disappeared upon time elongation without dose administration to 28th day. Conclusion: The conducted toxicity evaluation of methanolic leaf and root extracts in albino rats revealed no deleterious effects, henceforth, suggesting that T. vogelii could be safe to users using it as a medicinal plant. Keywords: Herbal medicines, Tephrosia vogelii Hook.f, Methanolic extracts, Lethality, Sub-acute toxicity
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    A new cinnamoylglycoflavonoid, antimycobacterial and antioxidant constituents from Heritiera littoralis leaf extracts
    (Taylor & Francis, 2014-01-21) Christopher, R.; Nyandoro, Stephen S.; Chacha, Musa; de Koning, C. B.
    A new cinnamolyglycoflavonoid 3-cinnamoyltribuloside (1), its precursor tribuloside and two known flavonoid glycosides afzelin and astilbin were isolated from Heritiera littoralis Dryand (Sterculiaceae) ethanolic leaf extract. The dichloromethane leaf extract afforded two known pentacyclic triterpenoids, 3β-taraxerol and friedelin. Extracts and compounds isolated therefrom, with the exception of 3β-taraxerol, exhibited antimycobacterial activity against the non-pathogenic Mycobacterium species Mycobacterium madagascariense and Mycobacterium indicus pranii, with a minimum inhibitory concentration (MIC) 5.0 mg/mL for the crude extracts and MICs in the range of 1.6-0.8 mg/mL for the pure compounds. The extracts together with 3-cinnamoyltribuloside (1), tribuloside and astilbin exhibited 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity. The compounds that showed dual activities could be further evaluated under clinical settings for co-administration with standard anti-tuberculosis drugs. Data on the essential oil composition of Fissistigma villosissimum, Fissistigma latifolium and Fissistigma glaucescens are reported for the first time.
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    Phytochemical Constituents of Vangueria Infausta: Their Radical Scavenging and Antimicrobial Activities
    (2007-01) Mbukwa, Elbert A.; Chacha, Musa; Majinda, Runner R. T.
    A new biflavonoid, 5,7,3',5'',7'',4'''-hexahydroxy (4'-O-3''')-biflavone (1) and a polyketide derivative, methylcylohex-1-ene (3) [previously reported only as a synthetic compound] were isolated from aerial parts of Vangueria infausta. In addition, eight other known flavonoids viz. (-)-epicatechin, epiafzelechin, dihydrokaempferol, quercetin, luteolin (2), dihydroquercetin-3'-O-glucoside, daidzein and genistein were also isolated from this plant. Structures were identified using 1D-and 2D NMR experiments as well as ESI-MS, IR and UV spectra. The new biflavonoid 1 showed higher radical scavenging activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) reagent compared to ascorbic acid (standard) using a spectrophotometric method. Compound 1 was less sensitive to Gram-positive and Gram-negative bacterial strains and yeast (Candida mycoderma) compared to luteolin and quercetin on the Bioautographic Agar Overlay Assay.