In Vitro Antimicrobial Activity of Conyza bonariensis and Tribulus terrestris Growing in Tanzania

Objective: The aim of this study was to evaluate antimicrobial activity of Conyza bonariensis and Tribulus terrestris growing in Tanzania. Background statement: The improvement of antimicrobial agents has protected and improved human life from fatal diseases since their discovery. The increase in microbial drug resistance demands for new effective drugs of which medicinal plants are a promising source. Methods: Minimum inhibitory concentration (MIC) in 96- well micro dilution was used to determine antimicrobial activity. The method involved loading of 50 μL of Sabouraud’s dextrose broth in each well. Then, 50 μL of plant extract fetched from 100 mg/mL stock solution to form 100 μL. Thereafter, 50 μL of the mixture from the first rows was repeatedly down the columns until the last row where 50 μL were discarded. Subsequently, 50 μl of microbial suspensions was added in each well and incubated at 37°C for 24 hours. In each well, 20 μL of 0.02% Para-iodonitrotetrazolium chloride dye (INT) was added to micro plates in order to distinguish between the wells with live microbes from those with dead microbes. Results: All extracts demonstrated antimicrobial activity to tested bacterial and fungal strains. Seven extracts namely C. bonariensis leaf chloroform, C. bonariensis leaf ethyl acetate, C. bonariensis stem chloroform, C. bonariensis stem ethyl acetate, C. bonariensis root ethyl acetate, T. terrestris leaf ethyl acetate and T. terrestris root ethyl acetate inhibited Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhimurium, Salmonella typhi and Cryptococcus neoformans at 0.78125 mg/mL. Plant extracts demonstrated synergistic effect of their chemical components against the tested microbes. The strongest bactericidal and fungicidal of combined extracts was exhibited on E. coli and C. neoformans respectively. The extracts from C. albicans and T. terrestris revealed antimicrobial activity against seven tested microbes. Conclusion: It was concluded that C. bonariensis and T. terrestris can be considered as possible sources of antimicrobial drug leads upon further phytochemical investigations

In vitro antifungal and cytotoxicity activities of selected Tanzanian medicinal plants

Purpose: To evaluate the antifungal and cytotoxic activities of four medicinal plants from Tanzania, namely, Mystroxylon aethiopicum, Lonchocarpus capassa, Albizia anthelmentica and Myrica salicifolia.Methods: The plant materials were subjected to extraction using dichloromethane, ethyl acetate and distilled water. The minimum inhibition concentration (MIC) of the extracts against Candida albicans and Cryptococcus neoformans was determined by microdilution method. The lowest concentration which showed no fungal growth was considered as MIC. The cytotoxic effect of the extracts was determined using brine shrimp toxicity assay.Results: Lonchocarpus capassa leaf extracts exhibited antifungal activity against test fungal strains with MIC range of 0.78 – 3.13 mg/mL with Lonchocarpus capassa aqueous leaf extract (LCAL) inhibiting C. albicans and C. neoformans at MIC value of 0.78 mg/mL. Cytotoxicity assay revealed that LCAL extract which displayed good antifungal activity, was cytotoxic against brine shrimp larvae with halfmaximal lethal concentration (LC,sub>50) value of 17.86 μg/mL. Interestingly, 33 % of plant extracts exhibited high cytotoxicity with LC50 values below that of the standard anticancer drug, cyclophosphamide (16.57 μg/mL).Conclusion: The results obtained suggest that LCAL needs to be further investigated for its phytochemical composition to unravel its antifungal secondary metabolites. Furthermore, some of the plant extracts are potential anticancer agents.Keywords: Antifungal, Cytotoxicity, Brine shrimp, Mystroxylon aethiopicum, Lonchocarpus capassa, Albizia anthelmentica, Myrica salicifoli

Effect of Plant Powders on Survival, Oviposition and Progeny Development of Callosobruchus Maculatus for Protection of Leguminous Seeds during Post Harvest

This research article published by the International Journal of Science and Research, Volume 3 Issue 8, August 2014Insect infestation on leguminous plants particularly cowpea causes high destruction that lead to nutritional and economic losses. Hence powders from two medicinal plants namely Bersama abyssinica and Aristolochia elegans were tested for their efficacy as survival, oviposition and progeny development inhibitors of Callosobruchus maculatus to ensure food security. The experiments were conducted under laboratory temperature and relative humidity conditions and the powders were applied at rates 0.5g per 30g of cowpea seeds as contact toxicity to insects placed in Petri dishes. Results of contact toxicity assay showed that powders of Bersama abyssinica root bark and Aristolochia elegans seeds were effective against the adult C. maculatus by inducing 100% mortality within 5 days of application at the rate of 0.5g/30g of cowpea seeds. Few number of eggs approximately 1.50 ± 0.65 - 4.25 ± 0.65 per 50 seeds of cowpea seeds were oviposited and there was no progeny development of the cowpea weevil in seeds treated with plant powders. In untreated experiment the adult Callosobruchus maculatus survived and were able to lay eggs. The eggs were hatched and developed to F1 generation where 3.75 ± 0.25 approximately 45.8% adult C. maculatus emerged after 4 weeks .In the positive control, 100% mortality of C. maculatus occurred within 24 h and there was negligible seed loss in treated seed where as in untreated cowpea seed loss incurred by 37.00 ± 0.00 %. This study showed that all the tested plant powders were toxic to cowpea weevil thus could be applied by farmers by mixing with cowpea seeds to avert hatching of the eggs and development of larva, a destructive stage for management of insects and maintain nutritional and seed value in cowpeas

Cytotoxicity activity of some wild mushroom species from Southern Highlands of Tanzania

This research article was published in the American Journal of Research Communication Vol 2(9), 2014The crude extracts from six wild mushroom species (Russula cellulata, Afrocantharellussymoensis, Lactarius sp, Lactarius denigricans, Russula kivuensis, Amanita muscaria and Amanita phalloides) collected from the Southern Highlands of Tanzania were evaluated for cytotoxicity effects against Brine shrimp (Artemia salina) nauplii. The lethal concentration which kills 50% of the larva, LC50 (μg/mL) of the wild mushroom extracts was evaluated. The results showed that, A. muscaria ethanol (MS1E) and petroleum ether (MS1PE) extracts exhibited highest cytotoxicity activity with LC50 of 11.00 and 13.72 μg/mL respectively. Lactarius. denigricans ethanol extract (BM10E) also possessed highest cytotoxicity activity with LC50 of 12.77 μg/mL as compared to its petroleum ether extract (BM10PE) with LC50 of 18.96 μg/mL, followed by chloroform (BM10C) and acetone (BM10A) extracts with LC50 of 32.56 μg/mL and 47.79 μg/mL respectively. In contrast, petroleum ether extract of A. symoensis (BM6PE) showed non-toxic effect on Brine shrimp larvae with LC50 of 202.96 μg/mL. The study on cytotoxicity effect of wild mushrooms will give an insight into possibility of isolating stronger anticancer agents

Wild edible mushroom value chain for improved livelihoods in Southern Highlands of Tanzania

This research article was published in the American Journal of Research Communication Vol 2(8), 2014A survey was conducted to assess mycological knowledge and socio-economic benefits along the wild edible mushrooms value chain among Benna and Hehe ethnic groups in the Southern Highlands of Tanzania. The mushroom hunters, collectors, processors and retailers from the local communities in Njombe and Iringa regions were interviewed. The information on indigenous mycological knowledge, collecting and retailing of wild edible mushrooms in Benna and Hehe communities were gathered. The wild edible mushrooms were collected in the Miombo woodland surrounding six villages during rainy season in January 2014. From the survey, mushroom collection and selling was gender oriented dominated by women at 70% and 93.5% respectively. Moreover, it was found that 30% of men were involved in collecting and only 6.5% in selling. About 45 species of wild edible mushrooms were collected mainly from Lactarius, Russula, Cantharellus and Amanita species. Mushroom collectors were able to collect 1000 to 1500 kilograms earning US $500 to 650 per season. Also, retailers were able to sell 750 to 800 kilograms, earning US$ 750 to 1000 per season. Generally, wild mushrooms collection and retailing can contribute to improved socioeconomic status, thus providing alternative employment and food security to rural minority especially women and elderly in Benna and Hehe communities in the Southern Highlands of Tanzania

Evaluation of acute toxicity and sub-acute toxicity of the methanolic extract of Aloe rabaiensis Rendle in BALB/c mice

This research article was published by Academic Journals in Vol.13(13), 2019This study was undertaken to evaluate preclinical acute and sub-acute toxicity of Aloe rabaiensis leaf methanolic extract (ARLME) on BALB/c mice following OECD guidelines 423 and 407, respectively. In an acute oral toxicity test, ARLME was administered to the mice by oral gavage at a single dose of 1000, 2000, 3000, 4000 and 5000 mg/Kg body weight. The mice were observed for toxic signs for 14 days. In sub-acute oral toxicity test, ARLME was administered to the mice by oral gavage at 500, 800 and 1000 mg/Kg body weight daily up to 28th day. At the end of the test, haematological and biochemical analyses of the collected blood sample were carried out as well as gross and microscopic pathology. The control group (F) received a single oral dose of 0.5 mL of 1% DMSO in normal saline. In acute oral toxicity, no treatment-related death or toxic signs at the dosage below 4000 mg/Kg was observed. Nevertheless, at the dosage of 4000 and 5000 mg/Kg, drowsiness and sedation were observed. It was, therefore, revealed that ARLME could be tolerated up to the dose of 3000 mg/Kg body weight and may be classified as category 5. Sub-acute toxicity study at dosage 500 and 800 mg/Kg displayed no adverse changes in the haematological parameter, body weights and histopathological examination. However, at a dosage of 1000 mg/Kg, the serum biochemical aspartate transaminase and alanine transaminase increased, and in histopathological examination of liver and kidney, there was a proliferation of bile duct and leucocytes infiltration respectively. Thus, observations from this study indicate that oral administration of ARLME had no adverse toxic effects in BALB/c mice at the dosage below 1000 mg/Kg, hence supports the use of Aloe rabaiensis in drug formulations

Molecular identification of Salmonella Typhimurium from village chickens based on invA and spvC genes

This research article published by Veterinary World, 2020Aim: This study aimed to identify Salmonella enterica serovars by polymerase chain reaction (PCR) based on virulence genes invasion A (inv A) and Salmonella plasmid virulence C (spvC). Materials and Methods: DNA extraction of eight bacteria isolates was done using the PowerSoil® DNA Isolation Kit. The amplification of invA and spvC genes was done using conventional PCR. The positive PCR products were purified using the GeneJET Purification Kit and then sequenced using ABI 3730 XL automated genetic analyzer. The sequences obtained were compared for similarities with other Salmonella serovars deposited on the NCBI GenBank using BLASTN. Results: Four out of eight samples were amplified by primers FS139/RS141 that target invA gene with products of about 284 bp, and three out of four of the same invA positive samples were also amplified by primers FSPV-1/RSPV-2 targeting spvC with a product of about 571 bp. One sample was not amplified by primers FSPV-1/RSPV-2 as it lacked virulence plasmid. Analysis of sequences indicated 100% homology with closely related serovars of S. enterica subspecies enterica serovar Typhimurium. Conclusion: Salmonella Typhimurium that contained invA and spvC genes are pathogenic and virulent strain

Acute and sub-acute toxicity studies of chloroform extracts of cucumis metuliferus and lippia kituiensis in mice and rats model

This research article was published in the World Journal of Pharmaceutical Research Volume 9, Issue 2, 2020Objective: To evaluate the acute and sub-acute oral toxicity of Cucumis metuliferus and Lippia kituiensis leaf chloroform extracts in mice and rats model. Methods: Acute oral toxicity study of chloroform extracts of L. kituiensis and C. metuliferus was carried out by administration of 300, 600, 1500, mg/kg body weight to mice in the respective groups. The LD50 of the C. metuliferus and L. kituiensis extracts was determined to be not greater than 2000 mg/kg body weight. Sub-acute toxicity study was conducted by oral administration of the extracts at daily doses of 150, 300 and 500mg/kg body weight in the respective groups of rats for 28 days, and a positive control consisting of 1% DMSO and 5 mL was given to each. Results: In acute toxicity, all treated groups revealed neither mortality nor significant alteration in behavior, body weight, and hematology parameters. However, the significance different was observed in organ weight at a dose of 600mg/kg and 1500mg/kg of the tested plant extract in both plants. In sub acute study the result revealed neither mortality nor significant alteration in behavior between treated and control. The significant different was observed in body weight in all doses in both plants and organ weight and haematological parameter in dose level 300 mg/kg and 500 mg/kg compared to control. Moreover the significant change was observed in biochemical parameters of both sexes in dose of 300 mg/kg and 500 mg/kg body weight of C. metuliferus and L. kituiensis extract. A significant histological change was observed in liver, kidney, lungs and spleen in all extract of C. metuliferus and L. kituiensis in a dose of 300 mg/kg and 500 mg/kg body weight. Conclusion: These plants can causes‟ severe toxicity to animals

Chemical composition of ethanolic extracts of some wild mushrooms from Tanzania and their medicinal potentials

This research article was published in the International Journal of Medicinal Mushrooms Volume 18, Issue 5, 2016The ethanolic extracts of 5 edible and inedible wild mushrooms collected from the Southern Highlands of Tanzania were characterized by gas chromatography–mass spectrometry. A total of 75 chemical compounds were obtained, mainly fatty acids, carotenoids, alkaloids, phenols, terpernes, steroids, pyranoside, saccharides, and amino acids. Chemical compounds were identified from the ethanolic extract of Russula cellulata, R. kivuensis, Lactarius densifolius, L. gymnocarpoides, and Lactarius sp. In addition, mass spectra of 4 major groups of compounds were also determined. This study confirms the presence of some important bioactive compounds, such as essential fatty acids (oleic and linoleic), amino acids, and carotenoids. The reported chemical profiles give an insight into the use of wild mushrooms as a potential source of bioactive compounds for nutraceuticals and pharmaceuticals

In vitro Antimycobacterial Activity of Sterculia quinqueloba (Garcke) K. Schumand Canthium crassum Hiern

This research article published European Journal of Medicinal Plants, 2015Aim: To screen for the anti-mycobacterial activity of Canthium crassum and Sterculia quinqueloba using two mycobacteria species the Mycobacteria madagascariense and Mycobacteria indicuspranii. Study Design: In vitro assay of anti-mycobacterial 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-microtitre serial micro-dilution method was used to determine anti-mycobacteria activity to plant extracts. Results: All extracts exhibited anti-mycobacterial activity to both mycobacteria tested. The minimum inhibition concentration (MIC) ranged from 0.39 – 12.5 mg/mL, with ethyl acetate leaf extract of S. quinqueloba being the most active extracts with MIC value of 0.39 mg/mL against Mycobacteria madagascariense (MM) and 0.78 mg/mL against Mycobacteria indicuspranii (MIP). Petroleum ether and ethyl acetate leaf extract of C. crassum also gave MIC value of 0.78 mg/mL against MM and MIP. Conclusion: Findings from the present study showed that both plants exhibited activity against mycobacterium species tested. These plants may therefore serve as a source for new ant-mycobacterium drugs worth further studies including isolation and identification of the active compounds