Assessment of heavy metals in Hibiscus sabdariffa calyces and Moringa oleifera leaves collected from different areas in Tanzania

Medicinal plants are known in prevention and curing of diseases. Contamination of medicinal plants by heavy metals is one of the factors affecting quality of medicinal products from medicinal plants. Heavy metals may enter the edible and medicinal plants through contaminated environment such as water bodies, air or soil.  Hibiscus sabdariffa calyces and Moringa oleifera leaves are used in Tanzania as nutritional and disease-remedial herbal drinks. This study assessed heavy metal contamination of Hibiscus sabdariffa calyces and Moringa oleifera leaves collected from Dodoma region (Vikonje, Msanga, Nzuguni A and Nzuguni B village), Pwani region (Kongowe and Chalinze village) and Shinyanga region (Mwime village). Lead, arsenic, chromium, cadmium and mercury were analyzed by Atomic Absorption Spectrometry. Microsoft excel 2010 software were used to analyze the means of heavy metal concentrations. Levels of chromium in the calyces and leaves of H. sabdariffa and M. oleifera ranged between 0.029-0.221 ppm and 0.019-0.088 ppm respectively while Arsenic was 0.096-0.204 ppm and 0.096-0.219 ppm, respectively. Mercury and Lead were found only in leaves of M. oleifera, mercury was between 0.017 ppm and 0.042 ppm and lead was 0.056 ppm. Cadmium was not detected in all plant materials. The concentrations of heavy metals in the selected samples were statistically significant at (P˂0.05). M. oleifera leaves and H. sabdariffa calyces, collected from different regions, had the low levels of heavy metals than recommended limits provided by the Tanzania Medicine and Medical Devices Authority (TMDA) and WHO

Mosquito Larvicidal Constituents from Lantana Viburnoides SP Viburnoides Var Kisi (A. rich) Verdc (Verbenaceae).

\ud \ud Lantana viburnoides sp viburnoides var kisi is used in Tanzania ethnobotanically to repel mosquitoes as well as in traditional medicine for stomach ache relief. Bioassay-guided fractionation and subtraction bioassays of the dichloromethane extract of the root barks were carried out in order to identify the bioactive components for controlling Anopheles gambiae s.s. mosquito larvae. Twenty late III or early IV instar larvae of An. gambiae s.s. were exposed to various concentrations of the plant extracts, fractions, blends and pure compounds, and were assayed in the laboratory by using the protocol of WHO 1996. Mean mortalities were compared using Dunnett's test (p < 0.05) and lethal concentration calculated by Lackfit Inversel of the SAS programme. The crude extract (LC50 = 7.70 ppm in 72 h) and fractions exhibited different level of mosquito larvicidal activity with subtraction of some fractions resulting in activity enhancement. The active fractions contained furanonaphthaquinones regio-isomers (LC50 = 5.48-5.70 ppm in 72 h) and the lantadene triterpenoid camaric acid (LC50 = 6.19 ppm in 72 h) as active principles while the lupane triterpenoid betulinic acid (LC50 < 10 ppm in 72 h) was obtained from the least active fraction. Crude extracts and some fractions had higher or comparable larvicidal activity to the pure compounds. These results demonstrate that L. viburnoides sp viburnoides var kisi extracts may serve as larvicides for managing various mosquito habitats even in their semi-purified form. The isolated compounds can be used as distinct markers in the active extracts or plant materials belonging to the genus Lantana

In vitro study for antifungal compounds from Parinari curatellifolia (Chrysobalanaceae) and Terminalia sericea (Combretaceae)

Parinari curatellifolia (Chrysobalanaceae) and Terminalia sericea (Combretaceae) have been traditionally used in Southern Highlands of Tanzania for treatment of various infectious disorders. The present study aimed to evaluate antifungal activity of the isolated&nbsp; compounds from Parinari curatellifolia and Terminalia sericea plant species. The ethyl acetate extract of the root barks from Parinari curatellifolia and Terminalia sericea were fractionated using column chromatography. The structures of compounds were established using both 1D and 2D-NMR spectroscopic techniques while antifungal activities of the fractions and isolated compounds were evaluated using broth microdilution assay against Candida albicans, Cryptococcus neoformans and Aspergillus niger species. Two known compounds toddalolactone (1) and 10-hydroxy-13-methoxy-9- methyl-15-oxo-20-norkaur-16-en-18-oic acid -lactone (2) from P. curatellifolia and two compounds Sericic acid (3) and sericoside (4) from T. sericea were isolated and their structures identified and confirmed by spectral data obtained and from the literatures. Strong antifungal activity was shown by Sericic acid (3) with MIC value of0.07 mg/ml against C. albicans and C. neoformans. Isolation of toddalolactone (1) from Parinari curatellifolia as well as the antifungal activity of Sericic acid (3) from Terminalia sericea is being reported for the first time. Bioactivity of these compounds support traditional use of the studied plants. Keywords: Sericic acid, toddalolactone, fungi, antifungal, Parinari curatellifolia, Terminalia sericea

Antibacterial and cytotoxic activities of Terminalia stenostachya and Terminalia spinosa

Plants that belong to the Combretaceae family have long history of use in the traditional medicine systems of Africa and Asia for treatment of diseases and conditions associated with HIV/AIDS-opportunistic infections. The objective of this study was to investigate the biological activities of extracts of Terminalia stenostachya Engl. & Diels and Terminalia spinosa Engl. (Combretaceae), to verify the rationale for their use by traditional health practitioners in the treatment of HIV/AIDS patients in Tanzania. Extracts of the leaves, stem barks and roots of T. stenostachya and extracts of stem barks and roots of T. spinosa have all shown strong activity against a number of standard microbial strains including Mycobacterium madagascariense and Mycobacterium indicus pranii, Streptococcus faecalis, Staphylococcus aureus, Vibrio cholera, Bacillus anthracis, Bacillus subtilis, Klebsiella pneumoniae, Salmonella typhi, Pseuodomonas aeruginosa and Escherichia coli. All extracts from the two plant species showed strong antimycobacterial activity against test organisms. The stem and root bark extracts were more active than leaves against both gram positive and negative bacteria. With the exception of two extracts from stem barks of T. spinosa, all other extracts from T. stenostachya and T. spinosa that were tested exhibited less activity against brine shrimp larvae with LC50 values ≥100µg/mL compared to cyclophosphamide, a standard anticancer drug. These results provide an indication that these plants may possess therapeutically potent antimicrobial compounds worth further development

Constituents of the Essential Oil of Suregada zanzibariensis Leaves are Repellent to the Mosquito, Anopheles gambiae s.s.

In traditional African communities, repellent volatiles from certain plants generated by direct burning or by thermal expulsion have played an important role in protecting households against vectors of malaria and other diseases. Previous research on volatile constituents of plants has shown that some are good sources of potent mosquito repellents. In this bioprospecting initiative, the essential oil of leaves of the tree, Suregada zanzibariensis Verdc. (Angiospermae: Euphobiaceae) was tested against the mosquito, Anopheles gambiae s.s. Giles (Diptera: Culicidae) and found to be repellent. Gas chromatography (GC), GC-linked mass spectrometry (GC-MS) and, where possible, GC-co-injections with authentic compounds, led to the identification of about 34 compounds in the essential oil. About 56% of the constituents were terpenoid ketones, mostly methyl ketones. Phenylacetaldehyde (14.4%), artemisia ketone (10.1%), (1S)-(-)-verbenone (12.1%) and geranyl acetone (9.4%) were the main constituents. Apart from phenylacetaldehyde, repellent activities of the other main constituents were higher than that of the essential oil. The blends of the main constituents in proportions found in the essential oil were more repellent to An. gambiae s.s. than was the parent oil (p < 0.05), and the presence of artemisia ketone in the blend caused a significant increase in the repellency of the resulting blend. These results suggested that blends of some terpenoid ketones can serve as effective An. gambiae s.s. mosquito repellents

Renal function outcomes in patients receiving TDF-containing antiretroviral therapy : a retrospective pilot study in Namibia

Introduction and aims: Combination antiretroviral therapy (cART) has improved morbidity and mortality in patients with HIV across countries including countries in sub-Sahara Africa. However, cART is associated with renal impairment. The lack of pre-cART data in a recently published study limited the discussion on renal-based treatment outcomes with cART, which could have important clinical implications. Consequently, the aim of this paper is to correct this. Methods: Longitudinal retrospective study, with renal function assessed pre-cART and at various time points on cART using the Cockcroft-Gault method. The data source was the patients’ care booklets. Results: 71 patients were included. The majority were adults and female. Before cART initiation, 70.4% and 29.6% had abnormal and normal CrCl, respectively. CrCl was normalised in 24% of patients, while abnormal in the remainder. The mean (median) time to normalisation was 47.4(33.7) months, observed more in paediatric than adult patients (p =0.014). However, in paediatric patients, normalisation took longer than in adult patients. The reduction in CrCl, was observed at variable time points. 9/16 patients experienced a decline during first-line cART and 7 of these were receiving TDF. 7/16 experienced this during second-line cART and 6 were receiving TDF. Conclusion: HIV is typically the cause of renal impairment prior to cART, with TDF likely to be the cause of renal impairment during cART. Consequently, co-administration of TDF with other nephrotoxic drugs should be undertaken with caution if unavoidable. Overall, improvement in renal impairment was faster in adults

Antibacterial, Anti-HIV-1 Protease and Cytotoxic Activities of Aqueous Ethanolic Extracts from Combretum Adenogonium Steud. Ex A. Rich (Combretaceae).

\ud \ud Records have shown that Combretum adenogonium Steud. Ex A. Rich (Combretaceae) is used in traditional medicine systems of several tribes in Tanzania. This study focused on the investigation of antibacterial activity, anti-HIV-1 protease activity, toxicity properties and classes of phytochemicals in extracts from C. adenogonium Steud. Ex A. Rich (Combretaceae) to evaluate potential of these extracts for development as herbal remedies. Dried plant material were ground to fine powder and extracted using 80% aqueous ethanol to afford root, leaf and stem bark extracts. The extracts were assayed for anti-HIV-1 protease activities, antibacterial activities using microdilution methods and cytotoxicity using brine shrimps lethality assay. Screening for major phytochemical classes was carried out using standard chemical tests. All extracts exhibited antibacterial activity to at least one of the test bacteria with MIC-values ranging from 0.31-5.0 mg/ml. Two extracts, namely, root and stem bark exhibited anti-HIV-1 PR activity with IC50 values of 24.7 and 26.5 μg/ml, respectively. Stem bark and leaf extracts showed mild toxicity with LC50 values of 65.768 μg/ml and 76.965 μg/ml, respectively, whereas roots were relatively non-toxic (LC50 = 110.042 μg/ml). Phytochemical screening of the extracts indicated presence of flavonoids, terpenoids, alkaloids, tannins, glycosides and saponins. These results provide promising baseline information for the potential development of C. adenogonium extracts in treatment of bacterial and HIV/AIDS-related opportunistic infections

Larvicidal, antimicrobial and brine shrimp activities of extracts from Cissampelos mucronata and Tephrosia villosa from coast region, Tanzania

<p>Abstract</p> <p>Background</p> <p>The leaves and roots of <it>Cissampelos mucronata </it>A. Rich (Menispermaceae) are widely used in the tropics and subtropics to manage various ailments such as gastro-intestinal complaints, menstrual problems, venereal diseases and malaria. In the Coast region, Tanzania, roots are used to treat wounds due to extraction of jigger. Leaves of <it>Tephrosia villosa </it>(L) Pers (Leguminosae) are reported to be used in the treatment of diabetes mellitus in India. In this study, extracts from the roots and aerial parts of <it>C. mucronata </it>and extracts from leaves, fruits, twigs and roots of <it>T. villosa </it>were evaluated for larvicidal activity, brine shrimps toxicity and antimicrobial activity.</p> <p>Methods</p> <p>Powdered materials from <it>C. mucronata </it>were extracted sequentially by dichloromethane followed by ethanol while materials from <it>T.villosa </it>were extracted by ethanol only. The extracts obtained were evaluated for larvicidal activity using <it>Culex quinquefasciatus </it>Say larvae, cytotoxicity using brine shrimp larvae and antimicrobial activity using bacteria and fungi.</p> <p>Results</p> <p>Extracts from aerial parts of <it>C. Mucronata </it>exhibited antibacterial activity against <it>Staphylococcus aureus</it>, <it>Escherichia coli</it>, <it>Pseudomonas aeruginosa</it>, <it>Salmonella typhi</it>, <it>Vibrio cholera</it>, <it>Bacillus anthracis</it>, <it>Streptococcus faecalis </it>and antifungal activity against <it>Candida albicans </it>and <it>Cryptococcus neoformans</it>. They exhibited very low toxicity to brine shrimps and had no larvicidal activity. The root extracts exhibited good larvicidal activity but weak antimicrobial activity. The root dichloromethane extracts from <it>C. mucronata </it>was found to be more toxic with an LC₅₀value of 59.608 μg/mL while ethanolic extracts from root were not toxic with LC₅₀>100 μg/mL). Ethanol extracts from fruits and roots of <it>T. villosa </it>were found to be very toxic with LC₅₀values of 9.690 μg/mL and 4.511 μg/mL, respectively, while, ethanol extracts from leaves and twigs of <it>T. villosa </it>were found to be non toxic (LC₅₀>100 μg/mL).</p> <p>Conclusion</p> <p>These results support the use of <it>C. mucronata </it>in traditional medicine for treatment of wounds. Extracts of <it>C. mucronata </it>have potential to yield active antimicrobial and larvicidal compounds. The high brine shrimp toxicity of <it>T. villosa </it>corroborates with literature reports that the plant is toxic to both livestock and fish. The results further suggest that <it>T. villosa </it>extracts have potential to yield larvicidal and possibly cytotoxic compounds. Further studies to investigate the bioactive compounds responsible for the observed biological effects are suggested.</p

A New Isoflavone Glycoside from Dalbergia vacciniifolia (Fabaceae)

5,5\u27-Dihydroxy-2\u27,4\u27-dimethoxy-7-[(6-O-β-D-apiofuranosyl-β-D-glucopyranosyl)-oxy]isoflavone (1) was isolated as the major constituent of Dalbergia vacciniifolia root bark ethanol extract together with the four known compounds 5,7-dihydroxy-2\u27,4\u27,5\u27-trimethoxyisoflavone (3), 5,7-dihydroxy-2\u27,4\u27-dimethoxy-isoflavone (4), 5-hydroxy-2\u27,4\u27,7-trimethoxyisoflavone (5) and 7-hydroxy-2\u27,4\u27,5\u27-trimethoxyisoflavone (6). Identification of compounds was achieved through extensive analysis of 1D and 2D NMR and MS spectroscopy