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

Chemical composition of essential oils from Eucalyptus globulus and Eucalyptus maculata grown in Tanzania

This study examined the chemical composition of essential oil from the leaves of Eucalyptus maculata and Eucalyptus globulus found in Tanzania. The chemical composition of essential oils of other species viz. E. saligna, E. citriodora and E. camaldulensis has been described, but due to low abundance of Eucalyptus globulus and Eucalyptus maculata the composition of these plants grown in different parts of Tanzania are unknown. The essential oil was extracted by steam distillation and was analyzed for various chemical compositions using GC–MS. The major identified compounds in the leaf essential oil of E. maculata were Eucalyptol (54.29%), p-cymene (10.10%), α-pinene (7.78%), β-myrcene (7.78%), γ-terpinene (1.73%) and citronellal (1.62%); while Eucalyptol (51.62%), α-pinene (23.62%), p-cymene (10%), β-myrcene (8.74%), Terpinen-4-ol (2.74%) and γ-terpinene (2.59%) were the major compounds for E. globulus

Screening of Plants Used as Traditional Anticancer Remedies in Mkuranga and Same Districts, Tanzania, Using Brine Shrimp Toxicity Bioassay

Background. Inadequate specialized cancer hospitals and high costs are contributing factors that delay cancer patients from accessing health care services in Tanzania. Consequently, majority of patients are first seen by Traditional Health Practitioners (THPs) before they access specialized services. This study presents ethnomedical information and preliminary evaluation of 25 plant species claimed by THPs in Mkuranga and Same districts of Tanzania on use for treatment of cancer. Literature search and laboratory investigation results are presented to support evaluation. Methods. This study was a single disease ethnomedical enquiry focusing on plants being used for cancer treatment. Face-to-face interviews and questionnaires were administered to eight (8) THPs in Mkuranga and Same districts on the claimed plants and their use for management of cancer. Plants were selected based on being frequently mentioned and emphasis given by THPs. Literature search and brine shrimp toxicity (BST) of methanol : dichloromethane (1:1) extracts was used as surrogates to evaluate strength of the claims. Results. This study reports 25 plant species used by the THPs in two districts of Tanzania. Eight plants (32%) have been reported in the literature to have activity against cancer cells. BST results revealed, 14 (56%) plants exhibited high toxicity against brine shrimps. The most active plants included Croton pseudopulchellus Pax (LC50 4.2 μg/ml), Dalbergia melanoxylon Guill. & Perr. (LC50 6.8 μg/ml), Loranthus micranthus Linn (LC50 4.0 μg/ml), Ochna mossambicensis Klotzsch (LC50 3.3 μg/ml), and Spirostachys africana Sond. (LC50 4.4 μg/ml); their toxicity was comparable to that of Catharanthus roseus (L) G. Don. (LC50 6.7 μg/ml), an established source of anticancer compounds. Nine other plants had LC50 values between (19.8 and 71.6) μg/ml, indicating also potential to yield anticancer. Conclusion. Literature search and BST results provide a strong support of the potential of the claimed plants to yield active anticancer compounds

Antimycobacterial activity of scopoletin from ethanolic extract of Hymenodictyon floribundum (Hochst. & Steud.) B.L.Rob. Stem bark

The available tuberculosis (TB) therapies are taken for long time with complex regimens associated with adverse effects and drug-drug interactions. The emergence of multidrug resistant (MDR) and extensively drug resistant (XDR) strains of Mycobacterium tuberculosis and HIV co-infections necessitates the need for continued search for new effective anti-TB alternative leads with different mechanisms of action and safety profile. The aim of this study was to isolate and characterize antimycobacterial compounds from Hymenodictyon floribundum (Hochst. & Steud.) B.L.Rob. a plant used traditionally in the management of HIV/AIDS-related conditions. Antimycobacterial activity of the plant extracts and its constituents against Mycobacterium indicus pranii (MIP) and Mycobacterium madagascariense (MM) was tested using a twofold broth micro-dilution technique. Bioassay-guided isolation was used to isolate active compounds. Isolated compounds were also tested for activity against clinical isolates of Mycobacterium tuberculosis (Mtb). The crude plant extract had antimycobacterial activity and its ethyl acetate fraction was the most active with minimum inhibitory concentration (MIC) values of 97 µg/ml and 197 µg/ml against MIP and MM respectively. Three compounds were isolated from the ethyl acetate fraction; 7‑hydroxy-6-methoxycoumarin (1), 7,7′-dihydroxy-6,6′-dimethoxy-3,3′-biscoumarin (2) and 7,7′-dihydroxy-6,6′-dimethoxy-8,8′-biscoumarin (3). Compound 1 had growth inhibitory activity against MIP, MM and Mtb with MIC values of 0.2 M against MIP, 0.41 M against MM, 0.78 M against Mtb1 and 1.63 M against Mtb2. In conclusion, 7-Hydroxy-6- methoxycoumarin exhibited moderate antimycobaterial activity. The findings from this study support the use of H. floribundum by traditional health practitioners for treatment of HIV and AIDS-related conditions

Safety and Tolerability of an Antimalarial Herbal Remedy in Healthy Volunteers : An Open-Label, Single-Arm, Dose-Escalation Study on Maytenus senegalensis in Tanzania

Background: Though Maytenus senegalensis is one of the medicinal plants widely used in traditional medicine to treat infectious and inflammatory diseases in Africa, there is a lack of safety data regarding its use. Therefore, the study aimed to asselss the safety and tolerability of the antimalarial herbal remedy M. senegalensis. Material and Methods: The study design was an open-label, single-arm, dose-escalation. Twelve eligible male healthy Tanzanians aged 18 to 45 years were enrolled in four study dose groups. Volunteers' safety and tolerability post-investigational-product administration were monitored on days 0 to 7,14, and 56. Results: There were no deaths or serious adverse events in any of the study groups, nor any adverse events that resulted in premature discontinuation. The significant mean changes observed in WBC (p = 0.003), Neutrophils (p = 0.02), Lymphocytes (p = 0.001), Eosinophils (p = 0.009), Alanine aminotransferase (p = 0.002), Creatinine (p = 0.03) and Total bilirubin (p = 0.004) laboratory parameters were not associated with any signs of toxicity or clinical symptoms. Conclusions: M. senegalensis was demonstrated to be safe and tolerable when administered at a dose of 800 mg every eight hours a day for four days. This study design may be adapted to evaluate other herbal remedies