Influence of Soil and Rain on the Levels of Inorganic Anions in Amaranth Leaves from Selected Parts of Kenya

The aim of this work was to determine the level of inorganic anions (NO3-, Cl-, SO42-, PO43-, F- and I-) in the leaves of two species of amaranth (Amaranthus hypochondriacus and Amaranthus cruentus) planted in Kenya. The mean levels of inorganic anions, nitrate (NO3-), chloride (Cl-), sulphate (SO42-), phosphate (PO43-), fluoride (F-) and iodide (I-), in the soil from four study regions (Kenyatta University (KU), Bureti, Kisii and Elgon) of Kenya were quantitatively determined. The levels were determined using spectrophotometric, potentiometric and titrimetric methods. The mean levels of  Cl-, SO42-, PO43-, NO3-, F- and I- in soils ranged from 1146.54 to 2733.31 mg/100 g, 1821.60 to 2185.33 mg/100 g, 828.54 to 1111.36 mg/100 g, 1015.55 to 1910.66 mg/100 g, 66.95 to 79.77 mg/100 g and  8.00 to 12.57 mg/kg respectively. The levels of most anions in leaves of A. hypochondriacus and A. cruentus were not significantly different. The means levels of the anions in leaves of the two species indicated that Cl- ion had range of 503.74 to 673.81 mg/100 g, SO42- 701.61 to 955.17 mg/100 g, PO43 532.36 to 629.46 mg/100 g, NO3- 495.79 to 880.99 mg/100 g, F- 7.22 to 9.67 mg/100 g while I- ranged from 2.54 mg/kg to 5.26 mg/kg dry weight. The levels of all inorganic anions determined were found to be within the allowed daily intake (ADI) values. Based on the results of this study, it is recommended that leaves and grains from both species of amaranthus grown in most regions in Kenya may be consumed for nutritional requirements. The consumption of between 250 g and 300 g of fresh amaranthus leaves is sufficient to provide the required daily intake of all the anions considered in this study for all healthy individuals. Keywords: Amaranth, Anions, Amaranthus, Tonui

In vitro and in vivo anti-trypanosomal activities of methanol extract of Azadirachta indica stem-bark

Background: Current chemotherapeutic agents for the treatment of African trypanosomiasis have become largely ineffective, necessitating the search for alternative compounds. The objective of this study was to evaluate in vitro anti-trypanosomal activities of methanol extracts of parts of Azadirachta indica against Trypanosoma brucei rhodesiense, Trypanosoma brucei brucei and Trypanosoma evansi and establish the in vivo efficacy of the most active extract.Materials and methods: Maceration of powdered leaves, stem bark and root bark of the plant in methanol afforded three extracts. In vitro assays were carried out with the extracts on the three trypanosome strains in 96-well microtitre plates at concentration ranges of 4000 - 1000μg/ml. The most active extract was assayed in vivo using Trypanosoma brucei rhodesiense infected Swiss albino mice at doses of 100, 200 and 400 mg/kg body weight. Melarsoprol and suramin served as positive controls. The infected untreated group served as the negative control. Parasitaemia levels, packed cell volume, body weight changes and mean survival period of all groups were monitored throughout the experimental period.Results: Methanol extract of the stem bark of A.indica was most active in vitro against all the three trypanosome strains (MIC values of 9.93±1.88, 16.25±0.92 and 9.97±0.44μg/ml for T. b. rhodesiense, T. b. brucei and T. evansi, respectively). The extract showed optimum activity at 400 mg/kg and was comparable to the positive control groups. Parasitaemia levels were kept at a significantly low level (p < 0.05) by the extract compared to the negative control. Notably, there was no significant difference (p>0.05) in mean survival time of mice treated with the extract at 400 mg/kg and the positive controls.Conclusion: In vitro and in vivo anti-trypanosomal activities of the methanol extract of A. indica stem bark could be attributed to the presence of constituents of moderate polarity.Keywords: Anti-trypanosomal activity, Azadirachta indica, Trypanosoma brucei brucei, Trypanosoma brucei rhodesiense, Trypanosoma evans

Antimicrobial and phytochemical investigation of herbal suspensions used in management of oral health in Nairobi County, Kenya

An increasing number of Kenyans are using natural herbal products for general and oral health care due to high cost of conventional medicine. Few of these products, however, have undergone rigorous testing, as evidenced by the limited amount of information on their safety and efficacy in the literature. This study investigated the antimicrobial and phytochemical properties of 10 suspensions based on herbal products sold in Nairobi Kenya. Phytochemical evaluation was carried out using standard methods while agar well diffusion was used to study antimicrobial work.  Results reveal lack of detectable levels of phytochemicals while 50% of the investigated products lacked antimicrobial activity against test bacteria (Staphyloccus aureus ATCC 25923, Pseudomonas aeruginosa (P.a) ATCC 27853, Proteus vulgaris ATCC 6380, Bacillus subtilis ATCC 14579, Candida albicans ATCC 10231, Esherichia coli ATCC 25922, Streptococcus mutans, Enterococcus faecalis, ATCC 9790 and Lactobacillus acidophilus). The study concludes that some products in the market may not be based on herbs as indicated in the label. Thorough investigation of antimicrobial, phytochemical work as well as toxicity should be carried out on such products. The results provide practitioners and consumers with insight into the claims of natural herbal products antimicrobial effects. Key words: antimicrobial activity, herbal products, activity index, phytochemica

IN VITRO AND IN VIVO ANTI-TRYPANOSOMAL ACTIVITIES OF METHANOL EXTRACT OF AZADIRACHTA INDICA STEM-BARK

Background: Current chemotherapeutic agents for the treatment of African trypanosomiasis have become largely ineffective, necessitating the search for alternative compounds. The objective of this study was to evaluate in vitro anti-trypanosomal activities of methanol extracts of parts of Azadirachta indica against Trypanosoma brucei rhodesiense, Trypanosoma brucei brucei and Trypanosoma evansi and establish the in vivo efficacy of the most active extract. Materials and methods: Maceration of powdered leaves, stem bark and root bark of the plant in methanol afforded three extracts. In vitro assays were carried out with the extracts on the three trypanosome strains in 96-well microtitre plates at concentration ranges of 4000 - 1000μg/ml. The most active extract was assayed in vivo using Trypanosoma brucei rhodesiense infected Swiss albino mice at doses of 100, 200 and 400 mg/kg body weight. Melarsoprol and suramin served as positive controls. The infected untreated group served as the negative control. Parasitaemia levels, packed cell volume, body weight changes and mean survival period of all groups were monitored throughout the experimental period. Results: Methanol extract of the stem bark of A.indica was most active in vitro against all the three trypanosome strains (MIC values of 9.93±1.88, 16.25±0.92 and 9.97±0.44μg/ml for T. b. rhodesiense, T. b. brucei and T. evansi, respectively). The extract showed optimum activity at 400 mg/kg and was comparable to the positive control groups. Parasitaemia levels were kept at a significantly low level (p 0.05) in mean survival time of mice treated with the extract at 400 mg/kg and the positive controls. Conclusion: In vitro and in vivo anti-trypanosomal activities of the methanol extract of A. indica stem bark could be attributed to the presence of constituents of moderate polarity

Repellent Properties of δ-Octalactone Against the Tsetse Fly, Glossina morsitans Morsitans

δ-octalactone, produced by several Bovidae, has been suggested as a potential repellant of tsetse fly attack. Racemic δ-octalactone was synthesized via an abbreviated route. The product was assayed against 3-day old starved teneral female tsetse flies, Glossina morsitans morsitans Wiedemann (Diptera: Glossinidae), in a choice wind tunnel and found to be a potent tsetse repellent at doses ≥0.05 mg in 200 µl of paraffin oil (0.05 >p >0.01)

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