Phytochemical composition, antioxidant and antiproliferative activities of Rosmarinus officinalis leaves

Phytochemicals in Rosmarinus officinalis leaves, their total phenolic content, antioxidant potential and antiproliferative activity against human prostate (DU145), colon (CT26) and cervical (HeLa 229) cancer cells were investigated. Extraction was done separately using hexane, dichloromethane, ethyl acetate and methanol. A total of 32 compounds were identified, eight of which were reported for the first time. The highest phenolic content was 476.80 ± 0.69 µg/ml for the methanolic extract which also had the highest antioxidant activity with a minimum inhibitory concentration of 5.39 ± 0.09 mg/ml. Extracts exhibited the highest toxicity against prostate cancer cells and the least against cervical cancer cells

Phytochemical Changes in Root Vegetables during Postharvest Storage

Root vegetables contain phytochemicals that are essential for human nutrition, in addition to offering desirable health benefits such as anti-oxidative, anti-cancer, and immunomodulatory activities. The quantity and stability of these phytochemicals vary greatly among root vegetable cultivars and landraces. Besides, freshly harvested root vegetables deteriorate rapidly thus causing significant losses in their quality attributes. To minimize these losses, various postharvest technologies have been assessed and shown efficacy in prolonging the shelf-life of stored vegetables. However, postharvest technologies may contribute to deterioration of nutrients and/or accumulation of toxic compounds such as glycoalkaloids. Therefore, this chapter summarizes information that has been reported on the influence of varied pre-storage treatments and storage systems on the quality of root vegetables. Quality attributes that are highlighted include changes in: root vegetable morphology such as sprouting, dehydration, and greening; phytochemical content of phenolics, flavonoids, glycoalkaloids, alkaloids, glycosides, and terpenoids; and nutritional content of carbohydrates, protein, vitamins, and carotenoids

Effects of lime, phosphorus and rhizobia on Sesbania sesban performance in a Western Kenyan acid soil

Aluminium (Al) toxicity, phosphorus (P) deficiency and low rhizobia populations limit Sesbania (Sesbania sesban) performance in tropical acid soils. The study determined the i) indigenous rhizobia populations that nodulate sesbania and ii) effects of lime (0 and 4 t/ha), P-fertilizer (0 and 60 kg/ha) and acid tolerant rhizobia (0 and inoculation) on soil and selected sesbania accessions performance in Western Kenya acid soil. Study site had acid soil, low available P, nitrogen (N) and rhizobia populations that nodulate Sesbania (146 cells/g soil). Lime increased soil pH, while both lime and P-fertilizer increased available P. Aluminium toxicity tolerant and P-efficient accessions (SSBSA004, SSUG3, SSUG4 and SSUG5) had faster growth, higher nodulation, shoot P, and shoot N and response to treatments than the sensitive one (SSBSA203). After 7 months of growth, SSUG3 had highest shoot length (306 cm) and dry matter (5.64 tons/ha), hence, most suitable for building poles and fuel wood. SSUG5 accumulated the highest shoot N (222 kg N/ha) and was therefore, most suitable soil N replenishment. Thus, in acid P deficient and low rhizobial population soils of Western Kenya, the use of lime, P-fertilizer, rhizobia inoculation and Al toxicity tolerant Sesbania are important for Sesbania establishment and growth. Key words: Rhizobia, Sesbania, soil acidity, aluminum toxicity, lime, phosphorus

MACROINVERTEBRATES AS BIOINDICATORS OF POINT SOURCE POLLUTION OF SAMBUL RIVER, KENYA

Water pollution is a major global concern which calls for regular evaluation of levels of contamination of water bodies. It has been suggested that water borne infections account for over 14,000 people daily in the world. Point source pollution can be defined as contaminants from a single identifiable source. The major environmental concern by the residents around Sambul River is pollution of waters of Sambul River by effluent from Moi University sewage treatment plant (STP). Sambul River is the main source of water for both domestic and agricultural use among residents of Sambul area. This study focused on analysis of efficacy of the (sewage treatment plant) using macro-invertebrates as bio-indicators of contamination of waters of Sambul River. Purposive sampling design was used to select three sampling points; downstream of Sambul River where bio-treated sewage has mixed with waters of Sambul River, at point of effluent discharge to the river and upstream (control) of Sambul River where the river water does not mix with STP effluent. Triplicate water samples were collected at each sampling point bi-weekly and transported to the Laboratory for analysis. Sampling was done from May to August 2015. The impact of bio-treated effluent on the abundance of aquatic macro invertebrates at Sambul River was evaluated using Shannon- Wiener diversity index. The findings revealed that treated effluent had no significant effect on the aquatic macro invertebrate abundance at the receiving river, as demonstrated by Shannon-Wiener diversity index (H) and ANOVA. H-values were; upstream (H=2.504), wetland (H=2.4096) and downstream (H=2.371). High H-value indicates less number of species diversity while a lower value of H indicates a higher diversity of macro-invertebrates. Higher biodiversity is an indicator that the effluent from the STP is treated to recommended standard as required by National Environmental Management Authority (NEMA). Phosphate values for the different sampled points ranged from 0.05 ± 0.01 to 5.50 ± 0.15 mg/L. Mean phosphate level for upstream (control) was significantly lower than that of outlet (F4, 115 = 1125.73; p < 0.0001) and inlet (F4, 115 = 1125.73; p < 0.0001), but showed no significant differences from that of downstream (F4, 115 = 1125.73; p = 0.9931) and wetland (F4, 115 = 1125.73; p = 1.0000).  The findings of this research are important to demonstrate to concerned parties, including the public and the government; NEMA that the effluent from Moi University STP is treated to expectation. This will return confidence to the public on consumption of water from Sambul River

Abundance and growth characteristics of Leguminosae nodulating bacteria in Embu and Taita benchmark sites of Kenya

The populations of Leguminosae nodulating bacteria (LNB) were assessed under glasshouse conditions in soils collected from various land use systems in Embu and Taita benchmark sites. The populations were estimated by the most-probable-number (MPN) plant infection technique using Macroptilium atropurpureum (DC.) Urban (siratro) as the trap host species. The LNB populations in Embu and Taita sampling points varied from <2.5 to 2.3 × 10 2 and <5.1 to 6.1 × 10 6 cells g -1 of soil, respectively. There was apparent land use effect on abundance of LNB in both sites with maize-bean cropping system most frequently giving high population estimates. LNB were isolated from root nodules of nodulated siratro inoculated with dilution series of the soils. Over 643 pure isolates were isolated from root nodules of siratro MPN plants. The isolates were characterized on yeast extract mannitol mineral salts agar (YEMA) media containing bromothymol blue. Abundance and growth characteristics of Leguminosae nodulating bacteria in Embu and Taita benchmark sites of Kenya (PDF Download Available). Available from: http://www.researchgate.net/publication/228510315_Abundance_and_growth_characteristics_of_Leguminosae_nodulating_bacteria_in_Embu_and_Taita_benchmark_sites_of_Kenya [accessed Sep 25, 2015]

EVALUATION OF SUSTAINABLE USE OF UNDERGROUND WATER IN PERI-URBAN CENTERS’ OF ELDORET MUNICIPALITY IN KENYA

The Kenyan national water quality standard recommends that water should be safe for human consumption. If not protected, ground water can easily be contaminated with many pollutants including biological pathogenic microorganisms. Waterborne diseases can be effectively controlled through proper sanitary procedures that result in use of good quality water through proper sanitary procedures. The main purpose of the study was to compare levels of pollution of ground water between 3 peri-urban centers in Eldoret Municipality; Langas, Munyaka and Huruma, using levels of coliforms and solids in underground waters as an indicator of point source pollution as varied over the dry and wet seasons. Six test sampling points were randomly selected per peri-urban area and another two water wells located above 31 m from garbage dumpsites and pit latrines were purposely selected from the three zones and served as control samples. A total of 40 samples were collected in duplicates during the dry season (January and March 2015) and another 40 samples were collected in duplicates during the wet season (April and May 2015). Standard plate count method was used for total coliforms incubated at 35±2°C for 24 hours. The total solids were determined by evaporation technique in which the total solid material was collected and determined gravimetrically.&nbsp; The mean total solids (TS), in each water well was within the permissible limits of 1.2 g/L. However, the means of the TS varied over the dry and wet seasons. Means, standards deviations, one way ANOVA and Pearson’s correlation analysis were used to analyze the relationship between variables in relation to seasons. Analysis of the collected data was done using JMP statistical software at 0.05 level of significance. Levels of coliforms in water wells were above the National Water Quality Standards of Nil/100 mL. Pearson`s correlation was used to test the relationship between the variables under study. The levels of&nbsp;Escherichia coli&nbsp;in well waters was positively influenced by the distance from the pit latrine and from the garbage dumpsites (r=-0.165, p=0.007) and (r=-0.246, p=0.024). There were no significant differences between the test and control samples, (ANOVA: F3,&nbsp;39=0.2249; p&lt;0.8487). During the dry season, total dissolved solids (TDS) levels of the test samples also showed no significant difference with the control sample (ANOVA: F3,&nbsp;39=0.7601; p=0.5239). &nbsp;This study concludes that topography is a key influence on proximity of water wells to pit latrines and garbage dumpsites in the study areas, thus affecting the number of coliforms in ground water. This study recommends the construction and use of standard communal water wells, review of the 30 m location distance of water wells and other water abstraction points from pollution sources and regular monitoring of ground water quality