Optimization of operating conditions for the application of Moringa oleifera (Zogale) seeds extract in water disinfection using response surface methodology

Good quality dry seeds of Moringa oleifera were selected and the seed coat and wings were removed  manually. The kernel was ground to fine powder using the coffee mill attachment of the Moulinex domestic food blender. The ground powder was then sieved through 210 ìm sieve. The seed powder was de-fatted using hexane in electro-thermal Soxhlet extractor. Moringa seeds extract was obtained using the  de-fatted seed cake and aqueous extraction. Different preparations of Moringa extract were added to 10 mL of the Escherichia coli suspension and incubated for 2 h without agitation. Survival of bacterial cells was assessed by making dilution series of bacterial suspensions, plating on non-selective LB medium  agar dishes, and incubating for 48 h at 37°C. Duplicates were made of every individual assay. Colonies  were counted on dishes and the bacterial cell survival ratio was estimated by comparison to a control  experiment where no Moring extract was added. The bacterial removal was optimized by varying the  mixing time, mixing speed, and Moringa seeds extract dosage. Statistical optimization was conducted by using central composite design (CCD). The experimental data was analyzed using statistical software DESIGN EXPERT, V6.4.8 DEC 10 2002 for Windows. The response surface model was used to determine  the optimum operating condition that yields the highest antimicrobial compounds activities from M.  oleifera seeds extracts. A cubic model was fitted to the data. The standard deviation for the cubic model was 0.56, with R2 = 0.9999 and adjusted R2 = 0.9994. The analysis of variance (ANOVA) showed that the effects of mixing time, mixing speed and Moringa dosage were significant (p < 0.05) in the extraction process. The Quadratic model was used in predicting the responses and the optimal conditions were  determined as 31 min mixing time, 85 rpm mixing speed and 3.25 mg/mL Moringa dosage. The results show that the predicted and experimental values were not significantly different and it was thus concluded that the model obtained can be used to optimize the process of antimicrobial bioactive compound  extraction from de-fatted M. oleifera seeds.Key words: Moringa oleifera, seeds extract, bacterial inactivation, optimization, response surface model

Statistical optimization of process parameters for the production of citric acid from oil palm empty fruit bunches

In this study, optimization of process parameters such as moisture content, incubation temperature and initial pH (fixed) for the improvement of citric acid production from oil palm empty fruit bunches through solid state bioconversion was carried out using traditional one-factor-at-a-time (OFAT) method and response surface methodology (RSM). The possible optimum level of moisture content, incubation temperature, and initial pH were found from the OFAT study to be 70%, 30 - 32oC and 5.5 - 8, respectively. The optimum moisture content of 70.3% (v/w) and incubation temperature of 33.1°C with initial pH of 6.5 gave the maximum production of citric acid (369.16 g/kg of dry EFB). The analysis of variance (ANOVA) of the statistical optimization using central composite design showed that moisturecontent (p<0.001) and incubation temperature (p<0.0001) as well as the interaction of these two parameters were highly significant for the citric acid production

Anti-cyanobacterial activity of Moringa oleifera seeds

Filtrates from crushed Moringa oleifera seeds were tested for their effects on growth and Photosystem II efficiency of the common bloom-forming cyanobacterium Microcystis aeruginosa. M. aeruginosa populations exhibited good growth in controls and treatments with 4- and 8-mg crushed Moringa seeds per liter, having similar growth rates of 0.50 (±0.01) per day. In exposures of 20- to 160-mg crushed Moringa seeds L−1, growth rates were negative and on average −0.23 (±0.05) .day−1. Presumably, in the higher doses of 20- to 160-mg crushed seeds per liter, the cyanobacteria died, which was supported by a rapid drop in the Photosystem II efficiency (ΦPSII), while the ΦPSII was high and unaffected in 0, 4, and 8 mg L−1. High-density populations of M. aeruginosa (chlorophyll-a concentrations of ∼270 µg L−1) were reduced to very low levels within 2 weeks of exposure to ≥80-mg crushed seeds per liter. At the highest dosage of 160 mg L−1, the ΦPSII dropped to zero rapidly and remained nil during the course of the experiment (14 days). Hence, under laboratory conditions, a complete wipeout of the bloom could be achieved. This is the first study that yielded evidence for cyanobactericidal activity of filtrate from crushed Moringa seeds, suggesting that Moringa seed extracts might have a potential as an effect-oriented measure lessening cyanobacterial nuisance

Association between Psychosocial Factors and Domains of Sexual Function among Men with Erectile Dysfunction

Background: Several psychosocial factors have been associated with erectile dysfunction (ED) either as causative factors or complications of ED. These can disrupt intimate relationships, quality of life, and family dynamics. The aim of this study was to determine the association of psychosocial factors with the domains of sexual function in men with ED.Methods: A cross-sectional study conducted among men attending the general outpatient clinic of a tertiary hospital between June and August 2018. Of the 901 men screened for ED with the International Index for Erectile Function (IIEF-5) tool, 310 participants were recruited. An interviewer-administered semi-structured questionnaire was used in collecting data which included sociodemographic characteristics. Depression, anxiety and stress were assessed with the Depression, Anxiety and Stress Scale (DASS-21) while the domains of sexual function were assessed using the International Index of Erectile Function (IIEF)-15. Data analysis was carried out with the Statistical Package for the Social Sciences (SPSS) version 20. Bivariate and multivariate analyses were carried out and the level of significance was set at 5%Results: The median age of participants was 40 years with interquartile range of 32-49 years. The majority (231, 75%) were married, of whom 93% were in monogamous marriages. Increasing age was associated with decreasing erectile function scores (p=.005), while being in a polygamous marriage was associated with higher erectile function scores (p=.037). Lower orgasmic function was associated with depression (p=.005) and anxiety (p<.001).Conclusions: Our study indicates that age, number of sexual partners and anxiety are important determinants of sexual function, and a biopsychosocial domain specific approach should be considered in the management of ED especially in young and middle-aged men with lower risks of organic aetiology of ED. Keywords: Impotence, Sociodemographic characteristics, Depression, Anxiety, Stres

HAEMATOLOGICAL AND HISTOPATHOLOGICAL CHANGES OF CASSIA OCCIDENTALIS LEAF EXTRACT IN RATS

The aqueous leave extract of Cassia occidentalis produced significant decreases in the packed cell volume (PCV), haemoglobin concentration (HB), and total red blood cell count (RBC) (

Development of sustainable drinking water quality solutions for rural communities in the developing world

In developed countries potable water is usually taken for granted, where advanced infrastructure and a strong economy has allowed waterborne diseases (such as cholera and dysentery) to be virtually eradicated. In contrast, developing countries have poor infrastructure, lack development, stability and vibrancy. Consuming untreated, and potentially contaminated, groundwater extracted from shallow wells is the only option. The primary aim of this study was to undertake an extensive field water quality-sampling programme in rural villages throughout Malawi. About 95 % of all the wells tested failed to meet safe drinking water values for untreated water in the wet season, while about 80 % of the wells failed in the dry season. The main forms of contamination emanate from bacteriological and physical constituents. As noted in the United Nations post-2015 water agenda, water quality is just as important as water quantity—the two are inextricably linked. Hence, there is currently a great need to develop more appropriate, cost-effective options to treat water; particularly to reduce the 3.5 million deaths related to inadequate water supply and sanitation each year. Subsequently the aim was directed towards investigating a sustainable, yet appropriate, way to treat shallow well water to significantly improve quality. The most suitable method to remove coliforms and turbidity from water is via the process of coagulation, using aluminium sulphate (alum) or ferric sulphate (ferric). The limited availability and relative expense of these chemicals has led to other more appropriate indigenous coagulants being sought for developing countries. Natural plant extracts have been available for water purification for many centuries. However, the science and engineering application of the use of plant extracts have not really been developed. To start to address this, Leeds Beckett University and the University of Malawi—The Polytechnic have shown that a locally available plant extract, Moringa oleifera, which grows wild throughout rural villages in developing countries, can be used to improve water quality in the order of 80–94 %. The flocculent capacity of M. oleifera is closely comparable to that of a well-established chemical coagulant, alum