Proceedings of the Nigerian Academy of Science (Journal)
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ORIGINAL RESEARCH ARTICLE - Potentials of microcrystalline cellulose prepared from wood dusts wastes of Ficus Platyphyla, Planatus Occidentalis and Gmelina Aborea
Full text linkThis research aims to prepare microcrystalline cellulose (MCCs) from native cellulosic wastes in order to find potential applications for each of the tree species. The physico-chemical characteristics of the MCCs were studied using physical and spectroscopic techniques. Acid hydrolysis in 2M HCl was used for the preparation of microcrystalline cellulose (MCC) obtained from agricultural waste sample, Gmelina aborea (GA) Ficus platyphyla (FP) and Planatus occidentalis (PO) wood dust. The MCCs obtained were off-white and powdery in appearance. The yield of MCCs were 67.55% for Ficus platyphyla, 77.00% Planatus occidentalis and 80% for Gmelina Aborea (GA). The functional groups in the MCC samples were confirmed by the Fourier transform infrared (FTIR) spectroscopic method with characteristic absorption bands of ;OH stretching at 3416 cm-1; C-H stretching at 2918 cm-1; -OH bending at1377 cm-1;, 1159 cm-1; and C-O-C pyranose ring skeletal vibrations at 1026-1033 cm-1, with crystallinity absorption bands showing up at 1432 and 850 cm-1 respectively. The thermal stabilities were determined from Thermogravimetric Analysis (TGA) and showed that the MCC samples are thermally stable (50% weight loss at 450OC or PO, 50% weight loss 470OC for FP and 50% weight loss at 590OC for GA). The characteristic morphological features were established by scanning electron micrograph (SEM) and the crystallinity of the microcrystalline cellulose were further confirmed using the X-Ray Diffraction (X-RD) technique which showed three main reflections at 2?=14.70, 22.09 and 34.24, this therefore indicates microcrystalline cellulose were cellulose I type and that acid pretreatment did not affect the structure of the MCC. The crystallinity index values were 69.4, 68.7 and 79.6 for FP, PO and GM MCCs and respectively. The Samples were tested for pH, Moisture content, Hydration and swelling capacities as well. These results showed that the wood dusts form the tree species are good potential sources of high-grade cellulose which can serve as useful starting materials for further processing and applications
ORIGINAL RESEARCH ARTICLE: Some differences in turnover kinetics of penams and cephems catalyzed by classes A and C ?-lactamases
Full text linkThe differences in the kinetic mechanism of catalysis of class A and class C ?-lactamases are shown by the manner by which these enzymes catalyze the hydrolyses of the penicillins and the cephalosporins. The hydrolysis of cephalosporins that are good substrates of the class C P99 ?-lactamase, where deacylation of an acyl-enzyme intermediate is rate-determining, has been shown to involve a free enzyme isoform (Adediran et al, 2021). We describe here how reconversion of this isoform to the native enzyme is accelerated by bases (e.g. imidazole) and salts (e. g. sodium chloride). The hydrolysis of penicillins by the P99 enzyme, where deacylation is also rate-determining, is not affected by imidazole and sodium chloride, a result that suggests that an enzyme isoform does not accumulate as an intermediate in turnover of this class of substrate. In support of these conclusions, solvent deuterium kinetic isotope effects on kcat values were changed by the presence of imidazole for turnover of cephalothin by the P99 enzyme but unaffected for benzylpenicillin turnover. The hydrolyses of cephalosporins and penicillins by the class A TEM-2 ?-lactamase were not affected by imidazole and sodium chloride and thus also may not involve an accumulating free enzyme isoform. Solvent deuterium kinetic isotope effects and proton inventories on the class A PC1 and P99 ?-lactamase-catalyzed hydrolyses of benzylpenicillin at saturating concentrations showed the deacylation transition states of these two classes of enzymes to be different with respect to proton motion
ORIGINAL RESEARCH ARTICLE: Antioxidant capacity and antibacterial activity of some phyto-spices against some bacterial isolates of foods origin
Full text linkSpices that are mostly of plant origin are used in the preparation of almost all processed food to enhance palatability, tastiness, sweetness, and its overall acceptability, without taking into consideration of its medicinal values. The study was conducted to determine the antioxidant capacity and antibacterial activity of the extracts ofAllium sativum,Syzygium aromaticum, andZingiber officinale against some bacterial isolates of foods origin including Bacillus cereus, Escherichia coli,Salmonella typhi,Shigella dysentriae,andStaphylococcus aureus. Bacterial isolates of food origin were collected from the laboratory unit of the Department of Microbiology, Kano University of Science and Technology, Wudil. Antioxidant capacity of the extracts used was determined using 2,2-diphenylpicrylhydrazyl (DPPH) assay while agar disc diffusion techniques were used in the determination of the antibacterial activity. Results show that extracts of the spices exhibited a strong antioxidants capacity that ranges from 89.5% to 97.5% at high concentrations of the extracts with methanol extracts being the most active. Methanolic extracts shows zone of inhibition ranging from 16.45mm to 5.26mm while that of aqueous extracts were 10.32mm to 4.32mm. Meanwhile isolates of E. coli and S. aureus were the most sensitive with 16.45 and 15.32. This study concluded that the antibacterial effect of methanolic extract of Allium sativum extract was stronger in comparison, followed by Syzygium aromaticum and Zingiber officinale against five test bacteria isolated of food origin. Therefore, this study revealed that spices produced using Allium sativum, Syzygium aromaticum and Zingiber officinale have an antibacterial property and can be used for food preservation
REVIEW PAPER - Environmental chemical risk factors of breast cancer in Nigeria I: Broad overview
Full text linkNigeria is currently experiencing a most disturbing level of incidence rate, morbidity and mortality from the ravages of female breast cancer, with its attendant burden of emotional, social and financial consequences. Tens of thousands of chemicals make their way into our everyday products and environment, with little regard for safety. The need to explore the impact of adverse environmental chemical exposures to breast health in Nigeria informed this study as there is need for public health approach to long term prevention.After exploring the robust scientific database on environmental chemical risk factors for female breast cancer, we found that many mammary toxicants are ubiquitous in our environment in Nigeria but have been taken for granted as inevitable in normal life exposures. This study identifies some of the potential environmental chemical risk factors of breast cancer in Nigeria. We describe the special exposure scenarios in Nigeria and prescribe some modest but practical ways to mitigate exposures. The factors that constitute risk to breast cancer could potentially be modified either through community education or government action and regulation. The subject is discussed in multiple Parts before releasing the manuscripts for publication to prevent criminalizing only a few chemicals if discussed and published to the exclusion of others.To our knowledge, this is the first ever comprehensive work on the subject in the African continent and is useful to typical developing countries as are found in sub-Saharan countries and elsewhere since findings and recommendations are usually generic in nature and mutually beneficial
ORIGINAL RESEARCH ARTICLE: Characterisation of graphite powder processed from waste dry cell batteries
Full text linkThe incessant nature of electrical power supplies in a developing country like Nigeria, the dependence on dry cell batteries for varying domestic applications such as transistor radios, torchlights, remote controls, amongst others continues to rise unabated. Improper disposal of these batteries poses serious adverse effect on the environment and human health. In this study, over 1000 dry cell batteries were collected from different locations in Ede, Osun State sorted and sectioned to harvest the carbon rods which is a key component of the battery cell. The rods were pulverized for about 15 hours and screened into different particle sizes using standard sieves. The microstructural characterization was investigated using Scanning Electron Microscopy (SEM), Energy Displacer Spectroscopy (EDS), X-ray Diffractometer (XRD), and Ultraviolet (UV) Spectroscopy. High yield graphite powders (98%) were obtained from the processing. Absorption peak was observed at 272.5 nm by UV spectroscopy while XRD plots yielded a narrow peak of 26.60. The characterization results show good agreement with those available in literature
REVIEW PAPER - Environmental chemical risk factors of breast cancer in Nigeria II: Adolescent hormonal contraceptives use
Full text linkGlobocan’s 2018 cancer statistics show increasing rates of breast cancer in Nigeria. There is sufficient evidence in humans that hormonal contraceptive is a breast cancer risk factor particularly among African American women who begin use before 20 years of age or before first pregnancy. Nigerian breast cancer patients have identical subtypes as African Americans i.e triple negative tumors, early age of onset, clinically aggressive, and poor prognosis.Data from Nigeria show that 37.4% adolescent girls engage in high-risk sexual behaviour. For adolescent girls, dual use of condom and other hormonal contraceptives have been recommended to prevent pregnancy and acquisition of STI/HIV. Adolescents in Nigeria have uncensored access to all the contraceptive mix including hormonal contraceptives. There are also some ethical concerns.There are extremely harmful socio-cultural and socio-economic determinants that promote early sexual debut, Teenage Pregnancy, and Child Marriage. There are also grave health related, social and economic consequences for mother and child, and the community. Both Teenage Pregnancy and Child Marriage undermine nearly every Millennium Development Goal. The notable reason given by some fathers for embracing Child Marriage was to protect daughters from what was perceived as “unwholesome” Western values that permit loss of virginity, pre-marital sex and high adolescent sexual networking, necessitating the use of contraceptives.Hormonal contraceptive is a modifiable risk factor of breast cancer. Appropriate early pre-adolescent and adolescent parental care and nurturing before the crisis stage in godly principles is the gold standard for preventing adolescents’ use of contraceptives. Adolescent pregnancy and Child Marriage are not safe options
ORIGINAL RESEARCH ARTICLE: Phytochemical constituent and oxidative potencies of acetone, methanol and aqueous leaf extracts of Acalypha Wilkesiana grown at the Kaura Namoda plant nursery
Full text linkAs a result of increased interest in the production of plant-based drugs for the treatment of many diseases has become a significant reason why people have become more coversant in the use of traditional medicine for the treatment of mild and serious illness. Due to increase in the thrust for the production of plant-based drugs, this present study was carried out to compare the phytochemical constituents and antioxidant potencies of acetone, methanol and aqueous leaf extracts of Acalypha wilkesiana collected from Kaura Namoda Botanical Garden in Zamfara State-Nigeria. The antioxidant activities was evaluated using various assays; The total phenolic content of aqueous, methanol and acetone leaf extract were 15.58 0.66 mg GAE/g, 14.10 2.17 mg GAE/g and 8.70 0.01 mg GAE/g respectively. Total flavonol contents; 207.10 11.53 mg QE/g, 196.08 5.53 mg QE/g and 112.04 8.27 mg QE/g respectively. Total flavonoid contents; 240.99 9.50 mg QE/g, 252.52 3.73 mg QE/g and 123.88 5.58 mg QE/g respectively. FRAP values were 679.14 0.45 mmol/g, 611.90 7.09 mmol/g and 292.07 11.38mmol/g respectively. ABTS activity of aqueous, methanol and acetone leaf extract were 24.30 5.86 mg AAE/g, 14.49 1.02 mg AAE/g and 7.00 0.57 mg AAE/g respectively, methanol leaf extract had the highest percentage DPPH Inhibition value of 42.64 5.13, followed by aqueous (31.77 4.08) at 0.25mg/ml while aqueous had the highest (52.63 0.67), followed by methanol extract (44.80 2.80) at 0.50mg/ml. Aqueous extract had the highest percentage inhibition of Nitric Oxide with a value of 59.74 1.30, followed by methanol extract (46.11 2.54) at 0.25mg/ml. inhibition for aqueous was also highest at 0.5 mg/ml. Aqueous extract had the highest percentage lipid peroxidation inhibition value of 22.66 2.93, followed by methanol leaf extract with the value of 18.89 0.80 while at 0.50mg/ml methanol leaf extract had the highest percentage inhibition of lipid peroxidation (39.42 3.10), followed by aqueous leaf extract with the value of 31.48 1.61. The results showed that aqueous and methanol leaf extract of Acalypha wilkesiana displayed potent antioxidant effects with the aqueous having an edge. This present study therefore supports the view that Acalypha wilkesiana can be used in the management of oxidative stress and other related diseases
EDITORIAL: A call to strengthen eco-innovation using indigenous resources and waste products
Full text linkWaste is often taken for granted, as a broad category, which encompasses materials we no longer need. Another category of waste would be local resources that we have hitherto not found use for. Although waste management has always existed, recent studies seem to suggest that waste management needs to be addressed principally in poorer countries, given that since the 1970s the developed world has promoted techniques and policies to tackle waste (Jgensen, 2013) and has also advanced innovative measures and practices often associated with green ideas and care for the environment. However, waste management associated with indigenous practices have long been in existence in Africa. For example, according to Solomon et al. (2016) the old use of ash and recycled material to make the soil fertile among indigenous groups in Liberia and Ghana, West Africa, has been ignored (Salim et. al., 2018).The concept of innovation refers to a broad guiding principle that mobilizes science and technology in the service of the goals of national development. Today as a favourite concept eco-innovation is developing new ideas, promoting new operations, products, and processes to protect the environment, thus obtaining environmental sustainability. Worldwide, eco-innovation is one of the leading strategies to promote resource and energy efficiency and create a low carbon society.Some of the articles published in this regular edition support the eco-innovation principle, which imagines resources with a life cycle perspective, they consider all phases of the product life cycle, from the extraction of raw materials through material processing, manufacturing, distribution, use, repair and maintenance to disposal or re-use. From the outcome of the publications in this edition, it is recommended that eco-innovative research should be fostered through strategic investment in exploiting local resources and waste products for home grown solutions to sustainable development challenges. This provides opportunities to improve resource management and ensure the reuse of waste or prevent waste by developing indigenous resources
ORIGINAL RESEARCH ARTICLE - Protective effect of Ocimum basilicum essential oil on Dimethylbenz[a]anthracene-induced breast tumor in mice
Full text linkBackground: Breast cancer is one of the most common cancers worldwide.7,12-dimethylbenz[a]anthracene (DMBA) is one of the xenobiotics that are implicated in various toxicological conditions including carcinogenesis. This study was conducted to assess the protective effect of Ocimum basilicum essential oil on Dimethylbenz[a]anthracene-induced breast tumor in mice.Method: Sixty (60) adult female mice were randomized into five groups (A-E) each containing twelve (12) mice: Group A- Control received distilled water, Group B- DMBA induced only, Group C- DMBA induced+100mg/kg bodyweight (bwt) essential oil, Group D- DMBA induced+200mg/kg bwt essential oil and Group E- DMBA induced + Tamoxifen, respectively. The animals were treated with Ocimum basilicum essential oil for 14 days. At the end of 14 days, assays for serum catalase, superoxide dismutase, malondialdehyde, reduced glutathione and glutathione-s- transferase also IL-1β, TNF-α, NF-κB and fragmented DNA were done.Result: Histopathology analysis of the skin of the mammary gland shows that DMBA-induced mice possessed enlarged skin tissue with epidermal necrosis and disruption of the entire layers of the skin, this suggesting tissue damage and cancer while positive control and group administered with Ocimum basilicum essential oil showed preserved epidermal, dermal and subcutaneous layers. There is increase in levels of IL-1β, TNF-α, NF-κB, fragmented DNA, SOD,CAT, GST activities and GSH level in the group administered with Ocimum basilicum essential oil when compared with the negative control
ORIGINAL RESEARCH ARTICLE - Environmental contribution to antimicrobial resistance: A largely ignored global health issue
Full text linkEnvironmental contribution to the continued occurrence of antibiotic resistance has been largely unexplored. There has been much focus on clinical isolates for their resistant nature but non-clinical bacterial isolates in the environment have been considered as the chief contributing factors that facilitate the spread and dissemination of antibiotic-resistant bacteria (ABR) and antibiotic-resistant genes (ARGs). The natural environment acts as a reservoir for bacteria, providing them with a favourable condition for their emergence and breeding of resistance. One such environmental leverage is inter/intra-specie exchange of genes encoding resistance factors. It was argued that human activities aid immensely in the emergence of antibiotic resistance in the environment. The rationale for this review is to examine extensively the complex interplay of antibiotic resistance from the natural environmental perspective and factors that influence the occurrence and dissemination of such resistance. It also seeks to stress the biological factors that facilitate the emergence of resistance and link it to general biological processes. The review has been structured to capture the general threat posed by the circulation of antibiotic-resistant bacteria and their genes, as well as the influence of the environment in contributing to this global health threat. In addition, the review looked at the effective methods used to tackle the silent pandemic, by controlling the spread of resistance in the environment. Environmental stakeholders and policymakers are recommended to be included in tackling the development of antibiotic resistance