Kola Nitida Research Articles

Green-based modifiable CaZnBr4 for solar cells application

Future revolution in photovoltaics will be hinged mainly on cost, health implication, and material stability and performance. Based on these criteria, lead-based inorganic photovoltaics, organic–inorganic hybrid, and silicon photovoltaics are screened-out. According to the literature, the lead-free inorganic perovskite solar cell is favorably disposed to cost and safe-health. However, the simultaneous solution to material stability, high defect density, and low power conversion efficiency (PCE) still remains a mystery that has not been solved. This research proposed the green-based modifiable CaZnBr4 as a potential candidate for lead-free solar cell application based on the principle of A-site cation with green-based additive incorporation. The green-based additive was obtained from Kola Nitida, Carica Papaya, Ficus Exasperata, and Musa paradisiaca. The elemental characterization of the green-based additives was performed using X-ray fluorescence spectroscopy (XRF). The optical, crystalline, and electronic properties were characterized using ultraviolet–visible (UV–Vis) spectroscopy, X-ray diffractometry, Quantum Espresso, scanning electron microscopy and SCAPS-1D. The green-base-modified CaZnBr4 showed significant PCE improvement by 3% with significant film and crystallinity formation. The stressed state of the parent compound CaZnBr4 shows that it may be better suited for thermovoltaics application. It is recommended that better results could be obtained when different synthetic routes and green-based additives are used to initiate the defect passivation protocols.

Phytochemical screening and antibacterial activity of <i>Garcinia kola</i> (hackel) and <i>Cola nitida</i> (vent) extracts

This study was designed to evaluate the phytochemical and antibacterial properties of Garcina kola (Orogbo) and Cola nitida (Obi) extracts. Fresh seeds of Cola nitida and Garcinia kola were collected from Ago-Iwoye market, Ogun State. The ethanolic and aqueous extracts of the test plants were used against selected test organisms, Streptococcus pneumonia, Staphylococcus aureus, Salmonella typhi, Pseudomonas euriginosa and Escherichia coli. Disc diffusion method was adopted to test for susceptibility of the selected test bacteria to the extracts. Minimum inhibition concentration (MIC) and Minimum bactericidal concentration (MBC) were determined. Bioassay data were statistically analyzed using two-way ANOVA. The result of the phytochemical screening confirmed the presence of flavonoid, phenol, alkaloid, saponins, tannins and phlobatanins. The result of the antibacterial activity showed that the ethanolic extract of the test plants recorded highest antimicrobial activity against test isolates compared to aqueous extracts. The tested plant seeds of both plants posses reasonable antibacterial activity but to varied zones of inhibition, with Staphylococcus aureus isolate having the highest inhibitory zones (21.33) mm while Pseudomonas aeuruginosa had the least inhibitory zone (6.00) mm. The antibacterial activity were however found to be concentration dependent (Fvalue= 3.996, Pvalue= < 0.05). All tested organisms were found to have definite MIC and MBC activities which ranges between 125 and 1000μg/ml for MIC except for Kola nitida that has no definite MBC below 1000μg/ml. The result confirms the potential of antibacterial activity of Garcinia kola and Cola nitida extracts.
 Keywords: Antimicrobial, Cola nitida, Garcinia kola, Phytochemical, Plant extracts

Concentration, Temperature and Kinetic Studies of <i>Kola nitida</i> Leaves Extract in Corrosion Prevention

Weight loss test method was used to study the inhibition and adsorption properties of kola nitida leaves extract addition on corrosion inhibition efficiency of mild steel in 2M HCl solution for various concentration, exposure time and working temperature. The results showed that ethanolic extract of kola nitida leaves is a potential inhibitor for the corrosion of mild steel in acidic medium. The corrosion rate of mild steel in 2M HCl decreases with increasing in the concentration of the extract. The inhibition efficiency increases progressively as the concentration of the extract increases but decreases with rise in temperature and exposure time. The highest inhibition efficiency observed in the presence of the extract was 88.51%. The kinetics of the reaction in the presence of the extracts revealed that it follows a first order reaction and the half life increases as the concentration of the extract increases. Adsorption studies revealed that Langmuir adsorption isotherm is the best adsorption model applicable to the adsorption of the extract on mild steel surface.

Concentration, Temperature and Kinetic Studies of <i>Kola nitida</i> Leaves Extract in Corrosion Prevention

Weight loss test method was used to study the inhibition and adsorption properties of kola nitida leaves extract addition on corrosion inhibition efficiency of mild steel in 2M HCl solution for various concentration, exposure time and working temperature. The results showed that ethanolic extract of kola nitida leaves is a potential inhibitor for the corrosion of mild steel in acidic medium. The corrosion rate of mild steel in 2M HCl decreases with increasing in the concentration of the extract. The inhibition efficiency increases progressively as the concentration of the extract increases but decreases with rise in temperature and exposure time. The highest inhibition efficiency observed in the presence of the extract was 88.51%. The kinetics of the reaction in the presence of the extracts revealed that it follows a first order reaction and the half life increases as the concentration of the extract increases. Adsorption studies revealed that Langmuir adsorption isotherm is the best adsorption model applicable to the adsorption of the extract on mild steel surface.

Evaluation of the Antimicrobial Potentials and Adverse Effect of Kolanut (Kola nitida Malvaceae) on the Oral Cavity and the Impact on Cariogenic Bacteria: A Socio-Demographic Study

Kola nut (Kola nitida, Malvaceae) is one of the nuts consumed for socio-cultural reasons in West Africa sub-region and it has been used in Western African and Anglo-American herbal medicine as an antidepressant. The aim of this study was to evaluate the beneficial and adverse effect of kola nut consumption on the oral cavity.
 This was a cross sectional survey conducted on Kola nuts consumers using a qualitative in-vitro analytical phyto-chemical screening and microbiological activity testing of the Kola nut samples.
 One hundred and two volunteers participated in the study that was made up of 66(64.4 %) males and 36(35.3%) of females. Kola nuts consumers had the age of participants ranging between 20 to 60 years and derived from all social classes of the West African community. There was a high prevalence of dental attrition 95(93.3 %), arrested caries 95(93.3 %), and extrinsic stains 91(90 %). The DMFT (Decayed/Missing/Filled Teeth) score was 4.7.
 The phytochemical screening of Kola nut showed the presence of phenol, tannin, flavonoids, alkaloids, anthocyanin, sterol, and antraquinone. Methanol extracts of Kola nitida showed no activity against the isolates of Candida spp. But there was less activity against Streptococcus spp and an average activity against Actinomycetes and isolate of Lactobacillus spp respectively.
 Kolanut exhibited some degree of remineralization oral hard tissues, causing esthetic problems (dental staining) and non-carious dental tooth wear (attrition). Kola nut inhibited the growth of cariogenic bacteria and did not inhibit the growth of Candida albicans. Studies on intra-oral activities needs some further investigations to establish its importance to dental oral care. Results showed that extract of Kola nitida had antibacterial effects by inhibiting the growth of cariogenic bacteria of the mouth at certain level of concentration. The poor oral health seeking behaviours of participants were observed as factors contributing to a poor oral hygiene status and consequently the impairment of oral health of the kola nut consumers.

English

Soil degradation and desertification pose a major threat to agricultural production in sub-Saharan Africa. The influence of cropping systems which had been established on selected physical and chemical properties of soil were investigated in Akinyode-Okinni community in Egbedore Local Government Area (LGA) of Osun State, Nigeria. The cropping systems included agri-silviculture (SCM), silvi-pasture (SPC), agri-horti-silviculture (PAH) and agroforestry (AFT) selected from existing farms in the community. The selected plots had cocoa (Theobroma cacao), oil palm (Elais guineensis) and kola-nut (Kola nitida) as permanent crops; coco-yam (Coco nucifera), guinea grass (Panicum maximum), plantain (Musa spp), maize (Zea mays), and cassava (Manihot utilissima) were the annual crops. The experiment was carried out for two cropping seasons. Results showed that in the AFT system bulk density (BD) decreased slightly from 1.22 to 1.16 g/cm3 in the top soil and from 1.18 to 1.09 g/cm3 in the subsoil after two seasons of crop growth. The pH varied between 6.40 and 7.05 in the first season and between 7.05 and 7.29 after two seasons. On average, the topsoil contained more organic carbon (OC) in the SPC (38 g kg-1) and SCM (36 g kg-1) systems than in the PAH and AFT systems. Similarly, the total phosphorus content was higher in the topsoil of SPC and SCM systems than in the other systems. There was a slight reduction in soil acidity and no significant changes occurred in the concentrations of exchangeable bases after two cropping seasons. Conclusively, these cropping systems have the potential to reduce soil deterioration and thus, further studies to develop appropriate management strategies are necessary. Key words: Cropping systems, exchangeable bases, organic carbon, silviculture, soil degradation. &nbsp

Effect of Aqueous Extract of Kola nitida on the Development of Biliary Atresia in Pups of Wistar Rats

Effect of Aqueous Extract of Kola nitida on the Development of Biliary Atresia in Pups of Wistar Rats

Natural products for materials protection: Corrosion protection of aluminium in hydrochloric acid by Kola nitida extract

The ethanol extract of Kola nitida seed (KN extract) was investigated for its ability to mitigate the corrosion of aluminium alloy AA3003 in acidic environment using joint experimental and computational approach. The obtained results revealed that KN extract hindered the corrosion reaction. The effectiveness of protection became more pronounced with increasing extract concentration but decreased with prolonged exposure time. Electrochemical data showed that organic constituents of the extract adsorbed on the Al surface, in agreement with the Langmuir equation and reduced the anodic and cathodic current densities. Computational simulations were adopted to visualize the adsorption of various constituents of KN extract on Al (110) slab.

Characterization and Experimental and Computational Assessment ofKola nitidaExtract for Corrosion Inhibiting Efficacy

Kola nitida (KN) extract was assessed for its ability to hinder corrosion of mild steel in 0.1 M HCl solution by means of gravimetric and electrochemical tests. KN extract was found to efficiently retard mild steel corrosion in this system, with the effect becoming more pronounced as KN extract concentration increased and slightly subdued as immersion time lengthened. From the polarization and impedance results, KN extract was seen to affect both the cathodic and the anodic reactions following adsorption of organic species from the extract on the metal/solution interface. The presence of such organics was confirmed by UV–visible spectrophotometry and gas chromatography–mass spectroscopy analyses. Selected constituents of the extract were modeled in order to assess their adsorbability using the density functional theory (DFT) and revealed remarkably high interaction energies, which corroborate the experimental findings.

Evaluation of Chemical Properties of Mistletoe Leaves from Three Different Trees (Avocado, African Oil Bean and Kola)

A comparative evaluation of the chemical composition of mistletoe leaves (Viscum album) growing on three different trees: avocado pear (Persea Americana), African oil bean (Pentaclethra macrophylla) and kola (Kola nitida) was undertaken. Fresh mistletoe leaves were obtained from the three different trees and thoroughly washed with water after which they were dried at room temperature (28 }10C) for 18 days during the dry season (December). After, the dried leaves were shredded and packaged. The samples were then subjected to phyto-chemical, vitamin and mineral analyses using standard methods of analyses. Anthocyanins ranged between 0.3.4 } 0.003 and 0.37 } 0.181 mg/g, Tannin, 2.09 } 1.141 and 3.24}0.003 mg/g, Chlorophyll a, 0.38 } 0.004 and 0.39 } 0.018 mg/g, Chlorophyll b 0.52 } 0.120 and 0.60 } 0.001 mg/g. Vitamin B1 ranged between 0.85 } 0.038 and 0.94 } 0.001 mg/g, Vitamin B2, 0.55 } 0.007 and 0.61 } 0.003 mg/g, Vitamin C, 0.77 } 0.003 and 1.98 } 0.003 mg/g, Folate 0.53 } 0.004 and 0.58 } 0.004 mg/g, Magnesium ranged between 0.21 } 0.002 and 0.92 } 0.003 mg/g, Calcium 2.14 } 0.004 and 2.26 } 0.001 mg/g, Sodium 0.01 } 0.000. Iron, 1.24 } 0.005 and 1.42 } 0.006 mg/g. Sample obtained from oil bean tree showed lower and differed significantly (p < 0.05) in Anthocyanin and Chlorophyll b with samples obtained from avocado and kola trees. The sample obtained from avocado tree showed higher Tannin content compared with samples obtained from oil bean and kola trees (P . 0.05). There were significant differences (P < 0.05) between the samples in all the vitamins. The minerals showed significant differences in the samples (P < 0.05) except in sodium content which was very low in all the samples. Mistletoe leaves are shown to have a rich chemical composition and could thus serve as a source of these phyto-chemicals, vitamins and minerals. Keywords : Trees, mistletoe, phyto-chemicals, vitamins, minerals

Flammability properties of low density polyethylene/wood fibre composites

Using simple combustion apparatus the effect of wood fibres on the flammability properties of Low Density Polyethylene (LDPE) was studied. Composite samples were prepared with LDPE and Kola Nitida (KN), and LDPE and Alstonia Boonei (AB) with fibre contents of 0, 5, 10, 15, and 20 wt. %. Test results show that ignition time and time for auto-combustion increased with increasing fibre content for both composite types. The flame propagation rate decreased with increasing fibre content for both composite samples. At 20 wt.%, LDPE/KN had about 650% and 1032% increment in ignition time and auto combustion time respectively, and showed a decrease of about 200% in FPR value, while LDPE/AB had about 290 % and 180 % increment in ignition time and auto combustion time respectively, and showed a decrease of about 110% in FPR value. The results show that LDPE/KN composites show better flame retardancy properties over LDPE/AB composites at 20 wt% fibre content.

Serum Protein Binding and the Antimicrobial Activities of Garcinia Kola, Kola Acuminata and Kola Nitida Seed Extracts on the Agents of Respiratory Tract Infections

The kinetics of bactericidal activity of the methanolic extracts of powdered seeds of Garcinia kola (Heckel), Kola acuminata and Kola nitida obtained by soxhlet extraction, were studied using two bacterial sensitive strains of Staphylococcus aureus and Pseudomonas aeruginosa. The study showed that the three extracts at the concentrations used against the two test organisms, Staphylococcus aureus OOUTH206 (0.5mg/ml for Garcinia kola, 4mg/ml for Kola acuminata and Kola nitida) and Pseudomonas aeruginosa UCH189 (8mg/ml for Garcinia kola, 15mg/ml for Kola acuminata and Kola nitida); had activity on the two microorganisms. There was a gradual reduction in the number of viable microbial counts as evident in the reduction in the cell number at the different time intervals. Similar procedure was carried out in the presence of 5% serum protein and it was observed that the activities of the various extracts were altered significantly indicating the effect of serum protein binding on the constituents of Garcinia kola, Kola acuminata and Kola nitida seed extracts. The results were expressed in percentage viable count of the inoculum size and showed that the percentage viable count decreases with time in varying degrees. The reduction was more intense with G. kola extract than the other extracts on S. aureus as well as on P. aeruginosa towards the third and fourth hours. The effect of serum protein was seen to affect the activities of all the extracts in varying degrees as shown in the graphs plotted.Key words: Garcinia kola, Kola acuminata, Kola nitida, methanolic extracts, respiratory tract infections, serum proteins.

Proximate composition of some agricultural wastes in Nigeria and their potential use in activated carbon production

The proximate composition of five agricultural wastes were determined and latter subjected to low temperature conversion process in the presence of nitrogen atmosphere.These agricultural wastes are Cocos nucifera husk,Theobroma cacao pod, Kola nitida pods and Plantago major peels(ripe and unripe peels). All the samples investigated have different intrinsic proximate compositions which affect the yields of their respective chars. Out of the sample investigated, Cocos nucifera husk recorded the lowest bulk density (0.0746g/cm3), ash content (3.95%),cellulose contents(0.52%) and has the lowest char yields.On the other hand ,Theobroma cacao pods recorded the highest cellulose content(41.92%),ash contents(12.67%), crude fiber content(33.60%) and has appreciably high char yields. The lignin contents of samples fell in the range of (6.06%-33.60%).The percentages of chars obtained after conversion at 4200C for each of the precursors were relatively lower to those obtained at 3600C.The percentage yield for all the samples fell within the range of 46 - 64% for 3600C and 43 - 58% for 4200C. Hence,because of their high carbon yields and their inherent compositions ,they can serve as precursors for activated carbon production.

In vitro study of the interaction between some fluoroquinolones and extracts of kola nitida seed

The cup diffusion method (CD) was used to evaluate the in vitro interaction of some fluoroquinolones (ciprofloxacin, pefloxacin and levofloxacin) with extracts ofKola nitida seed (KNS) against a clinical isolate of Escherichia coli. Minimum inhibitory concentration (MIC) of the drugs was determined separately and in combination with KNS extract in ratios of 0:5, 1:4, 2:3, 3:2, 4:1 and 5:0 against E. coli. The result of the study revealed that the MIC of the drugs decreased when combined with KNS extract. In other words, KNS extract potentiated the effects of the fluoroquinolones against E. coli. Key words: Interaction study, ciprofloxacin, pefloxacin, levofloxacin, Kola nitida seed

In vitro study of the interaction between some fluoroquinolones and extracts of kola nitida seed

The cup diffusion method (CD) was used to evaluate the in vitro interaction of some fluoroquinolones (ciprofloxacin, pefloxacin and levofloxacin) with extracts of Kola nitida seed (KNS) against a clinical isolate of Escherichia coli. Minimum inhibitory concentration (MIC) of the drugs was determined separately and in combination with KNS extract in ratios of 0:5, 1:4, 2:3, 3:2, 4:1 and 5:0 against E. coli. The result of the study revealed that the MIC of the drugs decreased when combined with KNS extract. In other words, KNS extract potentiated the effects of the fluoroquinolones against E. coli.

Microbiological exploitation of cardiac glycosides and alkaloids from Garcinia kola, Borreria ocymoides, Kola nitida and Citrus aurantifolia

The four medicinal plants, Garcinia kola (roots), Borreria ocymoides (leaves), Kola nitida (bark) and Citrus aurantifolia (roots) were screened for phytochemical components. They were found to contain tannins, phlobatannins, polyphenols, hydroxymethyl anthraquinones, glucides, saponins, alkaloids, cardiac glycosides, flavanoids and reducing compounds. The aqueous and alcoholic extracts as well as alkaloids and cardiac glycosides of the medicinal plants were tested on various pathogenic bacteria. They were found to inhibit such organisms as Staphylococcus aureus, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, beta-haemolytic streptococci, Escherichia coli and Neisseria gonorrhoeae. The usefulness of the phytochemical bases of these plants as potential sources of pharmaceutical drug preparation is discussed.