Bio-Research

Characterization and antimicrobial evaluation of biomimetically synthesized silver nanoparticles using aqueous leaf extract of Morinda lucida Benth. (Rubiaceae)

2023-08-30T13:02:44+00:00

Silver nanoparticles (AgNPs) are silver atom masses that are attracting widespread interest due to their diverse applications, particularly their activity as antimicrobial agents. Physico-chemical methods of AgNP synthesis are associated with high costs, high temperatures and toxic byproducts. Thus, the plant mediated pathway represents a better option. The indigenous medicinal plant Morinda lucida was employed in the fabrication of AgNPs. The nanoparticles were characterized using different analytical techniques and also evaluated for their antimicrobial potential. Phytochemical screening of the plant was also carried out. For the synthesis, 10 ml of aqueous M. lucida leaf extract was added to 90 ml of freshly prepared 3 mM silver nitrate (AgNO₃) solution in a flask. The mixture was allowed to stand at ambient temperature, in a dark cupboard for 48 hours. Positive AgNP synthesis, indicated by a colour change from red to brown was further validated by UV-vis spectroscopy wherein an absorption peak at 460.51 nm was recorded. The utilitarian aspects of the particles were further characterized using scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). The SEM images showed that particles were round to irregular in shape. Amide, amine, alkene and alkynes were the most occurring functional groups from the FTIR spectra. Quantitative phytochemical analysis revealed the presence of flavonoids, terpenoids, phenols, reducing sugars and alkaloids in varying amounts, which play a significant role in the synthesis and stabilization of the AgNPs. The XRD diffractogram of AgNPs showed two peaks at 45.53° and 77.17° that correspond to miller indices of (200) and (311) respectively and an average crystalline size of 62.60 nm obtained using the Debye-Scherrer’s formula. The DLS result indicated a Z–average size of 235.1 nm and a polydispersity index (PDI) of 0.4. EDX analysis showed that elemental silver (Ag) had the highest atomic concentration of 64.50 %. Using the agar well diffusion assay, the nanoparticles exhibited antimicrobial activity against P. aeruginosa (bacteria) and A. flavus (fungi). It can be concluded that M. lucida is capable of synthesizing stable, small-sized AgNPs with antimicrobial potential.

Antioxidant potential of ethanol extract of Annona muricata leaves and its inhibitory effect on lipid peroxidation in 1,2-dimethylhydrazine induced colon carcinogenesis

2023-09-09T13:49:57+00:00

Annona muricata, as it is scientifically called but known in most parts of Nigeria as soursop. A fruit tree with various therapeutic uses, the plant belongs to the family of Annonaceae and has several medicinal properties. The medicinal properties of Annona muricata are well known, and they can be used to treat a variety of illnesses and conditions. Effects of ethanol extract of Annona muricata leaves (EEAML) on the enzymatic antioxidants of the kidney and colon in Wistar rats induced with 1, 2 Dimethylhydrazine (DMH) at 25 mg/kg bodyweight s.c. were investigated in this study. Thirty-six male Wistar rats weighing 110–170g were acclimated for two weeks and randomized into six groups (six per group). Group A (control), Group B (extract; 120 mg/kg body weight of ethanolic extract of A. muricata), Group C (DMH only), Group D (DMH + EXTRACT), Group E (pretreatment), and Group F (posttreatment). The extract was administered daily via oral gavage, while the DMH was given subcutaneously at a dosage of 25 mg/kg bodyweight. This study reveals the carcinogenic effect of DMH induced oxidative stress were ameliorated by the administration of this leaf extract of EEAML at a dose of 120mg/kg b.w. The colon and kidney homogenates of rats administered EEAML (co-treated, pretreatment and post- treatment) showed increased enzymatic antioxidant; glutathione peroxidase, catalase activities and SOD activities. But a reduction in malondialdehyde levels was observed. These findings validate the use of Annona muricata in traditional medicine by showing that the ethanolic extract of the leaves can reduce DMH-induced oxidative stress and alter the enzymatic antioxidant profile in colon carcinogenesis.

Palm wines as potential Aedes mosquito repellant

2023-09-12T05:48:56+00:00

Globally, Aedes mosquitoes cause morbidity and mortality of dengue, yellow fever and other arboviral infections. There is no effective vaccine for Aedes transmitted diseases so mosquito control remains the mainstay for their control. Semiochemicals play significant role in modulating insect behavior so are utilized to lure mosquitoes to their destruction or to repel them to halt infection transmission. Palm wines are potent source of semiochemicals but their effect on Aedes mosquitoes in our locality is not well understood. This study was undertaken to ascertain whether palm wine could impact on mosquito inflections. Aedes larvae were collected and bred in the laboratory to adulthood. Female mosquitoes were selected and tested for their reactions to two categories of palm wine – the up-palm and down-palm wines. An olfactometer was fabricated and applied to find how Aedes mosquitoes reacted in it when subjected to odours from the palm wines within 5 minutes. Data obtained were prepared and one way analysis of variance was used to compare means. Only 3% of mosquitoes reached the up-wine arm on day 2. However, when both wines were tested, 2.78 ± 2.78% of mosquitoes reached the down-palm wine terminal. Both wines repelled mosquitoes consistently, confirmed by their refusal to seek any of the palm wine odours. Repellence increased as days passed: initially upstream mosquitoes ranged 36.36 – 60% at the beginning, declining to 3.3 – 6.36% on the 8^th day; whereas downstream ranged from 40 – 63.63% at the beginning to reach 93.63 – 100% on the 8^th day. Palm wines semiochemicals repelled Aedes mosquitoes. Further testing may be required before utilization in formulated repellents for public use.

Repellence of Aedes aegypti with oils from Citrus sinensis and Citrus paradisi fruit peelsi from Nsukka

2023-09-18T07:34:34+00:00

Aedes aegypti spread yellow fever, dengue fever, Zika virus and Chikungunya that can be prevented through vector control. Chemical insecticides are resisted by vectors, harm humans and the ecosystem thereby making their use opprobrious. Plants essential oils are safer alternatives. Oils of Citrus sinensis and Citrus paradisi fruit peels are readily available in Nsukka but their effect on Aedes aegypti remain uncertain so it became imperative to verify the effect of these oil extracts on them. The cold maceration method was used to extract essential oils from their peels. They were used singly and in various formulations to evaluate the behaviour of starved Ae. aegypti adults. WHO protocols were applied in obtaining the effective doses and complete protection time. Data collected were analysed using SPSS version 23.0. Various formulations repelled mosquitoes in the magnitude of 100 % > 75 % > 50% > 25% and significant differences (p < 0.05) noted between formulations. Formulations B and H showed highest repellence effects with 0 – 3 number of mosquito landings during the three minutes of test period. Probit analysis showed that 1.14 ml of formulation G was required to achieve 99% repellence. Formulation B demonstrated synergism of the oils attaining the highest complete protection time of 150 minutes. This study showed that oil extracts of C. sinensis and C. paradisi would prevent female Aedes aegypti adults from landing on or feeding from skins smeared with each of the oil or their combinations. The oils exhibited synergism when combined hence could be used to control this mosquito.

Histological and morphometric analysis of skeletal muscle in some vertebrates

2023-09-20T14:30:45+00:00

The skeletal system is primarily driven by the skeletal muscles to produce kinematic movements. The study evaluates the histological and morphometric properties of skeletal muscle in Clarias gariepenus (Cl. gariepinus), Bufo bufo (B. bufo), Agama agama (A. agama), Columba livia domestica (C. domestica) and Rattus rattus (R. rattus). The study was carried in order to relate the similarities and differences of skeletal muscles in these species with evolutionary trend. The epaxial muscle of Cl. Gariepinus, the biceps femoris muscle of B. bufo, R. rattus, puboischiotibialis of A. agama, and pectoral muscle from C. domestica were removed and assessed grossly for physical appearance then processed for histological analysis. The diameters of the muscle fibers were measured and one-way analysis of variance was used to compare the differences. The muscles of Cl. gariepinus, B. bufo and A. agama appeared whitish with scanty fusiform nucleus and large intermuscular space. However, the muscles of C. domestica and R. rattus appeared red with distinct round nucleus and small intermuscular space. No significant difference (P>0.05) was observed in the muscle diameter of Cl. gariepinus (8.86±0.13µm) compared to B. bufo (8.25±0.27µm). The muscle diameter of A. agama (10.18±0.25µm) was significantly higher (P<0.05) relative to Cl. gariepinus (8.86±0.13µm), B. bufo (8.25±0.27µm), C. domestica (3.38±0.13µm) and R. rattus (4.66±0.15µm). Conclusively, non-tetrapod vertebrates (Cl. gariepinus, B. bufo, and A. agama) have simple, white-colored skeletal muscle with few flat-shaped nuclei and large fiber diameters while higher vertebrates (C. domestica and R. rattus) have complex, red-colored skeletal muscle with numerous oval-shaped nucleus and small fiber diameter.

Effect of flamboyant flower (Delonix regia) powder on root knot nematodes (Meloidogyne incognita) infestation on tomato plant (Solanum lycopersicum) in Yola, Adamawa State

2023-09-20T16:28:31+00:00

Plant Parasitic Nematodes (PPN) are regarded as one of the major challenges of sustainable tomato production in the world. Their control which involves the use of synthetic chemicals is being restricted because of their toxicity coupled with the environmental risk associated with their use. To this effect this study was carried out to evaluate the effect of flamboyant flower powder on M. incognita inoculated on tomato plants as an alternative control strategy of PPN. Screen house experiment (potted experiment) was conducted at the landscape garden of Modibbo Adama University Yola to evaluate the efficacy of plant powder for the control of root- knot nematode in tomato plant. The experimental design used was the Completely Randomized Design (CRD) with five treatments replicated three times. D. regia powders were incorporated at different levels into the bucket each containing 4kg of sterilized soil. The plant powder was incorporated at the rate of 40g, 30g, 20g and 10g (T₁, T₂, and T₃) respectively and T₄ with no level of powder 0g. D. regia powder and 40g gave the best effect on M. incognita in the potted experiments as higher plant height, number of leaves; fresh shoot weight, galling index and least final nematode of both soil and roots were recorded. Therefore, from these findings, D. regia at 40g exhibited nematicidal effect on M. incognita in tomato plant followed by 30g, 20g, and 10g respectively. The nematicidal characteristics exhibited by this plant material (flamboyant flower) might be due to some phytochemical constituents present in the plant material. The control plant has least plant height, number of leaves, fresh shoot weight, plant fruit and higher fresh root weight as well as galling index and highest final root and soil nematode population.

Sodium sesquicarbonate elicits oxidative stress in erythrocytes, liver and kidney tissues

2023-09-20T16:36:38+00:00

Sodium sesquicarbonate also known as Sodium sesquicarbonate dihydrate (SSD) has been used globally for centuries in food and traditional medical practices. There is paucity of scientific information on the safety of this common food additive. This study was designed to find out if the oral administration of SSD is capable of generating oxidative stress in erythrocytes, liver and kidney using albino rats as experimental models. The total number of animals used for this study was fifteen. The experimental animals were grouped into three. There were five animals in each group. The rats in the first group which was the control group, were dosed with 1 ml distilled water, while groups 2 and 3 were treated with 400 mg/kg and 800 mg/kg body weight (bw) of SSD, respectively, once daily per os for 28 days. After the duration of treatment, the erythrocytes, hepatic and kidney tissues were processed for the analysis. The biomarkers of oxidative stress, superoxide dismutase (SOD), catalase; and thiobarbituric acid reactive substances/ malondialdehyde (TBARS/MDA) were assayed. The result indicated that catalase enzyme activity was overexpressed in the red blood cells, liver and kidneys of the group that consumed the lower dose of SSD. The dose-dependent increase in the lipid peroxidation of the tissues as indicated by increased levels of MDA in the erythrocytes and TBARS in the tissues of the treated groups was significant (P < 0.05). The SOD enzyme activity in all the tissues assayed showed a dose-dependent decrease, which was significant at the probability level of 0.05. The consumption of SSD therefore caused lipid peroxidation and reduction in activity of the antioxidants present in the tissues studied.