Leaf Extract Research Articles

SAMBILOTO LEAF NANOEMULSION AS A PHOTOPROTECTIVE AGENT: OPTIMIZATION OF TWEEN 20 AND PEG-400 CONCENTRATION USING THE REGULAR TWO-LEVEL FACTORIAL DESIGN

Objective: This study aims to determine the optimum concentration of Tween 20 and Polyethylene Glycol 400 (PEG-400) in Sambiloto leaf extract nanoemulsion. Methods: The formula of sambiloto leaf nanoemulsion was developed using the regular two-level factorial design based on responses of pH values, density, viscosity, and transmittance percentage. The optimum formula was tested for stability and photoprotective activity by determining the Sun Protection Factor (SPF) value and antioxidant activity. Results: Sambiloto leaf extract contains andrographolide at 3.397%. The optimum formula for nanoemulsion preparations was obtained at 10% of tween 20 and 10% of PEG-400. The optimum nanoemulsion had a distinctive green extract aroma, a transmittance percentage of 86.7±0.170, a globule size of 130.43±54.056 nm, a polydispersity index of 0.318±0.043, and a zeta potential of-26.5±0.544 mV. The optimum formula's photoprotective activity resulted in an SPF value of 42.944±0.026 and an IC50 of 103.611±1.085 ppm. There was no significant change in pH or transmittance percentage based on the stability test (p<0.05). Conclusion: The results show that the optimum formula of sambiloto leaf nanoemulsion could be a photoprotective agent that is also stable.

Evaluation of Antioxidant and Anti-Diabetic Potentials of the Ethyl Acetate Leaf Extracts of some Commonly used Medicinal Plants in Ogbomoso, Nigeria

Evaluation of Antioxidant and Anti-Diabetic Potentials of the Ethyl Acetate Leaf Extracts of some Commonly used Medicinal Plants in Ogbomoso, Nigeria

Alkaloids and Styryl Lactones from Goniothalamus tortilipetalus and Their Biological Activities.

Phytochemical investigations of the twig and leaf extracts of Goniothalamus tortilipetalus resulted in the isolation and identification of two new alkaloids, goniotortiline (1) and goniotortilactam (2), three new styryl lactone derivatives, goniotortilactone (3) and goniotortilols A (4) and B (5), and 25 known compounds. Their structures were elucidated by spectroscopic methods and HRESITOFMS data. Compounds 5, 13, 15, 16, 22, and 30 inhibited nitric oxide (NO) production with IC50 values ranging from 8.7 ± 0.1 to 17 ± 1 μM, revealing stronger effects than the standard drug, dexamethasone (IC50 16.9 ± 2.2 μM), and compound 30 possessed the most potent NO production inhibition. Compounds 12 and 29 demonstrated notable efficacy in enhancing glucose consumption with IC50 values of 77 ± 4 and 66 ± 4 μM, respectively, while their glucose uptakes were 1.7- and 2-fold, respectively.

PREPARATION, CHARACTERIZATION, AND IN VITRO EVALUATION OF GEL CONTAINING NANOPHYTO-PHOSPHOLIPID COMPLEX OF KOPASANDA LEAF EXTRACT (CHROMOLAENA ODORATA (L.) R. M. KING AND H. ROB)

Objective: This study aims to prepare, characterize, and in vitro evaluation of the gel containing nanophyto-phospholipid complex of kopasanda leaf extract. Methods: Kopasanda dried leaf was extracted by extraction reflux method, followed by total phenolic content of extract measurement using Spectrophotometry UV-Vis method. The nanophyto-phospholipid complex was prepared using an antisolvent evaporation method with various ratios between extract and phospholipid of 1:1; 1:2; 1:3. The optimum ratio was evaluated by entrapment efficiency (%). The nanophyto-phospholipid complex formation was characterized by polydispersity index, particle size, Fourier Transform Infra-Red (FT-IR), and the Transmission Electron Microscope (TEM) method. The optimum nanophyto-phospholipid complex was formulated into gel preparation. The in vitro permeation study was performed to discover the influence of gel containing nanophyto-phospholipid complex compared with gel-containing extract without the nanophyto-phospholipid complex formation. Results: Thetotal phenolic content of kopasanda leaf extract was 117.214±3.054 mg/GAE. The optimum ratio of kopasanda leaf extract and phospholipid was 1: 2 with entrapment efficiency (%), particle size, and polydispersity index equal to 99.897±0.001%, 130.1 nm and 0.394. The morphology of the nanophyto-phospholipid complex was spherical and the complex formation was confirmed by the FTIR spectrum. The permeation test showed that the gel containing nanophyto-phospholipid complex had better diffusion than the gel without the nanophyto-phospholipid complex formation. Conclusion: The gel containing nanophyto-phospholipid complex formation exhibited the potential drug delivery system to increase the phenolic content permeation of kopasanda leaf extract.

Comparative analysis of the antimicrobial activity and dye degradation of metal oxides (TiO2, CdO, Mn2O3, and ZnO) nanoparticles using a green approach.

A tremendous amount of recent work has been done on different metal oxide nanomaterials for biological activities and photocatalytic dye degradation. This work used the Cissus quadrangularis leaf extract to prepare TiO2, CdO, Mn2O3, and ZnO nanoparticles using a green synthesis approach. To ascertain the physicochemical characteristics of the generated metal oxide nanoparticles, various characterisation techniques were used. The X-ray diffraction technique was used to determine the composition of the crystal and phase. Metal oxide nanoparticles have been proven to be present through surface morphological investigations using a scanning electron microscope and energy dispersive spectroscopy analysis. UV-Vis and Fourier transform infrared spectra were used for spectroscopic analysis. X-ray photoelectron spectroscopy can determine a material's elemental composition in addition to the electronicand chemicalstates of its atoms. The nanomaterial's distinct morphology, which resembles rods, rose petals, platelets, and spheres, was discovered by scanning electron microscope. Synthesized metal oxide nanoparticles have demonstrated a remarkable efficiency of 87.5-90.6% when utilized as a catalyst towards the removal of the malachite green dye under UV light irradiation. Additionally, we use the disc diffusion method to assess antibiotic efficacy against Bacillus subtilis, Candida tropicalis, and Escherichia coli. ZnO nanoparticles had the greatest zones of inhibition for 80 μL doses, measuring 26.99mm for Bacillus subtilis, 27.57mm for Escherichia coli, and 25.28mm for Candida tropicalis. The antimicrobial activity was strongly impacted by the size of the nanoparticles and increased with decreasing particle size. Overall, our research demonstrates that metal oxide nanoparticles are a promising photocatalytic agent for wastewater treatment and biological applications.

Photocatalytic Degradation of Four Organic Dyes Present in Water Using ZnO Nanoparticles Synthesized with Green Synthesis Using Ambrosia ambrosioides Leaf and Root Extract

Currently, several organic dyes found in wastewater cause severe contamination problems for flora, fauna, and people in direct contact with them. This research proposes an alternative for the degradation of polluting dyes using ZnO nanoparticles (NPs) synthesized by an ecological route using leaf and root extracts of Ambrosia ambrosioides as a reducing agent (with a weight/volume ratio = 4%). Scanning Electron Microscopy (SEM) was used to determine the morphology, showing an agglomeration of cluster-shaped NPs. Using Transmission Electron Microscopy (TEM), different sizes of NPs ranging from 5 to 56 nm were observed for both synthesized NPs. The composition and structure of the nanomaterial were analyzed by infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), showing as a result that the NPs have a wurtzite-like crystalline structure with crystallite sizes around 32–37 nm for both samples. Additionally, the bandgap of the NPs was calculated using Ultraviolet Visible Spectroscopy (UV–Vis), determining values of 2.82 and 2.70 eV for the NPs synthesized with leaf and root, respectively. Finally, thermogravimetric analysis demonstrated that the nanoparticles contained an organic part after the green synthesis process, with high thermal stability for both samples. Photocatalytic analysis showed that these nanomaterials can degrade four dyes under UV irradiation, reaching 90% degradation for methylene blue (MB), methyl orange (MO) and Congo red (CR) at 60, 100 and 60 min, respectively, while for methyl red (MR) almost 90% degradation was achieved at 140 min of UV irradiation. These results demonstrate that it is effective to use Ambrosia ambrosioides root and leaf extracts as a reducing agent for the formation of ZnO NPs, also evidencing their favorable application in the photocatalytic degradation of these four organic dyes.

Evaluation of Phyto-extracts for the Management of Alternaria Leaf Blight of Cluster Bean (Cyamopsidis tetragonoloba L.) Caused by Alternaria cucumerina

The present study was carried out to evaluate the effect of selected phyto-extracts for the management of alternaria leaf blight of cluster bean (Cyamopsidis tetragonoloba L.) caused by Alternaria cucumerina under field conditions. Three replications of cluster bean were planted in a randomized block design at the research plot of the Central Research Field, Department of Plant Pathology, SHUATS, Prayagraj during Zaid season of 2023. Ginger rhizome extract @ 10%, onion bulb extract @ 10%, eucalyptus leaf extract @ 10%, neem leaf extract @ 10%, garlic clove extract @ 10% and mancozeb 0.2% were applied as foliar spray. All the treatments were found significantly reduced the disease severity and increased the yield. Among all the treatments garlic clove extract @ 10% was recorded minimum disease intensity (29.63) and maximum yield (2.50 t/ha). Neem leaf extract @ 10% was recorded maximum cost benefit ratio (1: 1.80), as compared to treated mancozeb @ 0.2%(treated) and T0 control.

Enhanced photocatalytic activity of BB41 and ROM2R dyes using green synthesized NiO nanoparticles: A response surface methodology approach

BackgroundNiO NPs are recognized for their potential in catalysis, energy storage, and environmental remediation. Green synthesis using plant extracts, such as Cucumis maderaspatanus L. (CmL.) leaves, offers an eco-friendly approach. This study focuses on synthesizing and analyzing the structural, optical, and photocatalytic properties of Cm-NiO NPs. MethodologyCm-NiO NPs were synthesized using CmL. leaf extract and calcinated at 300, 500, and 700 °C. XRD confirmed a face-centered cubic structure. Band gap values were 3.36 eV at 300 °C, 2.98 eV at 500 °C, and 3.15 eV at 700 °C. TEM showed spherical particles of 17.81 nm. The point of zero charge (pHpzc) was pH 7.95. The photocatalytic activity was tested on BB41 and ROM2R dyes under varying pH (4 – 10), dye concentrations (10 – 50 ppm), catalyst amounts (0.1 – 1.0 mg/mL), and light sources. Scavenger studies identified reactive compounds. Response surface methodology (RSM) optimized the degradation process. LC-MS analyzed degradation products, and ECOSAR software estimated their toxicity. Significant FindingsCm-NiO NPs showed high photocatalytic efficiency, degrading 93.60 % of BB41 and 88.76 % of ROM2R under UV light (250 W, 365 nm). The nanoparticles demonstrated a face-centered cubic structure and a pHpzc of 7.95. RSM effectively optimized the process, and toxicity analysis suggested a potential for environmental applications.

Biosynthesis of Gold Nanoparticles Using Sambiloto Leaf Extracts and its Characteristics

Gold nanoparticles (AuNPs) have been successfully synthesized using aqueous sambiloto (Andrographis Paniculata Ness) leaf extract as a reducing agent. This method of synthesizing nanoparticles is called biosynthesis. Characterization was carried out using various techniques including UV-Vis, FTIR, and TEM. The results showed that the optimal synthesis ratio, i.e., AuCl3 solution : sambiloto leaf extract, was 30 µl : 10 ml with a synthesis rate of 0.159 a.u./h. The characteristic of the gold nanoparticles synthesized is that the surface Plasmon resonance (SPR) wavelength is 529.00 nm; it was stable after 4 hours of synthesis and stayed until 24 hours at an SPR wavelength of 527.00-531.50 nm. The functional groups formed include O-H, aliphatic C-H, C=O stretch, aromatic C=C stretch, and C-O stretch. The size of the nanoparticles is in the range of 1-20 nm.

Insight into the Corrosion Inhibition Performance of Pistia stratiotes Leaf Extract as a Novel Eco-Friendly Corrosion Inhibitor for Mild Steel in 1 M HCl Solution

In this research, the Pistia stratiotes leaf (PSL) extract was evaluated as a green corrosion inhibitor for the corrosion of mild steel in 1 M HCl using electrochemical measurements and surface characterization. Electrochemical impedance spectroscopy (EIS) spectra showed that the inhibitory activity of the phytochemical compounds enhanced with increasing concentration up to 400 ppm, which was reflected in the increase in the charge transfer resistance and double-layer capacitance. Regarding the effect of immersion time, EIS results indicated that the persistence of the PSL extract was between 4 h and 8 h of exposure time. From polarization curve (PCC) results, the best performance of the corrosion inhibitor was achieved at 400 ppm with an inhibition efficiency of 93.7%. The PSL extract acted as a mixed-type corrosion inhibitor. The adsorption of the phytomolecules on the metal surface obeyed the Langmuir isotherm through a mixed mechanism (physical and chemical interactions) dominated by physisorption. Scanning electron microscopy (SEM) examinations and energy-dispersive X-ray spectroscopy (EDS) elemental analysis of the corroded samples confirmed the anticorrosive protection of the PSL extract. Chemical characterization of the PSL extract by GC-MS revealed the presence of phytol, steroids, and aromatic and long-chain unsaturated fatty acid esters, in order of abundance. Chemical quantum calculations by DFT allowed for determining that the phthalic acid, di(2-propylpentyl) ester compound has the most significant potential to act as the main active component in corrosion inhibition activity.

Inhibition Of Leaf Extract of Rubber Plant Against Enterobacteriaceae Isolated from Drinking Water Refill

Inhibition Of Leaf Extract of Rubber Plant Against Enterobacteriaceae Isolated from Drinking Water Refill

A comprehensive analysis of phytochemicals, antioxidant, anti-inflammatory, antibacterial, antifungal and phytoestrogenic properties of different parts of Tribulus terrestris.

Tribulus terrestris L., a medicinal plant rich in secondary metabolites, was studied for optimising bioactive compound extraction from various parts of the plant using ethanol-water (50:50), ethanol, and methanol solvents. Analysis of extracts for key phytochemicals like polyphenols, flavonoids, saponins, and alkaloids was performed using HPTLC, HPLC and gas chromatography. The ethanol-water mixture proved best for extracting saponins and polyphenols, ethanol for flavonoids, and methanol for alkaloids. The fruit yielded the highest saponin content (59.34% ± 3.87), while leaves were richest in polyphenols (18.94% ± 1.39), flavonoids (5.15% ± 1.01), and alkaloids (26.46% ± 1.71). Leaf extracts showed the highest antibacterial activity against B. subtilis and P. aeruginosa, and stem extracts were effective against E. coli. Root, stem, and leaf extracts exhibited antifungal activity with leaf extract also demonstrating strong phytoestrogenic activity. These findings highlight the varied phytochemical profiles and biological activities of T. terrestris, suggesting their potential therapeutic uses.

Unveiling the antibacterial and antioxidant capabilities of Diospyros buxifolia leaf and stem extracts via GC-MS analysis

Drug-resistant microorganisms pose a significant threat to public health as they can undermine the effectiveness of existing antibiotics and other medications. Additionally, the formation of free radicals, can contribute to various health problems. Diospyros buxifolia (D. buxifolia) belonging to Ebenaceae family is a large tropical evergreen tree utilised in traditional medicine to cure several health ailments. The present study was set out to separate bioactive speciation of aqueous and methanolic extracts of stem and leaves from D. buxifolia by using Gas Chromatography-Mass Spectrometry (GC-MS) followed by evaluation of its antimicrobial and antioxidant capabilities. GC-MS identified 14 different bioactive compounds, with four compounds common for both (leaf and stem) extracts. The methanolic extracts of leaf demonstrated significant antibacterial activity) while stem extracts exhibited notable antioxidant potential. Thus, D. buxifolia is proved source of natural antimicrobial and antioxidant agent, that could address the challenges posed by drug-resistant microorganisms and oxidative stress in global health.

Subacute Toxicity Study of Alchornea cordifolia Ethanolic Leaf Extract on the Pituitary Gland of Wistar Rats

Introduction: Herbal medicines are plant-based products used to treat various illnesses and their uses have dramatically increased over the past years in many developed and developing nations. Alchornea cordifolia is one of these plants with reports of its use in health promotion. Some plants exhibit toxicity due to the presence of phytochemicals inherent in them, therefore further studies are necessary in evaluating their toxicity levels. In this study, the sub-acute toxicity of ethanolic extract of Alchornea cordifolia leaves was investigated on the pituitary gland of adult male Wistar rats. The objective was to determine its effect on the histology of the anterior pituitary gland. Methods: Twenty (20) adult male Wistar rats weighing 140-200 were used for the research and were randomly divided into four groups labelled A, B, C. and D. Each group consisted of five (5) rats. Group A (normal control) received normal saline, while group B, C and D received 500 mg/kg, 1,000 mg/kg and 1,500 mg/kg body weight of Alchornea cordifolia extract respectively with the aid of an oral gavage. This was done for a duration of 28 days after which the rats were sacrificed and the pituitary gland obtained for histological analysis using H&E and PAS Orange G staining methods. Results: Histological observations showed that the various doses of the extract used had no detrimental effect of the anterior pituitary gland microstructure in groups B, C, and D when compared to group A. Conclusion: The findings showed that the various doses of Alchornea cordifolia leaf extract used in this study are non-toxic to the anterior pituitary gland in Wistar rats.

Retraction Note: ROS-mediated cytotoxic activity of ZnO and CeO2 nanoparticles synthesized using the Rubia cordifolia L. leaf extract on MG-63 human osteosarcoma cell lines.

Retraction Note: ROS-mediated cytotoxic activity of ZnO and CeO2 nanoparticles synthesized using the Rubia cordifolia L. leaf extract on MG-63 human osteosarcoma cell lines.

In vitro pharmacological evaluation of Methanolic leaf extract of Calotropis procera for antifungal and anti-breast cancer activities.

Medicinal plants remained the primary choice worldwide from several centuries due to many therapeutic effects in the management of infectious and non-infectious diseases. Therefore, exploration of new medicinalplants as a green medicine has the major concern of many research groups. Microbial infections and different types of cancers in human are among the common health problems both in developing as well as in developed countries. Medicinal plants as a source of anti-microbial and anti-cancer agents are still in their initial stage in modern medicine. So current research work was planned to explore the anti-fungal and anticancer potential of Calotropis procera. C. procera leaves were collected from local area of Faisalabad, Pakistan, and phytochemical, anti-microbial, and anti-cancer activities were studied following reference methods. In vitro anti-microbial study of methanolic extracts of C. procera leaves against different strains of fungal was performed. Results showed that plant extract in a dose of 5 mg/mL have significant (P<0.05) antifungal activity. Moreover, the methanolic leaf extract of C. procera displayed strong anti-cancer activity in breast cancer cells (MCF-7), with a cytotoxic activityat 200μg/mL comparable to that found for Taxol as standard drug. Findings of current research work showed that the leaf extracts of C. procera has strong potential as an antibacterial, antifungal and anti-cancer agent. However, characterization and purification of phytochemicals is required to develop drug from natural resources.

Impact of Nanoparticles Synthesized From Azadirachta indica (A. Juss) for Targeted Control of Malarial, Dengue, and Filariasis Vectors With Minimized Aquatic Toxicity

ABSTRACTIn the present study, biogenic silver nanoparticles (AgNPs) synthesized using Azadirachta indica leaf extract were evaluated for their toxic effects on both target and non‐target species. The botanical synthesized nanoparticles were tested against Anopheles stephensi, Aedes aegypti, and Culex quinquefasciatus and non‐targeted species Artemia salina and Eudrilus eugeniae at 24 h posttreatment. AgNPs were characterized using the following analytical techniques: UV‐Vis spectroscopy, FT‐IR, x‐ray diffraction (XRD), energy‐dispersive x‐ray spectroscopy (EDX), and scanning electron microscope (SEM) analysis. Results showed that AgNPs caused larvicidal activity with 90.66% mortality in An. stephensi, 97.33% in Ae. aegypti, and 93.33% in Cx. quinquefasciatus at 24 h posttreatment. A. indica‐derived AgNPs had lower LC50 (lethal concentration 50) and LC90 (lethal concentration 90) values of 44.803 and 252.886 ppm/mL in An. stephensi, 18.358 and 189.553 ppm/mL in Ae. Aegypti, and 36.492 and 219.800 ppm/mL in Cx. quinquefasciatus, respectively. Furthermore, AgNPs demonstrated lower toxicity effects with 50.66% mortality in A. salina and 38.66% mortality in E. eugeniae at 24 h posttreatment. Additionally, they exhibited lower LC50 and LC90 values of 240.996 and 533.618 ppm/mL in A. salina and 301.122 and 548.944 ppm/kg in E. eugeniae at 24 h posttreatment, respectively. The findings conclude that green‐synthesized AgNPs from plants offer a promising, cost‐effective, and target‐specific alternative for eco‐friendly mosquito larvicides. Future work should focus on developing these plant‐based agents with minimal non‐target toxicity to support sustainable pest control. Further research may explore large‐scale applications and assess the long‐term environmental impacts of AgNPs in integrated vector management programs.

Gas Chromatography-Mass Spectrometry and Fourier Transform Infrared Spectroscopy Analysis of Potential α-Glucosidase Inhibitors from Terminalia catappa Leaf Extracts

Aims: Postprandial hyperglyceamia is often caused by insulin insufficiency or cellular glucose uptake complications, and conventional treatments often yield undesirable side effects. The aim of the current work was to assess the α-glucosidase inhibitory activities of T. catappa leaf extracts and use spectroscopic techniques to partially characterize possible inhibitors. Study Design: Phytochemical screening, enzyme inhibition assay and spectrometric and spectroscopic characterization of bioactive compounds from leaf extract and fractions of T. catappa. Place and Duration of Study: The entire work was carried out at the Department of Applied Chemistry and Biochemistry, University for Development Studies, Ghana within nine months. Methodology: T. catappa leaf extract and fractions were qualitatively screened for phytochemicals and their biological activity assessed in α-glucosidase inhibition assay. The potential enzyme inhibitors were characterized by Gas Chromatography-Mass Spectrometry (GC-MS) and Fourier Transform Infrared (FT-IR) Spectroscopy. Results: Phytochemical screening of the extract and the various solvent fractions revealed the presence of alkaloids, flavonoids, saponins, flavanol glycosides, phenolics, and terpenoids. The α-glucosidase inhibition potential of the crude leaf extract was concentration-dependent with a half-maximal inhibitory concentration (IC50) of 337.5 µg/ml. Solvent fractions from the crude extract demonstrated α-glucosidase inhibitory activity with IC50 values ranging from 170.40 µg/ml for ethyl acetate (EtOAc) fraction to 71.90 µg/ml for n-hexane (n-Hex) fraction. Acarbose, the control drug, demonstrated significant α-glucosidase inhibition activity in a similar pattern with IC50 of 6.16 µg/ml. The enzyme inhibition kinetics parameters, specifically the Michaelis constant (KM) and Maximum reaction velocity (Vmax) values, suggested that the inhibition of α-glucosidase by T. catappa extract followed a competitive mode. GC-MS and FT-IR analysis of the n-Hexane fraction identified the compounds Eugenol, Urs-12-en-24-oic acid, 3-oxo-, methyl ester (+)-, phytol, trans-isoeugenol, α-amyrin, and squalene as the potential antidiabetic agents that might be responsible for reducing postprandial blood glucose levels. Conclusion: These findings show that T. catappa leaf extract contains α-glucosidase inhibitors and therefore serves as a valuable resource in the discovery of natural anti-diabetic agents.

PENGARUH EKSTRAK DAUN COCOR BEBEK (BRYOPHYLLUM PINNATUM) TERHADAP MORTALITAS LARVA NYAMUK

The aim of this research was to determine the effect of cocorbek (Bryophyllum pinnatum) leaf extract on mosquito larvae mortality. The research method uses a type of quantitative research with a true experimental approach (pure experiment). It is said to be true experimental because here the researcher intervenes by manipulating the independent variables used as factors, and to see the effects they cause. Researchers will closely observe all other factors that may be considered to influence, suppress and interfere with the results of the experiment. The research results were based on hypothesis testing using one way ANOVA analysis and the results obtained were an Fcount value of 34.536 and a sig value of 0.000. With the hypothesis that Fcount &gt; Ftable and it is said to be significant if the sig value &lt; 0.05. So if compared with Ftable in this study which is 2.77, then Fcount is 34.536 &gt; Ftable 2.77. So Ha is accepted (there is an effect of cocorbek leaf extract on mosquito larvae mortality) and Ho is rejected (there is no effect of cocorbek leaf extract on mosquito larvae mortality). The conclusion of the research is that cocorbek leaf extract has an effect on the mortality of mosquito larvae. In treatment P0, it showed that no mortality occurred because cocorbek leaf extract was not given. Treatment P1 given cocorbek leaf extract had the lowest average mortality value. Meanwhile, P5 treatment had the highest average mortality value. This shows that the higher the concentration of Cocor Bebek leaf extract given, the more mosquito larvae will die. Cocorbek leaf extract can affect the mortality of mosquito larvae because it contains active chemicals that can inhibit larval growth, such as alkoloids, flavonoids, saponins and tannins which are toxic to mosquito larvae.

Evaluation of the Total Antioxidant Capacity of Three Selected Plants in Guyana

Aims: This study aimed to evaluate the leaf extracts of three commonly used medicinal plants in Guyana, namely Brassica juncea (mustard), Struchium sparganophora (antsbush), and Psidium guajava (guava), for their total antioxidant capacity. Study Design: Experimental-based study. Place and Duration of Study: The experiments were performed at the chemistry laboratory in the Faculty of Natural Sciences and the main laboratory in the College of Medical Sciences at the University of Guyana from September 2022 to August 2023. Methodology: The leaves of these plants were collected, washed, and air-dried at 280C for approximately one month, then pulverised in a sterilised food processor. Leaf extracts were then obtained by maceration with various solvents such as hexane, ethyl acetate, chloroform, and methanol; followed by filtration and rotary evaporation. The extracts obtained were then subjected to total antioxidant quantification via the phosphomolybdate method using a spectrophotometer. The total antioxidant capacity of the extracts was expressed as ascorbic acid equivalents. Results: Antioxidant activity was seen for all the extracts but in varying quantities. The highest antioxidant capacity was observed for the P. guajava extracts with a mean of 5.2 mg/mL. The least activity was observed for the S. sparganophora extracts, with a mean of 0.9 mg/mL. The ethanolic extracts showed the highest antioxidant capacity (10.6 mg/mL for P. guajava; 2.5 mg/mL for B. juncea). The hexane extracts had the least (0.33 mg/mL for P. guajava; 0.24 mg/mL for B. juncea). Conclusion: The leaves of B. juncea, S. sparganophora, and P. guajava have antioxidant capacity but those of P. guajava have greater potential for use as complementary and alternative treatments for chronic diseases.