Search Results (28)

Botanical insecticides derived from neem (Azadirachta indica A. Juss.) seeds have gained significant interest due to their sustainable characteristics and low environmental impact. However, their use in sericulture remains contentious due to the heightened sensitivity of domesticated silkworms to environmental stressors. This study systematically investigates the toxicodynamic effects of aqueous neem seed extract (ANSE) on fifth instar larvae of Thai multivoltine Bombyx mori L., focusing on larval mortality and carboxylesterase (CarE) enzyme activity in essential detoxification organs. Larvae were exposed to ANSE concentrations ranging from 5 to 50 mg L⁻¹ for up to 72 h. Key findings highlight a pronounced dose- and time-dependent increase in mortality, with an accurately determined LC₅₀ value of 17 mg L⁻¹ at the longest time exposure, accompanied by mortality rates reaching approximately 83% at the highest concentration tested, indicating considerable susceptibility. Additionally, notable and distinct organ-specific responses were observed, with significant inhibition of CarE activity in the midgut contrasting with elevated activities in the fat body and Malpighian tubules. These differential enzymatic responses reveal previously undocumented adaptive detoxification mechanisms. Consequently, the study advocates cautious and regulated application of neem-based insecticides in sericulture, recommending precise management of concentrations and exposure durations according to silkworm strain sensitivities to ensure optimal silk production. Full article

Background: Neem seed oil (Azadirachta indica A. Juss) is widely used in the pharmaceutical, agricultural, and food industries due to its antiseptic, fungicidal, pesticidal, and antioxidant properties, attributed to over 300 bioactive compounds and a high content of unsaturated fatty acids. Methods: This study aimed to characterize a commercial sample of neem oil regarding its physicochemical properties and identity profile, using official methodologies from the American Oil Chemists’ Society (AOCS), and to compare the results with literature data. Results: The sample exhibited the following parameters: free fatty acids (2.0 ± 0.02%), acidity index (3.9 ± 0.04 mg KOH/g), peroxide value (3.2 ± 0.1 mEq/kg), iodine value (116 ± 12 g I₂/100 g), and saponification index (198 ± 8 mg KOH/g). The predominant coloration was yellowish, with total chlorophyll and carotenoid levels below the equipment’s quantification limits. Fatty acid composition was mainly long-chain (C16–C18), with notable levels of linoleic acid (46%), oleic acid (28%), palmitic acid (12%), linolenic acid (5.5%), and stearic acid (4.1%). The triacylglycerol profile showed a predominance of triunsaturated (51%) and diunsaturated species (41%). Differential scanning calorimetry (DSC) analysis revealed crystallization events between −6 °C and −57 °C and fusion events between −44 °C and −1 °C, consistent with the high unsaturation level of the lipids. Conclusions: The analyzed neem oil sample meets quality and identity criteria, making it suitable for various industrial applications. The characterization confirms its potential and aligns with literature data, emphasizing its relevance for industrial use. Full article

Azadirachta indica (Neem tree) has become widely naturalised and invasive across many countries and regions including northern Australia. To aid management of A. indica where it has become a weed, a series of studies were undertaken to determine its potential soil seed bank persistence. In a field trial, packets of seeds were buried, retrieved periodically over two years and the seed viability assessed. Viability declined rapidly, with a single viable seed retrieved after 12 months burial and none thereafter. Burial depth, soil type, and pasture cover (present and excluded) significantly influenced viability (%) at 3- and 6-month retrievals. Similar data were obtained from repeated runs of a controlled ageing laboratory experiment, which categorized seeds as forming a ‘transient’ seed bank. In a third trial, fresh fruits were placed on the soil surface in replicated field enclosures over two consecutive years and seedling emergence monitored fortnightly. In both years there was no emergence from pasture excluded soil plots and emergence ceased after 2.3 and 8.4 months in plots with pasture present. A fourth (glasshouse) trial found most seeds will emerge from the soil when buried from 1 to 4 cm. However, more fatal germination than successful emergence was recorded for seeds buried at 8 cm. Seed desiccation and fatal germination are factors in A. indica developing a transient soil seed bank, and infestations require shorter-term control programs where seed input is prevented. Full article

Azadirachta indica was designated the “Tree of the 21st century” by the United Nations, as it is believed to be the largest natural depository of bioactive phytochemicals. This study investigates genetic variability among 152 Candidate Plus Trees (CPTs) of A. indica selected from three agro-climatic zones (ACZs) in eastern India: the Lower Gangetic Plains (ACZ III), Middle Gangetic Plains (ACZ IV), and the Eastern Plateau and Hills region (ACZ VII). Phenotypic characters, fruit and seed morphology, kernel oil content (KOC), and Azadirachtin concentration (AC) were assessed to characterize the genetic diversity. Significant variation was observed across all parameters among individual CPTs. Girth at breast height ranged from 0.9 to 2.8 m, tree height from 6 to 16 m, and crown volume from 146.95 to 2339.86 m³. Fruit length varied from 13.55 to 21.55 mm and seed length from 9.21 to 17.37 mm. KOC ranged from 36.51 to 58.86%, with a mean of 47.22% (±0.4), while AC showed extreme variability (19.46–1823.45 μg/g seed). KOC exhibited strong positive correlations with crown diameter (R = 0.57, p ≤ 0.001) and crown volume (R = 0.45, p ≤ 0.001). Interestingly, AC did not correlate significantly with any studied parameter. Analysis of variance revealed significant differences (p < 0.05) between ACZs, but only for some traits. All of the parameters demonstrated high heritability and moderate to high genetic advance. Cluster analysis using Ward’s minimum variance criterion based on Euclidean square (D²) distances performed in RStudio grouped the CPTs into five clusters as per pooled effects of all parameters. The highest inter-cluster distance was observed between Clusters III and V (7.703), indicating a potential for heterosis in hybridization between these groups. Each cluster contained CPTs from all three ACZs, suggesting uniformly distributed variation across the study area rather than zone-specific patterns. This study provides valuable insights for improvement programs of the species and emphasizes the need for further research, including progeny trials, to comprehensively understand the genetic variability of A. indica in eastern India. Full article

An estimated 2000 plant species have been employed for pest control worldwide. The use of these botanical derivatives is thought to be one of the most cost-effective and sustainable options for pest management in stored grain. The present study was designed to assess the efficacy of five plant extracts viz; Nicotiana tabacum L., Nicotiana rustica L., Azadirachta indica A. Juss., Thuja orientalis L., and Melia azedarach L. against Callosobruchus maculatus L. Plant species extracts were applied at six different concentrations, i.e., 0.5, 1.0, 1.5, 2.0, 2.5, and 3.0% in four replications. The phytochemical analyses of ethanolic extracts of five plant species showed variable amounts of phytochemicals i.e., alkaloids, flavonoids, saponins, diterpenes, phytosterol, and phenols. Total phenolic and flavonoid compounds were also observed. The efficacy of A. indica was highest, characterized by the lowest infestation rate (16.65%), host seed weight loss (7.85%), mean oviposition (84.54), and adult emergence (58.40%). In contrast, T. orientalis was found to be the least effective against C. maculatus, with the highest infestation rate of 25.60%, host seed weight loss of 26.73%, mean oviposition of 117.17, and adult emergence rate of 82.01%. Probit analysis was performed by estimating LC₅₀ and LC₉₀. The toxicity percentages of N. tabacum (LC₅₀ = 0.69%, LC₉₀ = 14.59%), N. rustica (LC₅₀ = 0.98%, LC₉₀ = 22.06%), and A. indica (LC₅₀ = 1.09%, LC₉₀ = 68.52%) were notable in terms of the lower LC₅₀ and LC₉₀ values after the 96-h exposure period against C. maculatus. Repellency was assessed by using the area preference and filter paper method. The repellency of C. maculatus on plant extracts increased with the increasing dose and time, such that it was the highest after 48 h. Likewise, at a 3% concentration, A. indica demonstrated 100.00% (Class-V) repellency followed by N. tabacum (96.00%, Class-V), N. rustica (74%, Class-IV), M. azedarach (70.00%, Class-IV), and T. orientalis (68.00%, Class-IV). Based on the findings of this study, we recommend integrating N. rustica, N. tabacum, A. indica, and M. azedarach for effective management of C. maculatus and highlight the potential of these plant species in the formulation of new biocidal agents. Full article

(1) Background: The utilization of medicinal plants in the management of diabetes is of great importance to the health of the indigenous population on the African continent. The high cost of orthodox conventional medicines coupled with the perceived side effects encourages the high patronage of indigenous medicinal plants in the management of this metabolic disorder. We conducted a review on the indigenous African medicinal plants that could be useful in preclinical and clinical trials in the field of diabetes mellitus research. (2) Methods: Data were mined from research articles published and associated with the use of medicinal plants in the management of diabetes on the African continent (from January 2019 to March 2024). Literature from ethnobotanical studies on the African continent was searched from the Google Scholar, SCOPUS, Medline, Web of Science and PubMed databases. We employed the following keywords: “indigenous plants”, “diabetes in Africa” and “antidiabetic effect of medicinal plants”. (3) Results: A total of 52 medicinal plants belonging to 31 families were recorded in this study. Amaryllidaceae (14.28%), Fabaceae (9.52%) and Asteraceae (9.52%) were the most cited plant families. The frequently used indigenous medicinal plants on the African continent were Allium sativum L. (n = 6), Olea europaea L. (n = 6), Azadirachta indica A. Juss (n = 5), Allium cepa L. (n = 5) and Moringa oleifera Lam. (n = 5). The highly cited parts of the plant used in the management of diabetes were the leaves (45.55%), bark (14.44%) and bulbs (12.22%). The preferred methods of the preparation of herbal medicines were decoction (45.23%) and infusion (25%). Oral (52.32%) was the preferred route of the administration of herbal medicine on the African continent. (4) Conclusions: The data revealed some similarities in the way countries on the African continent manage diabetes. This interesting observation will assist in our quest towards obtaining a standardized protocol using indigenous medicinal plants to combat diseases on the African continent. Full article

Salinity poses a significant threat to agricultural productivity worldwide, with its detrimental effects on plant growth and physiological processes. Understanding the mechanisms by which plants respond to salt stress is crucial for developing strategies to mitigate its impact on crop yield and sustainability. To address this issue, a pot study was conducted to determine the effect of salt stress on the physiological and biochemical attributes of neem (Azdiarchta indica A. Juss). Plants were grown for 10 months in pots filled with soil having different salinity levels of 3, 6, 9, 12, 15, and 18 dS m⁻¹ and compared with a control of 1.7 dS m⁻¹. The results showed that plant growth and chlorophyll contents declined as salinity levels increased. Due to oxidative stress, the contents of H₂O₂ increased under higher salt levels. The mitigation of oxidative stress was achieved through the activation of antioxidant enzymes (catalase, ascorbate peroxidase, peroxidase, and superoxide dismutase). Multivariate analysis indicated that Na⁺ accumulation in plants was positively related to H₂O₂ production and enzymatic activities, and negatively related to plant biomass, chlorophyll contents, root and shoot K⁺ concentration, and root K⁺/Na⁺. The experimental results suggest that neem plants can be grown in moderate saline soils. Full article

Electrospinning is an advanced manufacturing strategy used to create innovative medical devices from continuous nanoscale fibers that is endowed with tunable biological, chemical, and physical properties. Innovative medical patches manufactured entirely by electrospinning are discussed in this paper, using a specific plant-derived formulation “1 Primary Wound Dressing©” (1-PWD) as an active pharmaceutical ingredient (API). 1-PWD is composed of neem oil (Azadirachta indica A. Juss.) and the oily extracts of Hypericum perforatum (L.) flowers, according to the formulation patented by the ENEA of proven therapeutic efficacy as wound dressings. The goal of this work is to encapsulate this API and demonstrate that its slow release from an engineered electrospun patch can increase the therapeutic efficacy for wound healing. The prototyped patch is a three-layer core–shell membrane, with a core made of fibers from a 1-PWD-PEO blend, enveloped within two external layers made of medical-grade polycaprolactone (PCL), ensuring mechanical strength and integrity during manipulation. The system was characterized via electron microscopy (SEM) and chemical and contact angle tests. The encapsulation, release, and efficacy of the API were confirmed by FTIR and LC-HRMS and were validated via in vitro toxicology and scratch assays. Full article

(1) Background: The neem tree, Azadirachta indica (A. Juss), is a well-known species used in traditional medicine for the treatment of skin conditions such as irritation, eczema, burns, and wounds. The objective of the current study was to investigate the physicochemical and wound-healing properties of A. indica fruits. (2) Methods: Gas chromatography coupled with mass spectrometry (GC-MS) was used to determine the content of fatty acids and phytosterols, and high-performance liquid chromatography (HPLC) was used to determine the tocopherol content. The wound-healing activity was observed on the backs of six adult male rabbits. (3) Results: The results showed that the plant contained fatty acids, as well as oleic (46.05%), palmitic (23.94%), linoleic (11.39%), and stearic (7.87%) acids. The phytosterols were three major compounds; in decreasing order of importance, they were β-sitosterol (97.26 mg/100 g), campesterol (18.94 mg/100 g), and stigmasterol (12.05 mg/100 g). There were also traces of cholesterol. The neem was a moderate source of vitamin E (α-tocopherol, 14.86 mg/100 g). The hexane extracts showed no acute toxicity and low eye and skin irritability and had reasonable safety and important wound-healing activity. (4) Conclusions: The results confirmed that A. indica is a valuable source of fatty acids, phytosterols, and vitamin E and is efficient in the process of wound healing. Full article

Bioherbicides are an alternative to minimize the damage caused to the environment using agrochemicals. This study had the objective of extracting neem oil from ripe waste fruits that Azadirachta indica A. Juss and optimizing the process using solvents (or a mixture of solvents) with different polarities. Then, through a solid-liquid extraction system (Soxhlet), the solvents hexane, methanol/hexane (1:1), ethanol, and hexane/ethanol (1:1) were used to determine the process with the highest yield and most efficiency. The physicochemical parameters of the extracted oil (density, acidity value, iodine value, saponification value, esters value, and molecular weight) and the % of free fatty acids were determined. In addition, the allelopathic properties of the oil (0%, 2%, 3%, and 4% m/v) on septic weed Senna occidentalis seeds were evaluated, analyzing their growth and development parameters (germination, germination speed, hypocotyl, and radicle length). Hexane was the most efficient (4 h) in neem oil extraction, with the highest yield (43%). It also provided a better oleic and linoleic acid content (41.3% and 18.6%), similar to ethanol extraction (41.1% and 20.22%). Moreover, the allelopathic properties were more prominent for the oils extracted with hexane and hexane/ethanol. This optimized process provides an efficient alternative to obtain a natural herbicidal potential for strategically controlling harmful plants. Full article

The objective of the present work was to optimize the microencapsulation conditions of neem (Azadirachta indica A. Juss) leaf extracts for the biocontrol of Tenebrio molitor. The complex coacervation method was used for the encapsulation of the extracts. The independent factors considered were the pH (3, 6, and 9), pectin (4, 6, and 8% w/v), and whey protein isolate (WPI) (0.50, 0.75, and 1.00% w/v). The Taguchi L9 (3³) orthogonal array was used as the experimental matrix. The response variable was the mortality of T. molitor after 48 h. The nine treatments were applied by immersion of the insects for 10 s. The statistical analysis revealed that the most influential factor on the microencapsulation was the pH (73% of influence), followed by the pectin and WPI (15% and 7% influence, respectively). The software predicted that the optimal microencapsulation conditions were pH 3, pectin 6% w/v, and WPI 1% w/v. The signal-to-noise (S/N) ratio was predicted as 21.57. The experimental validation of the optimal conditions allowed us to obtain an S/N ratio of 18.54, equivalent to a T. molitor mortality of 85 ± 10.49%. The microcapsules had a diameter ranging from 1–5 μm. The microencapsulation by complex coacervation of neem leaf extract is an alternative for the preservation of insecticidal compounds extracted from neem leaves. Full article

The quest for sustainable health, environmental protection, and the conservation of beneficial organisms makes the use of biopesticides a desirable option. This research aimed to identify the botanicals used in the management of farm and household pests in Plateau State, Nigeria. A cross sectional study was carried out using semi-structured questionnaires and on-the-spot, face-to-face interviews. The main issues captured include the pests, the plants used to manage the pest, the parts used, the cultivation status, the availability, the effects on the pests, the indigenous formulation methods, and the modes of application. The quantitative data were analyzed using the Frequency of Citation (FC), Relative Frequency of Citation RFC (%), and Use Value (UV). A total of 45 plant species belonging to 42 genera, 20 orders, and 30 families were found to be useful in the management of 15 different pests. The FC, RFC (%), and UV values identified the most popularly used plants as Mesosphaerum suaveolens (L.) Kuntze, Gymnanthemum amygdalinum (Delile) Sch.Bip., Azadirachta indica A. Juss, Canarium schweinfurthii Engl., Euphorbiaunispina N.E.Br., and Erythrophloem africanum (Benth.) Harms. The plants that showed broad uses by the ethnic groups include Azadirachta indica A. Juss (7 uses), Erythrophloem africanum (Benth.) Harms, Khaya senegalensis (Desr.) A. Juss., and Gymnanthemum amygdalinum (Delile) Sch.Bip. The perception of the respondents indicated that most of the biopesticides are available, affordable, effective, eco-friendly, and safe. This survey provides a pathway for the formulation of stable biopesticides. Full article

Effective alternative strategies and methodological approaches are critically necessary for cancer prevention and therapy. In this study, we investigated the antitumor potential of neem fruit mesocarp and epicarp extracts. The chemical composition of the derived extracts was characterized using GC–MS. Data were collected on the antimicrobial activity of the extracts in addition to the cytotoxicity effect evaluated against PC-3, MCF-7, and Caco-2 cancer cell lines, compared with the normal Vero cells. Cell-cycle arrest, apoptosis, and expression of apoptosis-related genes were assessed on PC-3 cells. Both extracts had significant antiproliferative effects on all tested cell lines in a dose-dependent manner, with the mesocarp extract being more potent. Both extracts also showed high antibacterial and antifungal activities. These results were related to the chemical constituents of the extracts identified by the GC–MS analysis. The extract of neem fruit mesocarp caused cell-cycle arrest at G2/M phase of PC-3 cells. The cytotoxicity of neem mesocarp extract is strongly correlated with the induction of apoptosis, where it caused downregulation of the antiapoptotic BCL2 gene but upregulation of the proapoptotic P53 and BAX genes. This study showed that neem fruit extract is potential anticancer material in the future. Full article

Phytoremediation is an efficient technique for the reclamation of salt-affected soils by growing plants. The present study aims to evaluate the intercropping of halophyte Atriplex nummularia Lindl. with naturally occurring species (Mimosa caesalpiniifolia Benth, Leucaena leucocephala (Lam.) de Wit and Azadirachta indica A. Juss.) adapted to semiarid regions as a management capable of enhancing the phytoremediation capacity of these species. A field experiment was conducted in a randomized block and contained four replicates. Species were cultivated alone and in association with A. nummularia to evaluate their potential uses in the reclamation of soils. Exchangeable Ca²⁺, Mg²⁺, Na^+, and K⁺, as well as salinity and sodicity variables, were evaluated. The evaluations were performed at 9 and 18 months of plant growth. The results indicated that A. nummularia individualized was the treatment most efficient; with reductions of 80%, 63%, and 84% in electrical conductivity, sodium adsorption ratio, and exchangeable sodium percentage values, respectively at 18 months compared to starting of the experiment. However, the use of A. nummularia and species adapted to the semiarid in association, or even alone, promoted beneficial effects on the soil quality after the establishment of the plants. Full article