The Neem Limonoid Nimbolide Modulates Key Components of the DNA Damage Response Signalling in Cellular and Animal Models of Oral Squamous Cell Carcinoma

BACKGROUND

Deregulated DNA damage response (DDR) network is implicated in cancer progression and therapy resistance.

OBJECTIVE

The present study was designed to investigate whether nimbolide, an anticancer neem limonoid, targets key components of the DDR signalling pathway in cellular and animal models of oral squamous cell carcinoma (OSCC).

METHODS

OSCC cells (SCC-4 and SCC-9), 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinoma model, chemoresistant OSCC patient-derived xenograft (PDX) model established in athymic nude mice, and tissue sections from patients with oral premalignant/malignant disease were used for the study. Key molecules that orchestrate the DDR, including the MRN complex, ATM, DNA-PKcs, H2AX, and p53, were analysed by qRT-PCR, immunoblotting, immunofluorescence, and immunohistochemistry. Cell proliferation and apoptosis indices were evaluated.

RESULTS

Nimbolide significantly reduced 8-oxodG levels, expression of MRN, ATMS1891, and γ-H2AX, with an increase in p-p53S15 in OSCC cells as well as in the HBP model. Nimbolide potentiated the effect of KU-55933 in ATM inhibition. In the PDX model, nimbolide suppressed tumor formation, stimulated DDR and apoptosis, inhibited cell proliferation, and enhanced sensitivity to cisplatin. Analysis of p-ATM expression revealed a significant increase during the sequential progression of hamster and human OSCC.

CONCLUSIONS

This study provides compelling evidence that nimbolide functions as a DDR inhibitor in cellular and hamster OSCC models and as a DDR activator in the PDX model primarily by targeting ATM. Small molecules like nimbolide that modulate DDR are of immense benefit in cancer therapy. The study has also unveiled p-ATM as a promising biomarker of tumour progression in human OSCCs.

Comparative Evaluation of Antimicrobial Effectiveness and Compressive Strength in Neem and Lemongrass-Modified Glass Ionomer Cement: An In Vitro Study

Background Glass ionomer cement (GIC) demonstrates biocompatibility and fluoride ion release, indicating their potential to inhibit a wide range of bacteria, although this remains uncertain. Lemongrass and neem are recognized for their potent antimicrobial activity against numerous pathogenic microorganisms. The objective of the study is to evaluate the antimicrobial effectiveness and compressive strength of GIC modified with neem and lemongrass. Methodology Lemongrass and neem were incorporated into conventional GIC at varying concentrations. Group I - neem-modified GIC (0.5%, 1%, 2%), group II - lemongrass-modified GIC (0.5%, 1%, 2%), and group III (non-modified GIC as a control group). The disk-shaped specimens were then compared to unmodified GIC (control). Antimicrobial effectiveness was assessed using the minimal inhibitory concentration (MIC) assay against Streptococcus mutans and Lactobacillus. Compressive strength was assessed using a Universal Testing Machine, with a crosshead speed set to 0.5 mm per minute. Statistical analysis was conducted with a significance level set at p < 0.05. Results Neem modification displayed superior antimicrobial effectiveness against both Streptococcus mutans and Lactobacillus at all concentrations when compared to the control, with 2% showing the least mean value of 0.262. In contrast, lemongrass modification exhibited a significant difference in effectiveness against Streptococcus mutans but no difference against Lactobacillus. Neem modification demonstrated superior performance compared to lemongrass (p < 0.05). Both modified groups showed no significant impact on compressive strength. Conclusions Neem-modified GIC demonstrated the highest antimicrobial efficacy against Streptococcus mutans and Lactobacillus without altering its compressive strength. This suggests its potential as a promising alternative material in restorative dentistry. Additional in vivo investigations are needed to assess the extended-term effectiveness of the material.

Alternative first-line malaria treatment

Malaria is a disease affecting millions of people, especially in Africa, Asia, and South America, and has become a substantial economic burden. Because malaria is contracted through the bite of a mosquito vector, it is very challenging to prevent. Bed nets and insect repellents are used in some homes; others do not have or use them even when available. Thus, treatment measures are crucial to controlling this disease. Artemisinin-based combination therapy (ACT) is currently the first-line treatment for malaria. ACT has been used for decades, but recently, there has been evidence of potential resistance. This threat of resistance has led to the search for possible alternatives to ACT. In sub-Saharan Africa, Azadirachta indica, or simply neem, is a plant used to treat a variety of ailments, including malaria. Neem is effective against one of the more deadly malaria parasites Plasmodium falciparum. Reports show that neem inhibits microgametogenesis of P. falciparum and interferes with the parasite's ookinete development. Although there is substantial in vitro research on the biological activity of A. indica (neem), there is limited in vivo research. Herein, we discuss the in vivo effects of neem on malaria parasites. With A. indica, the future of malaria treatment is promising, especially for high-risk patients, but further research and clinical trials are required to confirm its biological activity.

Comparative Extraction and Bioactive Potential of the Leaf Extracts of Azadirachta indica for Combatting Postoperative Head and Neck Infections: An In Vitro Study

INTRODUCTION

Surgical site infections (SSIs) following head and neck cancer surgery are very common postoperative sequelae. Delayed wound healing leads to a poor aesthetic outcome, delay in restarting oral intake, and delay in getting or starting adjuvant therapy. Antibiotic resistance is on the rise necessitating studies that use alternatives to combat the rising antibiotic resistance. Many plant compounds have been studied to explore the possibility. Neem (Azadirachta indica), a high medicinal value plant, possesses a vast array of phytocompounds, which are broadly grouped into isoprenoids and non-isoprenoids. These phytocompounds are crucial for its anti-inflammatory, antioxidant, antimicrobial, antipyretic, and various other pharmacological activities.

MATERIALS AND METHODS

In this study, we examined the impact of the extraction solvents on the bioactive potential of neem. Neem leaf samples were extracted with water and ethanol; followed by their biological activities like extraction yield, antioxidant, antimicrobial, and cytotoxicity studies were performed. The extraction yield was found to be higher in the ethanolic extract than in the aqueous extract, which also corroborates with increased antioxidant and antibacterial activity. Both the aqueous and ethanolic extracts of neem exhibited antibacterial activities against dental biofilm-producing pathogens like Staphylococcus aureus, Streptococcus mutans, Pseudomonas aeruginosa, and Escherichia coli. Results: Extraction yield was higher in the ethanolic extract of neem. Antioxidant activity was found to be higher in the ethanolic extract than in the aqueous extract. Neem extract has no toxicity, which was observed through hemolytic and zebrafish embryo toxicity assays. The ethanolic extract of neem was shown to be more effective against the Gram-positive and Gram-negative drug-resistant bacterial pathogen Discussion and conclusion: Thus, the utilization of neem extracts is certainly useful in controlling pathogenic bacterial growth in clinical applications. Further, a detailed mechanism of action of neem extract in bacterial growth inhibition at the molecular level is warranted to utilize their potential in disease management.

The Development and Evaluation of Melatonin-Loaded, Calcium Oxide Nanoparticle-Based Neem and Clove Extract: An In Vitro Study

Background Various local drug delivery systems have been tried so far to target microorganisms responsible for periodontitis. However, none of them were effective enough to destroy the periodontal pathogens. This study aimed to analyze the antimicrobial, antioxidant, and anti-inflammatory properties of melatonin-loaded, calcium oxide nanoparticles-based neem and clove extract against oral pathogens to be further used as a local delivery agent. Methodology Powdered fresh neem leaves and clove buds were weighed, added to double distilled water, and then boiled for half an hour. Boiling helps in activating the phytochemicals present in the extract. The solution was boiled further to obtain a concentrated solution. To this 0.241 g of melatonin powder dissolved in 10 mL of double distilled water was added to the previous mixture and left undisturbed in a stirrer overnight. Results The properties of the extract such as antioxidant, antibacterial, anti-inflammatory, cytotoxicity, and embryonic toxicology were studied. In the case of antimicrobial activity, at 100 μg/mL, the zone of inhibition (ZOI) was the highest at 18 ± 0.16 μg/mL and the lowest at 13 ± 0.3 at 25 μg/mL for Candida albicans. Similarly, at 100 μg/mL, the ZOI was the highest at 15 ± 0.25 μg/mL and the lowest was 13 ± 0.12 at 25 μg/mL for Streptococcus mutans and Staphylococcus aureus. Similarly, in the case of antioxidant and anti-inflammatory properties, they showed increased activity with increased concentrations of 10, 20, 30, 40, and 50 μg/mL. Conclusions This study proves that melatonin-added extracts have antimicrobial, antioxidant, anti-inflammatory, and cytotoxic properties which are almost equal to that of the standard. This indicates that they can be possibly further used as local delivery drugs. Further animal or cell line studies should be conducted before experimenting this is in clinical trials for periodontitis patients.

A Randomized Double-Blind Clinical Trial Evaluates the Efficacy of Alternative Herbal Mouthwashes

INTRODUCTION

The removal of dental plaque is the primary step in achieving good oral hygiene. Mechanical plaque removal measures have questionable efficacy in inaccessible areas and proximal aspects of the oral cavity. Out of the several types of mouthwash available, chlorhexidine (CHX) is regarded as the gold standard, but considering its adverse effects, herbal alternatives are being sought after. So, the aim of the study was to evaluate the efficacy of alternative herbal mouthwashes.

MATERIALS AND METHODS

In this randomized, double-blind study, 125 selected patients were divided into five groups. Group 1: negative control - distilled water (DW); group 2: positive control - hexidine mouthwash (ICPA, Gujarat, India); group 3: FeelFresh Herbal Mouthcare Gargle (Able Exports, Gujarat, India); group 4: HiOra mouthwash (Himalaya Wellness Company, Bengaluru, India); group 5: Colgate MaxFresh Fresh Tea mouthwash (Colgate-Palmolive, India). Plaque index (PI), gingival index (GI), and microbial count (CFU) were evaluated before and after the intervention.

RESULTS

The difference among the three types of herbal mouthwash was statistically non-significant. The lowest PI, GI, and CFU values were obtained in the subjects of group 4.

CONCLUSION

 Herbal mouthwashes are a promising alternative and are effective in maintaining oral hygiene.

Rosemary and neem methanolic extract: antioxidant, cytotoxic, and larvicidal activities supported by chemical composition and molecular docking simulations

This study aimed to employ GC-MS to assess the chemical composition of MeOH leaf extracts of R. officinalis and A. indica and evaluate their insecticidal, antioxidant, and antibacterial activities. Twelve components, representing 98.61% and 100% of the total volatile compounds, were deduced from the extracted R. officinalis and A. indica, respectively, using this method. In R. officinalis extract, limonene is typically positioned as the main component (23.03%), while the main chemicals identified in A. indica extract were methyl (E)-octadec-13-enoate (23.20%) and (2R)-1,3,8-trimethyl-4-propyl-5-ethyl-2-(1-hydroxyethyl)-7-methoxycardonylethyl-6-methylenecarbonyl-porphyrin (23.03%). Both extracts of R. officinalis and A. indica exhibited different toxicity against the stored grain pest T. castaneum, with LC₅₀ values of 1.470 and 2.588 mg/ml, respectively. Additionally, after 4 and 5 h of treatment at a concentration of 0.2 mg/ml, the A. indica extract showed the highest levels of repellent action (81.4% and 93.4%), and the R. officinalis extract showed a good repellent rate (64.9% and 80.7%) against T. castenum larvae. With an IC₅₀ value of 35.83 and 28.68 mg/L and a radical scavenging activity percentage of 67.76% and 72.35%, the leaf extract was found to be the most potent plant extract when tested for DPPH antioxidant activity. Overall results showed that MeOH extracts of R. officinalis and A. indica were more effective against S. aureus than E. coli. To determine how the investigated chemicals attach to the active sites of E. coli DNA gyrase A and S. aureus undecaprenyl diphosphate synthase, docking studies were carried out. The consensus score analysis showed that limonene exhibits the best binding energy with both enzymes in docking analysis and more stability in molecular dynamics simulations. The RMSD was obtained at 20.6 and 4.199 (Kcal/mole). The two compounds were successfully used in molecular dynamics simulation research to generate stable complexes with DNA gyrase A.

Efficacy of Azadirachtin in the Integrated Management of the Root Knot Nematode Meloidogyne incognita on Short- and Long-Cycle Crops

Activity of azadirachtin on phytoparasitic nematodes has been documented for some decades, but the relationship between its nematicidal efficacy and crop cycle length has not yet been clarified. This study aimed to assess the efficacy of an azadirachtin-based nematicide, for controlling the infestation of the root-knot nematode Meloidogyne incognita, on the short- and long-cycle crops, lettuce and tomato, respectively. Experiments on lettuce and tomato were carried out in a greenhouse infested by M. incognita, including non-treated soil, or treated with the nematicide fluopyram, as controls. In the experiment on the short-cycle lettuce crop, the azadirachtin product effectively suppressed M. incognita infestation and increased crop yield, without significant differences from fluopyram. In the tomato crop, both azadirachtin and fluopyram were not able to control nematode infestation, but resulted in significantly higher yields. Data from this study indicated that azadirachtin can be a valid alternative to fluopyram and other nematicides, for root-knot nematode control in short-cycle crops. Integration of azadirachtin with a synthetic nematicide or nematode-suppressive agronomical techniques, should be more suitable to long-cycle crops.

The Insecticidal Activity of Azadirachta indica Leaf Extract: Optimization of the Microencapsulation Process by Complex Coacervation

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.

Characterization and antimicrobial activity of cerium oxide nanoparticles synthesized using neem and ginger

The aim of this study is to analyze and characterize the antimicrobial effect of cerium oxide nanoparticles (NP) synthesized using neem and ginger. Finely grounded neem and ginger powder were taken and mixed with distilled water. This mixture was then heated and filtered. Ammonium cerium nitrate dissolved in distilled water. Both the mixtures were mixed and stirred magnetically. A double-beam ultraviolet-visible spectrophotometer was used to monitor color changes. The extract was centrifuged at 8000 rpm for 15 min. The final pellet was powdered using a hot air oven at 70°C for 24 h. Visualization was done by transmission electron microscopy and spherical morphology was noted, with an average diameter of 5 nm, in aggregated form. The sample containing 100 mg of cerium oxide shows the most significant effect on the zone of inhibition of 11 mm of Staphylococcus aureus. The results obtained in the current study confirmed that CeO-NP possessed antioxidant and cytotoxic properties.

Dose-dependent effects of neem crude extract on human dental pulp cell and murine osteoblast viability and mineralization

Neem has been used as a medicine due to its beneficial properties such as anti-microbial effects. Neem products for oral application are on the rise. Before recommendation for therapeutic use in human, its effects on cellular activities need to be examined. Therefore, the aim of this study was to test the effects of the ethanolic neem crude extract on dental pulp cells and osteoblasts in terms of cell viability, mineralization, and gene expressions. The ethanolic neem extract derived from dry neem leaves was subjected to chemical identification using GC-MS. Human dental pulp stem cells (hDPSCs) and pre-osteoblasts (MC3T3) were treated with various concentrations of the neem crude extract. Cell viability, mineralization, and gene expressions were investigated by MTT assay, real-time PCR, and alizarin red S assay, respectively. Statistical analysis was performed by one-way ANOVA followed by Dunnett test. GC-MS detected several substance groups such as sesquiterpene. Low to moderate doses of the neem crude extract (4 - 16 µg/ml) did not affect hDPSC and MC3T3 viability, while 62.5 µg/ml of the neem extract decreased MC3T3 viability. High doses of the neem crude extract (250 - 1,000 µg/ml) significantly reduced viability of both cells. The neem crude extract at 1,000 µg/ml also decreased viability of differentiated hDPSC and MC3T3 and their mineralization. Furthermore, 4 µg/ml of neem inhibited viability of differentiated hDPSC. There is no statistical difference in gene expressions related to cell differentiation. In conclusion, the neem crude extract affected cell viability and mineralization. Cell viability altered differently depending on the doses, cell types, and cell stages. The neem crude extract did not affect cell differentiation. Screening of its effect in various aspects should be examined before the application for human use.

Juss) Fruits Mitigates LPS-Induced Oxidative Stress and Inflammation in Zebrafish Larvae

Reactive oxygen species (ROS) produced by cell metabolism have a duplex role in oxidation and inflammation reactions which involve cell damage or repair responses. Excess ROS production has detrimental effects on the survival of cells. We examined the protective effect of a semi-natural compound NF2 (deacetylepoxyazadiradione), for its protective activity against free radical-mediated stress and inflammatory response to lipopolysaccharide (LPS) using zebrafish larvae. Preliminary antioxidant assays indicated an increase in scavenging of free radicals from NF2 than NF1 (Epoxyazadiradione) in a concentration-dependent manner. Cell cytotoxicity was determined using rat myoblast cell lines (L6), and more than 95 % of cell viability was obtained. Zebrafish developmental toxicity test indicated that NF2 is not toxic even at 150 μM. The percentage of ROS, lipid peroxidation, nitric oxide and apoptosis were reduced significantly in NF2 treated LPS-stressed zebrafish larvae. The reduced number of employed macrophages on NF2 treatment was observed in neutral red dye-marked macrophage localization images. Relative expression of antioxidant genes in zebrafish larvae after treatment with NF2 is significantly increased. The RT-PCR quantification of antioxidant and anti-inflammatory gene expression indicated decreased relative folds of pro-inflammatory cytokines, iNOS and increased relative folds of mitochondrial antioxidant genes (GR, GST and GPx) in LPS stressed zebrafish larvae after treatment with NF2. From the overall obtained results, it can be concluded that NF2 reduced the oxidative stress and inflammatory response by scavenging free radicals caused by LPS.

A literature review

OBJECTIVES

The neem (Azadirachta indica) have been used in herbal medicine for the treatment of multiple diseases, particularly cancer. The mechanism of anti-cancer properties of neem are far from clear. However, it is well accepted that anti-cancer effects of neem is mediated via its hepatic anti-oxidant activity. In the present review, we are going to classify in vitro and in vivo studies about anti-cancer activity of neem via its hepatic anti-oxidant activity. We also summarize its active ingredients and some therapeutic and toxic dosage forms.

METHODS

A systematic search in the literature was performed in PubMed, Scopus, Embase, Cochrane Library, Web of Science, as well as Google Scholar pre-print database using all available MeSH terms for neem, A. indica, anti-cancer, anti-tumor, carcinogen, liver, antioxidant activity, neem ingredients, and glutathione. Electronic database searches combined and duplicates were removed.

RESULTS

The neem plant have been used in herbal medicine for the treatment of various diseases, particularly cancer. The mechanisms of anti-cancer effects of neem are far from clear. Cancerous cells growth can induce imbalance the oxidant and anti-oxidant activity in various organs particularly in the liver. Therefore, it seems that neem have anti-cancer effects via restore of the antioxidant disturbances close to the control ones in the liver. Additionally, administration of neem extract can induce oncostatic potential via several mechanism including; suppression of the NF-κβ pathway, increased expression of tumor suppressor (such as p53 and pTEN), decreased expression of oncogenes (such as c-Myc), and increased apoptosis in cancerous cells. The median lethal dose (LD50) value for extracts of neem was higher than 2,500 mg/kg.

CONCLUSIONS

It is suggested that neem plays pivotal role in the prevention and treatment of cancer via its hepatic antioxidant activity. Indeed, application of neem extract can decreased tumor growth via restore of the antioxidant disturbances close to the control ones in the liver.

Antimicrobial effects of copper nanoparticles with green tea and neem formulation

Nanotechnology is the science which is about manipulating matter, atom by atom and is associated with particles smaller than 100 nm in size. Copper nanoparticles are used mainly due to its surplus amount, low cost, easy availability and biocompatible property. Green synthesis of copper nanoparticles is very simple, economical and eco-friendly method that does not involve any toxic chemicals. The aim of our study is green synthesis of copper nanoparticles using green tea and neem formulation and assessment of its antimicrobial effects. 20mM of copper sulphate solution is mixed with 40mL of plant extract and 60 mL of distilled water was added and made it into 100 ml solution. Once the copper nanoparticles are synthesized the solution is characterized using UV- vis-spectroscopy and was scanned in double beam UV-vis- spectrophotometer from 300 nm to 700nm wavelength. The antimicrobial property of copper nanoparticle is evaluated by agar well diffusion method. The colour change from green to brown and peak observed in UV-vis- spectrophotometer was associated with the synthesis of copper nanoparticles. Copper nanoparticle from green tea and tea extract has good antimicrobial activity against S.mutans, C.albicans, E.faecalis, & S.aureus. Copper nanoparticles can be efficiently synthesised from green and neem formulation. These copper nanoparticles showed good antibacterial properties and are effective against oral pathogens.

Metabolic Engineering of Saccharomyces cerevisiae for de Novo Dihydroniloticin Production Using Novel CYP450 from Neem (Azadirachta indica)

Azadirachtin, a limonoid isolated from the neem tree, has attracted considerable interest due to its excellent performance in pest control. Studies have also reported pharmaceutical activities of dihydroniloticin, an intermediate in azadirachtin biosynthesis, but these pharmaceutical activities could not be validated due to the limited supply. In this study, AiCYP71CD2 was first identified as involved in azadirachtin biosynthesis in neem by expressing it in Nicotiana benthamiana and yeast (Saccharomyces cerevisiae). Homology modeling and molecular docking analysis revealed that AiCYP71CD2 may exhibit a higher ability in catalyzing tirucalla-7,24-dien-3β-ol into dihydroniloticin compared with MaCYP71CD2 from Melia azedarach L. G310 was identified as the critical residue responsible for the higher catalytic ability of AiCYP71CD2. Condon-Optimized AiCYP71CD2 greatly improved the catalytic efficiency in yeast. De novo dihydroniloticin production using the novel AiCYP71CD2 was achieved by constructing the S. cerevisiae DI-3 strain, and the titer could reach up to 405 mg/L in a fermentor, which was an alternative source for dihydroniloticin.

Mycotoxins in Zea mays, their quantification and HPLC analysis of physico-biological detoxification

Present research delves in the isolation, extraction and identification of mycotoxins from ten corn samples collected from the northern province of Pakistan. Average concentration of aflatoxin B1 and B2 by HP-TLC found in all corn samples was 27.87 and 1.35 μg/kg, respectively. Following HP-TLC, detoxification of the identified and isolated mycotoxin was performed, which was analyzed by HPLC. Screening of mycoflora exhibited Aspergillus niger and Fusarium as the most dominant fungal strains. Aflatoxin B1 was physically detoxified under UV-Lamp and direct sunlight displaying detoxification percentage of 48% and 99%, respectively. Biological detoxification involved the use of botanicals such as neem leaves, garlic and ginger powder, which portrayed an approximate detoxification of 70% from corn samples. Current research concludes that the tested physical and biological methods can be easily adopted at field and storage rooms after the harvesting of crops to avoid fungal contamination and subsequent food spoilage.

Clinical study to assess efficacy and safety of Purifying Neem Face Wash in prevention and reduction of acne in healthy adults

BACKGROUND

Acne vulgaris is a chronic, inflammatory skin condition of pilosebaceous units. The standard treatment involves topical and oral antibiotics, retinoids, benzoyl peroxide, and other synthetic compounds, mostly associated with adverse effects. Hence, herbal skincare products are considered nowadays.

AIM

To evaluate the safety and efficacy of Purifying Neem Face Wash (PNFW), an herbal skincare product in the prevention and/or reduction of mild-to-moderate acne.

METHODS

An open-label, single-center, single-arm, four-week clinical study was conducted with subjects having either mild-to-moderate acne or oily skin and non-existent acne. The performance of PNFW in the reduction and/or prevention of acne was detected by counting cutaneous inflammatory and non-inflammatory acne lesions in each of the four visits. Sebum level and skin hydration of both cheeks were measured via sebumeter and corneometer, respectively. Self-assessment questionnaires were used to assess the subjects' responses toward PNFW.

RESULTS

Out of 120 study subjects, 79% and 72% showed either reduction or no new appearance of inflammatory and non-inflammatory acne lesions, respectively, from baseline to Visits 3 and 4. Skin sebum level and skin hydration showed a statistically significant decrease (p < 0.001) and increase (p < 0.001), respectively, in Visits 3 and 4. Self-assessment surveys showed the satisfaction of the subjects about the product in terms of condition improvement, ease in use, and fragrance.

CONCLUSION

The present study indicated the beneficial effect of the herbal ingredients (neem and turmeric) of Himalaya's PNFW in the prevention and reduction of mild-to-moderate acne with no side effects.

Aqueous Azadirachta indica (Neem) Extract Attenuates Insulin Resistance to Improve Glycemic Control and Endothelial Function in Subjects with Metabolic Syndrome

Neem (Azadirachta indica) exhibits multiple therapeutic benefits in preclinical studies, but clinical studies are lacking. This clinical study investigated the efficacy and safety of an aqueous A. indica leaf and twig extract (NEEM) on metabolic parameters in subjects with metabolic syndrome (MetS). Subjects were randomized to receive (1) placebo or (2) 125 mg, (3) 250 mg, or (4) 500 mg of NEEM twice daily (n = 20/group) for 12 weeks. Fasting blood sugar (FBS) and insulin, postprandial blood sugar (PPBS), insulin resistance (IR), hemoglobin A1c (HbA1c), endothelial function, circulating markers of inflammation and oxidative stress, lipid profiles, and platelet aggregation were measured at weeks 0, 4, 8, and 12. NEEM supplementation dose dependently improved the trajectories for FBS, PPBS, IR, and HbA1c over time, as well as endothelial function and most markers of inflammation and oxidative stress. Therefore, NEEM may be considered a promising therapeutic to attenuate the hyperglycemia and associated cardiometabolic derangements in people with MetS. Clinical trial registration no.: CTRI/2019/03/018034 [registered on: March 12, 2019].

Ameliorative Effect of Neem Leaf and Pomegranate Peel Extracts in Coccidial Infections in New Zealand and V-Line Rabbits: Performance, Intestinal Health, Oocyst Shedding, Carcass Traits, and Effect on Economic Measures

Healthy, weaned, coccidial-free male rabbits from two breeds (New Zealand white (NZ) and V-line (VL)) were divided into 10 equal groups (5 groups each for NZ and VL) (3 replicates/group, 6 rabbits/replicate, 18 rabbits/group). All rabbits were inoculated with 5 × 10⁴&nbsp;Eimeria spp. oocysts (E. intestinalis (67%), E. magna (22%), and E. media (11%)) except for the rabbits in the first group (G1), which were inoculated with a sterile solution and served as a negative control. The remaining four groups were treated as follows: G2, no treatment/positive control, G3, treated with neem leaf extract, G4, treated with pomegranate peel extract (PPE), and G5, treated with a combination of neem leaf extract and PPE. For both breeds, our results showed that the use of neem leaf and/or pomegranate peel extract resulted in improved growth performance, with a significant improvement in relative feed conversion ratio (FCR) compared to the positive control groups, which recorded the worst values, as well as a significant (p ≤ 0.05) reduction in mean oocyst count compared to the positive control groups. We also observed downregulation of mRNA levels of IL-1βα, IL6, and TNF-α in the herbal treatment groups compared with the mRNA levels of these genes in the positive control groups. Herbal treatment with neem leaf and/or pomegranate peel extracts had positive effects on the NZ and VL rabbits experimentally infected with mixed Eimeria species, as evidenced by their healthy appearance, good appetite, no mortalities, an anticoccidial index > 120, and a significantly higher total return and net profit when compared to the positive control groups of both breeds. In NZ rabbits, the treatment with neem leaf extract alone (G3) or in combination with PPE (G5) recorded the most efficient economic anticoccidial activity.

Antifungal Activity of Propyl Disulfide from Neem (Azadirachta indica) in Vapor and Agar Diffusion Assays against Anthracnose Pathogens (Colletotrichum gloeosporioides and Colletotrichum acutatum) in Mango Fruit

Microorganisms causing anthracnose diseases have a medium to a high level of resistance to the existing fungicides. This study aimed to investigate neem plant extract (propyl disulfide, PD) as an alternative to the current fungicides against mango’s anthracnose. Microorganisms were isolated from decayed mango and identified as Colletotrichum gloeosporioides and Colletotrichum acutatum. Next, a pathogenicity test was conducted and after fulfilling Koch’s postulates, fungi were reisolated from these symptomatic fruits and we thus obtained pure cultures. Then, different concentrations of PD were used against these fungi in vapor and agar diffusion assays. Ethanol and distilled water were served as control treatments. PD significantly (p ≤ 0.05) inhibited more of the mycelial growth of these fungi than both controls. The antifungal activity of PD increased with increasing concentrations. The vapor diffusion assay was more effective in inhibiting the mycelial growth of these fungi than the agar diffusion assay. A good fit (R², 0.950) of the experimental data in the Gompertz growth model and a significant difference in the model parameters, i.e., lag phase (λ), stationary phase (A) and mycelial growth rate, further showed the antifungal efficacy of PD. Therefore, PD could be the best antimicrobial compound against a wide range of microorganisms.

Biofilm formation by Bacillus subtilis is altered in the presence of pesticides

Bacillus subtilis uses swarming motility and biofilm formation to colonize plant roots and form a symbiotic relationship with the plant. Swarming motility and biofilm formation are group behaviours made possible through the use of chemical messengers. We investigated whether chemicals applied to plants would interfere with the swarming motility and biofilm-forming capabilities of B. subtilis in vitro. We hypothesized that pesticides could act as chemical signals that influence bacterial behaviour; this research investigates whether swarming motility and biofilm formation of B. subtilis is affected by the application of the commercial pesticides with the active ingredients of neem oil, pyrethrin, or malathion. The results indicate that all three pesticides inhibit biofilm formation. Swarming motility is not affected by the application of pyrethrin or malathion, but swarm expansion and pattern is altered in the presence of neem oil. Future studies to investigate the mechanism by which pesticides alter biofilm formation are warranted.

Antibacterial and Antifungal Properties of Composite Polyethylene Materials Reinforced with Neem and Turmeric

With the increased scientific interest in green technologies, many researches have been focused on the production of polymeric composites containing naturally occurring reinforcing particles. Apart from increasing mechanical properties, these additions can have a wide range of interesting effects, such as increasing the resistance to bacterial and fungal colonization. In this work, different amounts of two different natural products, namely neem and turmeric, were added to polyethylene to act as a natural antibacterial and antifungal product for food packaging applications. Microscopic and spectroscopic characterization showed that fractions of up to 5% of these products could be dispersed into low-molecular weight polyethylene, while higher amounts could not be properly dispersed and resulted in an inhomogeneous, fragile composite. In vitro testing conducted with Escherichia coli, Staphylococcus aureus, and Candida albicans showed a reduced proliferation of pathogens when compared to the polyethylene references. In particular, turmeric resulted in being more effective against E. coli when compared to neem, while they had similar performances against S. aureus. Against C. albicans, only neem was able to show a good antifungal behavior, at high concentrations. Tensile testing showed that the addition of reinforcing particles reduced the mechanical properties of polyethylene, and in the case of turmeric, it was further reduced by UV irradiation.

Holistic Care Approach for the Effective Management of Severe Radiation Dermatitis Using Neem (Azadirachta indica) and Honey after Head-and-Neck Radiotherapy

Head and neck cancer is the eighth common type among all cancer types around the world. Its treatment comprises surgery, radiation therapy, chemotherapy and /or a combination of restoration therapy and social support Conventional fraction size ranges from 1.8 to 3 Grays (Gy) per fraction over 4–6 weeks. The accumulative dose of radiation for the primary treatment of head and neck cancer treatment is 60 to 70 Gy, depending on the irradiation of the tumor. Ionizing Radiotherapy is used along with concurrent chemotherapy which is the standard treatment in locally advanced head and neck cancers. Radiation treatment is commonly delivered in the form of high energy photons through an external beam. These results in ionization of electrons that cause direct strand breaks of cellular DNA and the release of free radicals, resulting in cellular damage to both normal and tumor cells. Radiation disrupts the normal process of wound healing at various stages.

Deleterious action of azadirachtin against the mutualistic fungus of leaf-cutting ants

Leaf-cutting ants have a beneficial and obligatory relationship with the fungus that they grow. This mutualism allowed the evolutionary success of these ants. The great defoliation capacity of these insects, which often exceeds the level of tolerable economic damage, includes them as severe pests in many cultures. However, given the close relationship between these two agents of mutualism, it is expected that an impact on the fungus will reflect on the performance of the colony as a whole. Therefore, the effect of azadirachtin on the development, and the macronutrient composition of Leucoagaricus gongylophorus was evaluated. Azadirachtin reduced the final fungal mass at the end of treatment at all concentrations tested, but did not reduce the final growth area. A reduction in the amount of hyphae produced with increasing azadirachtin concentration was also observed. Regarding macronutrients, the compound did not affect their total amount in the fungus. Thus, it is observed that azadirachtin did not alter the composition of L. gongylophorus macronutrients, but inhibited its growth by reducing the number of hyphae produced. This reduction reflects directly on the amount of nutrients offered to the workers and the queen and may improve the management of these insects.

Microbiological and Clinical evaluation of Neem gel and Chlorhexidine gel on Dental Plaque and Gingivitis in 20-30 Years Old Adults: A Randomized Parallel-Armed, Double-Blinded Controlled Trial

Background

The etiological relationship between the plaque and the gingival inflammation has been long established. The long-term use of chemical antiplaque agents may lead to side effects such as teeth staining and alteration of taste. Therefore, natural plant extracts with potential antibacterial and anti-inflammatory activity have been explored, which are equally effective and safe for long-term use.

Objective

The aim of this study was to compare and evaluate effect of neem gel and chlorhexidine (CHX) gel on dental plaque, gingivitis, and bacterial count of Streptococcus mutans and Lactobacilli among 20-30-year-old school teachers in a city of western Maharashtra, over 90 days' usage.

Materials and Methods

A double-blind, parallel armed, controlled, randomized clinical study was conducted among 60 school teachers of 20-30 years' age group for 90 days. The two study groups were as follows: Group A--2.5% neem gel (n = 30) and Group B--0.2% CHX gel (n = 30). The plaque scores were recorded by Plaque Index (Löe H. The gingival index, the plaque index and the retention index systems. J Periodontol 1967;38:610-6) and gingival scores by Gingival Index (Löe H, Silness J. Periodontal disease in pregnancy. Acta Odontol Scand 1963;21:533-51). Streptococcus mutans and Lactobacilli species count by conventional culture method was carried out at baseline, 30th day and 90thday. Considering P value <0.05 as statistically significant, intergroup comparison was performed using unpaired t test. One-way analysis of variance (ANOVA) test was used followed by Tukey's post hoc test for intragroup comparison.

Results

The mean plaque, gingival scores, and microbial count of S. mutans and Lactobacilli showed significant reduction at 30th and 90th day in neem gel group as well as CHX gel group (P < 0.05). None of the parameter showed any significant change at 30th and 90th day (P > 0.05) on intergroup comparison.

Conclusion

The neem gel showed significant decrease in dental plaque, gingival inflammation, and microbial counts, which was comparable to CHX gel proving to be a good herbal alternative. No side effects were reported for use of neem gel over considered period of time.

Effect of Azadirachta indica (Sapindales: Meliaceae) Oil on the Immune System of Spodoptera frugiperda (Lepidoptera: Noctuidae) Immatures

The insect immune system includes several mechanisms responsible for defending against pathogens, parasites, and parasitoids. Some botanical insecticides, such as Azadirachta indica oil, cause changes in the immune system of various insect species. Spodoptera frugiperda is an important agricultural pest; thus, knowledge about the effect of neem oil on the immune system of this species can assist in its management. This study aimed to evaluate the effect of A. indica oil on the immune system of S. frugiperda. Caterpillars (2-3 mg) were placed individually in containers (50 ml) with approximately 10 g of diet, containing 125, 250, and 500 ppm of neem oil with propanone; the control group received only the propanone diet. In four experiments, the total number of hemocytes, the phagocytic activity, the activity of lysozyme-like enzymes, and phenoloxidase activity were measured in caterpillars at the end of the sixth instar. The total number of hemocytes in insects exposed to neem oil was 21% lower than in the control group. The percentage of cells that phagocyted the latex beads was similar among the caterpillars that ingested the different concentrations. The mean diameter of cell lysis halos was reduced only at concentrations of 125 and 250 ppm. Absorbance did not differ between treatments. Knowing that this oil reduces the number of circulation cells and the activity of lysozyme-like enzymes is of great importance to design control strategies, once the neem oil could be added to other biological agents for mortality reducing the chances of this insect surviving in the environment.

Effect of Plant Growth Regulators on Coloured Callus Formation and Accumulation of Azadirachtin, an Essential Biopesticide in Azadirachta indica

For centuries, Azadirachta indica or neem has been utilized as a primary source of medicine due to its antimicrobial, larvacidal, antimalarial and antifungal properties. Recently, its potential as an effective biopesticide has garnered attention, especially towards efficient and continuous production of its bioactive compounds. The present study investigated the effect of the plant growth regulators (PGRs) thiadiazuron (TDZ) and 2,4-dichlorophenoxyacetic acid (2,4-D) on the induction of colored callus formation and subsequent accumulation of azadirachtin (AZA) in A. indica. An efficient protocol was established for micropropagation and colored callus production of this species, followed by quantification of AZA (a mixture of azadirachtin A and B) and its safety assessment. For induction of the callus, leaf and petiole explants obtained from a young growing neem plant were excised and cultured on Murashige and Skoog (MS) medium supplemented with TDZ (0.2-0.6 mg L-1) and 2,4-D (0.2-0.6 mg L-1), either applied singly or in combination. Callus was successfully induced from both explant types at different rates, where media with 0.6 mg L-1 of TDZ resulted in the highest fresh weight (3.38 ± 0.08 g). In general, media with a single hormone (particularly TDZ) was more effective in producing a high mass of callus compared to combined PGRs. A culture duration of six weeks resulted in the production of green, brown and cream colored callus. The highest callus weight and accumulation of AZA was recorded in green callus (214.53 ± 33.63 mg g-1 dry weight (DW)) induced using TDZ. On the other hand, small amounts of AZA were detected in both brown and cream callus. Further experimentation indicated that the green callus with the highest AZA was found to be non-toxic (LC50 at 4606 µg mL-1) to the zebrafish animal model. These results suggested that the addition of different PGRs during in vitro culture could prominently affect callus and secondary metabolite production and can further be manipulated as a sustainable method for the production of a natural and environmentally friendly pesticide.

Assessment of Antimicrobial Effectiveness of Neem and Clove Extract Against Streptococcus mutans and Candida albicans: An In vitro Study

Background

There is increasing interest to develop antimicrobial aids from alternative sources such as medicinal plants for the treatment of infectious diseases. Neem and clove are known to have antimicrobial properties.

Aim

The study aimed at detecting the antibacterial and antifungal activity of neem and clove extract against Streptococcus mutans and Candida albicans.

Materials and Methods

Strains of S. mutans and C. albicans and selective media for growing micro-organisms were procured. Antimicrobial activity was assessed using two methods, by determining the minimum inhibitory concentration (MIC) using the broth dilution method and determining the zone of inhibition using well diffusion method on mitis salivarius bacitracin selective for S. mutans and Saboraud's dextrose agar plates for C. albicans. One way ANOVA with post hoc analysis was done to compare the antimicrobial activity of extracts and 0.2% chlorhexidine.

Results

MIC of neem extract was found to be 4.2 mg/ml and 5.0 mg/ml against S. mutans and C. albicans, respectively. While for cloves, it was 5.5 mg/ml for both. Neem had the highest antibacterial activity with a mean zone of inhibition of 11.4 mm followed by chlorhexidine and cloves whereas antifungal activity was highest for chlorhexidine (14.4 mm) followed by neem and clove.

Conclusion

The result of the study established that both plant extracts possess antimicrobial activity against common microbes present in the oral cavity.

Inhibitory Effect of Aqueous and Ethanolic Extracts of Neem Parts on Fungal Rot Disease of <i>Solanum tuberosum</i>

BACKGROUND AND OBJECTIVE

The processing and preservation of Irish potato tubers like many other crops has been affected by various pathogens like fungi (particularly storage rot) which causes a major constraint to Irish potato production in Nigeria resulting to enormous post-harvest spoilage. The inhibitory effect of aqueous and ethanolic extracts of neem leaves, stem bark and seeds on fungal rot disease of Solanum tuberosum (Irish potato) as an alternative treatment for fungal storage disease on Irish potato tubers cultivated in Nigeria has been determined in this study.

MATERIALS AND METHODS

Neem parts were harvested from Wukari, Nigeria and were processed for the experiment. Isolation of fungi and sub-culturing of the isolates was carried out to obtain pure culture. Pathogenicity study was carried out and effect of the plant extracts on mycelia growth of the test fungi was studied using the food poisoning techniques. The qualitative and quantitative phytochemical studies of the neem parts were carried out using standard methods.

RESULTS

Qualitative phytochemical screening of the selected parts of neem plant showed the presence of alkaloids, glycoside, flavonoids, carbohydrates, reducing sugar, steroids, tannins and saponins. The quantitative test revealed that the percentage quantity of phytochemicals in these plant parts ranged from 10.17-23.88%. Effect of the extracts on the test organisms was significant (p<0.05). Ethanolic extract of the seed (ESE) exhibited the highest inhibitory effect on Aspergillus niger (88.37%) followed by aqueous extract of stem bark (ABE) (87.21%), while aqueous seed extract (ASE), ethanolic leaves extract (ELE), aqueous leaves extract (ALE) and ethanolic stem bark extract (EBE) exhibited inhibition of 81.78, 77.52, 72.87 and 39.53%, respectively. The inhibitory effect of EBE was significantly (p<0.05) lower than that of other extracts, while there was no significant difference in the inhibitory effects of ESE, ASE and ABE compared to ketoconazole on Aspergillus niger. The ethanolic extracts of the seed and leaves had 100% inhibitory effect on Fusarium oxyporium with 87.60% inhibition by aqueous extract of the leaves. The seed and the leaves ethanolic extracts exhibited the highest inhibitory effects on Pythium spp. and Fusarium oxyporium, while the aqueous leaves extract showed the least inhibition on Fusarium oxyporium.

CONCLUSION

The plant extracts in this study were found to be very effective in inhibiting fungal mycelia growth and hence can be potentially effective for preservation during storage of Irish potatoes to minimize post-harvest lost.

Botanical Insecticides in the Twenty-First Century-Fulfilling Their Promise?

Academic interest in plant natural products with insecticidal properties has continued to grow in the past 20 years, while commercialization of new botanical insecticides and market expansion of existing botanicals has lagged considerably behind. Insecticides based on pyrethrum and neem (azadirachtin) continue to be standard bearers in this class of pesticides, but globally, their increased presence is largely a consequence of introduction into new jurisdictions. Insecticides based on plant essential oils are just beginning to emerge as useful plant protectants. Some countries (such as Turkey, Uruguay, the United Arab Emirates, and Australia) have relaxed regulatory requirements for specific plant extracts and oils, while in North America and the European Union, stricter requirements have slowed progress toward commercialization of new products. Botanicals are likely to remain niche products in many agricultural regions and may have the greatest impact in developing countries in tropical regions where the source plants are readily available and conventional products are both expensive and dangerous to users.

Evaluation of the Effect of an Aqueous Extract of Azadirachta indica (Neem) Leaves and Twigs on Glycemic Control, Endothelial Dysfunction and Systemic Inflammation in Subjects with Type 2 Diabetes Mellitus - A Randomized, Double-Blind, Placebo-Controlled Clinical Study

PURPOSE

Neem tree (Azadirachta indica) offers different bioactives ranging from pesticides to therapeutic molecules, depending on which part of the plant is used and the extraction methodology and the solvent used. This study was aimed at evaluating the safety and efficacy of a standardized aqueous extract of Azadirachta indica leaves and twigs (NEEM) on glycemic control, endothelial dysfunction, and systemic inflammation in patients with type 2 diabetes mellitus (T2DM).

METHODS

In this randomized, double-blind, placebo-controlled clinical study (RCT), 80 T2DM subjects, who have already been on standard metformin therapy, received either 125 mg, 250 mg, 500 mg of NEEM or placebo twice daily for 12 weeks. Postprandial blood sugar level (PPBS), fasting blood sugar level (FBS), glycosylated hemoglobin (HbA1c), insulin resistance (IR), endothelial function, oxidative stress, systemic inflammation, IL-6 and TNF-α, platelet aggregation and lipid profile were assessed. Adverse drug reactions, if any, were noted. GraphPad Prism 8 was used to perform statistical analysis.

RESULTS

NEEM at the doses of 125, 250, and 500 mg BID significantly reduced PPBS (from 194.4±14 to 173.1±12.8mg/dL, 192.3±17.1 to 161.8±9.7mg/dL, and 205.9±7.2 to 159.3±7.1mg/dL, respectively), FBS (from 119.2±5.0 to 109.2±5.7mg/dL, 115.5±4.4 to 103.7±4.2mg/dL, and 120.7±4.2 to 97.3±3.7mg/dL, respectively), HbA1c (from 6.87 ± 0.4% to 6.64 ± 0.4%, 7.52 ± 0.4% to 6.86 ± 0.3%, and 7.78 ± 0.2% to 6.26 ± 0.4%, respectively), and IR (from 4.5 ± 1.2 to 3.4 ± 0.9, 3.8 ± 1.1 to 2.5 ± 0.6, and 4.6 ± 1.3 to 2.0 ± 0.6, respectively) compared to placebo. Also, NEEM significantly improved endothelial function, decreased oxidative stress and systemic inflammation compared to placebo. The efficacy was significant with all the doses, but no effect on platelet aggregation or lipid profile was observed.

CONCLUSION

NEEM may significantly ameliorate hyperglycemia, endothelial dysfunction, and systemic inflammation, on top of what metformin could do, in subjects with T2DM.

United Forces of Botanical Oils: Efficacy of Neem and Karanja Oil against Colorado Potato Beetle under Laboratory Conditions

Neem and karanja oil are the most promising botanical insecticides in crop protection nowadays. Given that information about the insecticidal abilities of these oils is lacking, the aim was to explore the effects of neem and karanja oil binary mixtures. The insecticidal activity of NeemAzal T/S (Trifolio-M GmbH, Lahnau, Germany) (neem oil), Rock Effect (Agro CS a.s., Česká Skalice, Czech Republic) (karanja oil), and their binary mixes (at 1:1, 1:2, and 2:1 volume ratios) against the larvae of the Colorado potato beetle (CPB; Leptinotarsa decemlineata) was studied. In our bioassays, a synergistic effect of the mixtures, which was dose-dependent, was observed for the first time against this pest. The most effective blend was the 1:1 ratio. Its efficacy was more or less the same as, or even greater than, the neem oil alone. The LC₅₀ of neem oil two days after application was (0.075 g·L⁻¹) and the LC₅₀ of the mixture was (0.065 g·L⁻¹). The LC₅₀ of karanja oil was (0.582 g·L⁻¹), which was much higher than the LC₅₀ of neem oil. The LC₉₀ of neem oil five days after application was (0.105 g·L⁻¹) and the LC₉₀ of the mixture was (0.037 g·L⁻¹). The LC₉₀ of karanja oil was (1.032 g·L⁻¹). The results demonstrate that it is possible to lower the doses of both oils and get improved efficacy against CPB larvae; nevertheless, further verification of the results in field conditions is necessary.

Efficacy and repellency of some essential oils and their blends against larval and adult house flies, Musca domestica L. (Diptera: Muscidae)

House flies are global pests and notoriously difficult to control. Essential oils of vetiver, cinnamon, and lavender and their blends were tested for toxic and repellent effects against larval and adult flies. All of the oils had moderate toxicity for eggs. Mortality of 2^nd instar larvae was 57-78% in dipping assays, 38-100% in contact assays, and 94-100% in treated media. Lavender was less effective (38% mortality) than the others (91-100%) in contact bioassays. Oil blends were not more effective against larvae than individual oils. Vetiver and cinnamon oils were strongly repellent (84 and 78%, respectively) for larvae in treated media. None of the oils were repellent for adult house flies in olfactometer assays, but testing of additional products demonstrated significant repellency for neem oil, p-menthane-3,8-diol (PMD), and vanillin. Contact/fumigant toxicity of vetiver, cinnamon, and lavender oils was 100%, significantly higher than mortality from sunflower oil (67%). Blends of oils were not more effective against adults than the individual oils, but blends diluted with sunflower oil were as effective as the individual oils. Essentials oils of vetiver and cinnamon may have potential for fly management in situations where conventional insecticides cannot be used.

A comparison of the efficacy of two commercial acaricides (fipronil and amitraz) with Azadirachta indica (neem) on the brown dog tick (Rhipicephalus sanguineus) from canines in Trinidad

The brown dog tick (Rhipicephalus sanguineus) is prevalent on canids in Trinidad. It is directly (by causing anaemia) and indirectly (by acting as a vector of tick-borne pathogens) responsible for morbidity and mortalities in the canine population. The most commonly used commercial acaricides available to pet owners in Trinidad are amitraz and fipronil. Often, these acaricides may be abused and misused in a desperate attempt to rid pets of ticks. The objective of this study was to compare the efficacy of amitraz and fipronil with the herbal alternative, neem (Azadirachta indica). Triplicate in vitro trials utilizing the Larval Packet Test (LPT) were conducted using three concentrations (low, recommended and high) of fipronil (0.025%, 0.05% and 0.1%), amitraz (0.01%, 0.02% and 1%), neem oil (10%, 20% and 40%) and neem leaf extract (0.25%, 0.5% and 2%) for each trial. Statistical analysis using the mixed-effect Poisson regression analysis indicated that there was a significant difference (p < .05) in the survival of ticks pre-treatment versus post-treatment with amitraz, fipronil and all controls when compared to the neem oil. Fipronil and amitraz caused ≥99% mortality for all concentrations used in this study. Mortalities for neem oil and neem leaf extract ranged from 72.7% to 82% and 38% to 95.3%, respectively, with the greatest percentage of mortalities occurring at the lower concentrations. Neem oil and neem leaf extract can be used as alternative acaricides, and however, they are less efficacious against the brown dog tick than amitraz and fipronil.

The Highly Pure Neem Leaf Extract, SCNE, Inhibits Tumorigenesis in Oral Squamous Cell Carcinoma via Disruption of Pro-tumor Inflammatory Cytokines and Cell Signaling

Oral squamous cell carcinoma (OSCC) is a deadly disease that comprises 60% of all head and neck squamous cell cancers. The leaves of the Neem tree (Azadirachta indica) have been used in traditional Ayurvedic medicine for centuries to treat numerous oral maladies and are known to have significant anti-inflammatory properties. We hypothesize that a highly pure super critical CO₂ Neem leaf extract (SCNE) prevents initiation and progression of OSCC via downregulation of intra-tumor pro-inflammatory pathways, which promote tumorigenesis. Hence, we investigated the anticancer effects of SCNE using in vitro and in vivo platforms. OSCC cell lines (SCC4, Cal27, and HSC3) were treated with SCNE while inflammation, proliferation, and migration were analyzed over time. SCNE treatment significantly inhibited OSCC cell proliferation and migration and reduced MMP activity in vitro, suggesting its potential to inhibit tumor growth and metastasis. The preventive effects of SCNE in ectopic xenograft and 4NQO-1 (4-Nitroquinoline-1-oxide) carcinogen-induced mouse models of OSCC were also evaluated. Indeed, xenografted nude mice showed significant reduction of OSCC tumor volumes. Likewise, SCNE significantly reduced the incidence of tongue dysplasia in the 4NQO-1 OSCC initiation model. In both OSCC animal models, SCNE significantly depressed circulating pro-cancer inflammatory cytokines (host and tumor-secreted) including NFkB, COX2, IL-1, IL-6, TNFα, and IFNγ. In addition, we demonstrate that SCNE downregulates STAT3 and AKT expression and activity in vitro. We also demonstrate that the primary active component, nimbolide (NIM), has significant anticancer activity in established OSCC xenografts. Lastly, we show that SCNE induces an M1 phenotype in tumor associated macrophages (TAMS) in vivo. Taken together, these data strongly support SCNE as means of preventing OSCC via downregulation of pro-cancer inflammatory cascades and NIM as a potential new therapy for existing OSCC.

Identification of key enzymes responsible for protolimonoid biosynthesis in plants: Opening the door to azadirachtin production

Limonoids are natural products made by members of the Meliaceae and Rutaceae families. Some limonoids (e.g., azadirachtin) are toxic to insects yet harmless to mammals. The use of limonoids in crop protection and other applications currently depends on extraction from limonoid-producing plants. Metabolic engineering offers opportunities to generate crop plants with enhanced insect resistance and also to produce high-value limonoids (e.g., for pharmaceutical use) by expression in heterologous hosts. However, to achieve this the enzymes responsible for limonoid biosynthesis must first be characterized. Here we identify 3 conserved enzymes responsible for the biosynthesis of the protolimonoid melianol, a precursor to limonoids, from Melia azedarach and Citrus sinensis, so paving the way for limonoid metabolic engineering and diversification.

Limonoids are natural products made by plants belonging to the Meliaceae (Mahogany) and Rutaceae (Citrus) families. They are well known for their insecticidal activity, contribution to bitterness in citrus fruits, and potential pharmaceutical properties. The best known limonoid insecticide is azadirachtin, produced by the neem tree (Azadirachta indica). Despite intensive investigation of limonoids over the last half century, the route of limonoid biosynthesis remains unknown. Limonoids are classified as tetranortriterpenes because the prototypical 26-carbon limonoid scaffold is postulated to be formed from a 30-carbon triterpene scaffold by loss of 4 carbons with associated furan ring formation, by an as yet unknown mechanism. Here we have mined genome and transcriptome sequence resources for 3 diverse limonoid-producing species (A. indica, Melia azedarach, and Citrus sinensis) to elucidate the early steps in limonoid biosynthesis. We identify an oxidosqualene cyclase able to produce the potential 30-carbon triterpene scaffold precursor tirucalla-7,24-dien-3β-ol from each of the 3 species. We further identify coexpressed cytochrome P450 enzymes from M. azedarach (MaCYP71CD2 and MaCYP71BQ5) and C. sinensis (CsCYP71CD1 and CsCYP71BQ4) that are capable of 3 oxidations of tirucalla-7,24-dien-3β-ol, resulting in spontaneous hemiacetal ring formation and the production of the protolimonoid melianol. Our work reports the characterization of protolimonoid biosynthetic enzymes from different plant species and supports the notion of pathway conservation between both plant families. It further paves the way for engineering crop plants with enhanced insect resistance and producing high-value limonoids for pharmaceutical and other applications by expression in heterologous hosts.

Antibacterial efficacy of ethanolic extract of Camellia sinensis and Azadirachta indica leaves on methicillin-resistant Staphylococcus aureus and shiga-toxigenic Escherichia coli

OBJECTIVE

This study aims at investigating the antibacterial potential of ethanolic extract of Camellia sinensis (common name: Green tea) and Azadirachta indica (common name: Neem) leaves on methicillin-resistant Staphylococcus aureus (MRSA) and shiga-toxigenic Escherichia coli (STEC).

MATERIALS AND METHODS

Fresh leaves were processed and extracted by 99% ethanol and reconstituted with 50% ethanol before testing. Disk diffusion and broth microdilution methods were used to determine zone diameter of inhibition (ZDI) and minimum inhibitory concentration (MIC), respectively. Nutrient agar plate was used to estimate the minimum bactericidal concentration (MBC).

RESULTS

Maximum ZDI value was observed for green tea against MRSA (7.5 mm) and minimum for neem (4.9 mm). Moreover, the highest ZDI against STEC was also for green tea and the combination of green tea and neem (4.5 mm). The MIC values of green tea extract were 15.625 and 31.25 mg/ml against MRSA and STEC, respectively, whereas the MIC of neem was 31.25 and 125 mg/ml, respectively. The combination had similar MIC (46.87 mg/ml) against both organisms. Green tea showed the lowest MBC values, 31.25 and 62.5 mg/ml, against MRSA and STEC, respectively. However, MBC of neem and the combination against MRSA and STEC were found >250 mg/ml, >500 mg/ml and 93.75 mg/ml, >375 mg/ml, respectively.

CONCLUSION

Green tea and neem leaves showed good antimicrobial effects and can be used to explore novel antimicrobial compounds against MRSA and STEC.

Cross-Linking Chitosan into Hydroxypropylmethylcellulose for the Preparation of Neem Oil Coating for Postharvest Storage of Pitaya (Stenocereus pruinosus)

The market trend for pitaya is increasing, although the preservation of the quality of this fruit after the harvest is challenging due to microbial decay, dehydration, and oxidation. In this work, the application of antimicrobial chitosan-based coatings achieved successful postharvest preservation of pitaya (Stenocereus pruinosus) during storage at 10 ± 2 °C with a relative humidity of 80 ± 5%. The solution of cross-linked chitosan with hydroxypropylmethylcellulose with entrapped Neem oil (16 g·L^-1) displayed the best postharvest fruit characteristics. The reduction of physiological weight loss and fungal contamination, with an increased redness index and release of azadirachtin from the microencapsulated oil, resulted in up to a 15 day shelf life for this fruit. This postharvest procedure has the potential to increase commercial exploitation of fresh pitaya, owing to its good taste and high content of antioxidants.

Non-target toxicity of novel insecticides

Humans have used insecticides since ancient times. The spectrum and potency of available insecticidal substances has greatly expanded since the industrial revolution, resulting in widespread use and unforeseen levels of synthetic chemicals in the environment. Concerns about the toxic effects of these new chemicals on non-target species became public soon after their appearance, which eventually led to the restrictions of use. At the same time, new, more environmentally-friendly insecticides have been developed, based on naturally occurring chemicals, such as pyrethroids (derivatives of pyrethrin), neonicotinoids (derivatives of nicotine), and insecticides based on the neem tree vegetable oil (Azadirachta indica), predominantly azadirachtin. Although these new substances are more selective toward pest insects, they can still target other organisms. Neonicotinoids, for example, have been implicated in the decline of the bee population worldwide. This review summarises recent literature published on non-target toxicity of neonicotinoids, pyrethroids, and neem-based insecticidal substances, with a special emphasis on neonicotinoid toxicity in honeybees. We also touch upon the effects of pesticide combinations and documented human exposure to these substances.

Efficacy of a novel neem oil formulation (RP03™) to control the poultry red mite Dermanyssus gallinae

Dermanyssus gallinae (Mesostigmata: Dermanyssidae) is the most harmful ectoparasite of laying hens, represents an occupational hazard for poultry workers, and a growing threat to medical science per se. There is increasing demand for alternative products, including plant-derived acaricides, with which to control the mite. The present study investigated the efficacy of neem oil against D. gallinae on a heavily infested commercial laying hen farm. A novel formulation of 20% neem oil, diluted from a 2400-p.p.m. azadirachtin-concentrated stock (RP03™), was administered by nebulization three times in 1 week. Using corrugated cardboard traps, mite density was monitored before, during and after treatment and results were statistically analysed. Mite populations in the treated block showed 94.65%, 99.64% and 99.80% reductions after the first, second and third product administrations, respectively. The rate of reduction of the mite population was significantly higher in the treated block (P < 0.001) compared with the control and buffer blocks. The results suggest the strong bioactivity of neem, and specifically of the patented neem-based formulation RP03™, against D. gallinae. The treatment was most effective in the 10 days following the first application and its effects persisted for over 2 months. Further studies will aim to overcome observed side effects of treatment represented by an oily layer on equipment and eggs.

Ethanolic Extracts from Azadirachta indica Leaves Modulate Transcriptional Levels of Hormone Receptor Variant in Breast Cancer Cell Lines

Breast Cancer (BC) encompasses numerous entities with different biological and behavioral characteristics, favored by tumor molecular complexity. Azadirachta indica (neem) presents phenolic compounds, indicating its potential as an antineoplastic compound. The present study aimed to evaluate the cellular response of MCF10, MCF7, and MDA-MB-231 breast cell lines to ethanolic extracts of neem leaves (EENL) obtained by dichloromethane (DCM) and ethyl acetate (EA) solvent. Extracts’ antiproliferative activities were evaluated against MCF 10A, MCF7, and MDA-MB-231 for 24 and 48 h using MTT assay. ESR1, ESR2, AR, AR-V1, AR-V4, and AR-V7 transcripts were quantified through qPCR for 0.03125 μg/mL of DCM and 1.0 μg/mL for EA for 48 h. The EENL was tested on Drosophila melanogaster as a sole treatment and then also together with doxorubicin. Antiproliferative effect on tumor cell lines without affecting MCF 10A were 1.0 µg/mL (P < 0.001) for EA, and 0.03125 µg/mL (P < 0.0001) for DCM, both after 48 h. Transcriptional levels of AR-V7 increased after treatment. In vivo assays demonstrated that EENL induced fewer tumors at a higher concentration with doxorubicin (DXR). The behavior of AR-V7 in the MDA-MB-231 tumor lineage indicates new pathways involved in tumor biology and this may have therapeutic value for cancer.

Antifungal Efficacy and the Mechanical Properties of Soft Liners against Candida albicans after the Incorporation of Garlic and Neem: An In vitro Study

Objectives:

To evaluate the in vitro growth inhibition of Candida albicans, in the soft-liner material and Shore A hardness from resin-based denture soft lining materials modified by neem or garlic incorporation.

Materials and Methods:

Resin discs were prepared with poly methyl methacrylate (PMMA) and soft liners incorporated with varying concentrations of neem or garlic. For antifungal activity, resin discs were placed on agar plates inoculated with C. albicans and were evaluated after 2, 4, and 7 days using the streaking method. The hardness of the PMMA was evaluated with the use of Shore A at 2, 4, and 7 days. Data were statistically processed by SPSS software (IBM Company, Chicago, USA) using Kruskal–Wallis test, and post hoc comparisons were done using Dunn's test. P <0.05 was considered statistically significant.

Results:

Neem and garlic added to PMMA soft liner had an inhibitory effect on C. albicans. Both the neem and garlic when added showed positive results against C. albicans when compared to the control group. The soft liner hardness increased statistically by time but not for the different plant extract concentrations.

Conclusions:

Within the limitations of this in vitro study, it was found that neem and garlic can be used as an additive to tissue conditioner to reduce the adherence of C. albicans without significantly affecting the hardness of the heat-polymerized acrylic resin.

A comprehensive review of phytochemical profile, bioactives for pharmaceuticals, and pharmacological attributes of Azadirachta indica

Azadirachta indica L. is a multipurpose medicinal tree of family Meliaceae. It occurs in tropical and semitropical regions of the world. Different parts of this miraculous tree are used to treat pyrexia, headache, ulcer, respiratory disorders, cancer, diabetes, leprosy, malaria, dengue, chicken pox, and dermal complications. The tree is popular for its pharmacological attributes such as hypolipidemic, antifertility, microbicidal, antidiabetic, anti-inflammatory, hepatoprotective, antipyretic, hypoglycemic, insecticidal, nematicidal, antiulcer, antioxidant, neuroprotective, cardioprotective, and antileishmaniasis properties. A. indica is also rich in various phytochemicals for pharmaceuticals such as alkaloids, steroids, flavonoids, terpenoids, fatty acids, and carbohydrates. The fungicidal potential of the tree is due to the presence of azadirachtin and nimbin. Herein, we have compiled a comprehensive review of phytochemical profile, pharmacological attributes, and therapeutic prospective of this multipurpose tree.

Insights into bovine endometritis with special reference to phytotherapy

Postpartum reproductive disorders cause heavy economic losses in dairy sector. Uterine infections include endometritis, metritis, mucometra, and pyometra. Postpartum endometritis in dairy cows has been defined as inflammation of endometrium occurring 21 days or more after parturition without systemic signs of illness. The treatment of endometritis with antimicrobials has met with varying degrees of success, inconsistent recovery rate, high cost of treatment, milk disposal, emergence of microbial resistance, and reduced phagocytic activity of polymorphonuclear leukocytes In our country, around 20,000 medicinal plant species have been recorded, but more than 500 traditional communities use about 800 plant species for curing different diseases. Many herbs such as garlic, neem, ashwagandha, and turmeric have been tried for the treatment of endometritis in cows with a good success.

Control of Tungiasis in Absence of a Roadmap: Grassroots and Global Approaches

Tungiasis is a tropical skin disease caused by the sand flea Tunga penetrans. It inflicts misery upon tens of millions of people, mostly children, across Central and South America and sub-Saharan Africa, and yet there is no globally accepted roadmap for its control. Here we review how research in the last 15 years has developed control methods and report on new grassroots and digital mapping approaches. Treatment is now possible with a two-component dimethicone, used for the treatment of headlice in Europe, Asia and Canada, but not yet available in most tungiasis-endemic areas. Prevention is possible through the daily use of repellents based on coconut oil. A Kenyan coastal community has successfully controlled tungiasis using a neem and coconut oil mix produced locally to treat cases, combined with spraying floors with neem solution and distributing closed shoes. Development of affordable hard floor technology is underway, although not yet widely available, but is a priority to control off-host stages in the floors of homes. A new web-based digital mapping application will enable researchers and health officials to collaborate, share data and map the prevalence of tungiasis. We conclude that tungiasis can be controlled through a multi-disciplinary, One Health approach.

Management of Chinese Rose Beetle (Adoretus sinicus) Adults Feeding on Cacao (Theobroma cacao) Using Insecticides

The Chinese rose beetle (Adoretus sinicus Burmeister (Coleoptera: Scarabaeidae)) is an introduced, widely-established pest in Hawai’i. The adult beetles feed on the leaves of cacao (Theobroma cacao L.), which can lead to defoliation and even death of young trees. We evaluated the impact of five commercially available products with different active ingredients (imidacloprid, azadirachtin, Beauveria bassiana (Bals.-Criv.) Vuill., kaolin clay, and pyrethrin) and the presence or absence of weed mat cover in reducing adult beetle feeding on sapling cacao in the field. The use of weed mat cover reduced feeding damage compared to the untreated control, as did foliar application of imidacloprid, azadirachtin, and B. bassiana. In the laboratory, field-collected adult beetles were presented cacao leaf samples dipped in one of the five products and compared to a control. Beetles exposed to pyrethrin died rapidly. Among the other treatments, only exposure to imidacloprid significantly reduced survival relative to the control. Beetles fed very little on leaf samples with azadirachtin but their longevity was not significantly reduced. Imidacloprid, azadirachtin, and weed mat application had the most promise for reducing adult Chinese rose beetle feeding damage in young cacao and deserve further investigation for successful management of this significant pest.

Comparison of efficacy of herbal disinfectants with chlorhexidine mouthwash on decontamination of toothbrushes: An experimental trial

Background:

Toothbrushes in regular use can become heavily contaminated with microorganisms, which can cause infection or reinfection. There is a need for toothbrush disinfection methods, which are rapidly effective, cost-effective, nontoxic, and that can be easily implemented.

Aim:

To compare the efficacy of 3% neem, garlic of concentration 4.15 mg/mL and green tea of concentration 40 mg/mL with 0.2% chlorhexidine mouthwash as toothbrush disinfectants.

Materials and Methods:

The study was a parallel in vitro comparative experimental trial conducted among 75 randomly selected boys aged between 18 years and 21 years. The subjects were divided into five groups, namely, Group I, Group II, Group III, Group IV, and Group V. They were provided with a new set of precoded toothbrushes and nonfluoridated tooth pastes. After 14 days of tooth brushing, the toothbrushes were immersed in antimicrobial solution for 12 h [Group I––distilled water (control), Group II––3% neem, Group III––garlic of concentration 4.15 mg/mL, Group IV––green tea of concentration 40 mg/mL, and Group V––0.2% chlorhexidine] and then subjected to microbial analysis to check the presence of Streptococcus mutans. The t-test and analysis of variance (ANOVA) were done using Statistical Package for the Social Sciences (SPSS) software version 16.

Results:

All test solutions showed a statistically significant reduction of Streptococcus mutans count (P < 0.001). There was no statistical difference between the efficacies of neem, garlic, and green tea when compared with chlorhexidine mouthwash (P > 0.05).

Conclusion:

Neem, garlic, and green tea are equally efficacious as chlorhexidine and these herbal products can be used as potent alternatives to chlorhexidine as disinfectant for toothbrushes.

Effectiveness of Azadirachta indica (neem) mouthrinse in plaque and gingivitis control: a systematic review

OBJECTIVES

The aim of this systematic review was to evaluate the effectiveness of Azadirachta indica (neem)-based herbal mouthrinse in improving plaque control and gingival health.

METHODS

Literature search was accomplished using electronic databases (PubMed, Cochrane Central Register of Controlled Trials and EMBASE) and manual searching, up to February 2015, for randomized controlled trials (RCTs) presenting clinical data for efficacy of neem mouthrinses when used alone or as an adjunct to mechanical oral hygiene as compared to chlorhexidine mouthrinses for controlling plaque and gingival inflammation in patients with gingivitis.

RESULTS

Of the total 206 articles searched, three randomized controlled trials evaluating neem-based herbal mouthrinses were included. Due to marked heterogeneity observed in study characteristics, meta-analysis was not performed. These studies reported that neem mouthrinse was as effective as chlorhexidine mouthrinse when used as an adjunct to toothbrushing in reducing plaque and gingival inflammation in gingivitis patients. However, the quality of reporting and evidence along with methods of studies was generally flawed with unclear risk of bias.

CONCLUSION

Despite the promising results shown in existing randomized controlled trials, the evidence concerning the clinical use of neem mouthrinses is lacking and needs further reinforcement with high-quality randomized controlled trials based on the reporting guidelines of herbal CONSORT statement.

Antibacterial activity of neem nanoemulsion and its toxicity assessment on human lymphocytes in vitro

Neem (Azadirachta indica) is recognized as a medicinal plant well known for its antibacterial, antimalarial, antiviral, and antifungal properties. Neem nanoemulsion (NE) (O/W) is formulated using neem oil, Tween 20, and water by high-energy ultrasonication. The formulated neem NE showed antibacterial activity against the bacterial pathogen Vibrio vulnificus by disrupting the integrity of the bacterial cell membrane. Despite the use of neem NE in various biomedical applications, the toxicity studies on human cells are still lacking. The neem NE showed a decrease in cellular viability in human lymphocytes after 24 hours of exposure. The neem NE at lower concentration (0.7-1 mg/mL) is found to be nontoxic while it is toxic at higher concentrations (1.2-2 mg/mL). The oxidative stress induced by the neem NE is evidenced by the depletion of catalase, SOD, and GSH levels in human lymphocytes. Neem NE showed a significant increase in DNA damage when compared to control in human lymphocytes (P<0.05). The NE is an effective antibacterial agent against the bacterial pathogen V. vulnificus, and it was found to be nontoxic at lower concentrations to human lymphocytes.

Effect of Neem (Azadirachta indica) on the Survival of Escherichia coli O157:H7 in Dairy Manure

Escherichia coli O157:H7 (EcO157) shed in cattle manure can survive for extended periods of time and intervention strategies to control this pathogen at the source are critical as produce crops are often grown in proximity to animal raising operations. This study evaluated whether neem (Azadirachta indica), known for its antimicrobial and insecticidal properties, can be used to amend manure to control EcO157. The influence of neem materials (leaf, bark, and oil) on the survival of an apple juice outbreak strain of EcO157 in dairy manure was monitored. Neem leaf and bark supplements eliminated the pathogen in less than 10 d with a D-value (days for 90% elimination) of 1.3 d. In contrast, nearly 4 log CFU EcO157/g remained after 10 d in neem-free manure control. The ethyl acetate extractable fraction of neem leaves was inhibitory to the growth of EcO157 in LB broth. Azadirachtin, a neem product with insect antifeedant properties, failed to inhibit EcO157. Application of inexpensive neem supplements to control pathogens in manure and possibly in produce fields may be an option for controlling the transfer of foodborne pathogens from farm to fork.