Development and Evaluation of Acaricidal Soap Formulated from Azadirachta indica (Neem) and Carica Papaya (Papaya) Leaf Extracts Using Bio-Assay Guided Approach

BackgroundFluralaner is a novel isoxazoline eliciting both acaricidal and insecticidal activity through potent blockage of GABA- and glutamate-gated chloride channels. The aim of the study was to investigate the susceptibility of juvenile stages of common tick species exposed to fluralaner through either contact (Rhipicephalus sanguineus) or contact and feeding routes (Ornithodoros moubata).MethodsFluralaner acaricidal activity through both contact and feeding exposure was measured in vitro using two separate testing protocols. Acaricidal contact activity against Rhipicephalus sanguineus life stages was assessed using three minute immersion in fluralaner concentrations between 50 and 0.05 μg/mL (larvae) or between 1000 and 0.2 μg/mL (nymphs and adults). Contact and feeding activity against Ornithodoros moubata nymphs was assessed using fluralaner concentrations between 1000 to 10−4 μg/mL (contact test) and 0.1 to 10−10 μg/mL (feeding test). Activity was assessed 48 hours after exposure and all tests included vehicle and untreated negative control groups.ResultsFluralaner lethal concentrations (LC50, LC90/95) were defined as concentrations with either 50%, 90% or 95% killing effect in the tested sample population. After contact exposure of R. sanguineus life stages lethal concentrations were (μg/mL): larvae - LC50 0.7, LC90 2.4; nymphs - LC50 1.4, LC90 2.6; and adults - LC50 278, LC90 1973. After exposure of O. moubata nymphs to fluralaner lethal concentrations were (μg/mL): contact exposure - LC50 720, LC95 1133; and feeding exposure- LC50 0.00007, LC95 0.09.ConclusionsFluralaner demonstrates potent in vitro acaricidal activity against all life stages of the brown dog tick, R.sanguineus. The testing of fluralaner contact and feeding routes using O. moubata nymphs demonstrates a high acaricidal activity in both exposure routes.

ABSTRACT: Air-dried aqueous leaf extracts of Carica papaya, Chromolaena odorata and Azadirachta indica were screened for antifungal properties against Sclerotium rolfsii, causing cormel rot disease in cocoyam at 50, 70, and 100% concentrations and Trichoderma koningii (4.9x106spores/ml) in vivo. Dithane M45 (mancozeb) at 2% concentration was also used as positive control for better comparison. The aqueous extracts and T. koningii were applied as preventive and curative control measures against Sclerotium rolfsii. Spraying fresh and healthy cormels inoculated with Sclerotium rolfsii at 3.75x105spores/ml indicates that the plant extracts, Mancozeb and T. koningii had significant preventive and curative effects on disease severity and percentage weight loss on diseased cocoyam cormels. Preventive and curative application of T. koningii significantly reduced disease severity, though the later was not significantly different from the other control methods. Specifically, highest disease severity was observed in C. papaya at 50% concentration. The plant extracts and dithane M45 (fungicide) were more effective as curative, while T. koningii was more effective in the preventive method. On percentage weight loss, C. odorata at 70% concentration gave the highest (49.61%), followed by C. papaya (50%) with 47.85% and the least (23.77%) was observed in A. indica at 70% concentration. Therefore, the curative method revealed the effects of the different management methods on the percentage weight of cormels affected by rot. However, C. odorata and A. indica 50 at 100% concentration respectively, significantly reduced weight loss in cormels, while C. odorata (100% concentration) and the control gave the highest percentage weight loss in the curative treatment. From these findings, we conclude that the plant extracts and T. koningii were more effective in controlling cocoyam cormel rot and reduce weight loss than the synthetic fungicide Mancozeb.

In effort to combat environmental pollution, improve animal production and avoid drug residue, producers have resorted to the use of phytobiotics to inhibit ammonia producing microbes in the gut. Freshly harvested Azadirachta indica, Carica papaya, Saccharum officinarum, Chromolaena odorata, Eucalyptus camadulensis and Mangifera indica leaves were air dried, blended and extracted using five concentrations of solvent (100% water, 70% water + 30% methanol, 50% water + 50% methanol, 30% water + 70% methanol and 100% methanol). The antibacterial activities of the extracts and antibiotics (doxycycline) as control, were tested according to standard procedures against both gram positive (Bacillus subtilis, Staphylococcus aureus) and gram negative (Escherichia coli, Vibrio cholerae) ammonia producing bacteria. In most cases, it was observed that the inhibitory effect of methanolic extracts of Azadirachta indica, Carica papaya, Saccharum officinarum, Chromolaena odorata, Eucalyptus camadulensis and Mangifera indica leaves were not significantly different from that of synthetic antibiotics, doxycycline, when tested against the test bacteria, Bacillus subtilis, Staphylococcus aureus and Vibrio cholera. However, leave extracts showed significantly better inhibitory effect on Escherichia coli than the antibiotic drug. It can be concluded, therefore, that the leaf extracts of Azadirachta indica, Carica papaya, Saccharum officinarum, Chromolaena odorata, Eucalyptus camadulensis and Mangifera indica can serve as alternative to synthetic drugs in animal production due to their effective actions against microbial organisms.

Nepalese market has witnessed an impressive upsurge in the production and consumption of a variety of soaps in recent times since 2022 after covid pandemic. The physicochemical parameterization determines the quality, competency and cleaning properties of soap so that we urge sagacious use of these soaps to keep skin healthy. Due to scant knowledge about the quality of soaps, there is need to assess them. Ten parameters namely foam height, surface tension, pH, moisture content, conductance, total fatty matter, total alkali, free caustic alkali and chloride content of commercially available toilet (Dettol, Lifebuoy, Liril, Lux, No.1, Haldi Kanti, Neem Kanti and Neem Chiuri) and laundry soap (Aaha, Darshan, Dhoni and Xpert) samples collected from local market of Tansen were determined using different standard documented method of analysis. The physicochemical parameters examined in collected different soap samples are found as; foam height (20-120) ml, surface tension (38.857-67.192) dynes/cm, pH (6.67-10.54), moisture content (6.68-34.40) %, conductance (115-327) µs/cm, Total Fatty Matter or T.F.M. (42-85.10) %, total alkali (0.31-1.178) %, free caustic alkali (0.54-0.91) % and chloride content (0.1-0.69) %, indicating most of examined parameters for soap were in standard limit as quality criteria set by Bureau of Indian Standards, IS 286: 1978 except that of free caustic alkali content in laundry soaps. This study has recommended public to use toilet soap for bathing purpose as it removes dirt more and laundry soap are found to have good cleansing action for clothes.

Azadirachta indica (Neem ) is an important medicinal plant with proven strong antiseptic, antiviral, antifungal and antibacterial properties. The study here presents the antibacterial and QS (Quorum Sensing) inhibitory potential of biogenic Silver nanopaticles (AgNPs) from Azadirachta indica leaf extracts. The nanoparticles were synthesized using an aqueous extract of Azadirachta indica leaves and silver nitrate solution. The size, crystal structure, elemental composition and other physical properties of nanoparticles were determined using different microscopic and spectroscopic techniques. The average diameter of the nanoparticles was found to be between 20-43 nm with crystalline morphology. These extracellularly synthesized AgNPs strongly inhibited Gram negative pathogenic species and exhibited demonstrable anti- Quorum Sensing (QS) activity as evident from pigment inhibition and 75- 80% decrease in biofilm mass on AgNPs treatment in a dose dependent manner.

A facile, low cost and environment-friendly synthesis process of nanoparticles is very necessary due to the increasing concern for the environment. In this study, silver nanoparticles (AgNPs) were prepared from silver nitrate precursors using leaves from Azadirachta Indica plant, also referred to as the Neem tree. The presence of phytochemicals (alkaloids, flavonoids, proteins, terpenoids, etc.) in Azadirachta Indica leaf extract was mainly responsible to synthesis AgNPs. For the preparation of Azadirachta Indica leaf extract mediated silver nanoparticles (A.I-AgNPs), the synthesis parameters were chosen for pH 8, time 1.5 hrs, temperature 70ºC, plant extract: silver nitrate 1:8. The as-prepared A.I-AgNPs were characterized by ultraviolet-visible (UV-vis) spectroscopy, field emission scanning electron microscopy (FE-SEM), energy-dispersive x-ray spectroscopy (EDX), and Fourier transform infrared spectroscopy (FTIR) analysis. After the addition of plant extract into the silver nitrate solution, the color of the reaction mixture was changed from yellow to brown to dip brown which was the visual confirmation of silver nanoparticles formation. The surface plasmon resonance (SPR) characteristic of A.I-AgNPs was analyzed by UV–vis spectrophotometer test. The SPR peak was found at 460nm which confirmed the successful formation of silver nanoparticles. The FE-SEM analysis revealed that most of the nanoparticles are spherical in shape with the size ranging from 45nm to 111nm (average 84nm). EDX analysis showed an intense peak at 3KeV that strongly proved the presence of silver elements. FTIR analysis of the synthesized silver nanoparticles confirmed the presence of different functional groups on the A.I-AgNPs surface which ensured the successful reduction and capping of silver nanoparticles. The successful preparation of A.I-AgNPs suggested that the chosen synthesis parameters can be further used to prepare AgNPs for various applications.

Background: Nanotechnology is an emerging research field on nanoparticles. Nanoparticles are 1-100 nm in one dimension and are important in biomedical science, medical chemistry, atomic physics, and most other known fields. They are used because of their small size, orientation, and physical properties. Objectives: This study was designed to synthesize silver nanoparticles (AgNPs) using Azadirachta indica (Neem) leaf extract and evaluate their biomedical application. Methods: An aqueous extract of Azadirachta indica was used to synthesize AgNPs. 1 ml of the extract was added drop by drop to 30-60 ml of a 1mM solution of silver nitrate. The AgNPs were characterized by UV-Visible Spectroscopy, Fourier Transform Infrared Spectroscopy, Dynamic Light Scattering Spectroscopy, X-ray Diffraction, Transmission Electron Microscopy, and antibacterial activity studies. The biological synthesis of AgNPs was performed using the aqueous solution of Azadirachta indica leaf extract and AgNO3. A fixed ratio of plant extract to metal ion was used to prepare AgNPs and the formation of the nanoparticles was confirmed through the color change. The nanoparticles were characterized by UV-vis spectrophotometer, FTIR, DLS, XRD and TEM, and were found to range in size from 30-60 nm. Results: The biosynthesized AgNPs had a bactericidal effect against the antibiotic resistant pathogenic microorganisms Bacillus subtilis, Pseudomonas aeruginosa, and Bacillus cereus. Conclusion: Silver nanoparticles were synthesized from Azadirachta indica leaf extract and can be used as a therapeutic candidate for biomedical applications.

The effect of leaf extracts of Moringa oleifera and Azadirachta indica using ethanol as solvent on tannery waste water treatment was investigated for a period of five days and their phytochemical constituents were analyzed. All the extracts were found to be efficient in the clarification and sedimentation of total solids in the tannery waste water sample. On the 5th day, sample treated with 10 ml of extract showed higher reduction of electrical conductivity, pH, chloride, sulfate along with dissolved oxygen. The significant reduction of these pollution indicating parameters of the tannery effluent indicated its high applicability to treat the tannery wastes along with other waste water treatment in near future. This is the first report of decontamination of tannery waste water by Azadirachta indica leaf extract. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

This study explores potential application of silver nanoparticles (AgNPs) to treat periodontal infection using Azadirachta indica leaf extract. The eco-friendly green synthesis process uses Azadirachta indica as a natural stabilizer and reducer, allowing AgNPs to be formed. Experimental AgNPs were characterized through transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Zeta potential, ultraviolet-visible spectroscopy (UV-Vis) etc. The antimicrobial, antioxidant potential of AgNPs was tested to identify its efficacy against periodontal infections. AgNPs were found spherical, nanosized (86nm), with negative surface charge (-26.9mV). TEM study depicted clear formation of discrete nanosize particles with smooth surface texture. Results showed strong antibacterial and anti-oxidant action of experimental AgNPs, preventing biofilm growth and bacterial viability. A higher binding affinity was observed between Quercetin and the selected protein, which is implicated in bacterial growth and biofilm formation on teeth. The study suggests that Azadirachta indica derived AgNPs could be a safe, efficacious, and eco-friendly alternative in place of conventional therapies to treat periodontal infection. Future in vivo studies are however warranted.

Azadirachta indica A. Juss (neem) induced morphological changes on oocytes of Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) tick females

The study was carried out to assess the anthelminthic efficacy of Azadirachta indica commonly known as Neem (Dogoyaro). The phytochemical components of the leaf extract was accessed using Gas Chromatography Mass Spectrometry and the efficacy was carried out in vitro and in vivo using Toxocara canis (as worm model) of dogs. Twenty peaks of compounds were revealed in the GS-MS chromatogram, with Hexadecanoic acid which is saddled with anthelminthic effect as one of its major constituents. In the in vitro study, the lethal concentration was 92.48ml/mg at 6hrs. Percentage egg reduction of 76.2% and 83.9% from the Faecal Egg Count (FEC) at LC25 and LC50 respectively was recorded for the in vivo study. The overall blood count of all the puppies used for the experiment were 4.46 X 106µL for RBC, 31.32% for PCV and 11.23 X 103for WBC. Puppies treated with Azadirachta indica leaf extract showed minimal alteration of the three heamatological parameters (WBC, PCV and RBC) analyzed compared to the uninfected control group and group treated with Mbendazole. This indicates that Azadirachta indica leaf extract is effective in the treatment of gastrointestinal helminthiasis and also further investigations are recommended as it may be useful in the treatment of other diseases.

Acaricidal activity of fluralaner against Ornithodoros moubata and Ornithodoros erraticus argasid ticks evaluated through in vitro feeding

To the Editor, The acute infectious illness dengue is spread by mosquitoes and has a high death and morbidity rate affecting people of all ages and is spread by mosquito bites, most frequently by the Aedes aegypti and Aedes albopictus species1. In Asia, dengue is currently the top cause of hospitalization and fatalities among individuals, and about 70% of dengue illness cases worldwide are found in Asia2. Historically in Pakistan alone, dengue has been identified as a significant public health issue with several outbreaks reported in 2010, 2017, 2019, and 2020. In 2022, between January 1 and September 27, Pakistan has once again seen a resurgence of dengue with a total of 25,932 confirmed cases and 62 fatalities3. The treatment of dengue involves supportive care with increased fluid intake and antipyretics. However, with the increasing burden of dengue on hospitals in Pakistan, people have transitioned to seek other remedies such as papaya leaves, goat milk, guava, and neem tree leaves4. There has been a dramatic rise in demand for papaya leaf juice across Pakistan because of the recent dengue outbreak. The community quickly adopted the use of papaya in the treatment of dengue because of its perceived positive impact on the platelet count in the opinion articles, news stories, and blogs that have begun to appear in print, social media, and national media4. Despite the lack of specialized medication, papaya leaf extract (PLE) is a natural remedy for dengue. Patients who drink plant juice frequently report fewer symptoms of dengue fever and improved general health. The primary active compound in PLE that contributes to the anti-thrombocytopenic action and increases the patient’s blood platelet count is carpaine5. Numerous studies that have been published have found a connection between platelet count and the prognosis of dengue6. Furthermore, papaya leaf extract can boost the immune system and lower inflammation7. According to a meta-analysis, a viable option for raising the platelet count in dengue patients was Carica papaya leaf extract8. However, patient mortality, safety parameters, and side effects were not taken into consideration in this study which leaves doubts about implementing it into actual clinical practice. Even though these studies show that PLE has anti-thrombocytopenic capabilities, it is still unclear how effective PLE is at treating dengue symptoms. Results from another investigation showed that rats’ liver and reproductive systems were negatively impacted by papaya aqueous extract9. In another research, adult male rats’ sperm counts, sperm viability, and testosterone levels all significantly decreased. In addition, female rats also showed infertility issues along with an increase in maternal mortality10. Although the aforementioned trials used animals, it is still necessary to conduct descriptive studies to identify and assess the chemical components of the leaves, their concentrations, and their toxic side effects to properly utilize papaya plant parts and to commercialize the appropriate products for nutraceutical uses. Although papaya leaf has effective anti-thrombocytopenic properties, people using it may experience nausea and vomiting. Furthermore, the usage of papaya or its leaves does not benefit dengue patients in any way and can instead lead to diarrhea11. Given that dengue patients already require enough fluids, this might be fatal. Patients who lose excessive fluid risk developing hypovolemic shock. Multiorgan failure, disseminated intravascular coagulopathy, and gastrointestinal bleeding are also risks of protracted shock12. Considering the negative effects of PLE on patients suffering from dengue, it should be contraindicated to use papaya leaf to reduce death and morbidity. In conclusion, until descriptive research and clinical trials are carried out to ascertain its treatment effectiveness, the use of PLE for treating dengue symptoms in patients with dengue fever must be contraindicated. Insecticide-treated textiles, the use of mosquito repellent coils, the use of bed nets while in bed even during the day, and the development of the habit of wearing full-sleeve shirts and pants must all be encouraged. The general public must be informed and warned about the dangers and possible side effects of using papaya leaves during dengue fever. Ethical approval None. Sources funding None. Author contribution A.N. was involved in the study concept, the collection of the data, drafting, literature review, data validation, supervision, and editing of the manuscript. R.T. was responsible for the literature review and revising the manuscript for important intellectual content. Conflict of interest disclosure The authors declare that they have no financial conflict of interest with regard to the content of this report. Research registration unique identifying number (UIN) None. Guarantor None. Clinical trial registration None. Data availability statement None. Patient consent statement None.

Repellent and acaricidal activity of essential oils extracted from three varieties of basil (Ocimum basilicum L.) were evaluated on blacklegged ticks (Ixodes scapularis Say) and American dog ticks (Dermacentor variabilis Say) in laboratory conditions. Essential oils were extracted and characterized through gas chromatography-mass spectrometry, and tested at different concentrations for long-term repellent activity using horizontal bioassays. In addition, basil essential oils were combined with an inert material (i.e., granite rock dust) with known insecticidal and miticidal properties to assess acaricidal activities against adult ticks. Among the tested basil varieties, var. Jolina essential oil at 15% vol/vol concentration repelled 96% of tested ticks up to 2h post-treatment. The EC50 for I. scapularis nymphs was 4.65% vol/vol (95% confidence interval: 4.73-4.57). In acaricidal tests, the combination of essential oil from var. Aroma 2 at 10% wt/wt with rock dust resulted in 100% tick mortality after only 24h post-exposure, with a LD50 of 3.48% wt/wt (95% CI 4.05-2.91) for freshly prepared treatment tested on I. scapularis adults. The most common compounds detected in basil essential oils by GC-MS were linalool (52.2% in var. Nu Far, 48.2% in Aroma 2, 43.9% in Jolina), sabinene (6.71% in Nu Far, 8.99% in Aroma 2, 8.11% in Jolina), eugenol (11.2% in Jolina, 8.71% in Aroma 2), and estragole (18.2% in Nu Far). The use of essential oils alone and in combination with rock dust provides an innovative and environmentally friendly approach for managing ticks and inhibiting vector-borne disease transmission.

Azadirachta indica (Neem) and Ociumum gratissimum (clove Basil) have long been employed locally for the management of malaria. The present study compared antimalaria activities of the ethanolic leaf extracts of the individual plants, and assessed their combined effects on some organs of malaria-infected mice, at the Parasitology and Histopathology units, Federal Medical Centre (FMC), Owerri, from January to March, 2021. The leaves of the different plants were extracted with absolute ethanol (BDL 95%) for the test. Clean albino mice were experimentally infected intraperitoneally with chloroquine-sensitive Plasmodium berghei NK65 strain. Parasitaemia level was determined before parasite inoculation and at 24 hours post treatment period. Histopathological study on the liver, kidney, and heart was carried out using the Paraffin Setions method. Extracts of the leaves were administered orally, while chloroquine administration was intramuscular. The efficacy of the leaf extracts was tested on the P. berghei infected albino mice using the 4-day curative test. The lethal median dose (LD50) recorded for neem and clove basil leaf extracts were 31.62 and 1246.9 mg/kg body weight, respectively. Significant activity against the parasite was produced by infected mice treated with extracts of A. indica and O. gratissimum, and their combinations throughout the treatment period (P<.05). Highest reduction of parasitaemia was observed on day 4. Maximum parasitaemia reduction (78.65%) was attained with 30mg/kg of the combined extracts on the 7th day. Mild pathological lesions were observed in mice treated with A. indica leaf extract. These observations indicate better anti-malaria activity of the combination therapy as compared with the individual extracts of A. indica and O. grassimum, and indicate good antimalarial and protective roles of the plant extracts on the parasitized mice at large, as it slows down development of resistance.