Exploring research trends and priorities of genus Melia

The genus Melia is known for its secondary metabolites and recently, this genus is being explored for its timber. There are vast differences among its species. For instance, Melia azedarach is reported to be invasive and while another species, M. dubia, has diverse utility with complex germination and regeneration characteristics. Researchers globally have been working on various aspects of this genus; In this study, using topic modelling and science mapping approach, we attempted to understand research facets on this genus. The literature corpus of the Web of Science database was explored using a single keyword-"Melia" which yielded 1523 publications (1946-2022) and after scrutiny metadata of 1263 publications were used in the study. Although nine individual species were cited in the publications, only three species are accepted viz., M. dubia, M. azedarach, and M. volkensii. This implies taxonomic uncertainty, with potential confusion in assigning scientific findings to particular species. Thus, a taxonomic relook on this genus is warranted for a better assessment of the economic utility in many countries. More importantly, our results indicate that the research interests have recently shifted from the secondary metabolite constituents towards growth, biomass, wood properties, germination, plantation, and green synthesis. The shift in research focus toward wood properties of Melia sp. can impact the wood demand-supply at a global scale owing to its fast growth and the possibility of cultivation over a wider geographical range.

In vivo evaluation of the antiretroviral activity of Melia azedarach against small ruminant lentiviruses in goat colostrum and milk

This study aimed to evaluate in vivo the use of the extract from the leaves of Melia azedarach in the ethyl acetate fraction at a concentration of 150 µg/mL as an antiretroviral treatment against small ruminant lentiviruses (SRLV) in goat colostrum, and milk with a 90-min action. Two groups of six kids were treated with the extract. One group received three supplies of colostrum from does naturally positive for SRLV, treated with the ethyl acetate fraction of M. azedarach (EAF-MA) for three days, while the other group consumed milk from does also carrying the virus with the respective extract twice a day for five days. After undergoing treatment, all animals began to receive thermized milk until weaning (60 days) and were monitored for six months using nested polymerase chain reaction (nPCR) and western blot (WB) tests. The study revealed cumulative percentages of positive animals in WB or nPCR in the milk group of 66.66% on the seventh day, 83.33% in the following week, and 100% at 120 days, while the colostrum group showed values of 66.66% at 14 days, 83.33% at 90 days, and 100% at 120 days. Variation and intermittency were observed in viral detection, but all animals tested positive in WB or nPCR at some point. A potential delay in infection was observed, which was more significant in the colostrum group. The need for the combination of serological and molecular tests for a more efficient detection of the disease is also emphasized.

Facile and Green Synthesis of Carbon Dots from Melia Azedarach Leaves for pH Sensing and Cell Imaging

Carbon dots (CDs) have preeminent application prospects as a new star in the nanomaterials field. In this work, a green and facile method to synthesize the blue-emitting CDs was proposed with Melia azedarach leaves as the carbon precursors. Using nature materials without other expensive reagents and instruments, the processes were simple and environmental-friendly. The CDs had high fluorescence quantum yield (11.8%) and excellent luminescence properties. The size of them were among 1.5-2.5 nm and the emission spectrum exhibited a strong peak at 460 nm when excited at 380 nm. Additionally, the CDs were stable in most ions but sensitive to different pH values. As a result, a pH sensor was established for the detection of pH with a linear range of 3-10 pH. Moreover, it was demonstrated that the synthesized CDs had extremely low cytotoxicity. Due to their low toxicity and good biocompatibility, they entered into the A549 cells successfully for cell imaging.

Bioactive Azadirachta indica and Melia azedarach leaves extracts with anti-SARS-CoV-2 and antibacterial activities

The leaves of Azadirachta indica L. and Melia azedarach L., belonging to Meliaceae family, have been shown to have medicinal benefits and are extensively employed in traditional folk medicine. Herein, HPLC analysis of the ethyl acetate fraction of the total methanolic extract emphasized the enrichment of both A. indica L., and M. azedarach L. leaves extracts with phenolic and flavonoids composites, respectively. Besides, 4 limonoids and 2 flavonoids were isolated using column chromatography. By assessing the in vitro antiviral activities of both total leaves extracts against Severe Acute Respiratory Syndrome Corona virus 2 (SARS-CoV-2), it was found that A. indica L. and M. azedarach L. have robust anti-SARS-CoV-2 activities at low half-maximal inhibitory concentrations (IC50) of 8.451 and 6.922 μg/mL, respectively. Due to the high safety of A. indica L. and M. azedarach L. extracts with half-maximal cytotoxic concentrations (CC50) of 446.2 and 351.4 μg/ml, respectively, both displayed extraordinary selectivity indices (SI>50). A. indica L. and M. azedarach L. leaves extracts could induce antibacterial activities against both Gram-negative and positive bacterial strains. The minimal inhibitory concentrations of A. indica L. and M. azedarach L. leaves extracts varied from 25 to 100 mg/mL within 30 min contact time towards the tested bacteria. Our findings confirm the broad-spectrum medicinal value of A. indica L. and M. azedarach L. leaves extracts. Finally, additional in vivo investigations are highly recommended to confirm the anti-COVID-19 and antimicrobial activities of both plant extracts.

(Meliaceae) Leaves

Melia azedarach L. leaves have been traditionally used but not scientifically evaluated for antihypertensive activity. The focus of the present work was to carry out the detailed phytochemical profiling and antihypertensive potential of methanolic extract and subsequent fractions of this plant. The tandem mass spectrometry-based phytochemical profiling of M. azedarach extract (Ma.Cr) and fractions was determined in negative ionization mode while molecular networking was executed using the Global Natural Product Social (GNPS) molecular networking platform. This study resulted in the identification of 29 compounds including flavonoid O-glycosides, simple flavonoids, triterpenoidal saponins, and cardenolides as the major constituents. Ma.Cr at the concentration of 300 mg/kg resulted in a fall in blood pressure (BP), i.e., 81.44 ± 2.1 mmHg in high salt-induced hypertensive rats in vivo, in comparison to normotensive group, i.e., 65.36 ± 1.8 mmHg at the same dose. A decrease in blood pressure was observed in anaesthetized normotensive and hypertensive rats treated with extract and various fractions of M. azedarach. A reasonable activity was observed for all fractions except the aqueous fraction. The highest efficacy was shown by the ethyl acetate fraction, i.e., 77.06 ± 3.77 mmHg in normotensive and 88.96 ± 1.3 mmHg in hypertensive anaesthetized rats. Ma.Cr and fractions showed comparatively better efficacy towards hypertensive rats as compared to rats with normal blood pressure. Blood pressure-lowering effects did not change upon prior incubation with atropine. In vitro testing of Ma.Cr and polarity-based fractions resulted in L-NAME sensitive, endothelium-dependent vasodilator effects on aortic tissues. Pretreatment of aorta preparations with Ma.Cr and its fractions also blocked K+-induced precontractions indicating Ca2+ channel blocking activity comparable to verapamil. The extract and polarity-based fractions did not reveal a vasoconstrictor response in spontaneously beating isolated rat aorta. Ma.Cr and fractions when used in atrial preparations resulted in negative inotropic and chronotropic effects. These effects in atrial preparations did not change in the presence of atropine. These effects of extract and fractions explained the antihypertensive potential of M. azedarach and thus provided a scientific basis for its ethnopharmacological use in the treatment of hypertension. Among the constituents observed, flavonoids and flavonoid O-glycosides were previously reported for antihypertensive potential.

Pharmacokinetics Study of Jin-Gu-Lian Prescription and Its Core Drug Pair (Sargentodoxa cuneata (Oliv.) Rehd. et W and Alangium chinense (Lour.) Harms) by UPLC-MS/MS

Jin-Gu-Lian (JGL) is traditionally used by Miao for the treatment of rheumatism arthralgia. At the same time, the combination of Sargentodoxa cuneata (Oliv.) Rehd. et W (SC) and Alangium chinense (Lour.) Harms (AC), the core drug pair (CDP) in the formula of JGL, is used at high frequencies in many Miao medicine prescriptions for rheumatic diseases. However, previous research lacks the pharmacokinetic study of JGL, and study on the compatibility of its CDP with other medicinal herbs in the formula is needed. This study aims to establish a simple, rapid, and sensitive Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS) method for the simultaneous determination of four main bioactive components of JGL in rat plasma, including Salidroside (Sal), Anabasine (Ana), Chlorogenic Acid (CA), and Protocatechuic Acid (PCA), and compare the pharmacokinetic properties of two groups of rats after being orally administrated with JGL and its CDP extracts, respectively. The results showed that area under the plasma concentration-time curve (AUC), mean retention time (MRT), and clearance rate (CL), of Sal, Ana, CA and PCA in the two groups of rats were changed in different degrees. The CDP combined with other drugs could significantly increase the absorption of Sal and Ana, prolong its retention time in vivo, and may accelerate the absorption rate of CA and PCA. This indicated that the combination of CDP and other herbs may affect the pharmacokinetics process of active components in vivo, increase the exposure and bioavailability of compounds in the JGL group, and prolong the retention time, which may be the reason why JGL has a better inhibitory effect on inflammatory cytokines, providing a viable orientation for the compatibility investigation of herb medicines.

Evaluation of Melia azedarach extract-loaded poly (vinyl alcohol)/pectin hydrogel for burn wound healing

Background

In this study, a hydrogel comprising poly (vinyl alcohol)/pectin (PVA/PET) was prepared by the addition of Melia azedarach extract for epithelial restoration. M. azedarach extract (MAE) contains volatile organic plant-derived compounds with antimicrobial properties. MAE has a variety of physiological properties, including antimicrobial, insecticidal, and anti-inflammatory activity. This study aimed to investigate whether MAE-loaded PVA/PET hydrogels have protective effects against burn wound healing.

Methods and findings

To mix M. azedarach with the gel, nanoparticles containing M. azedarach were prepared using chitosan/maltodextrin as the wall material. A PVA/PET hydrogel containing M. azedarach was developed and its applicability as a wound dressing was evaluated. In the in vitro scratch assay, MAE treatment showed a scratch recovery-promoting effect comparable to that of the positive control TGF-β1. The MAE-PVA/PET hydrogel was found to be non-toxic, and the antibacterial activity of the hydrogel was excellent against both gram-positive and gram-negative bacteria. Furthermore, as the formulated hydrogel demonstrated strong antimicrobial activity, its wound-healing efficacy was investigated in vivo using a rat model.

Conclusion

MAE was found to be effective against burn wounds and to have antimicrobial activity in vitro and in vivo.

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.

(Meliaceae) leaves: chemical variability upon environmental factors

The chemical composition of the essential oils extracted from the leaves of Melia azedarach L. collected monthly from July 2019 to June 2020 was examined via gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) techniques. Analysis of the essential oils identified about 17 compounds representing more than 85% of the oil. Oil yields were higher in the months of June and August, and the primary compounds identified were β-caryophyllene (3.50-63.41%), benzaldehyde (3.50-55.98%), and azulene (1.27-19.05%). A correlation analysis was performed to determine the relationship between yields and climatic conditions, and between constituent concentration and temperature and precipitation values during the study period. As per our findings, although not significant, a positive correlation was determined between yield and climatic parameters. However, the oil components were categorized into four groups based on their correlation with temperature and precipitation indices. Among the major components of the essential oils, only azulene and β-caryophyllene exhibited a negative correlation with both precipitation and temperature. The results show substantial differences in the chemical composition of M. azedarach essential oils and provide further insight into the phytochemical constituents that are sensitive to climate fluctuations. Furthermore, it provides an indication of the optimal time that the plant produces the important mono- and sesquiterpene components and the biological significance of their regulation.

Acaricidal activity of Artemisia herba-alba and Melia azedarach oil nanoemulsion against Hyalomma dromedarii and their toxicity on Swiss albino mice

Biopesticides such as essential oils (EOs) are considered an improvement for integrated pest control as they appear to be less toxic to the environment than chemical acaricides. The current study aimed to evaluate the acaricidal activity of Artemisia herba-alba and Melia azedarach oil loaded nano-emulsion as alternatives for chemical acaricides against the camel tick Hyalomma dromedarii, besides evaluating their toxic effect on Swiss albino mice. Transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) were used for the characterization of loaded nano-emulsions.The immersion test was used for the bioassay of both loaded nanoemulsions on tick stages (egg, nymph, larva, and adult). Mortality percentages and LC₅₀ values of each tick stage were calculated. Reproductive performance for the survived engorged females after treatment was monitored. The toxicity of both loaded nano-emulsions was evaluated on Swiss albino mice by an oral dose of 1500 mg/kg/day for five successive days. The hematological, biochemical, and histopathological changes were evaluated. TEM characterization revealed spherical droplets for A. herba-alba and M. azedarach oil loaded nano-emulsion with droplet size ranging from 62 to 69 nm and 52-91 nm, respectively. FTIR revealed the absence of extra peaks in the loaded nano-emulsions that confirmed no chemical changes existed by ultrasonication. The LC₅₀ values of A. herba-alba and M. azedarach oil loaded nano-emulsion on embryonated eggs, larvae, engorged nymphs, and unfed adults were 0.3 and 1.1%, 0.7 and 1.7%, 0.3 and 0.4%, 4.4 and 22.2%, respectively. The egg productive index (EPI), egg number, and hatchability percentage were lower in the treated females compared with Butox 5% (deltamethrin) and control. The hematological picture and biochemical analysis revealed insignificant changes in the treatment group compared with the negative control group. The liver of the A. herba-alba and M. azedarach oil loaded nano-emulsion treated group exhibited vacuolar degeneration and infiltration of lymphocytic cells. The kidney of mice treated with A. herba-alba and M. azedarach oil loaded nano-emulsion showed hemolysis and slight degeneration of epithelial cells of tubules. It is concluded that A. herba-alba and M. azedarach oil loaded nano-emulsion have good acaricidal activity against camel tick H. dromedarii.

Isolation of bioactive limonoids from the fruits of Melia azedarach

Two previously undescribed limonoids, 1-O-benzoyl-3-O-deactylnimbolinin C (1) and a pair of epimers named toosendalactonins A and B (12a and 12b), together with ten known compounds (2-11) were isolated from the fruits of Melia azedarach L. Their structures were determined by extensive spectroscopic methods, including 1D-, 2D-nuclear magnetic resonance, and mass spectrometry. All the isolated compounds were evaluated for their nitric oxide (NO) inhibition in lipopolysaccharide-activated microglia and nerve growth factor (NGF) production in astrocytes. Compounds 1-2 and 5-8 significantly inhibited NO production, which is comparable to the positive control, L-NMMA. Previously undescribed limonoid, compound 12, and two known limonoids, munronin K (3) and 12-O-methyl-1-O-deacetyl-nimbolinin B (4), showed the highest potency to increase the NGF production in C6 astrocytes. [Formula: see text].

Melia Azedarach Ingestions Reported to Texas Poison Centers

BACKGROUND

Melia azedarach, also known as the chinaberry tree, is native to Southeast Asia and northern Australia but has become an invasive species in the United States. M. azedarach contains limonoid tetranotriterpenes, found in highest concentrations in its berries. Ingestion has been reported to result in adverse clinical effects affecting the gastrointestinal, cardiovascular, respiratory, and neurologic systems.

OBJECTIVE

The objective of this investigation was to describe M. azedarach ingestions in Texas.

METHODS

Cases were M. azedarach ingestions reported to Texas poison centers from 2000-2018. The distribution of cases was determined for various factors related to patient demographics, ingestion circumstances, management, and outcome.

RESULTS

Of 990 total M. azedarach ingestions, 87.4% involved the berry. There was a seasonal pattern with 42.9% reported between March and May. The patients were male in 55.1% of cases; 86.6% of the patients were ≤5 years of age. Patients were managed outside of a health care facility in 89.9% of cases; 95.2% of the ingestions resulted in no or at most minor clinical effects. The most frequently reported clinical effects were gastrointestinal (8.9%) and neurologic (2.1%). The most common treatments were dilution (67.2%) and food/snack (16.8%).

CONCLUSION

In this study that focused on M. azedarach ingestions reported to Texas poison centers, the ingestions tended to involve berries. Most of the patients were young children. The ingestions often occurred between March and May. The ingestions typically were managed outside of a health care facility and did not result in serious outcomes. The most common clinical effects were gastrointestinal and neurologic.

Control of biofouling on pearl oysters Pinctada imbricata using wax and Chinese herbs

Biofouling poses severe challenges to pearl oyster Pinctada imbricata culture in China, and controlling it is both labor- and capital-intensive. The antifouling properties of wax, and wax mixed with Chinese herbs, sprayed onto pearl oyster shell surfaces during peak biofouling seasons were evaluated. Pearl oysters coated with three wax treatments (plain wax, Chinaberry seed extract, Chinese honeylocust fruit extract) and a control (no treatment), were cultured in nets for up to 60 days. Mortality rate, fouling organism and pearl-oyster weights, and shell height are reported for individual oysters on each of six sampling dates. With the exception of oysters submerged for 12 days, all oysters were significantly affected by treatment type and submersion duration. Fouling weight increased more rapidly over time in the control-treatment oysters. Wax-based coatings deterred fouling-organism settlement on oysters for at least 2 months during the intensive fouling season, reducing mortality and not adversely effecting growth.

Removal of aqueous Cr(VI) by a magnetic biochar derived from Melia azedarach wood

Magnetic biochar (MMABC) prepared from Melia azedarach wood was used for aqueous Cr(VI) removal. MMABC was a mesoporous material with S_BET 5.219 m²/g and superparamagnetic magnetization 17.3 emu/g contributed by the contained Fe₃O₄. The MMABC showed higher removal efficiency (99.8%) than biochar under conditions of dosage 5 g/L, pH = 3.0, and Cr(VI) concentration 10 mg/L. The saturation magnetization (16.1emg/g) of MMABC still remained after adsorption. According to FTIR and Raman results, the benzene-ring adjacent carbonyl did not showed obvious positive effects on Cr(VI) removal. A potential mechanism and corresponding apparent kinetic model indicated the Cr(VI) removal process by MMABC followed adsorption-reduction-adsorption steps. Cr(VI) was firstly adsorbed on surface and subsequently reduced to Cr(III), which was further adsorbed on MMABC surface. Langmuir isotherm (with maximal adsorption capacity of 25.27 mg/g) and pseudo second-order kinetic model were suitable for adsorption step.

Formulations of Melia azedarach to Control Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae) Larvae in Corn and Plant Enhancement

We evaluated oil and powder formulations of Melia azedarach for controlling larvae of Diabrotica speciosa (Germar) in corn and plant enhancement. Five concentrations of each formulation were evaluated and compared to fipronil (negative control) and distilled water (positive control). After treatment, the number of surviving insects (larvae, pupae, and adults), the adult body weight, the sex ratio, and the longevity were recorded, while the height, dry weight of aerial part and roots, and number of leaves of plants were measured. The oil formulation at 4.0 mL reduced the larvae population of D. speciosa similarly to the insecticide fipronil, which resulted in greater height, dry weight of the root system, and number of leaves. Powder formulation at concentrations of 40, 80, and 160 mg caused larval mortality above 80%; however, these concentrations did not prevent reduction of plant height and dry weight of aerial part. Further studies assessing the residual period of M. azedarach control against D. speciosa larvae and its phytotoxicity, which are common traits associated with azadirachtin application, are necessary to subsidize the next steps of this alternative control strategy.

and Piper longum Linn and their combination on CCl4 induced hepatotoxicity in rats

A comparison of analysis in evaluating the hepatoprotective action of ethanolic extract of M. azedarach (MAE) and P. longum (PLE) with their combination biherbal extract (BHE) against carbon tetrachloride (CCl4) induced hepatic damage is reported in albino rats. There was a marked elevation of serum marker enzyme levels in CCl4 treated rats, which were restored towards normalization in the drug (MAE and/or PLE:50 mg/kg body weight po, once daily for 14 days) treated animals. The biochemical parameters like total protein, total bilirubin, total cholesterol, triglycerides, and urea were also restored towards normal levels. The combined BHE showed more significant reduction of the enzymes than MAE or PLE against CCl4 induced hepatotoxicity. The results strongly indicate that BHE has more potent hepatoprotective action than MAE or PLE individually against CCl4 induced hepatic damage in rats. Among these extracts, BHE showed similar hepatoprotective action to silymarin, which was the positive control in this study.

[Effects of tomato genotypes and aqueous extracts of Melia azedarach leaves and Azadirachta indica seeds on Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)]

Insecticide plants are an important tool among the new alternatives for pest control in IPM systems because they reduce the use of synthetic insecticides, preserving human health and the environment. We investigated the effects of aqueous extracts of Melia azedarach leaves and Azadirachta indica seeds and three tomato genotypes, 'Santa Clara', 'IPA-5'--Solanum lycopersicum (=Lycopersicon esculentum Mill), and LA444-1--S. peruvianum (=L. peruvianum), on the development, reproduction and longevity of the tomato pinworm Tuta absoluta (Meyrick), under laboratory conditions. The trials were set up in a completely randomized design, with nine treatments [three genotypes x two extracts (M. azedarach and A. indica) and control]. The replication consisted on five tubes, each with three newly hatched larvae, totalizing 90 individuals per treatment. The larvae were fed with tomato leaves treated with aqueous extracts at 0.1% concentration or distilled water (control) and daily observed until adults' emergence. Larval and pupal development and mortality, pupal weight, longevity and fecundity were evaluated. The accession LA444-1 negatively affected the development and reproduction of T. absoluta; the tomato pinworm had similar development and reproduction on 'IPA-5' and 'Santa Clara' (the susceptible control). The association of resistant tomato genotypes and extracts of M. azedarach leaves and neem seeds did not result in synergistic or antagonistic effects on T. absoluta.

Ethnopharmacological application of medicinal plants to cure skin diseases and in folk cosmetics among the tribal communities of North-West Frontier Province, Pakistan

AIM OF THE STUDY

The present investigation is an attempt to find out ethnopharmacological application of medicinal plants to cure skin diseases and in folk cosmetics.

METHOD

We interviewed respondents in 30 remote sites of North-West Frontier Province by a structured interview form in the local language and respondents were queried for the type of herbal cure known to him.

RESULTS

A total of 66 plant species belonging to 45 families have been recorded. Seventy-five medications for 15 skin diseases and cosmetics were documented. The mode of application was topical as well as oral administration. Water, milk, ghee, oil, eggs, sulphur and butter are used during administration of herbal remedies. About 15 plant species are known for their use to cure multiple skin diseases. Among these Berberis lyceum, Bergenia ciliata, Melia azedarach, Otostegia limbata, Phyla nodiflora, Prunus persica and Zingiber officinale constitutes major plants. The herbal cosmetics products range from face freshness, removal of ugly spots, hair care, and colouring of palm, feet, gums, and teeth.

CONCLUSION

Most of the reported species are wild and rare; this demands an urgent attention to conserve such vital resources so as to optimize their use in the primary health care system. Since most of the skin diseases are caused by bacteria, viruses and fungi in this context, phytochemical screening for active constituents, biological activities and clinical studies is of global importance.

Effect of fruit and leaves of Meliaceae plants (Azadirachta indica and Melia azedarach) on the development of Lutzomyia longipalpis larvae (Diptera: Psychodidae: Phlebotominae) under experimental conditions

This no-choice, laboratory study focuses on the feeding of dried, ground, homogeneous powdered, unprocessed fruit and leaves of Azadirachta indica and Melia azedarach to Lutzomyia longipalpis larvae to determine the effects on their mortality and metamorphosis. A. indica and M. azedarach fruit and leaves significantly increased larval mortality in comparison to larvae fed the untreated, standard diet. A. indica fruit and leaves blocked the molting of the larvae to the fourth instar, resulting in them remaining as third instars until the end of the experiment. M. azedarach fruit also blocked the molting of larvae, which remained permanently in the fourth instar. Feeding M. azedarach leaves resulted in greater molt inhibition. All insects in this group stopped their development as second-instar larvae. No antifeedant effect was detected for any experimental treatment. The results indicate that nontoxic, unprocessed materials obtained from A. indica and M. azedarach are potent development inhibitors of L. longipalpis larvae.

In vitro pediculicidal and ovicidal activity of an extract and oil from fruits of Melia azedarach L

BACKGROUND

Head louse infestation is difficult to control because of increasing lice resistance to synthetic pediculicidal drugs.

OBJECTIVE

To test the activity of extract and oil obtained from fruits of Melia azedarach L. against the head louse Pediculus humanus capitis.

METHODS

A filter paper diffusion bioassay was carried out in order to determine the pediculicidal and ovicidal activity of extract and oil from M azedarach L. fruits.

RESULTS

Both vegetable products, tested either individually or in combinations, showed high levels of mortality on adult lice, with values ranging between 62.9% and 96.5%. The highest mortality rate was obtained with a combination of 20% ripe fruit extract with 10% ripe fruit oil. A formulation made with both extract and oil at 10% plus the addition of emulsifier and preserving agents showed 92.3% pediculicidal activity. The products were also successful in delaying or inhibiting nymph emergence, with the formulation being the most effective, with a complete inhibition of emergence.

LIMITATIONS

Because adult lice are sensitive to starvation and therefore control mortalities are often higher than 20% in tests with field specimens, the results may not reflect the direct effect of the extract.

CONCLUSIONS

These results demonstrate the possibility of using Melia products for controlling head lice, which are difficult to control because of their resistance to the currently used anti-louse agents.

Insecticide and antifeedant activity of different plant parts of Melia azedarach on Xanthogaleruca luteola

In laboratory choice and no-choice bioassays, treatment of elm leaves with extracts obtained from unripe fruits and green or senescent leaves of Melia azedarach at 1-10% concentration significantly deterred feeding by adults of the elm leaf beetle, Xanthogaleruca luteola. Also, in no-choice tests, adults fed on leaves treated with 2, 5 or 10% extract showed a dramatic increase in mortality rates. Extracts from the different plant structures were similarly active, and starvation as a consequence of their strong antifeedant activity could play a significant role in the high mortality values observed.

Ethnobotany of medicinal plants used by Assamese people for various skin ailments and cosmetics

The present paper deals with the medicinal plants used by the people of Assam for curing different skin ailments and for cosmetics. A total of 85 plants belonging to 49 families have been documented for their therapeutic use against skin diseases and as herbal care. The herbal medicines were prepared from various plant parts of single plant, or multiple plants. The majority of the preparation was made using water as the medium. The mode of application was topical, but in many cases it was also administered orally. In several cases the pure herbal preparations was administered along with milk, ghee, honey, coconut oil, curd, etc. Remedies for 18 skin ailments were documented through this study. About 14 plants are known for their use to cure multiple skin diseases. Among these Curcuma longa and Melia azaderach constitute the major plants. The herbal cosmetic products used by the people of Assam ranges from the enhancement of skin colour, hair care, removal of ugly spots, colouring of nails, palms, and teeth. However, many of the plant preparations used for enhancing beauty were also applied for therapeutic use. Herbal remedies were also available for skin burns, prickly heat and pimples. Information on nine plants used for managing dry skin also emerged from this study.

Role of energy metabolism in the pregnancy interceptive action of Ferula assafoetida and Melia azedarach extracts in rat

Ethanolic extract of Ferula assafoetida and chloroform fraction of Melia azedarach, both devoid of estrogenic activity, were examined for their pregnancy interceptive property. Treatment of rats from days 1 to 7 of pregnancy with either of the plant extracts resulted in pregnancy failure in about 65-85% of the animals. The possible role of energy metabolism in the antifertility action was investigated by measuring changes in activities of the key enzymes of carbohydrate metabolism in uterus on day 7 of pregnancy. It was observed that on the day 7 of pregnancy, one key enzyme of glycolytic pathway (phosphofructokinase) was significantly reduced in the uteri of treated rats as compared to controls. Hexosemonophosphate pathway also appeared to be sensitive to treatment with the plant extracts and showed an inhibitory effect on the enzyme activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase. Oxidative energy metabolism through tricarboxylic acid cycle, which is considered to be the main source of energy to the uterus at this stage, was maximally affected by the treatment with several enzymes showing significant inhibition. The two plant materials appeared to interrupt the latter metabolic pathway more significantly. It is thus concluded that plants lacking phytoestrogens may intercept pregnancy by their ability to disrupt energy metabolism in rat uterus during implantation, especially the oxidative pathway.

in adult female Sprague-Dawley rats

Ethanolic extract of the root of Melia azedarach Linn. (family: Meliaceae) collected from the Institute campus intercepted pregnancy in 60% and 75% adult female rats when administered at 250 and 500 mg/kg daily doses, respectively, on Days 1-10 post-coitum by the oral route. On fractionation, the activity was localized in the chloroform fraction of the ethanolic extract, which showed 80-100% activity at 250 mg/kg daily dose in repeat tests. In animals that became pregnant, there was also a significant reduction in mean number of implantations and all the implantations exhibited signs of resorption. Of the four major compounds isolated in sufficient quantity and characterized from the active chloroform fraction, two compounds showed only marginal (50%) contragestational effect. Further exploration of the active chloroform fraction, which is also devoid of estrogen agonistic activity at the contraceptive dose in immature rat bioassay, is being undertaken to identify and characterize the active principle(s).

Effect of meliacine, a plant derived antiviral, on tumor necrosis factor alpha

The effect of meliacine (MAS) and two fractions MAB 1 and MAB 2 obtained from it on the in vitro production of TNF-alpha of murine macrophages induced by bacterial lipopolysaccharide (LPS) (from Escherichia coli) was tested. Simultaneous administration of the above fractions (ranging from 14 to 56 microg/ml) and LPS (10 microg/ml) to a macrophage culture significantly increased the amount of TNF-alpha released at 24 h of induction in a dose-dependent manner. Meliacine alone, at a concentration of 56 microg/ml, is a weak inducer of TNF-alpha production.

Antibacterial effect of Melia azedarach flowers on rabbits

A methanol extract of Melia azedarach flowers showed potent antibacterial action in rabbits suffering from a skin infection produced by Stapyhlococcus aureus. The healing effects were found comparable to neomycin.