In vitro and in vivo evaluation of the anti-infective potential of the essential oil extracted from the leaves of Plectranthus amboinicus (lour.) spreng against Klebsiella pneumoniae and elucidation of its mechanism of action through proteomics approach.

ETHNOPHARMACOLOGICAL RELEVANCE: Members of Plectranthus genus such as Plectranthus amboinicus (Lour.) Spreng is a well-known folkloric medicine around the globe in treating several human ailments such as cardiovascular, respiratory, digestive, urinary tract, skin and infective diseases. Its therapeutic value is primarily attributed to its essential oil. Although several properties of Plectranthus amboinicus essential oil have been documented, its mechanism of action and safety has not been completely elucidated. AIM OF THE STUDY: To investigate the anti-infective potential of Plectranthus amboinicus essential oil against Klebsiella pneumoniae using in vitro and in vivo bioassays and identify its mode of action. The study was conducted to scientifically validate the traditional usage of Plectranthus amboinicus oil and propose it as a complementary and alternative medication to combat Klebsiella pneumoniae infections due to emerging antibiotic resistance problem. MATERIALS AND METHODS: Plectranthus amboinicus essential oil was extracted through steam distillation and was chemically characterized using Gas Chromatography Mass Spectrometry (GC-MS). The antibacterial activity was assessed using microbroth dilution assay, metabolic viability assay and growth curve analysis. The mode of action was elucidated by the proteomics approach using Nano-LC-MS/MS followed by in silico analysis. The results of proteomic analysis were further validated through several in vitro assays. The cytotoxic nature of the essential oil was also confirmed using adenocarcinomic human alveolar basal epithelial (A549) cells. Furthermore, the safety and in vivo anti-infective efficacy of Plectranthus amboinicus essential oil was evaluated through survival assay, CFU assay and histopathological analysis of vital organs using zebrafish as a model organism. RESULTS: The chemical characterization of Plectranthus amboinicus essential oil revealed that it is predominantly composed of thymol. Thymol rich P. amboinicus essential oil demonstrated potent inhibitory effects on Klebsiella pneumoniae growth, achieving a significant reduction at a concentration of 400 µg/mL within 4 h of treatment The nano-LC-MS/MS approach unveiled that the essential oil exerted its impact by disrupting the antioxidant defense system and efflux pump system of the bacterium, resulting in elevated cellular oxidative stress and affect the biosynthesis of biofilm. The same was validated through several in vitro assays. Furthermore, the toxicity of Plectranthus amboinicus essential oil determined using A549 cells and zebrafish survival assay established a non-toxic concentration of 400 µg/mL and 12.5 µg/mL respectively. The results of anti-infective potential of the essential oil using Zebrafish as a model organism demonstrated significantly improved survival rates, reduced bacterial load, alleviated visible signs of inflammation and mitigated the adverse effects of infection on various organs, as evidenced by histopathological analysis ensuring its safety for potential therapeutic application. CONCLUSION: The executed in vitro and in vivo assays established the effectiveness of essential oil in inhibiting bacterial growth by targeting key proteins associated with the bacterial antioxidant defense system and disrupted the integrity of the cell membrane, highlighting its critical role in addressing the challenge posed by antibiotic-resistant Klebsiella pneumoniae.

Exploring the Potential of Essential Oil from Plectranthus amboinicus Leaves against Breast Cancer: In vitro and In silico Analysis.

Plectranthus amboinicus leaves were subjected to hydrodistillation to obtain essential oil (EO). Phytochemical analysis using gas chromatography-mass spectrometry revealed a diverse range of compounds in the EO, with p-cymen-4-ol (18.57%) emerging as the most predominant, followed by isocaryophyllene (12.18%). The in vitro antiproliferative activity of EO against breast cancer was assessed in MCF-7 and MDA-MB-231 cell lines. The MTT assay results revealed that EO showed IC50 values of 42.25 µg/mL and 13.44 µg/mL in MCF-7 cells and 63.67 µg/mL and 26.58 µg/mL in MDA-MB-231 cells after 24 and 48 h, respectively. The in silico physicochemical and pharmacokinetic profiles of the EO constituents were within acceptable limits. Molecular docking was conducted to investigate the interactions between the constituents of the EO and protein Aromatase (PDB ID:3S79). Among the EO constituents, 4-tert-butyl-2-(5-tert-butyl-2-hydroxyphenyl)phenol (4BHP) exhibited the highest dock score of -6.580 kcal/mol when compared to the reference drug, Letrozole (-5.694 kcal/mol), but was slightly lesser than Anastrozole (-7.08 kcal/mol). Molecular dynamics simulation studies (100 ns) of the 4BHP complex were performed to study its stability patterns. The RMSD and RMSF values of the 4BHP protein complex were found to be 2.03 Å and 4.46 Å, respectively. The binding free energy calculations revealed that 4BHP displayed the highest negative binding energy of -43 kcal/mol with aromatase protein, compared to Anastrozole (-40.59 kcal/mol) and Letrozole (-44.54 kcal/mol). However, further research is required to determine the safety, efficacy, and mechanism of action of the volatile oil. Taking into consideration the key findings of the present work, the development of a formulation of essential oil remains a challenging task and novel drug delivery systems may lead to site-specific and targeted delivery for the effective treatment of breast cancer.

Plectranthus amboinicus and rosemary (Rosmarinus officinalis L.) essential oils effects on performance, antioxidant activity, intestinal health, immune response, and plasma biochemistry in broiler chickens.

This work aimed to assess the effects of Plectranthus amboinicus essential oil (PAE) and rosemary (Rosmarinus officinalis L.) essential oil (ROE) as feed additives on performance, antioxidant activity, intestinal microbiota, intestinal morphology, immune response, and plasma biochemistry using 320 unsexed 1-day-old Ross 308 broiler chickens. The chickens were assigned randomly into four treatments containing eight replicates with 10 chickens each. Treatment diets included a basal diet as a control group, 100 mg/kg PAE, 200 mg/kg PAE, and 100 mg/kg ROE. ROE affected the growth performance in the starter phase by improving (p = .01) the feed conversion ratio (FCR) compared with the control diet. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity in the plasma were elevated (p < .0001) by both feed additives. Supplementation of additives could increase (p < .006) total antioxidant capacity (TAC). Furthermore, malondialdehyde (MDA) values in the breast (p < .0001) and thigh (p < .001) for all supplemented diets were less than the control group. The essential oils (EOs) reduced (p < .005) coliform counts in the ileum and increased (p = .029) lactic acid bacteria counts. In addition, villus height (VH) and crypt depth (CD) increased, whereas the density of goblet cells decreased in the small intestine when feed additives were included. Also, the antibody titers against sheep red blood cells (SRBC) and Newcastle disease virus (NDV) were increased (p < .0001) by EOs. Plasma total protein (p = .04) and globulin (p = .02) were increased, and cholesterol was reduced (p = .002) by supplemented diets. Our study revealed that PAE could effectively improve the antioxidant activity, intestinal microbiota population, intestinal morphology, immune response, and plasma biochemistry parameters in broiler chickens.

Hepatoprotective activity of ethanolic extract of Plectranthus amboinicus (lour.) spreng leaf in DMBA induced rats.

The hepatoprotective activity of ethanolic of Plectranthus amboinicus Lour Spreng leaf extract (PEE) on blood biochemical profiles, non-specific immune system, liver histology were evaluated in rats induced DMBA. Twenty five female rats were divided into five groups, each with 5 rats. The negative control group (NC) received only food and water. The positive control group (PC) administered orally DMBA 20 mg/kg body weight (bw) once every four days for 32 days. The treatment groups received the PEE with three different doses of 175 (T1), 350 (T2), 700 (T3) mg/kg bw, respectively for 27 days after DMBA induction. At the end of the treatment, blood samples were collected to investigate the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), bilirubin, total protein, albumin and globulin as well as the hematological parameter, such as neutrophils, monocyte, mean corpuscular hemoglobin (MCH), mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and red cell distribution width (RDW) were monitored. The results showed an increased level in ALT, AST, ALP, and bilirubin in the PC group. However, the T3 group (PEE 700 mg/kg) showed a significant decrease value (p < 0.05) in ALT, ALP, and bilirubin compared to the PC group. Our finding revealed that all PEE treatments had a significant increase (p < 0.05) in the total protein, albumin and globulin compared to the PC group. The neutrophils (18.60 ± 4.64) and monocytes (61.40 ± 4.99) are lowest in the T2 groups as well as the value of MCH, RDW and MCV were significantly alleviated compared to all other groups. Histopathological observation demonstrated that the administration of PEE improved hepatocyte architecture and reduced the number of necrosis and hydrophilic degeneration. In conclusion, PEE has hepatoprotective activity by improving liver function, enhancing the non-specific immune system and recovering histopathological hepatocytes in rats exposed to DMBA.

Design and development of orally disintegrating films: A platform based on hydroxypropyl methylcellulose and guar gum.

From a design of experiments (DOE) performed under four independent variables, with the filmogenicity conditions and shortest disintegration time as the answers, a new oral disintegrating film (ODF) based on hydroxypropyl methylcellulose (HPMC) and guar gum (GG) with the essential oil of Plectranthus amboinicus L. (EOPA) was developed. Sixteen formulations were tested for filmogenicity, homogeneity, and viability. The better selected ODF required 230.1 s for complete disintegration. The retention rate of the EOPA was quantified using the nuclear magnetic resonance hydrogen technique (H1 NMR), which identified the presence of 0.14 % carvacrol. The scanning electron microscopy showed a smooth and homogeneous surface with the presence of small white dots. Through the disk diffusion test, the EOPA was able to inhibit the growth of clinical strains of the Candida genus and gram-positive and gram-negative bacterial strains. This work opens new perspectives for the development of antimicrobial ODFS used in clinical practice.

Anticancer Effect of Plectranthus Amboinicus and Glycyrrhiza Glabra on Oral Cancer Cell Line: An Invitro Experimental Study.

BACKGROUND AND OBJECTIVE: Oral cancer is a commonly encountered type of cancer with multifactorial etiology. The number of oral cancer cases are increasing in the recent past. Advancements in cancer therapy are continuously evolving. In spite of that, the survival rate is very low along with adverse effects associated with each treatment modality. This poses a need for a constant search for newer or alternative treatment options. Herbal medicines or plant-based medicines are derived from plant sources. Evidence supports that incorporating herbal medicines in cancer therapy offers many advantages. Hence, exploring plant species for anticarcinogenic properties can potentially benefit cancer therapy. Studies show that the two medicinal herbs Plectranthus amboinicus (Indian borage, Karpooravalli) and Glycyrrhiza glabra (Liquorice, Athimathuram) have shown excellent anticancer activity on various cancers. The present study aimed to evaluate and assess the anticancer property of two medicinal plants Plectranthus amboinicus (Indian borage, Karpooravalli) and Glycyrrhiza glabra (Liquorice, Athimathuram) on oral cancer (KB) cell line. MATERIALS AND METHODS: Ethanolic extracts of leaves of Plectranthus amboinicus and roots of Glycyrrhiza glabra were prepared. The oral cancer (KB) cell line was procured and cultured. Cell viability (MTT) assay was performed using various concentrations of both the plant extracts on oral cancer cells. The percentage of cell viability for each concentration was calculated and the IC50 value was derived for the two plant extracts. RESULTS: The results revealed a significant decrease in the percentage of viable cells with increasing concentration of the extracts. The IC50 values of Plectranthus amboinicus and Glycyrrhiza glabra were 53.0 µg/ml and 43.6 µg/ml respectively. On comparing the anticancer effect of the two extracts, Glycyrrhiza glabra was more cytotoxic than Plectranthus amboinicus on oral cancer (KB) cells. CONCLUSION: The two medicinal plants Plectranthus amboinicus and Glycyrrhiza glabra exhibited potent anticancer activity against oral cancer (KB) cells.

Biological screening of herbal extracts and essential oil from Plectranthus species: α-amylase and 5-lipoxygenase inhibition and antioxidant and anti-Candida potentials

Abstract The phenolic compound content, the antioxidant and α-amylase inhibition potentials of different extracts of the Plectranthus amboinicus, P. barbatus and P. ornatus were evaluated. We also evaluated the influence of plant growth and harvest time on the chemical composition of the essential oil (EO) of P. amboinicus, its antioxidant and anti-Candida activities and the α-amylase and lipoxygenase inhibitions. The turbo-extract of P. barbatus showed the greatest phenolic compound content and antioxidant activity. No α-amylase inhibition activity was observed in the analyzed extracts, but the turbo-extraction and refluxing extracts possessed high antioxidant activities. Protected cultivation and morning harvest conditions gave the best antioxidant activities, which was associated to the highest carvacrol content. P. amboinicus EO antioxidant activity could contribute to the reduction of oxidative stress in diabetes. Causal Candida strains of diabetic foot ulcers showed sensitivity to P. amboinicus EO. C. albicans and C. dubliniensis were the most sensitive of the selected Candida strains. Turbo-extracts or refluxing of the three species extracts and the EO of P. amboinicus should be considered as a potential candidate for the management the complications of type 2 diabetes.

Molecular docking analysis of bioactive compounds from Plectranthus amboinicus with glucokinase.

Natural remedies from medicinal plants are known to be effective and reliable appropriate medicine for illnesses. The current research examined Plectranthus amboinicus' anti diabetic property by docking the bioactive compounds of certain target proteins. We document the molecular docking analysis of bioactive compounds from Plectranthus amboinicus with protein Glucokinase. Molecular docking experiments were carried out in PyRx software. Results of these docking experiments showed that most of the compounds showed very strong interaction with the target protein Glucokinase. Based on the scoring parameters we have selected best four compounds (Rutin, Salvianolic acid, Luteolin and Salvigenin) which showed very good docking score and hydrogen bond interaction for diabetics.

New Horizons of Macrophage Immunomodulation in the Healing of Diabetic Foot Ulcers.

Diabetic foot ulcers (DFUs) are one of the most costly and troublesome complications of diabetes mellitus. The wound chronicity of DFUs remains the main challenge in the current and future treatment of this condition. Persistent inflammation results in chronic wounds characterized by dysregulation of immune cells, such as M1 macrophages, and impairs the polarization of M2 macrophages and the subsequent healing process of DFUs. The interactive regulation of M1 and M2 macrophages during DFU healing is critical and seems manageable. This review details how cytokines and signalling pathways are co-ordinately regulated to control the functions of M1 and M2 macrophages in normal wound repair. DFUs are defective in the M1-to-M2 transition, which halts the whole wound-healing machinery. Many pre-clinical and clinical innovative approaches, including the application of topical insulin, CCL chemokines, micro RNAs, stem cells, stem-cell-derived exosomes, skin substitutes, antioxidants, and the most recent Phase III-approved ON101 topical cream, have been shown to modulate the activity of M1 and M2 macrophages in DFUs. ON101, the newest clinically approved product in this setting, is designed specifically to down-regulate M1 macrophages and further modulate the wound microenvironment to favour M2 emergence and expansion. Finally, the recent evolution of macrophage modulation therapies and techniques will improve the effectiveness of the treatment of diverse DFUs.

Formulation and evaluation of oral disintegrating films using a natural ingredient against Streptococcus mutans.

Background: Oral disintegrating films (ODFs) are one of the forms of drug delivery system with better patient compliance. The advantage is that it disintegrates quickly when placed on the tongue and has better bioavailability. Aim: The aim of this study is to develop an ODF using Vaccinium oxycoccos and Plectranthus amboinicus targeting Streptococcus mutans. Setting and Design: This in vitro study was conducted at an institutional laboratory. Materials and Methods: The chemical composition of aqueous extracts of Vaccinium oxycoccos and Plectranthus amboinicus was examined using gas chromatography (GC)-mass spectrometry (MS). Extracts were added at its minimal inhibitory concentration (MIC) into the hydroxy propylmethyl cellulose (HPMC) polymer matrix solution to develop active ODF. The study concentrated on assessing the physical properties such as thickness of film, PH of the film, folding endurance, swelling test, disintegration, and dissolution test. Color analysis, Fourier transform infrared (FTIR), spectroscopy, and scanning electron microscope (SEM) were the mechanical properties of the film assessed. Statistical Analysis: Data were analyzed statistically, one-way analysis of variance followed by post hoc analysis for the assessment of MIC. Descriptive statistics were performed for the analysis of film properties. Results: MIC was 25 µg/ml for Vaccinium oxycoccos and 50 µg/ml for Plectranthus amboinicus. Three percentage HPMC with 1% citric acid and 1% aspartame was used to develop a polymer matrix. Films pH was between 6 and 7. FTIR and SEM analysis were done to confirm the attachment of active compound in a polymer matrix. Conclusion: Vaccinium oxycoccos and Plectranthus amboinicus showed good antibacterial activity, therefore could be a potent source to minimize the incidence of S. mutans.

Insecticidal Activity of Plectranthus amboinicus Essential Oil against the Stable Fly Stomoxys calcitrans (Diptera: Muscidae) and the Horse Fly Tabanus megalops (Diptera: Tabanidae).

The stable fly, Stomoxys calcitrans (Diptera: Muscidae), and the horse fly, Tabanus megalops (Diptera: Tabanidae), are important ectoparasites of livestock in Thailand. These species affect animal health and cause economic losses. This study investigated the insecticidal activity of Plectranthus amboinicus essential oil against S. calcitrans and T. megalops through contact and fumigant toxicity tests and evaluated the effects of the essential oil on these flies through histopathological and scanning electron microscopic (SEM) studies. The results of the contact toxicity test indicated that the median lethal dose against S. calcitrans and T. megalops was 12.05 and 131.41 µg/fly, and the 90% lethal dose was 45.53 and 200.62 µg/fly, respectively. The results of the fumigant toxicity test showed that the median lethal concentration against S. calcitrans and T. megalops was 1.34 and 7.12 mg/L air, and the 90% lethal concentration was 4.39 and 30.37 mg/L air, respectively. Histopathology revealed neuronal degeneration in the brain of S. calcitrans and interstitial neuronal edema of the brain and ovarian necrosis in T. megalops. No external morphological changes were observed via SEM. Given its insecticidal properties against S. calcitrans and T. megalops, P. amboinicus essential oil could be developed into a natural insecticide to control these fly species.

Molecular docking analysis of SARS-CoV-2 linked RNA dependent RNA polymerase (RdRp) with compounds from Plectranthus amboinicus.

It is of interest to document the moelcular docking analysis of SARS-CoV-2 linked RNA dependent RNA polymerase (RdRp) with compounds from Plectranthus amboinicus. Hence, we report the binding features of rutin, Luteolin, Salvianolic acid A, Rosmarinic acid and p-Coumaric acid with the target protein SARS-CoV-2 linked RNA dependent RNA polymerase (RdRp) for further consideration.

Phytochemical Profile and Antioxidant Activities of Coleus amboinicus Lour. Cultivated in Indonesia and Poland.

Coleus amboinicus Lour., Lamiaceae, is a perennial herb that is native to Indonesia and also cultivated in Africa, Asia and Australia. The major phytochemicals responsible for its bioactivity are rosmarinic acid (RA) and its analogues, flavonoids and abietane diterpenoids. The possibility of cultivation in a colder climate would extend the use of this herb and provide new opportunities to herb growers and livestock farmers. Our study to compare feed value and phytochemical composition of C. amboinicus plants cultivated in its original region, Indonesia, and in Poland. The crude protein content was significantly higher in plants cultivated in Indonesia compared to those cultivated in Poland-21% and 13% of dry matter, respectively. The higher ADF contents were detected in C. amboinicus cultivated in Indonesia, 38-41%, in comparison to 34% in plants cultivated in Poland. The phytochemical composition was also significantly influenced by the cultivation location. Polish samples were higher in polyphenols (RA and its analogues), and also had 1.5-2-fold higher antioxidant potential, as measured by DPPH scavenging, phosphomolybdenum reduction and Fenton reaction driven lipid peroxidation. The Indonesian samples contained more diterpenoid compounds, such as dihydroxyroyleanone, and the sum of terpenoids was ca. 10 times higher than in samples from Poland (15.59-23.64 vs. 1.87 µg/g of extracts). In conclusion, C. amboinicus is suitable for cultivation in non-optimal climatic conditions but some nutritional properties and bioactivity are significantly affected.

Cytotoxicity, in vivo toxicity, and chemical composition of the hexane extract of Plectranthus amboinicus (Lour.) Spreng.

Cancer is a universal health issue, and many anticancer therapeutic drugs have been isolated from natural products. This study analyzed the cytotoxic and apoptotic activity of Plectranthus amboinicus leaf hexane (PALH) extract in MDA-MB-231 (median inhibitory concentration [IC50] = 39.26 µg/mL) and MCF7 (IC50 = 89.05 µg/mL) breast cancer cell lines. Cells appeared rounded and shrunken, indicating morphological changes due to apoptosis induction. The primary constituent of PALH was phenol, 5-methyl-2-(1-methylethyl) (44%). PALH extract treatment increased the percentage of late apoptotic cells in the MDA-MB231 cell line (58% ± 1.5% at 200 µg/mL) compared to the control group, as evidenced by the activated caspase-3 and caspase-7 identified and captured by fluorescence microscopy. The relative migration rate in MDA-MB-231 cells treated with 10 µg/mL of PALH extract for 48 h was significantly lower compared to the control group. Analysis of acute (2000 mg/kg/BW) and subacute (250 and 500 mg/kg/BW) toxicity of PALH extract in mice showed no mortality or adverse effects in the kidney and liver histology compared to the control group. PALH extract can be considered nontoxic as it does not cause any adverse changes and so can be proposed as a potential breast anticancer agent.

Determination of the antimicrobial property of oregano (Plectranthus amboinicus (Lour.) Spreng.) crude aqueous leaf extract against throat pathogens using broth and checkerboard dilution methods

@#<p style="text-align: justify;"><strong>Objective:</strong> This study aimed to determine the antimicrobial property of oregano (Plectranthus amboinicus) crude leaf extract against pathogens that infect the throat, specifically Streptococcus pyogenes and Candida albicans using the broth and checkerboard dilution methods.</p><p style="text-align: justify;"><strong>Methods:</strong> This study employed an experimental study design using broth dilution method for the determination of the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) against Streptococcus pyogenes ATCC 19615, and minimum fungicidal concentration (MFC) against Candida albicans ATCC 14053 of P. amboinicus crude extract (PA extract). Checkerboard dilution method was then used for determination of the synergy between PA extract and the standard antimicrobials.</p><p style="text-align: justify;"><strong>Results:</strong> In vitro growth inhibition of S. pyogenes (MIC 0.13 g/mL) and C. albicans (MIC 0.03 g/mL) was exhibited by the PA extract. The highest concentration of PA extract used in this study was not sufficient to demonstrate bactericidal and fungicidal activity (MBC >0.25 g/mL, MFC >0.25 g/mL). Results of checkerboard dilution method revealed that PA extract when combined with either penicillin (for S. pyogenes) or nystatin (for C. albicans) demonstrated indifference.</p><p style="text-align: justify;"><strong>Conclusion:</strong> The crude extract of Plectranthus amboinicus has the capability to inhibit the growth of both S. pyogenes and C. albicans. This demonstrates its potential use in the treatment of throat infections caused by these organisms.</p><p style="text-align: justify;"><strong>Key Words:</strong> Plectranthus amboinicus, oregano, antimicrobial, throat infections, herbal medicine</p>

Electrochemical Determination of Nicotine in Tobacco Products Based on Biosynthesized Gold Nanoparticles.

In this work, gold nanoparticles were biosynthesized via Plectranthus amboinicus leaf extract as the reducing agent. A series of techniques were used for sample analysis. The biosynthesized gold nanoparticles (bAuNPs) are a uniform size with a spherical shape. The FTIR analysis reveals the presence of many oxygen-containing functional groups on the bAuNP surface. The cyclic voltammetry and electrochemical impedance spectroscopic characterizations reveal that while the bAuNPs have a slightly lower conductivity than chemically synthesized AuNPs (cAuNPs). However, the bAuNPs have a superior electrocatalytic performance toward nicotine reduction. After optimization, the bAuNP-modified SPE could detect nicotine linearly from 10 to 2,000 µM with a low detection limit of 2.33 µM. In addition, the bAuNPs/SPE have been successfully used for nicotine-containing-product analysis.

Phytochemical profiling and biological activity of Plectranthus amboinicus (Lour.) mediated by various solvent extracts against Aedes aegypti larvae and toxicity evaluation

Objective: To analyze the phytochemical compounds and to investigate the bio-toxic efficacy of various solvent extracts of Plectranthus amboinicus against mosquito larvae activity and lethality on non-targeting organisms. Methods: The methanol, ethyl acetate, hexane, and aqueous extracts of Plectranthus amboinicus were subjected to analyze the mosquitocidal activity against the dengue vector, Aedes aegypti and toxicity assays on zebra fish and brine shrimp. Three replications were performed, and negative control was also maintained. Amongst, ethyl acetate extract of Plectranthus amboinicus was chosen for the determination of bio-active compounds. Results: The mosquitocidal assays of methanol and ethyl acetate extracts of Plectranthus amboinicus showed the maximal activity with minimal concentration against the 4th instar mosquito-larvae of Aedes aegypti through the following lethal concentration (LC50 and LC90) values: 53.36 & 92.51 μg/mL and 13.64 & 86.09 μg/mL, respectively. In addition, the plant extracts showed no toxicity on zebra fish embryo and brine shrimp assays. The gas-chromatography analysis of the ethyl acetate extract of Plectranthus amboinicus revealed the presence of seven different compounds. Among them, PAEA-fraction 60 contained a major active bioactive compound, hexadecanoic acid, methyl ester (270.0). Conclusions: Plectranthus amboinicus possesses mosquitocidal properties and could be used as a potential alternative source for preparing the mosquitocidal agents.

Phytochemical profiling and biological activity of Plectranthus amboinicus (Lour.) mediated by various solvent extracts against Aedes aegypti larvae and toxicity evaluation

Objective: To analyze the phytochemical compounds and to investigate the bio-toxic efficacy of various solvent extracts of Plectranthus amboinicus against mosquito larvae activity and lethality on non-targeting organisms. Methods: The methanol, ethyl acetate, hexane, and aqueous extracts of Plectranthus amboinicus were subjected to analyze the mosquitocidal activity against the dengue vector, Aedes aegypti and toxicity assays on zebra fish and brine shrimp. Three replications were performed, and negative control was also maintained. Amongst, ethyl acetate extract of Plectranthus amboinicus was chosen for the determination of bio-active compounds. Results: The mosquitocidal assays of methanol and ethyl acetate extracts of Plectranthus amboinicus showed the maximal activity with minimal concentration against the 4th instar mosquito-larvae of Aedes aegypti through the following lethal concentration (LC50 and LC90) values: 53.36 & 92.51 μg/mL and 13.64 & 86.09 μg/mL, respectively. In addition, the plant extracts showed no toxicity on zebra fish embryo and brine shrimp assays. The gas-chromatography analysis of the ethyl acetate extract of Plectranthus amboinicus revealed the presence of seven different compounds. Among them, PAEA-fraction 60 contained a major active bioactive compound, hexadecanoic acid, methyl ester (270.0). Conclusions: Plectranthus amboinicus possesses mosquitocidal properties and could be used as a potential alternative source for preparing the mosquitocidal agents.

Extract From Plectranthus amboinicus Inhibit Maturation and Release of Interleukin 1ß Through Inhibition of NF-κB Nuclear Translocation and NLRP3 Inflammasome Activation.

Uncontrolled inflammation may produce massive inflammatory cytokines, in which interleukin 1ß (IL-1ß) plays a key role, resulting in tissue damage and serious disorders. The activation of NLRP3 inflammasome is one of the major mechanisms in maturation and release of IL-1ß. Plectranthus amboinicus is a perennial herb. Several pharmacological activities of natural components and crude extracts from P. amboinicus have been reported including anti-inflammation; however, the underlying mechanism is not clear. Phorbol-12-myristate 13-acetate-differentiated THP-1 monocytic leukemia cells were used as a reliable model in this study to examine the effect on inflammasome signaling pathway by PA-F4, an extract from Plectranthus amboinicus. PA-F4 inhibited ATP-induced release of caspase-1, IL-1ß, and IL-18 from lipopolysaccharides (LPS)-primed cells. PA-F4 induced a concentration-dependent inhibition of both ASC dimerization and oligomerization in cells under LPS priming plus ATP stimulation. Co-immunoprecipitation of NLRP3 and ASC demonstrated that PA-F4 significantly blunted the interaction between NLRP3 and ASC. Furthermore, PA-F4 completely abolished ATP-induced K+ efflux reaction in LPS-primed cells. Taken together, PA-F4 displayed an inhibitory activity on NLRP3 inflammasome activation. Moreover, PA-F4 also inhibited LPS-induced p65 NF-κB activation, suggesting an inhibitory activity on LPS priming step. Further identification showed that rosmarinic acid, cirsimaritin, salvigenin, and carvacrol, four constituents in PA-F4, inhibited LPS-induced IL-6 release. In contrast, rosmarinic acid, cirsimaritin and carvacrol but not salvigenin inhibited ATP-induced caspase-1 release from LPS-primed cells. In conclusion, PA-F4 displayed an inhibitory activity on activation of NLRP3 inflammasome. PA-F4 inhibited LPS priming step through block of p65 NF-κB activation. It also inhibited ATP-induced signaling pathways in LPS-primed cells including the inhibition of both ASC dimerization and oligomerization, K+ efflux reaction, and the release reaction of caspase-1, IL-1ß, and IL-18. Rosmarinic acid, cirsimaritin, salvigenin, and carvacrol could partly explain PA-F4-mediated inhibitory activity on blocking the activation of NLRP3 inflammasome.

The Anti-Proliferative and Pro-Apoptotic Properties of Ethanol Plectranthus amboinicus (Lour.) Spreng. Leaves Ethanolic Extract Nanoparticles on T47D Cell Lines

Objectives: Plectranthus amboinicus (Lour.) Spreng. is a plant which has the potential as an anti-cancer agent. To enhance the bioavailability of an extract, it is necessary to transform the extract into nanoparticles. This research aimed to create nanoparticles of the extract and investigate the anti-proliferative and pro-apoptosis effects on T47D breast cancer cell lines. Materials and Methods: The extraction with ethanol was performed using maceration method. The nanoparticles were prepared by using the ionic gelation method. Cytotoxic assay method evaluation of the proliferation of T47D cell line (using doubling time) was carried out using the MTT assay. Apoptosis was observed using the flow cytometry assay. Results: Treatment with Plectranthus amboinicus (Lour.) Spreng. ethanolic extract nanoparticles (PAEEN) inhibited the proliferation of T47D cell lines after 48 hours and 72 hours of incubation at concentrations of 22.3 µg/mL, 44.6 µg/mL, and 89.2 µg/mL. The viable cells were 93%, 86%, 54% (48 hours), and 98%, 71%, 57% (72 hours), respectively. The nanoparticles of extract also induced apoptosis at concentrations of » IC50 (2.16%), ½ IC50 (1.57%), and IC50 (2.43%). Conclusion: PAEEN exhibits the anti-proliferative effect on T47D breast cancer cells via apoptosis. Further study is required to confirm the mechanism of PAEEN in the cell cycle arrest and apoptosis induction on T47D cells.