Influence of light-emitting diodes (LEDs) on the 2,4-diclorophenoxyacetic acid phytoremediation by plectranthus neochilus.

2,4-Dichlorophenoxyacetic acid (2,4-D) is an herbicide widely used in crops against broadleaf weeds. However, 2,4-D residues are considered an environmental pollutant in bodies of water. Phytoremediation with Plectranthus neochilus is a substantial strategy to remove 2,4-D from the aquatic environment. The objective of this study was to verify the efficiency of the association of the photostimulus by Light Emitting Diodes (LED) with P. neochilus to improve phytoremediation of 2,4-D in water. Phytoremediation was evaluated with the following samples: natural light, white LED, blue LED, and red LED, with and without the plant as controls. The data corresponding to the validation of the method were in accordance with the required parameters: R2: 0.9926; RSD: 1.74%; LOD: 0.075 mg.L-1; LOQ: 0.227 mg.L-1 and recovery by SPE was 76.57%. The efficiency of the association of LED with P. neochilus in the 28 days was: ambient light + plant (47.0%); white light + plant (37.10%); blue light + plant (26.80%); red light + plant (3.32%). This study demonstrated, for the first time, the efficiency of using LEDs light in association with P. neochilus for the phytoremediation of 2,4-D in water.

Phytoremediation of organic compounds in water is a time-consuming process and generally unfavorable to the plant. This study demonstrated that the photostimulation with blue and red LED lights can accelerate the phytoremediation of the herbicide by P. neochilus, decreasing the t_1/2 of 2,4-D in water by 2 and 5 times, respectively. We equate the time of this process to physical-chemical degradation methods, but without the use of reagents, creating a green strategy to accelerate the decontamination of water resources contaminated with pesticides.

Development of PU foam dressings loaded with extract of Plectranthus amboinicus for burn wound healing.

OBJECTIVE: To develop Plectranthus amboinicus extract loaded Polyurethane foam dressing for burn wound healing. SIGNIFICANCE: Plectranthus amboinicus is traditionally used as an anti-inflammatory and wound-healing agent. Its incorporation in a PU foam dressing will offer the dual benefits of foam dressing as well as the healing potential of P. amboinicus. METHODS: PU foam dressings were prepared and loaded with P. ambionicus leaf extract (PAE). The dressings were prepared with varying concentrations (0.5-2%) of extract along with Toluene diisocyanate, polypropylene glycol (PPG), and liquid paraffin. The dressings were characterized by Scanning Electron Microscopy and evaluated for Moisture Vapor Transmission Rate, absorption rate, porosity, and mechanical strength followed by in vivo burn wound-healing studies in comparison to a marketed dressing. RESULTS: The MVTR was found to be optimum in formulations FD2-FD4 with values ranging from 2068.06 ± 0.99 to 2095.00 ± 0.25 g/m2/day. Absorption rate was found to be between 1.27 ± 0.01, 1.31 ± 0.00, and 1.30 ± 0.02 g/cm2 for formulations FD2-FD4. Formulations FD1, FD2, FD3, FD4 showed better porosity when compared to other formulations. Formulation FD4 was further characterized by micro-CT and a porosity of 46.32% was obtained. Tensile strength measurement indicated that the selected formulations were flexible enough to withstand regular handling during dressing changes. Acute dermal irritation performed on rabbits showed no irritation, erythema, eschar, and edema. In vivo wound-healing studies performed on albino wistar rats showed that the FD4 formulation has better wound healing property. CONCLUSION: Plectranthus ambionicus-loaded PU foam dressing demonstrated promising burn wound-healing potential.

Biological Properties of Extracts Obtained from In Vitro Culture of Plectranthus scutellarioides in a Cell Model.

Plectranthus scutellarioides (L.) R.Br. is a medicinal plant that has long been used in traditional medicine to treat conditions such as abscesses, ulcers, and ear and eye infections. It is known to have a wide range of biological properties, such as antibacterial, antioxidant, antifungal, anti-inflammatory, anti-diabetic and anti-cancer effects. In this study, we established in vitro cultures from both the aerial parts and roots of Plectranthus scutellarioides. Subsequently, we compared the basic phytochemical profile of the obtained extracts and conducted a biological analysis to assess their potential for inducing apoptosis in breast (MCF-7) and lung (A549) cancer cells. Phytochemical analysis by HPLC-MS revealed the presence of compounds belonging to phenolic acids (ferulic, syringic, vanillic, rosmarinic, chlorogenic, caffeic, coumaric, dihydroxybenzoic acids), flavonoids (eriodyctiol and cirsimaritin), and terpenes such as 6,11,12,14,16-Pentahydroxy-3,17diacetyl-8,11,13-abietatrien-7-one, 6,11,12,14,16-Pentahydroxy-3,17-diacetyl5,8,11,13-abietatetraen-7-one, and 3,6,12-Trihydroxy-2-acetyl-8,12-abietadien7,11,14-trione. The results show that both extracts have a cytotoxic and genotoxic effect against MCF-7 and A549 cancer cells, with a different degree of sensitivity. It was also shown that both extracts can induce apoptosis by altering the expression of apoptotic genes (Bax, Bcl-2, TP53, Fas, and TNFSF10), reducing mitochondrial membrane potential, increasing ROS levels, and increasing DNA damage. In addition, it has been shown that the tested extracts can alter blood coagulation parameters. Our results indicate that extracts from in vitro cultures of Plectranthus scutellarioides aerial parts and roots have promising therapeutic application, but further research is needed to better understand the mechanisms of their action in the in vitro model.

Exploring the Anticancer Potential of Semisynthetic Derivatives of 7α-Acetoxy-6ß-hydroxyroyleanone from Plectranthus sp.: An In Silico Approach.

The diterpene 7α-acetoxy-6ß-hydroxyroyleanone isolated from Plectranthus grandidentatus demonstrates promising antibacterial, anti-inflammatory and anticancer properties. However, its bioactivity may be enhanced via strategic structural modifications of such natural products through semisynthesis. The anticancer potential of 7α-acetoxy-6ß-hydroxyroyleanone and five derivatives was analyzed in silico via the prediction of chemicals absorption, distribution, metabolism, excretion, and toxicity (ADMET), quantum mechanical calculations, molecular docking and molecular dynamic simulation. The protein targets included regulators of apoptosis and cell proliferation. Additionally, network pharmacology was used to identify potential targets and signaling pathways. Derivatives 7α-acetoxy-6ß-hydroxy-12-O-(2-fluoryl)royleanone and 7α-acetoxy-6ß-(4-fluoro)benzoxy-12-O-(4-fluoro)benzoylroyleanone achieved high predicted binding affinities towards their respective protein panels, with stable molecular dynamics trajectories. Both compounds demonstrated favorable ADMET parameters and toxicity profiles. Their stability and reactivity were confirmed via geometry optimization. Network analysis revealed their involvement in cancer-related pathways. Our findings justify the inclusion of 7α-acetoxy-6ß-hydroxy-12-O-(2-fluoryl)royleanone and 7α-acetoxy-6ß-(4-fluoro)benzoxy-12-O-(4-fluoro)benzoylroyleanone in in vitro analyses as prospective anticancer agents. Our binding mode analysis and stability simulations indicate their potential as selective inhibitors. The data will guide studies into their structure optimization, enhancing efficacy and drug-likeness.

Enhancement of Forskolin Production Using Aeroponic Cultivation of Coleus forskohlii and the Impact on the Plant Phytochemistry.

Accessing plant resources to extract compounds of interest can sometimes be challenging. To facilitate access and limit the environmental impact, innovative cultivation strategies can be developed. Forskolin is a molecule of high interest, mainly found in the roots of Coleus forskohlii. The aim of this study was to develop aeroponic cultivation methods to provide a local source of Coleus forskohlii and to study the impact of abiotic stress on forskolin and bioactive metabolite production. Three cultivation itineraries (LED lighting, biostimulant, and hydric stress) along with a control itinerary were established. The forskolin content in the plant roots was quantified using HPLC-ELSD, and the results showed that LED treatment proved to be the most promising, increasing root biomass and the total forskolin content recovered at the end of the cultivation period threefold (710.1 ± 21.3 mg vs. 229.9 ± 17.7 mg). Statistical analysis comparing the LED itinerary to the control itinerary identified stress-affected metabolites, showing that LEDs positively influence mainly the concentration of phenolic compounds in the roots and diterpenes in the aerial parts of Coleus forskohlii. Moreover, to better define the phytochemical composition of Coleus forskohlii cultivated in France using aeroponic cultivation, an untargeted metabolomic analysis was conducted using UHPLC-HRMS/MS analysis and molecular networks on both the root and aerial parts. This study demonstrates that aeroponic cultivation, especially with the application of an LED treatment, could be a very promising alternative for a local source of Coleus forskohlii leading to easy access to the roots and aerial parts rich in forskolin and other bioactive compounds.

Anticancer Effects of Abietane Diterpene 7α-Acetoxy-6ß-hydroxyroyleanone from Plectranthus grandidentatus and Its Semi-Synthetic Analogs: An In Silico Computational Approach.

The abietane diterpenoid 7α-acetoxy-6ß-hydroxyroyleanone (Roy) isolated from Plectranthus grandidentatus demonstrates cytotoxicity across numerous cancer cell lines. To potentiate anticancer attributes, a series of semi-synthetic Roy derivatives were generated and examined computationally. ADMET predictions were used to evaluate drug-likeness and toxicity risks. The antineoplastic potential was quantified by PASS. The DFT models were used to assess their reactivity and stability. Molecular docking determined cancer-related protein binding. MS simulations examined ligand-protein stability. Additionally, network pharmacology was used to identify potential targets and signaling pathways. Favorable ADME attributes and acceptable toxicity profiles were determined for all compounds. Strong anticancer potential was shown across derivatives (Pa 0.819-0.879). Strategic modifications altered HOMO-LUMO gaps (3.39-3.79 eV) and global reactivity indices. Favorable binding was revealed against cyclin-dependent kinases, BCL-2, caspases, receptor tyrosine kinases, and p53. The ligand exhibited a stable binding pose in MD simulations. Network analysis revealed involvement in cancer-related pathways. In silico evaluations predicted Roy and derivatives as effective molecules with anticancer properties. Experimental progress is warranted to realize their chemotherapeutic potential.

Phytochemical profiling, antioxidant, cytotoxic, and anti-inflammatory activities of Plectranthus rugosus extract and fractions: in vitro, in vivo, and in silico approaches.

BACKGROUND: Inflammation is a key biological reaction that comprises a complex network of signals that both initiate and stop the inflammation process. PURPOSE: This study targets to evaluate the anti-inflammatory potential of the leaves of the Plectranthus rugosus (P. rugosus) plant involving both in vitro and in vivo measures. The current available drugs exhibit serious side effects. Traditional medicines impart an essential role in drug development. P. rugosus is a plant used in traditional medicine of Tropical Africa, China, and Australia to treat various diseases. METHODS: Lipopolysaccharide (LPS), an endotoxin, kindles macrophages to discharge huge quantities of pro-inflammatory cytokines like TNF-α and IL-6. So, clampdown of macrophage stimulation may have a beneficial potential to treat various inflammatory disorders. The leaves of the P. rugosus are used for swelling purpose by local population; however, its use as an anti-inflammatory agent and associated disorders has no scientific evidence. RESULTS: The extracts of the plant Plectranthus rugosus ethanolic extract (PREE), Plectranthus rugosus ethyl acetate extract (PREAF), and the compound isolated (oleanolic acid) suppress the pro-inflammatory cytokines (IL-6 and TNF-α) and nitric oxide (NO), confirming its importance in traditional medicine. CONCLUSION: The pro-inflammatory cytokines are inhibited by P. rugosus extracts, as well as an isolated compound oleanolic acid without compromising cell viability.

GC/MS Profiling and Evaluation of Leaf Essential Oil for Bactericidal Effect and Free Radical Scavenging Activity of Plectranthus amboinicus (Lour.) Spreng Collected from Odisha, India.

Plectranthus amboinicus (Lour.) Spreng, known as the Indian borage or Mexican mint, is one of the most documented species in the family Lamiaceae for its therapeutic and pharmaceutical values. It is found in the tropical and subtropical regions of the world. The leaf essential oil has immense medicinal benefits like treating illnesses of the skin and disorders like colds, asthma, constipation, headaches, coughs, and fevers. After analyzing earlier reports with regard to the quantity and quality of leaf oil yield, we discovered that the germplasm taken from Odisha is preferable to other germplasms. The objective of the present work is to evaluate the free radical scavenging activity and bactericidal effect of leaf essential oil (EO) of Plectranthus amboinicus (Lour.) Spreng collected from the state of Odisha, India. The hydro distillation technique has been used for essential oil extraction. Upon GC/MS analysis, approximately 57 compounds were identified with Carvacrol as the major compound (peak area=20.25 %), followed by p-thymol (peak area=20.17 %), o-cymene (peak area=19.41 %) and carene (peak area=15.89 %). On evaluation of free radical scavenging activity, it was recorded that the best value of inhibitory concentration, was for DPPH with IC50 =18.64 ppm and for H2 O2 with IC50 =9.35 ppm. The EO showed efficient bactericidal effect against both gram positive (Mycobacterium smegmatis, Staphylococcus aureus, Enterococcus faecium) and gram negative (Escherichia coli, Vibrio cholerae, Klebsiella pneumoniae) bacteria studied through well diffusion method. Fumigatory action of the essential oil was found against M. smegmatis, the model organism for tuberculosis study. Alamar Blue assay, gave a result with MIC value for M. smegmatis i. e., 0.12 µg/ml and the MBC value of 0.12 µg/ml. Hence, P. amboinicus found in Odisha can be suggested as an elite variety and should be further investigated for efficient administration in drug formulation.

Comparative Effects of Two Forms of Chitosan on Selected Phytochemical Properties of Plectranthus amboinicus (Lour.).

In response to stress factors, plants produce a wide range of biologically active substances, from a group of secondary metabolites, which are applied in medicine and health prophylaxis. Chitosan is a well-known elicitor affecting secondary metabolism in plants, but its effect on the phytochemical profile of Plectranthus amboinicus has not been assessed yet. In the present experiment, the effectiveness of the foliar application of two forms of chitosan (chitosan suspension or chitosan lactate) was compared in order to evaluate their potential to induce the accumulation of selected polyphenolic compounds in the aboveground parts of P. amboinicus. It was shown that chitosan lactate had substantially higher elicitation efficiency, as the use of this form exerted a beneficial effect on the analysed quality parameters of the raw material, especially the content of selected polyphenolic compounds (total content of polyphenols, flavonols, anthocyanins, and caffeic acid derivatives) and the free radical-scavenging activity of extracts from elicited plants. Concurrently, it had no phytotoxic effects. Hence, chitosan lactate-based elicitation can be an effective method for optimisation of the production of high-quality P. amboinicus raw material characterised by an increased concentration of health-promoting and antioxidant compounds.

Effect of Ecotype and Starch Isolation Methods on the Physicochemical, Functional, and Structural Properties of Ethiopian Potato (Plectranthus edulis) Starch.

The Ethiopian potato (Plectranthus edulis) is an annual tuber crop indigenous to Ethiopia. The crop is underutilized and not much studied despite its high yield of starch, which has a good potential to contribute to the effort in meeting the quickly growing demand for starch. In this study, the effects of the ecotype and isolation methods on the physicochemical, functional, structural, and crystalline properties of starches were evaluated. Starches were isolated from two Ethiopian potato ecotypes (Loffo and Chanqua) using distilled water (DW), 0.01% sodium metabisulphite (SMS), and 1M sodium chloride (NaCl) in the isolation media. The results showed that the lowest starch yield was obtained from Chanqua using DW (97.4%), while the maximum was from Loffo using SMS (99.3%). The L* (lightness) and whiteness values of the starches obtained from Loffo were higher than those of Chanqua starches, with NaCl and SMS extractants yielding the highest values. The bulk density, water activity (aw), pH, proximate composition (moisture content, protein, ash, fat, crude fiber, and carbohydrate contents), and techno-functional properties were established. The majority of these parameters varied depending on both the isolation method and the ecotype. The crystallinity pattern of all starches showed B-type diffraction, with differences in diffraction peak intensities between all starches. FTIR tests showed structural changes as a function of the ecotype and isolation procedure used. The Loffo ecotype exhibited considerably better results, and the SMS isolation method was found to be the most effective way to acquire the highest starch quality in most of the characteristics evaluated.

Plectranthus Species with Anti-Inflammatory and Analgesic Potential: A Systematic Review on Ethnobotanical and Pharmacological Findings.

The use of medicinal plants to treat inflammatory conditions and painful processes has attracted the attention of scientists and health professionals due to the evidence that natural products can promote significant therapeutic benefits associated with fewer adverse effects compared to conventional anti-inflammatory drugs. The genus Plectranthus is composed of various plants with pharmacological potential, which are used to treat various diseases in traditional communities worldwide. The present study systematically reviewed Plectranthus species with anti-inflammatory and analgesic potential. To this end, a systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. The search was conducted on the following databases: PubMed, ScienceDirect, SciVerse Scopus, and Web of Science. Different combinations of search terms were used to ensure more excellent article coverage. After the selection, a total of 45 articles were included in this review. This study identified twelve Plectranthus species indicated for the treatment of different inflammatory conditions, such as wounds, fever, bronchitis, abscess, asthma, hepatitis, labyrinthitis, tonsillitis, and uterine inflammation. The indications for pain conditions included headache, sore throat, heartburn, menstrual cramp, colic, toothache, stomachache, migraine, chest pain, abdominal pain, local pain, labor pain, and recurring pain. Among the listed species, ten plants were found to be used according to traditional knowledge, although only four of them have been experimentally studied. When assessing the methodological quality of preclinical in vivo assays, most items presented a risk of bias. The SR results revealed the existence of different Plectranthus species used to treat inflammation and pain. The results of this systematic review indicate that Plectranthus species have the potential to be used in the treatment of diseases with an inflammatory component, as well as in the management of pain. However, given the risk of biases, the experimental analysis of these species through preclinical testing is crucial for their safe and effective use.

Evaluation of the Effect of Leaf Development in Plectranthus amboinicus L. on Antimicrobial Activity and Virulence Factors of Pseudomonas aeruginosa PAO1 and Staphylococcus aureus NCTC8325.

Plectranthus amboinicus is widely recognized as a potential source of antimicrobial compounds due to the presence of bioactive components (essential oils) secreted by the glandular trichomes borne on the leaves. As such, an understanding of the effect of leaf development on the production of these essential oils (EOs) is of crucial importance to its medicinal applications. The current study represents the first comparative investigation of the effect of different stages of leaf development (lag, log, and stationary phase) upon the yield and bioactivity of phytochemicals produced. The effects of leaf extracts on the antimicrobial activity, cell surface hydrophobicity, biofilm formation, and motility of P. aeruginosa and Staphylococcus aureus were evaluated. Cryo-scanning electron microscopy was used to record the abundance and distribution of both glandular and non-glandular trichomes during leaf development. Gas chromatography-mass spectrometry analysis revealed that the potent phytochemical thymol is present primarily in log (30.28%) and stationary phase (20.89%) extracts. Log phase extracts showed the lowest minimum inhibitory concentration (25 mg/ml) when compared to other phases of development. Stationary phase extracts were shown to exhibit the highest biofilm dispersal activity against P. aeruginosa (80%), and log phase extracts against biofilms of S. aureus (59%). Log phase extracts showed the highest biofilm inhibitory activity against P. aeruginosa (66%) and S. aureus (63%). In conclusion, log phase leaf extracts of P. amboinicus exhibited a multimodal mechanism of action by displaying antimicrobial, antibiofilm activities and reducing the motility and hydrophobicity, which are important virulence factors in P. aeruginosa and S. aureus pathogenesis.

Protective effect of Coleus forskohlii leaf-extract compound on progression of cataract against Fructose-Induced experimental cataract in rats.

The present study was designed to determine protective effects of Coleus forskohlii hydroalcoholic leaf-extract along with its fractions against fructose-induced cataract rat model. The Coleus forskolii leaf extract was subjected to silica gel column chromatography and fractions were collected. A major high yielding fraction of the leaf extract, designated as fraction B6 was pharmacologically evaluated in Sprague Dawley albino rats at three doses 0.1, 1 and 10 mg/kg respectively. Compound B2; isolated from B6 fraction, identified as 'gallic acid' was also pharmacologically evaluated at three different doses. Cataract was induced by concurrent administration of fructose solution (10% w/v, per oral, dissolved in drinking water) for eight consecutive weeks. Mean arterial pressure, blood glucose level and lenticular opacity were determined. At the end of eight weeks, C. forskohlii leaf extract fraction and gallic acid reduced mean arterial pressure and glucose level in a dose dependent manner. In addition, C. forskohlii led to significant restoration of lens antioxidants enzyme level and reduced cataract formation in rats. These results showed the concentration dependent protective effect by C. forskohlii leaf extract against cataract formation due to restoration of oxidative stress markers.

Anticancer Properties of Plectranthus ornatus-Derived Phytochemicals Inducing Apoptosis via Mitochondrial Pathway.

Since cancer treatment by radio- and chemotherapy has been linked to safety concerns, there is a need for new and alternative anticancer drugs; as such, compounds isolated from plants represent promising candidates. The current study investigates the anticancer features of halimane (11R*,13E)-11-acetoxyhalima-5,13-dien-15-oic acid (HAL) and the labdane diterpenes 1α,6ß-diacetoxy-8α,13R*-epoxy-14-labden-11-one (PLEC) and forskolin-like 1:1 mixture of 1,6-di-O-acetylforskolin and 1,6-di-O-acetyl-9-deoxyforskolin (MRC) isolated from Plectranthus ornatus in MCF7 and FaDu cancer cell lines. Cytotoxicity was assessed by MTT assay, ROS production by Di-chloro-dihydro-fluorescein diacetate assay (DCFH) or Red Mitochondrial Superoxide Indicator (MitoSOX) and Mitochondrial Membrane Potential (MMP) by fluorescent probe JC-1 (5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolylcarbocyanine iodide). In addition, the relative amounts of mitochondrial DNA (mtDNA) were determined using quantitative Real-Time-PCR (qRT-PCR) and damage to mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) by semi-long run quantitative Real-Time-PCR (SLR-qRT-PCR). Gene expression was determined using Reverse-Transcription-qPCR. Caspase-3/7 activity by fluorescence was assessed. Assessment of General In Vivo Toxicity has been determined by Brine Shrimp Lethality Bioassay. The studied HAL and PLEC were found to have a cytotoxic effect in MCF7 with IC50 = 13.61 µg/mL and IC50 = 17.49 µg/mL and in FaDu with IC50 = 15.12 µg/mL and IC50 = 32.66 µg/mL cancer cell lines. In the two tested cancer cell lines, the phytochemicals increased ROS production and mitochondrial damage in the ND1 and ND5 gene regions and reduced MMP (ΔΨm) and mitochondrial copy numbers. They also changed the expression of pro- and anti-apoptotic genes (Bax, Bcl-2, TP53, Cas-3, Cas-8, Cas-9, Apaf-1 and MCL-1). Studies demonstrated increase in caspase 3/7 activity in tested cancer cell lines. In addition, we showed no toxic effect in in vivo test for the compounds tested. The potential mechanism of action may have been associated with the induction of apoptosis in MCF7 and FaDu cancer cells via the mitochondrial pathway; however, further in vivo research is needed to understand the mechanisms of action and potential of these compounds.

Bioactive Properties of Extracts from Plectranthus barbatus (Coleus forskohlii) Roots Received Using Various Extraction Methods.

The aim of this study was to verify various extraction methods: shaking water bath extraction (SWA), ultrasound-assisted extraction (UAE) and microwave assisted extraction (MAE), and their parameters to optimize the extraction yield as well as maximize the concentration of polyphenols in Plectranthus barbatus extracts. Extracts were obtained from dried roots of P. barbatus in various degrees of fragmentation and analyzed for content of polyphenols, antioxidant capacity and flavonoids. Additionally, phenolic compounds in extracts were analyzed using the UHPLC-DAD-ESI-MS/MS method. The conducted research showed that roots of P. barbatus are rich in polyphenolic compounds. A total of 15 phenolic compounds, belonging to the group of phenolic acids and their derivatives, were identified. The extraction yield was similar for all extraction methods and averaged 31%. Irrespective of the extraction method, the yield was the lowest in the case of using 80% ethanol as the solvent. The extracts obtained from the finer fraction were characterized by a higher antioxidant capacity as well as a higher concentration of polyphenolic compounds including flavonoids. UAE seems to be the most effective method for extraction of polyphenols from P. barbatus roots. Regardless of the extraction method, ethanol was a better extractant than distilled water. All ethanolic extracts were characterized by a high antioxidant capacity. The 80% ethanol solution was considered the best solvent for the extraction of flavonoids, while the 40% and 60% ethanol solutions were sufficient for the effective extraction of polyphenolic compounds in general.

Phytochemical Study and Antiglioblastoma Activity Assessment of Plectranthus hadiensis (Forssk.) Schweinf. ex Sprenger var. hadiensis Stems.

Glioblastoma (GB) is the most malignant form of primary astrocytoma, accounting for more than 60% of all brain tumors in adults. Nowadays, due to the development of multidrug resistance causing relapses to the current treatments and the development of severe side effects resulting in reduced survival rates, new therapeutic approaches are needed. The genus Plectranthus belongs to the Lamiaceae family and is known to be rich in abietane-type diterpenes, which possess antitumor activity. Specifically, P. hadiensis (Forssk.) Schweinf. ex Sprenger has been documented for the use against brain tumors. Therefore, the aim of this work was to perform the bioguided isolation of compounds from the acetonic extract of P. hadiensis stems and to investigate the in vitro antiglioblastoma activity of the extract and its isolated constituents. After extraction, six fractions were obtained from the acetonic extract of P. hadiensis stems. In a preliminary biological screening, the fractions V and III showed the highest antioxidant and antimicrobial activities. None of the fractions were toxic in the Artemia salina assay. We obtained different abietane-type diterpenes such as 7α-acetoxy-6ß-hydroxyroyleanone (Roy) and 6ß,7ß-dihydroxyroyleanone (DiRoy), which was also in agreement with the HPLC-DAD profile of the extract. Furthermore, the antiproliferative activity was assessed in a glioma tumor cell line panel by the Alamar blue assay. After 48 h treatment, Roy exerted strong antiproliferative/cytotoxic effects against tumor cells with low IC50 values among the different cell lines. Finally, we synthesized a new fluorescence derivative in this study to evaluate the biodistribution of Roy. The uptake of BODIPY-7α-acetoxy-6ß-hydroxyroyleanone by GB cells was associated with increased intracellular fluorescence, supporting the antiproliferative effects of Roy. In conclusion, Roy is a promising natural compound that may serve as a lead compound for further derivatization to develop future therapeutic strategies against GB.

Encapsulation of wild oregano, Plectranthus amboinicus (Lour.) Spreng, phenolic extract in baker's yeast for the postharvest control of anthracnose in papaya.

BACKGROUND: Anthracnose caused by Colletotrichum gloeosporioides is considered as a major postharvest disease affecting many fruits. This plant disease is traditionally managed with synthetic fungicides, which are generally toxic and are linked to pathogen resistance. Recently, microencapsulated bioactives have been developed as potential alternative strategies to these methods, while utilizing natural fungicides and other phytochemicals. Wild oregano, Plectranthus amboinicus (Lour.) Spreng, contains potent antimicrobial phenolics, but these compounds are volatile and relatively unstable, which limits their efficacy during application. Herein, a baker's yeast microencapsulation system was applied to improve the stability of wild oregano phenolic extract (WOPE) and enhance its antifungal activity against anthracnose. RESULTS: Encapsulation of WOPE in plasmolyzed yeast cells afforded a high encapsulation efficiency (93%) and yielded WOPE-loaded yeast microcapsules (WLYMs) with an average diameter of 2.65 µm. Storage stability studies showed WLYMs are stable for at least 4 months. A 24 -h in vitro release experiment showed that WLYMs had an initial burst release upon redispersion in water, followed by a controlled release to about 80% of the loaded WOPE. Upon application as a spray-type postharvest treatment for papaya, WLYMs exhibited a significantly improved mycelial inhibitory action against C. gloeosporioides and greatly reduced the anthracnose symptoms in papaya fruits. CONCLUSION: This study presented a yeast microencapsulation system that can effectively stabilize WOPE and enhance its antifungal activity, making this microparticle formulation a promising environmentally safe postharvest treatment option to combat anthracnose symptoms in papaya fruits. © 2022 Society of Chemical Industry.

Effects of Autoclaving and Freeze-Drying on Physicochemical Properties of Plectranthus esculentus Starch Derivatives.

The goal of this research was to assess the effects of autoclaving followed by freeze-drying on acetylated xerogel (AXS) and carboxymethylated (CMS) derivatives of Plectranthus esculentus starch as potential vaccine stabilizers. Starch extracted from tubers of P. esculentus were modified by single (carboxymethylation) and dual (acetylation followed by xerogel formation) methods. The derivatives were formulated into vaccine stabilizer suspensions, autoclaved, and freeze-dried without additives or antigen. The derivatives and freeze-dried products were assessed by physical appearance, titration, moisture content (MC), TGA, DSC, XRD, SEM, and FTIR analyses. The degrees of substitution (DS) of the CMS and AXS derivatives were 0.345 and 0.033, respectively. Modification significantly reduced the MC of the derivatives. Freeze-dried AXS (FAXS) had lower MC than freeze-dried CMS (FCMS). The lower degree of hydrophilicity/MC of AXS and FAXS was confirmed by TGA and FTIR band intensities and shifts. Reduction in DSC water desorption/evaporation enthalpies (ΔH) from - 1168.8 mJ (NaS) to - 407.48 mJ (AXS) confirmed the influence of modification on moisture. FTIR confirmed acetylation and carboxymethylation of the derivatives by the presence of 1702.9 cm-1 and 1593 cm-1 bands, respectively (FTIR). Increasing concentrations of the derivatives yielded uncollapsed/unshrunken lyophilisates. SEM and XRD showed that modification, autoclaving, and freeze-drying yielded beehive-like microstructures of FCMS and FAXS that were completely amorphous. Processing (autoclaving and freeze-drying), therefore, enhanced the amorphousness of the starch derivatives which is required in vaccine stability during processing and storage. These findings indicate that these starch derivatives have potential as novel vaccine stabilizers.

Differences in diterpenoid diversity reveal new evidence for separating the genus Coleus from Plectranthus.

Covering: up to 2019The large and medicinally important tropical plant genus Plectranthus (Lamiaceae) was recently split into three separate genera on the basis of molecular and morphological evidence; Plectranthus sensu stricto, Coleus and Equilabium. We found striking differences between the diterpenoids which strongly support this taxonomic split. Coleus is characterised by abietanes oxygenated at C-14 such as royleanones, spirocoleons and acylhydroquinones, which could be useful chemotaxonomic markers to distinguish this genus from Plectranthus s.s. In contrast, the abietanes in Plectranthus s.s. lack C-14 oxygenation, but are often acylated with unusual acids. Equilabium species do not seem to produce diterpenoids. The structures of the nearly 240 abietanes so far reported from Coleus and Plectranthus and their distribution are presented. The aim of this Highlight is to provide an overview of the differences in diterpenoid diversity between these newly defined genera, which are relevant to predict which previously understudied species could hold untapped potential for their medicinal and other economic uses, and to underpin future research on how these plants have evolved to synthesise distinct abietane types.

Quorum sensing modulatory and biofilm inhibitory activity of Plectranthus barbatus essential oil: a novel intervention strategy.

The essential oil (EO) from the roots of Plectranthus barbatus Andr. (Syn. Coleus forskohlii Briq.) was evaluated for quorum sensing (QS) inhibitory activity. P. barbatus EO was screened for inhibition of QS regulated violacein production in Chromobacterium violaceum (ATCC 12472) wild-type strain. At inhibitory (6.25% v/v) and sub-inhibitory concentrations (3.125% v/v) of the EO, dose-dependent response in the inhibition of violacein production was observed in C. violaceum. Similarly, sub-MIC (6.25% v/v) of P. barbatus EO disrupted QS regulated biofilm formation by 27.87% and inhibited swarming and twitching motility in Pseudomonas aeruginosa PA01 implying its anti-infective and QS modulatory activity. Fluorescence microscopy studies confirmed the disruption of biofilm formation by EO in P. aeruginosa PAO1. Promising antibacterial activity was recorded at concentrations as low as 3.12% v/v for Listeria monocytogenes (ATCC 13932) and at 6.25% v/v for both Salmonella enterica subsp. enterica serovar Typhimurium (ATCC 25241) and Escherichia coli (ATCC 11775). Furthermore, significant dose-dependent inhibition was observed for biofilm formation and motility in all the tested pathogens in different treated concentrations. GC-MS analysis revealed α-pinene, endo-borneol, bornyl acetate, 1-Hexyl-2-Nitrocyclohexane as the major phytoconstituents. P. barbatus EO or its constituent compounds with QS modulatory, antimicrobial and biofilm inhibitory property could be potential new-age dietary source based intervention and preservation technologies.