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.

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.

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.

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.

First Report of Orobanche cumana on Coleus in Xinjiang, China.

Coleus (Plectranthus scutellarioides [L.] R.Br., [syn.: Solenostemon scutellarioides], Lamiaceae) is a popular ornamental plant for its colorful and showy foliage, and widely planted as a garden plant, and a medicinal herb in some countries, including India, Indonesia, Mexico (Zhu et al. 2015). In March 2022, parasitism of broomrape, on coleus plants was found in a greenhouse (86° 3' 36" E, 44° 18' 36" N, 500 m elevation) at Shihezi University, Xinjiang, China. A few plants (6%) were parasitized with 2.5 emerged broomrape shoots per host plant. The host-parasite connection was confirmed by microscopy. Morphological characteristics of the host were consistent with coleus described by Cao et al. (2023). The broomrapes were: stem simple and slender, slightly bulbous at the base, glandular-pubescent; inflorescence usually many-flowered, lax, dense in the upper third; bracts 8 to 10 mm long, ovate-lanceolate; calyx segments free, entire, seldom bifid with markedly unequal subulate teeth; corolla markedly curvate, dorsal line inflected, white at the base, bluish violet in the upper part; stamens adaxial with filaments 6 to 7 mm long; abaxial stamens with filaments 7 to 10 mm long; gynoecium 7 to 10 mm long; ovary 4 to 5 mm long, glabrous; style with short glandular hairs; stigma white, keyed to sunflower broomrape (Orobanche cumana Wallr.) (Pujadas-Salvà and Velasco 2000). Total genomic DNA of this parasite flowers was extracted and the trnL-F gene and ribosomal DNA internal transcribed spacer (ITS) region were amplified using the primer pairs C/F and ITS1/ITS4, respectively (Taberlet et al. 1991; Anderson et al. 2004). Sequences of ITS (655 bp) and trnL-F (901 bp) were obtained (GenBank ON491818 and ON843707). BLAST analysis showed the ITS sequence was identical to that of sunflower broomrape (MK567978.1), also the trnL-F sequence matched that of sunflower broomrape (MW809408.1, identity 100%). Multi-locus phylogenetic analyses of the two sequences showed this parasite is clustered with sunflower broomrape. Together, morphological and molecular evidences confirmed the parasite on coleus plants was sunflower broomrape, a root holoparasitic plant with a narrow host range, which mainly posed a devastating threat to sunflower planting industry (Fernández-Martínez et al. 2015). To verify that coleus sunflower broomrape parasitic association, seedlings of this host were planted in 1.5-L pots containing compost-vermiculite-sand mixture (1:1:1 v:v:v) and sunflower broomrape seeds (50 mg seeds per 1 kg, soil). Three coleus seedlings, transplanted into pots without sunflower broomrape seeds, served as control. Ninety-six days later, the infected plants were smaller, their leaf color was observed to a lighter green than those of control plants and were similar to the broomrape-infected coleus plants observed in the greenhouse. The coleus roots with sunflower broomrape were carefully washed with running water, 10 to 15 emerged broomrape shoots and 14 to 22 underground attachments were observed on the coleus roots. The parasite grew well in coleus roots, from germination, attachment to host roots, and tubercles development. At the tubercle stage, the endophyte of sunflower broomrape had connected with the vascular bundle of the coleus root, confirming the sunflower broomrape-coleus connection. To the best of our knowledge, this was the first report of sunflower broomrape parasitizing coleus in Xinjiang, China. This indicates that sunflower broomrape can be propagated and survived by coleus, in fields or greenhouses with sunflower broomrape. To limit the spread of sunflower broomrape, preventive field management is needed for the coleus farmlands and greenhouse where the root holoparasite is prevalent.

Biofabrication of Mg-doped ZnO nanostructures for hemolysis and antibacterial properties.

The aim of this work was to synthesize 0.02 and 0.06 Mg-doped ZnO nanoparticles (NPs) using the aqueous extract of Plectranthus barbatus leaf. The structural integrity of the hexagonal phase was emphasized by X-ray diffraction analysis. The average crystallite size (D) of 0.02 and 0.06 Mg-doped ZnO NPs was found to be 23.83 and 26.95 nm, respectively. The scanning electron microscope images revealed a surface morphology of irregular nano-shapes of about 83 nm diameter with an elongated one-dimensional structure. The hemolysis activity demonstrated the safe nature of the synthesized materials at low doses. Antibacterial activity against S. aureus and E. coli, which assessed using the disc diffusion method, indicated that the prepared NPs could inhibit S. aureus but not E. coli. These findings suggest that the synthesized NPs could be explored for potential applications in biotechnology and medicine.

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.

First Report of Phelipanche aegyptiaca on Plectranthus scutellarioides in Xinjiang, China.

Coleus (Plectranthus scutellarioides [L.] R.Br.[syn.: Solenostemon scutellarioides]) is a perennial plant in the Lamiaceae family. It produces variegated leaves of various colors. It is commonly cultivated as an ornamental plant or grown in commercial greenhouses (Garibaldi et al. 2019). Phelipanche aegyptiaca Pers. is a dicotyledonous holoparasitic flowering plant that parasitizes more than 30 food crops (e.g., tomato, sunflower, and chickpea), ornamental crops, and others in different parts of the world, causing heavy economic losses (Nosratti et al. 2020). In 2016 and 2017, broomrape was observed parasitizing coleus in the greenhouse (86° 3' 36" E, 44° 18' 36" N, 500 m elevation) in Shihezi, Xinjiang, China (Supplementary Figure 1A-D). A single coleus plant could be parasitized by average 6-10 broomrape plants, and 20% of coleus plants were infested. The infection was confirmed by verifying the attachment of the broomrape to the coleus root. The inflorescences of the broomrape were normal and healthy and produced germinable seeds (germination rate: 80-90%). The morphological characteristics of the coleus are shown in Supplementary Figures 6 and 7. The main botanical features of the broomrape are as follows: (i) stem 20.65±7.07 cm tall, erect, branched, frail, rather hairy, bulbous at the base with secondary roots; (ii) inflorescence usually many-flowered, lax and cylindrical; (iii) bracts 6.87±0.93 mm long, ovate to lanceolate; (iv) calyx 1.09±0.09 cm long, shortly campanulate; (v) corolla 3.38±0.19 cm long, erect to suberect, white at the base, blue-purple in the upper part, sparsely glandular-villous; (vi) stamens 4, filaments inserted 5-6 mm from the base of the corolla, 1.26±0.11 cm long, anthers with villous; (vii) pistil 2.9±0.15 cm long, ovary glabrous, style with short glandular hairs, stigma bilobed, white (Supplementary Figure 2) (Teimoury et al. 2012; Piwowarczyk et al. 2019). For molecular identification, total genomic DNA was extracted from the flowers of the broomrape (found parasitizing coleus plants), and the ribosomal protein S2 (rps2) and ribosomal DNA internal transcribed spacer (ITS) region were amplified by PCR using the primer pairs rps2F/rps2R, ITS1/ITS4 (Table 1) (Park et al. 2007; Anderson et al. 2004). Two sequences with 580 bp (ITS) and 443 bp (rps2) were obtained (GenBank accession No. MW811482 and MW883573). BLAST analysis showed that the ITS sequence was most similar (identity 100%) to P. aegyptiaca (KC811171) and the rps2 sequence (identity 99%) also matched that of P. aegyptiaca (KC814957). Phylogenetic analysis of the ITS regions and rps2 genes showed that broomrape was fallen into P. aegyptiaca groups (Supplementary Figure 3). Morphological and molecular findings strongly support the conclusion that the broomrape on coleus was P. aegyptiaca. In order to verify that coleus was a host of P. aegyptiaca, coleus seedlings were collected and moved to 1.5-L pots containing a mixture of compost-vermiculite-sand (1:1:1 v:v:v) and seeds of P. aegyptiaca harvested from the host coleus (50 mg of P. aegyptiaca seeds per 1 kg of the substrate). Another three coleus seedlings were transplanted into pots of the same size containing the same mixture as above without P. aegyptiaca seeds. These served as controls. After 90 days of inoculation, the leaves of the infected hosts were lighter in color than those of uninfected hosts (Supplementary Figures 4A, 6). The roots of coleus and P. aegyptiaca were carefully washed with water, and an average of 3-4 emerged broomrape shoots and 50-60 underground attachments were observed on coleus roots (Supplementary Figure 4B). P. aegyptiaca can develop normally in the root of the coleus plant, from germination through attachment to host roots and development of tubercles (Supplementary Figure 5 A-E). Longitudinal and transverse sections of the parasite and host roots at the tubercle stage revealed that the endophytic tissues of P. aegyptiaca had reached and connected to the host vascular bundle (Supplementary Figure 5F-I), confirming the normal biological development and function of P. aegyptiaca haustoria. To the best of our knowledge, this is the first report of P. aegyptiaca parasitizing coleus in Xinjiang, China. Coleus is a very widely cultivated horticultural ornamental plant, and it grows in the same environments favored by P. aegyptiaca; so, the plant can aid the transmission of P. aegyptiaca to previously clear regions. It is necessary to improve the management of coleus in places where P. aegyptiaca is prevalent so as to reduce its spread. References: Garibaldi, A., et al. 2019. Plant Dis. 104:590. https://doi.org/10.1094/PDIS-07-19-1399-PDN Crossref, ISI, Google Scholar Nosratti, I., et al. 2020. Weed Sci. 68:555-564. https://doi.org/10.1017/wsc.2020.61 Crossref, ISI, Google Scholar Teimoury, M., et al. 2012. Plant Dis. 96:1232. https://doi.org/10.1094/PDIS-01-12-0068-PDN Crossref, ISI, Google Scholar Piwowarczyk, R., et al. 2019. Phytotaxa. 386:001-106. https://doi.org/10.11646/phytotaxa.386.1.1 Crossref, ISI, Google Scholar Park, J. M., et al. 2007. Mol. Phylogenet. Evol. 43: 974-985. https://doi.org/10.1016/j.ympev.2006.10.011 Crossref, ISI, Google Scholar Anderson, I. C., et al. 2004. Environ. Microbiol. 6: 769-779. https://doi.org/10.1111/j.1462-2920.2004.00675.x Crossref, ISI, Google Scholar.

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.

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.

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.

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.

DNA barcoding of some medicinally important plant species of Lamiaceae family in India.

Several species of the Lamiaceae family are the primary source of bioactive aromatic oils and secondary metabolites, having broader applications in the cosmetics, pharmaceuticals, food, confectionery and liquor industries. Due to the scarcity of raw materials and high costs of this family's economically vital species, its products often adulterated to cater to the market's high demand. The present study provides a DNA based approach for identifying different species of this family. Henceforth, the performance of three already proposed barcode loci (matK, trnH-psbA and trnL) was examined for their PCR amplification and species recognition efficacy on various Lamiaceae species and cultivars using three different approaches such as pairwise genetic distance method, BLASTn and phylogenetic tree based on maximum likelihood (ML) analysis. Results illustrate that among all the DNA barcoding loci, matK locus can accurately and efficiently distinguish all the studied species followed by trnH-psbA and trnL. Present investigation may help diminish the illegal trade and events of adulteration of medicinally important plants species in genus Mentha, Ocimum and Plectranthus. This investigation will also help fulfil the scarcity of sequences of barcode loci of these species in the NCBI database. Apart from providing a molecular level reference for identifying processed herbal products, this technique also offers a convenient method for species identification and germplasm conservation of the Lamiaceae family.

Screening the dermatological potential of plectranthus species components: antioxidant and inhibitory capacities over elastase, collagenase and tyrosinase.

A series of Plectranthus spp. plant extracts (aqueous, acetonic, methanolic and ethyl acetic) obtained from eight different species, and previously isolated compounds (ranging from polyphenols, diterpenes and triterpenes), were assayed for in vitro inhibition of the skin-related enzymes tyrosinase, collagenase and elastase, and for studying their antioxidant properties. The ethyl acetic extracts of P. grandidentatus and P. ecklonii registered the highest antioxidant activity, whereas acetonic, methanolic and ethyl acetic extracts of P. ecklonii, P. grandidentatus, P. madagascariensis and P. saccatus concerning the enzymatic inhibition assays revealed high anti-tyrosinase and anti-collagenase activities. From the isolated compounds tested, abietane diterpenes and triterpenes were highly active against tyrosinase and elastase activity. Overall, the experimental results showed the powerful antioxidant and inhibitory action on skin-related enzymes tyrosinase, collagenase and elastase of Plectranthus spp. extracts and/or isolated compounds, supporting their further research as bioactive metabolites against skin sagging and hyperpigmentation in cosmetic and pharmaceutical formulations.

HPLC/DAD, Antibacterial and Antioxidant Activities of Plectranthus Species (Lamiaceae) Combined with the Chemometric Calculations.

The increase in antibiotic resistance and the emergence of new bacterial infections have intensified the research for natural products from plants with associated therapy. This study aimed to verify the antibacterial and antioxidant activity of crude extracts of the genus Plectranthus species, being the first report on the modulation of aminoglycosides antibiotic activity by Plectranthus amboinicus extracts. The chemical composition was obtained by chemical prospecting and High-Performance Liquid Chromatography with diode arrangement detector (HPLC/DAD). The antibacterial activities of the extracts alone or in association with aminoglycosides were analyzed using the microdilution test. The antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. The phytochemical prospection allowed the flavonoids, saponins, tannins and triterpenoids to be identified. Quercetin, rutin, gallic acid, chlorogenic acid, caffeic acid, catechin, kaempferol, glycosylated kaempferol, quercitrin, and isoquercitrin were identified and quantified. The principal component analysis (PCA) observed the influence of flavonoids and phenolic acids from Plectranthus species on studied activities. Phytochemical tests with the extracts indicated, especially, the presence of flavonoids, confirmed by quantitative analysis by HPLC. The results revealed antibacterial activities, and synergistic effects combined with aminoglycosides, as well as antioxidant potential, especially for P. ornatus species, with IC50 of 32.21 µg/mL. Multivariate analyzes show that the inclusion of data from the antioxidant and antibacterial activity suggests that the antioxidant effect of these species presents a significant contribution to the synergistic effect of phytoconstituents, especially based on the flavonoid contents. The results of this study suggest the antibacterial activity of Plectranthus extracts, as well as their potential in modifying the resistance of the analyzed aminoglycosides.

Abietane Diterpenes of the Genus Plectranthus sensu lato.

Plectranthus (Lamiaceae), which-according to the latest systematic revision-includes three separate genera (Coleus, Plectranthus sensu stricto, and Equilabium), is a genus widely used in traditional medicine-mainly in the treatment of various ailments of the digestive tract, respiratory tract, and skin. Many species of Plectranthus s.l. have been shown to produce phenolic compounds and terpenes. Diterpenes, especially those of the abietane class, are the most studied group of secondary metabolites found in Plectranthus s.l., which is characterized by a significant structural diversity arising from the oxygenation and further rearrangement of the basic tricyclic abietane skeleton to a complete aromatization of the ring system. This review summarizes the known information on abietane diterpenes, showing their structures, sources, and biosynthesis. A classification of these compounds into nine groups, according to the arrangement of their ring C, is used. Royleanones, spirocoleons, and hydroquinones are the largest classes of abietane diterpenes, covering more than 70% of all the compounds reviewed.

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.

Physicochemical, antioxidant and FTIR-ATR spectroscopy evaluation of Kashmiri honeys as food quality traceability and Himalayan brand.

Three types of honeys viz. Robinia pseudoacacia (RSA), Plectranthus rugosus (PR) and multifloral honey (MF) from Kashmir Himalayas of India were characterized on the basis of physicochemical, antioxidant and FTIR-ATR spectroscopic features. The physicochemical parameters indicated that ash content, electrical conductivity, redness (a*) and yellowness (b*) were higher in MF honey, moisture content, Hydroxymethylfurfural (HMF) and lightness (L*) in PR honey and Water activity (aw) and proline content in RSA honey (P ≤ 0.05). Significantly higher values of total sugar, total reducing sugar and sucrose content was observed in MF honey (P ≤ 0.05). The total phenolic content (TPC), total flavonoids, ferric reducing antioxidant power and 1, 1-diphenyl-2-picrylhydrazy-IC50 (DPPH- IC50) free radical scavenging activity showed that MF honey had significantly higher antioxidant activity (P ≤ 0.05). ATR-FTIR analysis demonstrated that the absence of peaks at broad band around 1653.454-1637.656 cm-1 in MF honey, 1185.989-1153.072 cm-1 and 918.570-916.544 cm-1 wavenumbers in PR honey thus clearly discriminating different types of honeys. The results revealed that physico-chemical, antioxidant and spectroscopic characteristics of honey types vary with geographic origin and their floral sources and MF honey have a high therapeutic potential.

Activity to Breast Cancer Cell Lines of Different Malignancy and Predicted Interaction with Protein Kinase C Isoforms of Royleanones.

Plants have been used for centuries to treat several illnesses. The Plectranthus genus has a vast variety of species that has allowed the isolation of cytotoxic compounds with notable activities. The abietane diterpenes 6,7-dehydroroyleanone (DeRoy, 1), 7α-acetoxy-6ß-hydroxyroyleanone (Roy, 2), and Parvifloron D (ParvD, 3) were obtained from Plectranthus spp. and showed promising biological activities, such as cytotoxicity. The inhibitory effects of the different natural abietanes (1-3) were compared in MFC7, SkBr3, and SUM159 cell lines, as well as SUM159 grown in cancer stem cell-inducing conditions. Based on the royleanones' bioactivity, the derivatives RoyBz (4), RoyBzCl (5), RoyPr2 (6), and DihydroxyRoy (7), previously obtained from 2, were selected for further studies. Protein kinases C (PKCs) are involved in several carcinogenic processes. Thus, PKCs are potential targets for cancer therapy. To date, the portfolio of available PKC modulators remains very limited due to the difficulty of designing isozyme-selective PKC modulators. As such, molecular docking was used to evaluate royleanones 1-6 as predicted isozyme-selective PKC binders. Subtle changes in the binding site of each PKC isoform change the predicted interaction profiles of the ligands. Subtle changes in royleanone substitution patterns, such as a double substitution only with non-substituted phenyls, or hydroxybenzoate at position four that flips the binding mode of ParvD (3), can increase the predicted interactions in certain PKC subtypes.