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.

Comparison Study of Different Extracts of Plectranthus madagascariensis, P. neochilus and the Rare P. porcatus (Lamiaceae): Chemical Characterization, Antioxidant, Antimicrobial and Cytotoxic Activities.

Medicinal plants of the Plectranthus genus (Lamiaceae) are known for their ethnopharmacological relevance, mainly against infectious, dermatologic and gastrointestinal pathologies. Three Plectranthus species originated from South Africa, namely P. madagascariensis, P. neochilus and the rare P. porcatus were hereby screened for their antimicrobial and cytotoxic activities related with their known and/or potential ethnomedicinal uses. Twenty-six extracts were prepared by the combination of extraction methods (infusion, decoction, microwave-assisted, ultrasound-assisted, maceration and supercritical fluid extraction) with different polarity solvents (water, methanol, acetone and supercritical CO2). The comparison study of these extracts was elucidated through the corresponding chemical characterization and cytotoxic activity data. Therefore, the acetone extract from P. madagascariensis prepared by ultrasound extraction method revealed potent antibacterial activity against Gram-positive bacteria (1.95 < minimum inhibitory concentration (MIC) < 7.81 µg/mL), including a methicillin-resistant Staphylococcus aureus (MRSA) strain. Additionally, acetone extracts from both P. madagascariensis and P. neochilus exhibited relevant antibacterial activity against Gram-negative Klebsiella pneumonia (0.48 < MIC < 3.91 µg/mL), validating the traditional uses of such plants as anti-infectious agents. All methanolic extracts showed potent antioxidant effects at 100 µg/mL measured as their radical scavenging activity (60.8-89.0%) in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The P. madagascariensis extract obtained by maceration in acetone showed moderate cytotoxic effects in the MDA-MB-231 cell line (triple negative human breast carcinoma). The extract concentration that caused a 50% inhibition in cell viability (IC50) was 64.52 µg/mL. All extracts in this comparative study were profiled by high-performance liquid chromatography-HPLC with a diode-array detector-DAD (HPLC-DAD) and the main known bioactive components were identified in each extract, which included polyphenols (caffeic 1, chlorogenic 2 and rosmarinic 3 acids), abietane diterpenes (7α-acetoxy-6ß-hydroxyroyleanone 4 and coleon U 5) and flavone glycosides (rutin 6 and naringin 7).

Antitubercular and anti-inflammatory properties screening of natural products from Plectranthus species.

AIM: Confirm the use of Plectanthus spp. plants in traditional medicine, particularly as anti-inflammatory and anti-infective agents. MATERIALS & METHODS: Compounds previously isolated from Plectranthus spp. were studied for their anti-inflammatory activity using the SNAP assay and RAW 264.7 cells, by the quantification of nitric oxide. An halimane diterpene and its derivatives were tested in infected macrophages with M. tuberculosis H37Rv, using CFU counts assay, at their minimum inhibitory concentration values. Results: The isolated compounds tested at noncytotoxic concentrations, did not reveal nitric oxide scavenging in the S-nitroso-N-acetylpenicillamine and the cellular assays. On the other hand, promising results were obtained regarding one semisynthetic halimane derivative (11R*,13E)-halima-5,13-diene-11,15-diol), previously prepared (2.1 × 105 CFU/mL), with an effect similar to the antitubercular drugs ethambutol (2.0 × 105 CFU/mL) and isoniazid (1.2 × 105 CFU/mL). CONCLUSION: The present report demonstrates the relevance of Plectranthus spp. in medicinal chemistry drug development for TB and other infective respiratory complaints. Also, this work suggests that further studies involving other inflammatory mediators are needed to validate the anti-inflammatory use of these medicinal plants.

Rosmarinus officinalis L.: an update review of its phytochemistry and biological activity.

The worldwide interest in the use of medicinal plants has been growing, and its beneficial effects being rediscovered for the development of new drugs. Based on their vast ethnopharmacological applications, which inspired current research in drug discovery, natural products can provide new and important leads against various pharmacological targets. This work pioneers an extensive and an updated literature review on the current state of research on Rosmarinus officinalis L., elucidating which compounds and biological activities are the most relevant. Therefore, a search was made in the databases PubMed, ScienceDirect and Web of Science with the terms 'rosemary', 'Rosmarinus officinalis', 'rosmarinic acid' 'carnosol' and 'carnosic acid', which included 286 articles published since 1990 about rosemary's pharmacological activities and their isolated compounds. According to these references, there has been an increasing interest in the therapeutic properties of this plant, regarding carnosic acid, carnosol, rosmarinic acid and the essential oil. The present manuscript provides an updated review upon the most reported activities on R. officinalis and its active constituents.

Anticancer Hybrid Combinations: Mechanisms of Action, Implications and Future Perspectives.

The exponential growth of cancer cases worldwide together with recent advances concerning the pathophysiological mechanisms of the disease at the molecular level led to a paradigm shift in chemotherapy, from monotherapy to targeted drug combination regimens. However, adverse effects and the emergence of multidrug resistance (MDR) limit the effectiveness of these therapies. In this context, hybrid combinations mixing anticancer drugs and bioactive phytochemical components from medicinal plants, or even plant extracts, that can act synergistically on multiple targets and signaling pathways represent a promising approach with the potential to expand the current therapeutic arsenal. This review aims to provide a synopsis on anticancer hybrid combinations based on their multi-target mechanisms and synergistic effects from an extensive literature search focusing mainly on publications from the last ten years. In most of these combinations, the phytochemical component was shown to enhance the anticancer activity of the chemotherapeutic agent and to sensitize chemoresistant tumors in several types of cancer. Hybrid combinations, due to synergistic interactions, are also associated with less severe adverse events since lower doses can be used to achieve the same therapeutic effect. Further preclinical and clinical studies are needed, as well as the development of an adequate regulatory framework, before hybrid combination therapy can be translated into clinical practice.

Development of novel sophorolipids with improved cytotoxic activity toward MDA-MB-231 breast cancer cells.

Sophorolipids (SLs) are glycolipid biosurfactants, produced as a mixture of several compounds by some nonpathogenic yeast. In the current study, separation of individual SLs from mixtures with further evaluation of their surface properties and biologic activity on MDA-MB-321 breast cancer cell line were investigated. SLs were biosynthesized by Starmerella bombicola in a culture media supplemented with borage oil. A reverse-phase flash chromatography method with an automated system coupled with a prepacked cartridge was used to separate and purify the main SLs. Compositional analysis of SLs was performed by high-performance liquid chromatography with electrospray ionization mass spectrometry and tandem mass spectrometry. The following diacetylated lactonic SLs were isolated and purified: C18:0, C18:1, C18:2, and C18:3. The critical micelle concentration (CMC) and surface tension at CMC (γCMC ) of the purified SLs showed an increase with the number of double bonds. High cytotoxic effect against MDA-MB-231 cells was observed with C18:0 and C18:1 lactonic SLs. The cytotoxic effects of C18:3 lactonic SL on cancerous cells were for the first time studied. This cytotoxic effect was considerably higher than the promoted by acidic SLs; however, it induced a lower effect than the previously mentioned SLs, C18:0 and C18:1. To our knowledge, for the first time, C18:1 lactonic SL, in selected concentrations, proved to be able to inhibit MDA-MB-231 cell migration without compromising cell viability and to increase intracellular reactive oxygen species.