Development and characterization of monoterpene loaded microemulsions as novel scolicidal agents

Cystic echinococcosis (CE) is one of the most important zoonotic diseases. The primary treatment is surgery and chemical sterilization of the parasitic layers by injection of a scolicidal agent. Available scolicidals possess side effects, and may cause postoperative complications. Several studies reported the scolicidal properties of monoterpene phenols and alcohols such as carvacrol, thymol, and geraniol. The present study aimed to develop, characterize, and assess monoterpene loaded microemulsions as novel green scolicidals products. For this purpose, microemulsions composing 0.37%, 0.75%, and 1.5% of monoterpenoid(s), thymol, carvacrol, and geraniol, alone or in binary or ternary mixtures were formulated. Samples were analyzed by visual inspection, polarizing optical microscope, and dynamic light scattering (DLS). The stability of the samples was evaluated up to a 3-month storage. For the scolicidal bioassay, samples at different concentrations of 200, 100, 50, 25, and 10 μg/ml were added to wells containing 10⁴ viable protoscoleces and mortality rates were recorded at 2, 5, 10, and 20 min after exposure. Results of the present study showed that microemulsions formulated with 0.75% of pure carvacrol or the binary mixture of thymol and carvacrol at 0.375% are promising scolicidal agents.

Developing a Highly Stable Carlina acaulis Essential Oil Nanoemulsion for Managing Lobesia botrana

The growing interest in the development of green pest management strategies is leading to the exploitation of essential oils (EOs) as promising botanical pesticides. In this respect, nanotechnology could efficiently support the use of EOs through their encapsulation into stable nanoformulations, such as nanoemulsions (NEs), to improve their stability and efficacy. This technology assures the improvement of the chemical stability, hydrophilicity, and environmental persistence of EOs, giving an added value for the fabrication of natural insecticides effective against a wide spectrum of insect vectors and pests of public and agronomical importance. Carlina acaulis (Asteraceae) root EO has been recently proposed as a promising ingredient of a new generation of botanical insecticides. In the present study, a highly stable C. acaulis-based NE was developed. Interestingly, such a nanosystem was able to encapsulate 6% (w/w) of C. acaulis EO, showing a mean diameter of around 140 nm and a SOR (surfactant-to-oil ratio) of 0.6. Its stability was evaluated in a storage period of six months and corroborated by an accelerated stability study. Therefore, the C. acaulis EO and C. acaulis-based NE were evaluated for their toxicity against 1st instar larvae of the European grapevine moth (EGVM), Lobesia botrana (Denis & Schiffermüller, 1775) (Lepidoptera: Tortricidae), a major vineyard pest. The chemical composition of C. acaulis EO was investigated by gas chromatography-mass spectrometry (GC-MS) revealing carlina oxide, a polyacetylene, as the main constituent. In toxicity assays, both the C. acaulis EO and the C. acaulis-based NE were highly toxic to L. botrana larvae, with LC₅₀ values of 7.299 and 9.044 µL/mL for C. acaulis EO and NE, respectively. The C. acaulis-based NE represents a promising option to develop highly stable botanical insecticides for pest management. To date, this study represents the first evidence about the insecticidal toxicity of EOs and EO-based NEs against this major grapevine pest.

Mosquitocidal and Anti-Inflammatory Properties of The Essential Oils Obtained from Monoecious, Male, and Female Inflorescences of Hemp (Cannabis sativa L.) and Their Encapsulation in Nanoemulsions

Among the various innovative products obtainable from hemp (Cannabis sativa L.) waste biomass originating from different industrial processes, the essential oil (EO) deserves special attention in order to understand its possible application in different fields, such as cosmetics, pharmaceuticals, and botanical insecticides. For the purpose, in the present work, we studied the chemical composition of EOs obtained from different hemp varieties, namely Felina 32 and Carmagnola Selezionata (CS) using monoecious, male, and female inflorescences, and we evaluated their mosquitocidal activities on larvae and pupae of two main malaria vectors, Anopheles gambiae and An. stephensi. Then, in order to evaluate the safe use of hemp EOs for operators, the potential pro- or anti-inflammatory effect of hemp EOs together with their toxicological profile were determined on dermal fibroblasts and keratinocytes. Given the promising results obtained by insecticidal and anti-inflammatory studies, a preliminary evaluation of EOs encapsulation into nanoemulsions (NEs) has been performed with the aim to develop a formulation able to improve their poor physicochemical stability. Felina 32 and CS inflorescences provided EOs with an interesting chemical profile, with monoterpene and sesquiterpene hydrocarbons as the major components. This study highlighted the potential application of male inflorescences, which are usually discharged during hemp product processing. These EOs could be exploited as potential sustainable and eco-friendly insecticides, given their capability to be toxic against mosquitoes and the possibility to use them to prepare stable and safe formulations. The LC₅₀ values found in this study (<80 ppm) are lower, on average, than those of many plant EOs, with the advantage of using an industrial waste product. From MTT assay and gene and protein expression analysis, EOs showed no cytotoxicity at the appropriate doses and exerted an anti-inflammatory effect on the human cell lines tested. These findings encourage further applied research on hemp EOs in order support their industrial exploitation.

An Overview of Micro- and Nanoemulsions as Vehicles for Essential Oils: Formulation, Preparation and Stability

The interest around essential oils is constantly increasing thanks to their biological properties exploitable in several fields, from pharmaceuticals to food and agriculture. However, their widespread use and marketing are still restricted due to their poor physico-chemical properties; i.e., high volatility, thermal decomposition, low water solubility, and stability issues. At the moment, the most suitable approach to overcome such limitations is based on the development of proper formulation strategies. One of the approaches suggested to achieve this goal is the so-called encapsulation process through the preparation of aqueous nano-dispersions. Among them, micro- and nanoemulsions are the most studied thanks to the ease of formulation, handling and to their manufacturing costs. In this direction, this review intends to offer an overview of the formulation, preparation and stability parameters of micro- and nanoemulsions. Specifically, recent literature has been examined in order to define the most common practices adopted (materials and fabrication methods), highlighting their suitability and effectiveness. Finally, relevant points related to formulations, such as optimization, characterization, stability and safety, not deeply studied or clarified yet, were discussed.

Linear Viscoelastic Properties of Selected Polysaccharide Gums as Function of Concentration, pH, and Temperature

Hydrocolloids have been intensively investigated due to their ability to modify the rheology of the system where they are employed. They find application as thickening and gelling agents in many food, cosmetic, and pharmaceutical preparations, due to their biocompatibility and biodegradability. The present study aims to provide an exhaustive and comprehensive viscoelastic characterization of a series of hydrocolloid formulations, as function of concentration, pH, and temperature. Glucomannan, xanthan gum, tara gum, guar gum, konjac gum, and gellan gum have been analyzed at two concentrations (0.5% w/w and 1.5% w/w), using three different pH conditions (pH 1.2, 5.5, and 6.8). Their viscoelastic properties have been monitored measuring the main rheological parameters, namely, storage modulus G' and loss modulus G'' as function of frequency, time, and temperature. The results obtained show a clear dependence of the linear viscoelastic properties of the systems on concentration and pH, while the temperature was not a critical factor. Glucomannan, xanthan gum, tara gum, and guar gum samples prepared in phosphate buffer (pH 6.8) at the final concentration of 1.5% (w/w) have been selected as the most promising systems for further investigations, exploring the possibility of combinations to improve the rheological properties. PRACTICAL APPLICATION: Glucomannan, xanthan gum, tara gum, guar gum, konjac gum, and gellan gum have been chosen among the most common thickening agents derived from plants to perform a systematic investigation of the influence of pH, concentration, and temperature on the rheological properties of their water dispersions. The data obtained may be useful for further application of these hydrogels in the nutraceutical field as thickeners, texture modifiers, emulsifiers, stabilizers, and gelling agents.

Patient perspectives of early detection of melanoma: the experience at the Brescia Melanoma Centre, Italy

AIM

Skin self-examination is usually recommended for early melanoma diagnosis. Given the current lack of a standardized Skin Self-Examination method, we raised the issue about the suitable approach to explain to patients what can be considered a suspicious lesion. Hereinafter, we report the results of a pilot-study carried out at the Melanoma Centre, University Hospital Spedali Civili Brescia, Italy.

METHODS

A consecutive sample of 200 melanoma patients entered into the Melanoma Prevention Project. A detailed survey revealed who had the first suspicion of the melanoma lesion. When melanoma was Self- or Relative-detected, we investigated the signs/symptoms that had alerted patients with reference to the ABCDE rule. The study included also socio-demographic variables, family history of melanoma, skin type, number and type of nevi, and melanoma features.

RESULTS

Eighty-seven melanoma had been Self-Detected and 44 Relative-Detected. Patients report most commonly signs/symptoms such as dark colour (58%) and changing in size (47%). Seventy-nine percent of these patients have less than ten nevi and 92% have small and regular moles.

CONCLUSION

Sometimes the signs of melanoma seem to be easy to identify. Our patients say that they recognized melanoma on the base of the Colour and the Change in size. Therefore, we propose the short "CC" acronym that could facilitate the melanoma self-diagnosis. The aim is to give a short and effective message that leads patients to have the doubt of a suspicious lesion of melanoma so that they seek medical attention.

The controversial management of giant congenital melanocytic nevi. When would it be better "to wait and see"?

AIM

A giant congenital nevus is a melanocytic nevus present at birth with wide extent on the skin surface. The management of this nevus remains controversial and needs to be personalized for each patient.

METHODS

A retrospective multicenter study was carried out in the Dermatological Departments of Brescia, Padua, and Pavia, Italy. The inclusion criterion was the diagnosis of a giant congenital melanocytic nevus on the basis of clinical observation.

RESULTS

Nine patients with giant congenital nevus are reported. None developed melanoma, whereas giant congenital nevi have been slowly fading in pigmentation.

CONCLUSION

Having regard to the doubts on treatment that persist in the literature, we should consider that decisional management of giant congenital melanocytic nevi can be really complex, because of the size and depth of lesions. Indeed, the ablative surgery or other treatments might cause significant troubles and complete excision of deeper layers of the lesion is almost impossible to achieve. Moreover, the treatment does not reduce the risk of melanoma and might lead to a greater difficulty in clinical and dermoscopic observation due to the scarring occurrence after therapy. In our retrospective study, the pigmentation of giant congenital melanocytic nevi slowly faded on its own and until now none developed melanoma. Therefore, we suggest a close regular follow-up which should be focused on the exclusion of possible complications. Perhaps, it would be better "to wait and see" since other procedures do not decrease the risk of melanoma, but rather might lead the patient to underestimate it.

Association between multiple cutaneous melanoma and other primary neoplasms

BACKGROUND

The risk of a subsequent cancer is an important issue for patients with melanoma. The development of a second primary cancer in patients with a solitary melanoma has been discussed in several studies. However, to our knowledge, the incidence of second primary cancer (SPC) in patients with multiple primary melanoma (MPM) has not been thoroughly investigated.

AIM

To quantify the incidence of SPC in patients with MPM, with the aim of possibly developing further preventive measures.

METHODS

In a retrospective study, 76 patients with MPM were identified from 2155 patients being followed up at our unit.

RESULTS

Of the 76 patients, 12 (16%) developed another neoplasm, with 59% of them having nonmelanoma skin cancer (NMSC), and 41% other noncutaneous cancers. By contrast, only 8% of those with single primary melanoma had other neoplasms (21% of whom had NMSC).

CONCLUSIONS

Patients with MPM, especially men with skin phototype II, have a significantly increased incidence of developing SPC, particularly NMSC. Thus, careful monitoring is essential not only to detect recurrence of the original cancer or development of another primary melanoma, but also development of new malignancies of different types, particularly NMSC.