The Botanical, Chemical and Ethnobotanical Diversity of Southern African Lamiaceae

Phlomis crinita Cav. From Algeria: A source of bioactive compounds possessing antioxidant and wound healing activities

ETHNOPHARMACOLOGICAL RELEVANCE

Phlomis crinita Cav. (Lamiaceae), locally known as "El Khayata" or "Kayat El Adjarah", is traditionally used in Algeria for its wound-healing properties.

AIM OF THE STUDY

Investigate, for the first time, the phytochemical profile, safety, antioxidant and wound-healing activities of the flowering tops methanolic extract of P. crinita (PCME) collected from Bouira Province in the North of Algeria.

MATERIALS AND METHODS

Preliminary phytochemical assays were carried out on PCME to quantify the main classes of bioactive compounds, such as total phenols, flavonoids, and tannins. An in-depth LC-DAD-ESI-MS analysis was carried out to elucidate the phytochemical profile of this plant species. Antioxidant activity was investigated by several colorimetric and fluorimetric assays (DPPH, TEAC, FRAP, ORAC, β-carotene bleaching and ferrozine assay). The acute oral toxicity of PCME (2000 mg/kg b.w.) was tested in vivo on Swiss albino mice, whereas the acute dermal toxicity and wound-healing properties of the PCME ointment (1-5% PCMO) were tested in vivo on Wistar albino rats. Biochemical and histological analyses were carried out on biological samples.

RESULTS

The phytochemical screening highlighted a high content of phenolic compounds (175.49 ± 0.8 mg of gallic acid equivalents/g of dry extract), mainly flavonoids (82.28 ± 0.44 mg of quercetin equivalents/g of dry extract). Fifty-seven compounds were identified by LC-DAD-ESI-MS analysis, belonging mainly to the class of flavones (32.27%), with luteolin 7-(6″-acetylglucoside) as the most abundant compound and phenolic acids (32.54%), with salvianolic acid C as the most abundant compound. A conspicuous presence of phenylethanoids (15.26%) was also found, of which the major constituent is forsythoside B. PCME showed a strong antioxidant activity with half-inhibitory activity (IC50) ranging from 1.88 to 37.88 μg/mL and a moderate iron chelating activity (IC50 327.44 μg/mL). PCME appears to be safe with Lethal Dose 50 (LD50) ≥ 2000 mg/kg b.w. No mortality or toxicity signs, including any statistically significant changes in body weight gain and relative organs' weight with respect to the control group, were recorded. A significant (p < 0.001) wound contraction was observed in the 5% PCMO-treated group with respect to the untreated and petroleum jelly groups between 8 and 20 days, whereas no statistically significant results were observed at the two lower doses (1 and 2% PCMO). In addition, the 5% PCMO-treated group showed a statistically significant (p < 0.05) wound healing activity with respect to the reference drug-treated group, showing, at the end of the study, the highest wound contraction percentage (88.00 ± 0.16%).

CONCLUSION

PCME was safe and showed strong antioxidant and wound-healing properties, suggesting new interesting pharmaceutical applications for P. crinita based on its traditional use.

Biological Activity of 6,7-Dehydroxyroyleanone and Derivatives Obtained from Plectranthus aliciae (Codd) A.J.Paton

The Plectranthus genus (Lamiaceae) is known to be rich in abietane diterpenes. The bioactive 6,7-dehydroxyroyleanone (DHR, 1) was previously isolated from Plectranthus madagascariensis var. madagascariensis and var. aliciae. This study aimed to explore the occurrence of DHR, 1, in P. aliciae and the potential bioactivities of new semisynthetic derivatives from DHR, 1. Several extraction methods were evaluated, and the hydrodistillation, using a Clevenger apparatus, afforded the highest yield (77.8 mg/g of 1 in the essential oil). Three new acyl derivatives (2-4) were successfully prepared from 1 (yields of 86-95%). Compounds 1-4 showed antioxidant activity, antibacterial effects, potent cytotoxic activity against several cell lines, and enhanced anti-inflammatory activity that surpassed dexamethasone (positive control). These findings encourage further exploration of derivatives 2-4 for potential mechanisms of antitumoral, antioxidant, and anti-inflammatory capabilities, studying both safety and efficacy.

Emulsification of Rosemary and Oregano Aqueous Extracts and Their In Vitro Bioavailability

Due to their richness in phenolic compounds, Mediterranean plants such as rosemary and oregano are increasingly recommended for consumption for their numerous health benefits. The pH shift and the presence of digestive enzymes significantly reduce the bioavailability of these biochemicals as they pass through the gastrointestinal tract. To prevent this degradation of phenolic compounds, methods such as emulsification of plant aqueous extracts are used. The aim of this study was to investigate the effects of emulsification conditions on the chemical properties (total polyphenolic content and antioxidant activity) of emulsified rosemary and oregano extracts. Response surface methodology was applied to optimize sunflower oil concentration, rotational speed, and emulsifier concentration (commercial pea protein). The emulsions prepared under optimal conditions were then used in bioavailability studies (in vitro digestion). The antioxidant activity of the emulsified rosemary/oregano extracts, measured by the DPPH method, remained largely stable when simulating in vitro digestion. Analysis of antioxidant activity after in vitro simulation of the gastrointestinal system revealed a higher degree of maintenance (up to 76%) for emulsified plant extracts compared to aqueous plant extracts. This article contributes to our understanding of how plant extracts are prepared to preserve their biological activity and their application in the food industry.

Moroccan medicinal plants traditionally used for the treatment of skin diseases: From ethnobotany to clinical trials

ETHNOPHARMACOLOGICAL RELEVANCE

Skin diseases are among the most common human health affections. A healthy skin promotes a healthy body that can be achieved through modern, allopathic and natural medicines. Therefore, medicinal plants can be a reliable therapy in treating skin diseases in humans through a diverse range of bioactive molecules they contain.

AIM OF THE STUDY

This review aims to provide for the first-time scientific evidence related to the dermatological properties of Morocco's medicinal plants and it aims to provide a baseline for the discovery of new drugs having activities against skin issues.

METHODS

This review involved an investigation with different search engines for Moroccan ethnobotanical surveys published between 1991 and 2021. The plants used to treat skin diseases have been determined. Information regarding pharmacological effects, phytochemical, and clinical trials related to the plants listed in this review was collected from different scientific databases like PubMed, Science Direct, Google Scholar, Web of Science and Scopus. The data were analyzed and summarized in the review.

RESULTS

A total of 401 plants belonging to 86 families mainly represented by Asteraceae, Lamiaceae, Fabaceae, and Apiaceae which have been documented to be in common use by Moroccans for managing skin diseases. Among those plants recorded, the most commonly used are Allium cepa L, Chamaeleon gummifer (L.) Cass and Salvia rosmarinus Schleid. Mill. Leaves were the most commonly used plant part, while powder and decoction were the most common method of traditional drug preparation. 107 of the 401 plants (27%) have undergone pharmacological validation. A total of 44 compounds isolated from 27 plants were investigated to treat different types of skin diseases, and 25 plants have been clinically studied for their activities against skin diseases.

CONCLUSION

The beneficial effects of using Moroccan medicinal plants to treat skin diseases, according to traditional practices, have been proven in numerous scientific studies. Therefore, other studies should focus on isolating and identifying specific bioactive compounds from plant extracts, revealing more valuable therapeutic properties. Furthermore, additional reliable clinical trials are needed to confirm their beneficial effect on patients with skin diseases.

Comparative Genomics and Phylogenetic Analysis of the Chloroplast Genomes in Three Medicinal Salvia Species for Bioexploration

To systematically determine their phylogenetic relationships and develop molecular markers for species discrimination of Salvia bowleyana, S. splendens, and S. officinalis, we sequenced their chloroplast genomes using the Illumina Hiseq 2500 platform. The chloroplast genomes length of S. bowleyana, S. splendens, and S. officinalis were 151,387 bp, 150,604 bp, and 151,163 bp, respectively. The six genes ndhB, rpl2, rpl23, rps7, rps12, and ycf2 were present in the IR regions. The chloroplast genomes of S. bowleyana, S. splendens, and S. officinalis contain 29 tandem repeats; 35, 29, 24 simple-sequence repeats, and 47, 49, 40 interspersed repeats, respectively. The three specific intergenic sequences (IGS) of rps16-trnQ-UUG, trnL-UAA-trnF-GAA, and trnM-CAU-atpE were found to discriminate the 23 Salvia species. A total of 91 intergenic spacer sequences were identified through genetic distance analysis. The two specific IGS regions (trnG-GCC-trnM-CAU and ycf3-trnS-GGA) have the highest K2p value identified in the three studied Salvia species. Furthermore, the phylogenetic tree showed that the 23 Salvia species formed a monophyletic group. Two pairs of genus-specific DNA barcode primers were found. The results will provide a solid foundation to understand the phylogenetic classification of the three Salvia species. Moreover, the specific intergenic regions can provide the probability to discriminate the Salvia species between the phenotype and the distinction of gene fragments.

Essential Oil Composition and Traditional Uses of Salvia dentata, a Poorly Known Medicinal Plant from Namaqualand, South Africa

South Africa has a rich history of medicinal plant species and their documented uses as traditional medicines, and is also home to three well-known, blue-flowered sage species of ethnobotanical importance. The Namaqualand bloublomsalie (Salvia dentata) has so far remained unstudied and apparently overlooked. Our study is the first to report on the essential oil chemistry of this medicinally relevant species and provide a comparison with the other two (well-studied) closely related Cape bloublomsalies (Salvia africana and S. chamelaeagnea). The data, generated from three geographically isolated populations comprised of 13 individual plants of S. dentata, revealed diagnostically high levels of camphor (14.37%), α-pinene (11.43%), camphene (10.18%), 1,8-cineole (eucalyptol) (9.42%) and bornyl acetate (8.56%) which provide a distinct chemical profile from the other two species.

Valorization of a Waste Product of Edible Flowers: Volatile Characterization of Leaves

(1) Background: The leaves of some plants are reported for their culinary uses, while in edible flowers, they are one of the discarded products in the supply chain. We investigated the volatile profile (VP) and the essential oil (EO) compositions of leaves from 12 Lamiaceae species, of which nine belong to the Mentheae tribe and three to the Ocimeae tribe. (2) Methods: Phytochemical analyses were performed using a GC-MS instrument. (3) Results: More than 53% of the Ocimeae tribe VP was represented by sesquiterpene hydrocarbons (SH), followed by phenylpropanoids, except for O. × citriodorum, where oxygenated monoterpenes (OM) were the second main class. OM prevailed in six species of the Mentheae tribe except for Agastache ‘Arcado Pink’, Salvia discolor, and S. microphylla, where SH dominated. The EO composition of Ocimeae tribe showed a similar behavior to that of VP concerning the predominant classes. O. basilicum ‘Blue Spice’ (Ob-BS) was an exception, since it showed oxygenated sesquiterpenes (OS: 29.6%) as a second principal class. Sesquiterpene compounds were also present in a high amount in two species of the Salviinae subtribe (S. microphylla and S. discolor) and two of the Nepetinae subtribe (Nepeta × faasenii and A. ‘Arcado Pink’). The remaining species of the Mentheae tribe were characterized by OM. (4) Conclusions: Many of the main compounds found were reported for their importance in human health and thus are important as ingredients in several new industrial products.

Challenges in Medicinal and Aromatic Plants DNA Barcoding-Lessons from the Lamiaceae

The potential value of DNA barcoding for the identification of medicinal plants and authentication of traded plant materials has been widely recognized; however, a number of challenges remain before DNA methods are fully accepted as an essential quality control method by industry and regulatory authorities. The successes and limitations of conventional DNA barcoding are considered in relation to important members of the Lamiaceae. The mint family (Lamiaceae) contains over one thousand species recorded as having a medicinal use, with many more exploited in food and cosmetics for their aromatic properties. The family is characterized by a diversity of secondary products, most notably the essential oils (EOs) produced in external glandular structures on the aerial parts of the plant that typify well-known plants of the basil (Ocimum), lavender (Lavandula), mint (Mentha), thyme (Thymus), sage (Salvia) and related genera. This complex, species-rich family includes widely cultivated commercial hybrids and endangered wild-harvested traditional medicines, and examples of potential toxic adulterants within the family are explored in detail. The opportunities provided by next generation sequencing technologies to whole plastome barcoding and nuclear genome sequencing are also discussed with relevant examples.

A Themed Issue in Honor of Professor K. Hüsnü Can Baser-Outstanding Contributions in the Fields of Pharmacognosy, Phytochemistry, Botany and Ethnopharmacology

Dear Colleagues, [...].