In vitro micropropagation and conservation of endangered medicinal plant Nepeta asterotricha Rech.f. (Lamiaceae): genetic fidelity, phytochemical and biological assessment

An efficient in vitro protocol was introduced for the conservation of Nepeta asterotricha, a vulnerable and endangered medicinal species found in the central of Iran for the first time. Growth, phytochemical, and biological traits of in vitro regenerated plant (RP) and acclimated plant (AP) were compared to the mother plant (MP). In addition, the genetic stability of AP was assessed by using inter-simple sequence repeats (ISSR) markers. The highest number of lateral branches (4.25) was obtained from the medium with 3 mg/mL kinetin (KIN), while the highest length of lateral branches (13.25 cm) was achieved on the medium culture fortified with 3 mg/mL thidiazuron (TDZ) and 6-benzylaminopurine (BAP). The highest number of leaves (20.25) and main branch length (12.25 cm) were obtained from the medium containing 3 mg/mL TDZ. The highest number of roots (46.25) and root length (2.25 cm) was measured from the medium fortified with 1 mg/mL indole-3-butyric acid (IBA) and 0.6 mg/mL indole-3-acetic acid (IAA), respectively. RP was successfully acclimated (85%) in vivo. Molecular analysis showed that the AP was true to the type of the MP. cis-Sabinene hydrate (26.8-57.7), 1,8-cineole (6.2-24.1), 4aα,7β,7aα-nepetalactone (4.1-12.3), and terpinene-4-ol (3.2-15.0) were the major essential oils compounds. The studied samples contained rosmarinic acid (2.55-5.97 mg/g DW), cichoric acid (1.68-12.7 mg/g DW), chlorogenic acid (1.91-64.21 mg/g DW), rutin (0.59-1.09 mg/g DW), apigenin (0.52-0.72 mg/g DW), betulinic acid (0.17-2.20 mg g DW), oleanolic acid (0.84-5.37 mg/g DW) and ursolic acid (3.46-15.70 mg/g DW). Acclimated plant exhibited the highest antioxidant activity (IC50 = 196.4 μg/mL), while the methanolic extract of MP displayed the highest antibacterial activity (MIC = 8 mg/mL) against Staphylococcus aureus.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12298-024-01416-x.

Chemical composition, anthelmintic activity, and mechanism of action of Lippia dominguensis Mold. essential oil on Haemonchus contortus

Gastrointestinal nematode parasitism is a major burden to small ruminant production globally, compounded by increasing anthelmintic resistance. Previous studies have identified essential oils (EOs) from the Lippia genus with antiprotozoal and anthelmintic effects. Lippia dominguensis Moldenke (Ld), an endemic species from the Dominican Republic, has similar popular uses, however, is chemically and pharmacologically yet uncharacterized. Here, we investigated the in vitro anthelmintic activity of LdEO and its ultrastructural effects on eggs and adult nematodes of Haemonchus contortus multidrug-resistant isolated. The GC-MS analysis showed linalool (33.85%), 1,8-cineole (30.88%), and δ-terpineol (10.61%) as the main EO constituents. The LdEO showed an IC50= 0.523 mg/mL in the egg hatch test, and the motility in the adult worm motility test was 95.8% at 1 mg/mL. The confocal scanning laser microscopy of eggs indicated permeabilization or disruption of egg cell membranes as the possible mechanism of action of LdEO. The scanning electron microscopy of adult worms showed wrinkling, undulations, and cuticular disruptions. The LdEO displayed significant in vitro anthelmintic activity on eggs and adult worms of H. contortus. Additionally, the LdEO showed low oral toxicity in mice at 2,000 mg/kg. Thus, additional in vivo studies are justified to determine its anthelmintic efficacy in small ruminants.

Ethnopharmacological survey of endemic plants used in ethnomedicinal knowledge of Soqotra Island

ETHNOPHARMACOLOGICAL RELEVANCE

Due to the long biogeographical isolation since ancient times, Soqotra Island (southern Yemen) is rich in medicinal endemic plants. However, information on their traditional therapeutic knowledge is scarce in scientific literature and still not completely documented.

AIM OF THE STUDY

(1) Documentation and search the native traditional therapeutic knowledge focusing on the medicinal plants which are endemic to Soqotra (2) Identification of the important endemic plants treating diseases by quantitative analysis of the collected data.

MATERIALS AND METHODS

Ethnobotanical data were collected from 105 local informants through open interviews, semi-structured questionnaires and field survey in February 1990 to document the traditional medicinal plants in Soqotra Island. Of them we reported in this study the data of the endemic species, due to their wide biodiversity in the island. The quantitative data were analyzed for use reports (URs) and the informant consensus factor (ICF). The reported diseases were classified according to the International Classification of Primary Care-2 (ICPC-2). New reported medicinal plants in this study were identified compared to literature review. The level of traditional Soqotri knowledge among Islanders was observed during 1990-2003.

RESULTS

In the study, 86 medicinal endemic plants with 7654 therapeutic URs were explored for 69 ailments types belongs to 11 (ICPC-2) groups. The highest ICF value (0.99) were calculated for both eye and ear diseases categories, followed by general and unspecified ailments (0.98), digestive and skin (0.97 for each), and musculoskeletal ailments (0.96) among all diseases categories. While the highest URs (2276) were identified for skin diseases, followed by digestive diseases (URs = 2146). All the 86 recorded medicinal plant species were endemic to Soqotra, belonging to 57 genera and 29 families. Euphorbiaceae and Burseraceae were the dominant families, followed by Apocynaceae, Fabaceae and Asteraceae. Shrubs were the dominant growth form (41 species, 47.67%), followed by herbs (27; 31.4%), and trees (14; 16.28%). Leaves (45 species; 31.25%) were the most frequently used parts, followed by stems (34 species; 23.61%) and barks (species 23; 15.97%). The most cited preparation method was paste for 51 species followed by liquid exudates (48 species) and powder (26 species). Based on the comparative literature review, we recorded 36 new endemic medicinal plants and reported new traditional therapeutic uses for the remaining 50 endemic plants for the first time. On the other hand, all the reported endemic medicinal plants have been enlisted in the IUCN Red List of Threatened Species, of them 21 endemic species enlisted as highest threatened species.

CONCLUSION

According to the quantitative data analyzed, Soqotra Island has a valuable traditional knowledge in several medicinal endemic plants that used by local people in the primary health care until the study time at 1990. This study emphasizes the importance of early time in documenting traditional indigenous knowledge before losing and to protect and conserve the endemic plants against highly endangered. Consequently, these ethnomedicinal data could be used in the future as guide for pharmacological and phytochemical studies to discover new therapeutic drugs.

Plant diversity of Hyrcanian relict forests: An annotated checklist, chorology and threat categories of endemic and near endemic vascular plant species

In this paper a critical annotated checklist of 256 endemic and near endemic species belonging to 152 genera and 50 families of flowering plants known from Hyrcanian relict forests is presented. Distribution maps of taxa, elevational range, number of known records, chorotypes, life forms, IUCN threat categories and habitat types are also provided. The chorotypes are categorized into eight main patterns: 1) the Omni-Hyrcanian pattern (OH), 2) West Hyrcanian pattern (WH), 3) Manjil-Rudbar pattern (MR), 4) Central Hyrcanian pattern (CH), 5) Central and East Hyrcanian pattern (CEH), 6) East Hyrcanian pattern (EH), 7) Alborz-Hyrcanian pattern (AH), and 8) Euxino-Hyrcanian pattern (XH). The richness and distribution maps were generated based on 5408 records gained from herbarium specimens and literature records. The life form spectra show that the majority of taxa (54.7%) belong to hemicryptophytes, followed by the tuberous, bulbous and parasitic geophytes with 45 species (17.6%) and phanerophytes with 28 taxa (10.9%). The conservation status of species according to IUCN criteria indicates that 30 taxa are Critically Endangered, 52 taxa Endangered, 30 taxa Vulnerable, 25 taxa Near Threatened and 81 taxa are of Least Concern. Our present data were not sufficient to evaluate 38 taxa that are categorized here as Data Deficient. The new combination of Leutea translucens (=Peucedanum translucens) is validated with inclusion of Peucedanum hyrcanicum as its synonym. The disjunct occurrence of the Caucasian species Gentiana grossheimii is reported from the eastern parts of the Hyrcanian forests in Iran for the first time. We conclude that (i) the Hyrcanian forests and associated habitats in the northern slopes of the Alborz Mountains harbour tremendous floristic diversity of high conservation priority, and (ii) the Hyrcanian forest zone is an important and unique center of endemism within the Euro-Siberian region that should be considered a floristic province with a large number of relict species.

Fatty acid composition, enzyme inhibitory effect, antioxidant and anticancer activity of extract from Saponaria prostrata WILLD. subsp. anatolica HEDGE

This study attempts to evaluate the antioxidant, enzyme inhibitory, and anticancer properties as well as fatty acid compositions of endemic Saponaria prostrata WILLD. subsp. anatolica HEDGE. The gas chromatography-mass spectrometry (GC-MS) was used to determine the fatty acid content of methanol: dichloromethane extract from S. prostrata subsp. anatolica (SPA). Enzymatic activity was measured against acetylcholinesterase, butyrylcholinesterase and α-glucosidase. DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity and Ferric reducing antioxidant power assay (FRAP) were conducted to antioxidant properties. The anticancer effect of SPA on human MCF-7 breast cancer and human HCT116 colorectal cancer cell line was evaluated by WST-1 cell viability assay, colony formation assay and wound healing assay. In addition, human VEGF Elisa method was used to determine the anti-angiogenic effect, and the quantitative real-time PCR (qRT-PCR) method on p53, Bax and Bcl-2 mRNA levels were used to evaluate apoptosis. While high amounts of palmitic acid (40.8%), linoleic acid (17.75%) and α-linolenic acid (16.84%) were detected in the SPA, the total amount of unsaturated fatty acid (51.34%) was higher than the total amount of saturated fatty acid (48.66%). SPA displayed the most promising acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and α-glycosidase (AG) inhibitory activities (AChE: IC₅₀: 18.03 µg/mL, BuChE: IC₅₀: 44.24 µg/mL and AG: IC₅₀: 210.85 µg/mL). The half maximum inhibitory concentration (IC₅₀) of SPA in MCF-7 and HCT116 cells was determined as 259.79 µg/mL and 97.24 µg/mL, respectively. In addition, it was determined that SPA suppresses colony formation and wound closure, and suppresses angiogenesis as well as triggering apoptosis at a significant level. It is true that endemic S. prostrata subsp. anatolica is a potential source of functional food ingredients, but more analytical and in vivo experiments are needed to explore further secondary metabolite diversity and pharmacological properties.

Effects of environmental heterogeneity on phenotypic variation of the endemic plant Lilium pomponium in the Maritime and Ligurian Alps

Geographical limits of species’ distributions are assumed to be coincident with ecological margins, although this assumption might not always be true. Indeed, harsh environments such as Alpine and Mediterranean ecosystems may favour high phenotypic variability among populations, especially those in peripheral sites. Floral traits are often found to be less variable and less affected by environmental heterogeneity than vegetative traits because variation in the former may have negative effects on fitness. For this reason, it is important to quantify variation in floral traits and plant fecundity in study range limits. The objective of the study is to examine phenotypic variation and differences in reproduction in endemic Lilium pomponium in the Maritime and Ligurian Alps in relation to environmental variation across its distribution range. In this species, marginal climatic populations occur both in the peripheral and central geographical locations of the distribution range; hence, geographical and ecological gradients are not concordant. Floral trait variation is related to local environmental conditions with an array of interactions among resource availability, potential pollen limitation and population size that are differentially related to floral traits. Contrary to the general expectation, all central and peripheral populations had similar, moderate seed production with each group limited by different factors acting on different stages of the life-history strategy. Our results are in line with the idea that general expectations are confirmed only when its assumptions are met and that the differences in pollination environment along an environmental gradient may not be the main determinant of the distribution limit.

Mass propagation of Plectranthus bourneae Gamble through indirect organogenesis from leaf and internode explants

The present study describes the plant propagation via indirect organogenesis from in vitro derived leaf and internode explants of Plectranthus bourneae, an endemic plant to south India. Leaf and internodal explants successfully callused on Murashige and Skoog medium (MS) supplemented with different concentrations of auxins [2,4-D (2,4-dichlorophenoxyacetic acid), NAA (α-naphthalene acetic acid), IAA (indole-3 acetic acid), IBA (indole-3-butyric acid) and PIC (Picloram); 0.1-2.0 mg/l] in combination with BA (6-benzyladenine) (0.5 mg/l). Maximum callus induction (98 %) was achieved from leaf explant followed by internodal explant (89 %) at 1.0 mg/l NAA, 0.5 mg/l BA. Leaf derived callus showed better shoot regeneration (29.71 shoots) on MS medium containing 1.0 mg/l KN (kinetin), 0.7 mg/l NAA, and 50 mg/l CH (casein hydrolysate) followed by internodal callus (19.71). A maximum of 19.14 roots/shoot was observed at 1.0 mg/l IBA. The rooted plantlets were successfully hardened and transferred to greenhouse condition with 80 % survival. This system could be utilized for large-scale multiplication of P. bourneae by tissue culture.