(common mullein): A review

Medicinal plants represent rich sources of traditional medicines and numerous currently used medicines are either directly or indirectly derived from plants. Verbascum thapsus L. (great mullein or common mullein), a medicinal herb indigenous to northern Africa, western and central Asia, and Europe, has been brought to the Americas and Australia. It has been used as a medicine for lung, skin and throat disorders and has a long history of therapeutic importance, particularly as an astringent and calming agent. Presently, the dried leaves, flowers, various plant extracts and flower oil are used in several formulations within Indian traditional medicine. An extract taken from the roots is useful in minimizing toothache, and it also relieves stiffness and seizures. V. thapsus contains a wide variety of phytoconstituents, such as flavonoids, iridoid, phenylethanoid and phenylpropanoid glycosides, saponins, as well as vitamin C and minerals. The most valuable constituents are coumarin and hesperidin, which possess healing properties. Emerging literature based on experimental studies on V. thapsus demonstrates various biological and pharmacological properties, including antiviral, antioxidant, analgesic, sedative, anti-inflammatory, hypnotic, antibacterial, antifungal, as well as anticancer activities. The present review provides an updated, comprehensive, and critical evaluation of various health-promoting and disease-mitigating properties of V. thapsus.

Assessment the copper-induced changes in antioxidant defense mechanisms and copper phytoremediation potential of common mullein (Verbascum thapsus L.)

In this research, the Cu phytoremediation capacity of common mullein (Verbascum thapsus L.) was evaluated concerning plant growth, antioxidant enzymes, and photosynthetic activities. Plants were subjected to five Cu concentrations (0, 125, 250, 375, and 500 mg/L) under the hydroponic conditions for 2 weeks. The results showed that at 125 mg/L, root and shoot biomass and chlorophylls remained the same as that of the control and then declined with increasing concentrations of Cu, when compared with control. The carotenoid contents remained unchanged up to 250 mg/L compared with control and then dropped with raising Cu dose. The raising of antioxidant enzymes activity reflected the occurrence of stress due to Cu exposure as manifested by increased MDA and ion leakage level. However, increased antioxidant enzymes may be associated with the tolerance capacity of V. thapsus to protect the plant from oxidative damage. Except for the highest concentration (500 mg/L), Cu accumulation in the roots and shoots all increased significantly with increasing Cu concentration, and the Cu accumulation in shoots was greater than roots. The Cu accumulation reached its maximum level at 375 mg/L Cu concentration, with 492.8 and 447.3 mg/kg DW in shoots and roots, respectively, which is highly greater than the threshold value for a Cu (hyper)accumulator plant. The extraction coefficient (EC) close to 1, and translocation factor (TF) > 1 from 125 to 375 mg/L Cu, suggested that V. thapsus could be used as a viable plant species for Cu phytoextraction.

Induction of Apoptosis by Alcoholic Extract of Combination Verbascum thapsus and Ginger officinale on Iranian Isolate of Trichomonas vaginalis

BACKGROUND

The protozoan Trichomonas vaginalis is a sexually transmitted disease (STD). Metronidazole is a chosen drug for the treatment. This study evaluated the anti trichomonal activity of alcoholic extracts of combination Verbascum thapsus and Ginger officinale.

METHODS

This experimental study was conducted in the Parasitology Laboratory, Kashan University of Medical Sciences, Kashan, Iran in 2015, on 23 women with suspected trichomoniasis referring to Kashan clinical centers. Medium TYI-S-33 was used for culture of three T. vaginalis isolates. Different concentrations (25, 50, 100, 200, 400, 800 μg/ml) of V. thapsus and G. officinale ethanol extract added to Trichomonas trophozoites in 48-well plates and metronidazole considered as positive control and the negative control was TYI-S33 containing Trichomonas trophozoites without any drug. In all of mentioned groups, trophozoites number counted 12, 24, 48 h after culture. Results were analyzed using ANOVA statistical test, to evaluate the toxicity of extract, measured by MTT assay. Induced apoptosis of T. vaginalis after treatment with different concentrations of extract was determined by Flow Cytometry.

RESULTS

IC50 of alcoholic extract of combination V. thapsus and G. officinale and metronidazole after 24h was 73.80 μg/ml and 0.0326 μg/ml, respectively. The toxicity percentage of 25-800 μg/ml concentrations of this combination were between 0.2-1.98. In different concentrations of extract (25,50,100,200 and 400 μg/ml) apoptosis percent after 48h was 18.97 to 77.19 and necrosis percent was calculated 1.35, 3.18, 3.10, 1.16 and 4.09, respectively.

CONCLUSION

Alcoholic extract of combination V. thapsus and G. officinale induces programmed death in T. vaginalis. Due to no toxicity on macrophages, it can be examined in vivo studies.

Geographic structuring and transgenerational maternal effects shape germination in native, but not introduced, populations of a widespread plant invader

PREMISE OF THE STUDY

Germination is critical in determining species distributions and invasion dynamics. However, is it unclear how often invasive populations evolve germination characteristics different from native populations, because few studies have isolated genetic variation by using seed from garden-grown plants. Additionally, while herbivore-induced transgenerational effects are common, it is unknown whether maternal herbivory differentially shapes germination in native and introduced offspring.

METHODS

We explored germination in native and introduced populations of the North American invader Verbascum thapsus using seed from garden-grown maternal plants, half of which were protected from herbivores. To elucidate (1) germination niche breadth and (2) whether germination conditions affected expression of genetic structuring among populations, we germinated seed under four ecologically relevant temperature regimes.

KEY RESULTS

Native populations had a wide germination niche breadth, germinating as well as or better than introduced populations. At cooler temperatures, native populations exhibited a genetically based environmental cline indicative of local adaptation, with populations from warmer locales germinating better than populations from cooler locales. However, this cline was obscured when maternal plants were attacked by herbivores, revealing that local stressors can override the expression of geographic structuring. Introduced populations did not exhibit clinal variation, suggesting its disruption during the introduction process.

CONCLUSIONS

Native and introduced populations have evolved genetic differences in germination. The result of this difference manifests in a wider germination niche breadth in natives, suggesting that the invasive behavior of V. thapsus in North America is attributable to other factors.

Physiological basis of differential zinc and copper tolerance of Verbascum populations from metal-contaminated and uncontaminated areas

Metal contamination represents a strong selective pressure favoring tolerant genotypes and leading to differentiation between plant populations. We investigated the adaptive capacity of early-colonizer species of Verbascum recently exposed to Zn- and Cu-contaminated soils (10-20 years). Two Verbascum thapsus L. populations from uncontaminated sites (NMET1, NMET2), one V. thapsus from a zinc-contaminated site (MET1), and a Verbascum lychnitis population from an open-cast copper mine (MET2) were exposed to elevated Zn or Cu in hydroponic culture under glasshouse conditions. MET populations showed considerably higher tolerance to both Zn and Cu than NMET populations as assessed by measurements of growth and net photosynthesis, yet they accumulated higher tissue Zn concentrations in the shoot. Abscisic acid (ABA) concentration increased with Zn and Cu treatment in the NMET populations, which was correlated to stomatal closure, decrease of net photosynthesis, and nutritional imbalance, indicative of interference with xylem loading and divalent-cation homeostasis. At the cellular level, the sensitivity of NMET2 to Zn and Cu was reflected in significant metal-induced ROS accumulation and ion leakage from roots as well as strong induction of peroxidase activity (POD, EC 1.11.1.7), while Zn had no significant effect on ABA concentration and POD activity in MET1. Interestingly, MET2 had constitutively higher root ABA concentration and POD activity. We propose that ABA distribution between shoots and roots could represent an adaptive mechanism for maintaining low ABA levels and unaffected stomatal conductance. The results show that metal tolerance can occur in Verbascum populations after relatively short time of exposure to metal-contaminated soil, indicating their potential use for phytostabilization.

TO DEFOLIATION IN RELATION TO NITROGEN SUPPLY. New Phytol 1986;104:121-129. [PMID: 33873804 DOI: 10.1111/j.1469-8137.1986.tb00640.x]

The effects of defoliation of Cynoglossum officinale L. and Verbascum thapsus L. on growth, net assimilation rate and dry matter distribution were studied under various nitrogen regimes. At high levels of nitrogen supply, there was a higher net assimilation rate (NAR) and a higher leaf weight ratio in defoliated plants than in undefoliated plants resulting in a faster growth of defoliated plants. In V. thapsus growth of defoliated plants did not differ significantly from undipped plants. In a low nitrogen regime all defoliated V. thapsus plants died. In the same regime C. officinale had a low NAR and thus showed little regrowth. Leaf nitrogen content was not significantly different from control plants.

EFFECTS OF IRRADIANCE AND SPECTRAL QUALITY ON THE GERMINATION OF VERBASCUM THAPSUS L. AND OENOTHERA BIENNIS L. SEEDS

Germination of Verbascum thapsus L. and Oenothera biennis L. seeds was investigated over a range of irradiance levels and under different canopy types in the laboratory. Both species colonize early successional and disturbed habitats, and their seedlings establish only in bare soil. In the laboratory, Verbascum seeds germinated to equivalent levels (70 to 80%) over a broad range of irradiance levels and required only brief exposure to light (5 s) to germinate subsequently in darkness. In contrast, germination of Oenothera seeds increased with irradiance to a maximum of approximately 80% at 13 W m^-2 . Oenothera seeds also required a longer duration of exposure (1 h) to induce germination, and percentage germination increased directly with exposure time to a maximum of 80 % after 22 h of exposure. Germination of both species was significantly reduced in light filtered through leaves, but the responses differed under different canopy types. Exposure to red and blue light had no effect on germination of Verbascum seeds but had an inhibitory effect on that of Oenothera seeds. The results are discussed in relation to the observed patterns of seedling emergence and survival of these species in the field; a possible evolutionary basis is suggested for their differences in response to light.