Alkannin/shikonin mixture from roots ofOnosma echioides(L.) L.: Extraction method study and quantification

Unraveling the interaction of copper, cadmium, calcium, and nitrate on phenolics, flavonoids, and shikonin contents of Onosma dichroantha calli by statistical modeling

Increased anthropogenic activities have led to the accumulation of certain minerals to ecotoxic levels in the environment, which could influence the secondary metabolism of plants. Shikonin, an exudate from the roots of Onosma dichroantha, is a secondary metabolite involved in plant defense and invasion success; however, the interactive effects of copper (Cu), cadmium (Cd), calcium (Ca), and nitrate (NO₃) in shikonin biosynthesis and accumulation are not known. Here, the individual, curvilinear, and pairwise effects of these elements on shikonin biosynthesis in callus culture of O. dichroantha have been investigated by means of a statistical modeling approach and multivariate regression analyses. Although the main effects of the examined minerals seemed to be suppressive, their combined interactions could enhance callus growth and secondary metabolism of O. dichroantha. Accordingly, maximum values were recorded for the callus growth index (6.85 at 23.25 μM Cu, 70 mM NO₃, 1 mM Ca, 27.50 μM Cd), total phenolics (24.83 mg gallic acid equivalent at 9.75 μM Cu, 70 mM NO₃, 1 mM Ca, 62.50 μM Cd), total flavonoids (6.12 mg quercetin equivalent at 30 μM Cu, 80 mM NO₃, 1.5 mM Ca, 45 μM Cd), and shikonin (24.33 μg g^-1 FW at 9.75 μM Cu, 70 mM NO₃, 2 mM Ca, 27.5 μM Cd). Overall, these data show that increasing concentrations of the examined minerals in culture medium can markedly influence the secondary metabolism of O. dichroantha cells and suggest that a comparable phenomenon may exist in a wider range of medicinal plants, grown on polluted environments, which may affect their invasive capabilities.

Ethnobotanical, Phytochemistry, and Pharmacological Activity of Onosma (Boraginaceae): An Updated Review

The genus Onosma belongs to the Boraginaceae family and contains over 230 species. The present review sheds light on the ethnopharmacology, phytoconstituents, bioactivity, and toxicology of the Onosma species from previous investigations. Furthermore, the paper also highlights the unresolved issues for the future investigations. The review included previous studies of the genus Onosma available from Google Scholar and Baidu Scholar, Science Direct, SciFinder, Wiley Online Library, and Web of Science. Until now, more than 200 chemical compounds have been detected from the genus Onosma, including naphthoquinone (33), flavonoids (30), hydrocarbon (23), phenolic (22), ester (17), alkaloids (20), aromatics (12), carboxylic acid (11), fatty acids (9), terpenoids (10), while the most important ones are rosmarinic, ferulic, protocatechuic, chlorogenic, caffeic, p-coumaric acids, and apigenin. The Onosma species are reported as traditional medicine for wound healing, heart disease, and kidney disorders, while the pharmacological investigations revealed that the extracts and the phytochemicals of Onosma species have different therapeutic properties including antioxidant, enzyme inhibitory, antitumor, hepatoprotective, antiviral, anti-inflammatory, and antimicrobial actions. The summarized knowledge in this review provides valuable ideas for the current and future drug discovery and a motivation for further investigation on the genus Onosma.

Onosma L. as a source of anticancer agents: phytochemistry to mechanistic insight

Onosma (O.) is a genus of perennial flowering plants in the family Boraginaceae with approximately 250 species widely dispersed in temperate, tropical, and subtropical areas. It is traditionally used to treat rheumatism, fever, asthma, stomach irritation, and inflammatory ailments. The bioactive constituents present in the genus O. include benzoquinones, naphthazarins, alkaloids, phenolic, naphthoquinones, and flavonoids whereas shikonins and onosmins are the most significant. The review compiled contemporary research on O. L., including its distribution, morphology, traditional applications, phytochemistry, ethnopharmacology, and toxicology. This review also highlights a few critical challenges and possible future directions for O. L. research. Modern research has demonstrated a wide range of pharmacological effects of different species of O. L., including anti-diabetic, anticancer, anti-inflammatory, and cardiovascular protective. However, the studies on the O. genus are still not fully explored, therefore, researchers need to discover novel products with their toxicity studies, molecular mechanism, and associated side effects. Future exploration of potent constituents from this genus and clinical trials are required to explore its pharmacological importance.

A Development Strategy of Tailor-made Natural Deep Eutectic Solvents for the Enhanced Extraction of Hydroxynaphthoquinones from Alkanna tinctoria Roots

Natural hydroxynaphthoquinone enantiomers (HNQs) are well-described pharmaceutical and cosmeceutical agents especially present in the roots of Alkanna tinctoria (L.) Tausch, a species native to the Mediterranean region. In this work, eco-friendly natural deep eutectic solvents (NaDESs) were developed for the selective extraction of these compounds. An extensive screening was performed using more than sixty tailor-made NaDESs. The impact of the intrinsic physicochemical properties on the HNQs extraction efficiency as well as the specificity towards the different enantiomeric pairs was thoroughly investigated. As a result of a multivariate analysis and of the one factor-a-time solvent optimization, the eutectic mixture composed of levulinic acid and glucose (LeG) using a molar ratio of 5 : 1 (mol_HBA : mol_HBD) and 20% of water (w/w) was found as the most appropriate mixture for the highest extraction efficiency of HNQs. Further optimization of the extraction process was attained by response surface methodology, using a temperature of 45 °C, a solid-to-liquid ratio of 30 mg/mL, and an extraction time of 50 min. A maximum extraction output of 41.72 ± 1.04 mg/g was reached for HNQs, comparable to that of the commonly used organic solvents. A solid-phase extraction step was also proposed for the recovery of HNQs and for NaDESs recycling. Our results revealed NaDESs as a highly customizable class of green solvents with remarkable capabilities for the extraction of HNQs.

Investigating the hemostatic effect of medicinal plant Arnebia euchroma (Royle) I.M.Johnst extract in a mouse model

ETHNOPHARMACOLOGICAL RELEVANCE

Arnebia euchroma (Royle) I.M.Johnst (AE) has been reported to be a potentially useful medicinal herb for the treatment of several circulatory diseases in traditional Chinese medicine. It shows effects such as "cooling of the blood," promotion of blood circulation, detoxification, and rash clearance.

AIM OF THE STUDY

To explore the hemostatic effect of the ethyl acetate extract of AE in mice.

MATERIALS AND METHODS

In this study, we explored the effects of AE on bleeding time, blood coagulation time, platelet count, and blood coagulation parameters in normal Kunming mice. Different doses of the AE extract (5, 10, and 20 g kg^-1·day^-1) were administered to mice for 14 days. Sodium carboxymethyl cellulose (CMC-Na at 0.5%) and Yunnan Baiyao (0.8 g kg^-1·day^-1) were administered as negative and positive control treatments, respectively. Bleeding time, blood coagulation time, platelet count, blood platelet aggregation, blood platelet adhesion to fibrinogen, platelet factor 4 (PF-4) secretions from blood platelets, and blood coagulation parameters including prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen (FIB) levels were measured on day 15 of administration.

RESULTS

Bleeding and blood coagulation time were significantly lower and TT was shorter in the AE extract-treated groups than in the control groups. Furthermore, FIB levels and platelet count were higher, whereas blood platelet aggregation, blood platelet adhesion to fibrinogen, and PF-4 secretion from blood platelets were more obvious in the AE extract-treated groups than in the control group. However, no significant differences were detected for PT and aPTT between the extract-treated and control groups.

CONCLUSIONS

The ethyl acetate extract of AE showed potential hemostasis effects in mice by shortening the bleeding and coagulation time. In addition, the extract increased platelet count and induced blood platelet aggregation, blood platelet adhesion to fibrinogen, PF-4 secretion from blood platelets, and FIB level, while it shortened TT.

Redox status, DNA and HSA binding study of naturally occurring naphthoquinone derivatives

In the present work we modified the procedure for isolation of naphthoquinones α-methylbutyrylshikon (1), acetylshikonin (2) and β-hydroxyisovalerylshikonin (3) from Onosma visianii Clem. We also investigated possible mechanisms of 1, 2 and 3 as antitumor agents. Accordingly, we estimated concentrations of superoxide anion radical (O₂^.-), nitrite (NO₂ ^-) and glutathione in HCT-116 and MDA-MB-231 cell lines. Compounds 1 and 3 expressed significant prooxidative activity, while all tested compounds exhibited significant increase in nitrite levels. Also, all examined compounds significantly increased the concentration of oxidized glutathione (GSSG), suggesting significant prooxidative disbalance. The levels of reduced glutathione (GSH) were also elevated as a part of antioxidative cell response. The data indicate that induced oxidative imbalance could be one of the triggers for previously recorded decreased viability of HCT-116 and MDA-MB-231 cells exposed to tested naphthoquinone derivatives. Moreover, we examined interactions mode of compounds 1, 2 and 3 with CT-DNA as one of the crucial targets of many molecules that express cytotoxic activity. The results obtained by UV-visible, fluorescence and molecular docking study revealed that 1, 2 and 3 bound to CT-DNA through minor groove binding. Furthermore, the interactions between HSA and 1, 2 and 3 were examined employing the same methods as for the CT-DNA interaction study. Based on the obtained results, it can be concluded that naphthoquinones 1, 2 and 3 could be effectively transported by human serum albumin. As a conclusion, this study provides further insight of antitumor activity of selected naphthoquinones.

Onosma L.: A review of phytochemistry and ethnopharmacology

The genus Onosma L. (Boraginaceae) includes about 150 species distributed world-wide in which only about 75 plants has been described for its morphology and less than 10 plants for their chemical constituents and clinical potential. The phytochemical reports of this genus revels that it comprise mainly aliphatic ketones, lipids, naphthazarins, alkaloids, phenolic compounds, naphthoquinones, flavones while most important are shikonins and onosmins. The plants are traditionally used as laxative, anthelmintic and for alexipharmic effects. The plants are also equally use in eye, blood diseases, bronchitis, abdominal pain, stangury, thirst, itch, lecoderma, fever, wounds, burns, piles and urinary calculi. The flowers of various plants are prescribed as stimulants, cardiotonic, in body swelling while leaves are used as purgative and in cutaneous eruptions. The roots are used for coloring food stuffs, oils and dying wool and in medicinal preparations. This review emphasizes the distribution, morphology, phytochemical constituents, ethnopharmacology, which may help in future research.

Callus culture of Echium italicum L. towards production of a shikonin derivative

Callus induction and proliferation of Echium italicum L. (Boraginaceae) were investigated using cotyledon, hypocotyl and root explants. Calli were initiated and established using B5, LS, 1/2LS and White media supplemented with different auxins, including 2,4-dichlorophenoxyacetic acid (2,4-D), indole-3-acetic acid (IAA) and 1-naphthaleneacetic acid (NAA) in combination with kinetin. The maximum pigmented callus induction (100%) was observed in the White medium. The n-hexane extract of proliferated callus tissues were analysed by TLC and HPLC. The major secondary metabolite was separated by preparative HPLC and its structure was elucidated by UV, ¹H and ¹³C-NMR spectroscopy. As a result, shikonin acetate was identified by various spectroscopic methods from callus culture of E. italicum. These findings highlight the shikonin production potential of the E. italicum callus, which may be considered as a new source for the production of shikonin and its derivatives for industrial use.