Rubia tinctorum root extracts: chemical profile and management of type II diabetes mellitus

Phenolic enriched fraction of Clerodendrum glandulosum Lindl. leaf extract ameliorates hyperglycemia and oxidative stress in streptozotocin-nicotinamide induced diabetic rats

BACKGROUND

Clerodendrum glandulosum Lindl. is an important ethnomedicinal shrub of Northeast India, used by traditional healers to control various ailments like diabetes, hypertension, arthritis, etc. OBJECTIVES: The present study was conducted to explore the anti-hyperglycemic and antioxidative effects of the polyphenol-rich fraction (PRF) of C. glandulosum leaf extract and identification of its major bioactive compounds. Further, an in-silico molecular docking study was also performed to understand the molecular interactions of the identified major compounds with some target proteins associated with diabetic complications.

MATERIALS AND METHODS

PRF was purified from the hydromethanolic (80% MeOH) extract of leaves and subjected to assessment of in-vitro antioxidant and anti-diabetic properties. It was also subjected to evaluate the ameliorative effect during streptozotocin-nicotinamide-induced hyperglycemia in Wistar albino rats. An in-silico molecular docking study was also performed to complement the in-vitro/in-vivo studies.

RESULTS

Chemical analysis of PRF showed the presence of phenolics like caffeic acid, verbascoside, isoverbascoside, and apigenin, of which verbascoside (598.14 ± 1.24 mg/g) was found to be the principal compound. In-vitro studies showed potent antioxidant (IC50 of DPPH:32.45 ± 2.16 μg/mL; ABTS:39.08 ± 0.53 μg/mL) properties and excellent aldose reductase inhibition potential (IC50 2.18 ± 0.10 μg/mL). Treatment with PRF showed reduced blood glucose levels and increased plasma insulin levels. The results also indicate an improvement of endogenous antioxidants and suppression of inflammatory cytokines (IL-6 and TNF-α) comparable to the standard. Molecular docking studies predicted promising interactions between the identified molecules and the crucial amino acid residues of the enzymes involved in the development of hyperglycemia.

CONCLUSION

This study revealed the antihyperglycemic and antioxidant potential of partially purified fraction PRF of C. glandulosum leaves.

Cytotoxic, apoptotic activities and chemical profiling of dimorphic forms of Egyptian halophyte Cakile maritima scop

Cakile maritima ssp. aegyptiaca (Wild.) Nyman is growing with dimorphic leaf forms (entire or pinnatifid lamina) along the Mediterranean coast of Egypt. The cytotoxic activities of dried shoot systems of the two morphological forms were evaluated by testing and comparing the effects of ethanolic and aqueous extracts on the viability of five human cell lines. GC-MS analysis was performed to identify the bioactive and anticancer compounds present in the most active extracts. MTT assay indicated that both aqueous and ethanolic extracts have selective cytotoxic activities against cancer cell lines with no inhibitory activities against normal Wi38 or Vero cell lines. The underlying mechanism of cytotoxicity involved the induction of G2/M phase arrest in targeted cells MCF-7 and HCT-116 associated with inducing apoptosis in both cell lines, as indicated by Annexin-V assay. Apoptosis investigation in MCF-7 and HCT-116 cells treated with ethanolic extracts, was further investigated through RT-PCR, which exhibited elevation of proapoptotic genes of P53, BAX, Capase-3,6,7,8,9, and downregulation of antiapoptotic gene (BCL-2) upon treatment. The GC-MS analysis of ethanolic extracts of pinnatifid and entire forms revealed the existence of 18 and 13 compounds, respectively, with eleven compounds that were detected in pinnatifid form only and seven compounds were identified exclusively in the entire form. Molecular Docking study revealed that the identified compounds exhibited good binding affinity towards BCL-2 inhibition, and this agreed with the suggested apoptotic mechanism. To the best of authors' knowledge, this is the first scientific evidence underline the variability in the chemical composition associated with variable anticancer activities of dimorphic forms of C. maritima.Communicated by Ramaswamy H. Sarma.

Collection of Hairy Roots as a Basis for Fundamental and Applied Research

Due to population growth, instability of climatic conditions, and reduction of the areas of natural ecosystems, it becomes necessary to involve modern biotechnological approaches to obtain highly productive plant material. This statement applies both to the creation of plant varieties and the production of new pharmaceutical raw materials. Genetic transformation of valuable medicinal plants using Agrobacterium rhizogenes ensures the production of stable and rapidly growing hairy roots cultures that have a number of advantages compared with cell culture and, above all, can synthesize root-specific substances at the level of the roots of the intact plant. In this regard, special attention should be paid to the collection of hairy roots of the Institute of Plant Physiology RAS, Russian Academy of Sciences, the founder of which was Dr. Kuzovkina I.N. Currently, the collection contains 38 hairy roots lines of valuable medicinal and forage plants. The review discusses the prospects of creating a hairy roots collection as a basis for fundamental research and commercial purposes.

Evaluation of Halophyte Biopotential as an Unused Natural Resource: The Case of Lobularia maritima

Halophytes are plant species widely distributed in saline habitats, such as beaches, postindustrial wastelands, irrigated lands, salt flats, and others. Excessive salt level, known to limit plant growth, is not harmful to halophytes, which have developed a variety of defense mechanisms allowing them to colonize harsh environments. Plants under stress are known to respond with several morpho-anatomical adaptations, but also to enhance the production of secondary metabolites to better cope with difficult conditions. Owing to these adaptations, halophytes are an interesting group of undemanding plants with a high potential for application in the food and pharmaceutical industries. Therefore, this review aims to present the characteristics of halophytes, describe changes in their gene expression, and discuss their synthesized metabolites of pharmacognostic and pharmacological significance. Lobularia maritima is characterized as a widely spread halophyte that has been shown to exhibit various pharmacological properties in vitro and in vivo. It is concluded that halophytes may become important sources of natural products for the treatment of various ailments and for supplementing the human diet with necessary non-nutrients and minerals. However, extensive studies are needed to deepen the knowledge of their biological potential in vivo, so that they can be introduced to the pharmaceutical and food industries.

BIOLOGICAL ACTIVITIES AND CHEMICAL COMPOSITION OF Rubia tinctorum (L) ROOT AND AERIAL PART EXTRACTS THEREOF

In the present study, the phytochemical composition, antioxidant and anti-hemolytic activities of root and aerial part Rubia tinctorum hydromethanolic extracts were investigated. Phytochemical screening reveals the presence of phenol, alkaloids, coumarin, flavonoids, and tannins in both extracts. LC-ESI-MS/MS analysis showed the presence of 15 and 17 components in the root and the aerial part extracts, respectively. The quantitative analysis indicates the richness of root extracts in phenolic compounds (118.38 mg GAE/g) and flavonoids (45.29±0.04 mg GAE/g), the aerial part extract has the highest levels in tannins (134.1±0.1 mg GAE/g). Besides, aerial part extracts revealed the highest antioxidant activity for DPPH (83.23 %) and FRAP (1.51±0.22), while the root extract exhibited the highest potential for TAC and antihemolytic activity (61.09 %). Rubia tinctorum contains different active compounds to prevent diseases related to oxidative stress.

Activity of Anthracenediones and Flavoring Phenols in Hydromethanolic Extracts of Rubia tinctorum against Grapevine Phytopathogenic Fungi

In this work, the chemical composition of Rubia tinctorum root hydromethanolic extract was analyzed by GC-MS, and over 50 constituents were identified. The main phytochemicals were alizarin-related anthraquinones and flavoring phenol compounds. The antifungal activity of this extract, alone and in combination with chitosan oligomers (COS) or with stevioside, was evaluated against the pathogenic taxa Diplodia seriata, Dothiorella viticola and Neofusicoccum parvum, responsible for the so-called Botryosphaeria dieback of grapevine. In vitro mycelial growth inhibition tests showed remarkable activity for the pure extract, with EC50 and EC90 values as low as 66 and 88 μg·mL-1, respectively. Nonetheless, enhanced activity was attained upon the formation of conjugate complexes with COS or with stevioside, with synergy factors of up to 5.4 and 3.3, respectively, resulting in EC50 and EC90 values as low as 22 and 56 μg·mL-1, respectively. The conjugate with the best performance (COS-R. tinctorum extract) was then assayed ex situ on autoclaved grapevine wood against D. seriata, confirming its antifungal behavior on this plant material. Finally, the same conjugate was evaluated in greenhouse assays on grafted grapevine plants artificially inoculated with the three aforementioned fungal species, resulting in a significant reduction in the infection rate in all cases. This natural antifungal compound represents a promising alternative for developing sustainable control methods against grapevine trunk diseases.

Chemical Profiling, Antioxidant, Cytotoxic Activities and Molecular Docking Simulation of Carrichtera annua DC. (Cruciferae)

Our investigation intended to analyze the chemical composition and the antioxidant activity of Carrichtera annua and to evaluate the antiproliferative effect of C. annua crude and phenolics extracts by MTT assay on a panel of cancerous and non-cancerous breast and liver cell lines. The total flavonoid and phenolic contents of C. annua were 47.3 ± 17.9 mg RE/g and 83.8 ± 5.3 mg respectively. C. annua extract exhibited remarkable antioxidant capacity (50.92 ± 5.64 mg GAE/g) in comparison with BHT (74.86 ± 3.92 mg GAE/g). Moreover, the extract exhibited promising reduction ability (1.17 mMol Fe+2/g) in comparison to the positive control (ascorbic acid with 2.75 ± 0.91) and it displayed some definite radical scavenging effect on DPPH (IC50 values of 211.9 ± 3.7 µg/mL). Chemical profiling of C. annua extract was achieved by LC-ESI-TOF-MS/MS analysis. Forty-nine hits mainly polyphenols were detected. Flavonoid fraction of C. annua was more active than the crude extract. It demonstrated selective cytotoxicity against the MCF-7 and HepG2 cells (IC50 = 13.04 and 19.3 µg/mL respectively), induced cell cycle arrest at pre-G1 and G2/M-phases and displayed apoptotic effect. Molecular docking studies supported our findings and revealed that kaempferol-3,7-O-bis-α-L-rhamnoside and kaempferol-3-rutinoside were the most active inhibitors of Bcl-2. Therefore, C. annua herb seems to be a promising candidate to further advance anticancer research. In extrapolation, the intake of C. annua phenolics might be adventitious for alleviating breast and liver malignancies and tumoral proliferation in humans.