Exploration of diacerein as a neuroprotective adjuvant to Adenium obesum: An in-vivo study

BACKGROUND

Since the dawn of civilization, medicinal plants have been essential in the treatment of numerous human ailments. Medicinal plants have been the reliable sources to treat various diseases. Over 25% of prescription medications on the market today are made from natural resources. In the present study the selected medicinal plant, is Adenium obesum, of family Apocynaceae. The plant contains various chemical groups, including carbohydrate, cardiac glycoside, flavonoid, polyphenols, terpenoids, pregnanes, etc. OBJECTIVE: Millions of peoples worldwide are affected with neurodegenerative diseases. Parkinson's disease, Alzheimer's disease & Huntingtons disease are important among them. Since ancient times, medicinal herbs have been used to treat illnesses. The objective of present study is to prepare an effective & safe drug formulation to treat neurological diseases.

MATERIAL & METHODS

Methanolic extract of A. obesum (200 mg/kg, 400 mg/kg) alone as well as with diacerein (100 mg/kg) is used to treat the haloperidol (1 mg/kg) & iron (10 mg/kg) induced Parkinsonism & Isotretinoin induced depression in albino wistar rats. The efficacy of plant extract as well as diacerein were measured by various behavioral models, with the help of histopathological studies & antioxidant assay like GSH, SOD, CAT, and LPO.

RESULTS

A. obesum alone & with diacerein is effective to treat neurological complications like Parkinson's disease & depression which can be seen in various behavioral models like, staircase test, rotarod test, forced swim test, hole board test etc. Histopathological evidences also suggest the significance of plant extract alone & with diacerein.

CONCLUSION

The findings of present research work revealed the neuroprotective effect of both A. obesum extract as well as diacerein.

First report of stem rot of Adenium obesum and leaf spot of Persea americana caused by Aspergillus niger in Kazakhstan

Adenium (Adenium obesum) and avocado (Persea americana) are commonly grown as exotic houseplants in city apartments of Kazakhstan. In April-May 2020, the wilting symptom was observed on the young stems of five 2-year-old A. obesum plants in a city apartment in Saryarqa District, Astana, Kazakhstan (71°25'E, 51°11'N). Leaves turned yellow and then dried up. Plants were completely wilted within 10 days (Fig. 1A). Similar symptoms were observed in newly grown A. obesum plants in November, 2021. At the same time, lesions were found on the leaves of three 3-month-old P. americana plants. Infected leaves displayed dry, dark-brown lesions and fell off easily (Fig. 2A). Both plants were cultivated side by side. The incidence of affected A. obesum was 80% out of 5 plants and P. americana was 100% out of 3 plants. To isolate the causal agent, the infected tissues from different leaves and stems of A. obesum and P. americana plants were cut into small pieces (5 × 5 mm), washed in 70% ethanol for 5 min, and then rinsed three times with sterile distilled water. Cut pieces were placed on potato dextrose agar (PDA) (Laboratorios Conda S.A., Spain) and incubated at 28°C for 7 days. Ten isolates were obtained from leaves and stems of the A. obesum and P. americana symptomatic samples. All fungal colonies were white initially, turned black gradually, reverse side light yellow (Fig. 1B and Fig. 2B), conidiophores biseriate with globose vesicles, conidia were spherical vesicles, light tan to black color, smooth-walled to roughened, and sizes ranged from 3.0 to 3.5 μm (n = 15) (Fig. 1C and Fig. 2C). These observations indicated that all the isolates resembled Aspergillus spp. (Bryan and Fennell 1965). DNA was extracted using the liquid nitrogen and phenol-chloroform extraction method (Butler 2012). A 526 bp product of the ITS region on rDNA and 568 bp product of the calmodulin protein-coding gene was amplified using following primer pairs ITS4/ITS5 (Abliz et al. 2003) and cmd5/cmd6, respectively (Hong et al. 2005). The PCR reaction was done under the following conditions: initial denaturation at 94°C for 5 min, 35 cycles at 95°C for 30 s to denature, 52°C for 40 s for annealing, and 72°C for 50 s for extension. A final extension step at 72°C for 7 min was also included. The sequencing was done using BigDye® Terminator v3.1 Cycle Sequencing Kit (Applied Biosystems) and the sequence was deposited in GenBank with accession nos. ON519078 (A. obesum ITS), ON519079 (P. americana ITS), OQ358173 (A. obesum calmodulin) and OQ358174 (P. americana calmodulin). These sequences were compared with other sequences of A. niger in GenBank using BLAST analysis (MG569619.1, MT588793.1, MH478660.1, MZ787576.1 and MW086485.1). The results showed that the sequences of ten isolates were identical and had 98-100% identity with those of Aspergillus niger (Fig. 3). The phylogenetic analysis was carried out with MEGA 11 (Tamura et al. 2021). To confirm the pathogenicity, three asymptomatic plants of each were inoculated with a suspension of conidia via pin-prick inoculation (1.0×106 conidia/ml; obtained from 2-week-old cultures). Control plants were inoculated with sterile distilled water. The inoculated plants were placed in climate chamber (BINDER, Germany) and incubated for 10 days at 28°C. Symptoms were developed in leaves of inoculated plants after 2 days in P. americana and after 5 days in A. obesum. Affected leaves turned yellow and their stems started drying. Symptoms of leaves were similar to those observed on naturally infected plants, while control plants remained asymptomatic. Re-isolation of the pathogen confirmed the presence of the A. niger pathogen. To our knowledge, this is the first report of A. niger causing stem rot of A. obesum and leaf spot of P. americana in Kazakhstan. Since different ornamentals are often planted together in gardens and nurseries, growers should be aware of potential transmission of A. niger among them. This finding provides a foundation to further investigate the biology and epidemiology of this disease so the developmentf diagnostic tools and management measures against it.

The cp genome characterization of Adenium obesum: Gene content, repeat organization and phylogeny

Adenium obesum (Forssk.) Roem. & Schult. belonging to the family Apocynaceae, is remarkable for its horticultural and ornamental values, poisonous nature, and medicinal uses. In order to have understanding of cp genome characterization of highly valued medicinal plant, and the evolutionary and systematic relationships, the complete plastome / chloroplast (cp) genome of A. obesum was sequenced. The assembled cp genome of A. obesum was found to be 154,437 bp, with an overall GC content of 38.1%. A total of 127 unique coding genes were annotated including 96 protein-coding genes, 28 tRNA genes, and 3 rRNA genes. The repeat structures were found to comprise of only mononucleotide repeats. The SSR loci are compososed of only A/T bases. The phylogenetic analysis of cp genomes revealed its proximity with Nerium oleander.

Molecular docking elucidates the plausible mechanisms underlying the anticancer properties of acetyldigitoxigenin from Adenium obesum

Adenium obesum (Forssk.) Roem. & Schult. is a promising medicinal plant belonging to the Apocynaceae family. It is a rich source of various phytochemicals such as cardiac glycosides, flavonoids, terpeniods, pregnanes etc. which have different pharmacological properties such as anticancer, antibacterial, acaricidal etc. While previous reports showed the anticancer activity of the aerial parts of the plant extract of A. obesum, the mechanisms of action of its chemical constituents are not known. The present study is aimed at elucidation of plausible mechanisms of anticancer activity of the plant by evaluating the binding interaction of its nine major selected compounds with macromolecular receptors implicated in the initiation and progression of cancer using various in silico approaches. Molecular docking results showed that the compound Δ16-3-Acetyldigitoxigenin (16-anhydro-3-acetylgitoxigenin) scored the best binding energy scores with the majority of the target proteins. The molecular binding of the compound was stabilized through hydrogen bonds as well as hydrophobic interactions, and also possesses favorable drug-like properties without significant toxicities.

Complete chloroplast genome of medicinally important poisonous shrub Adenium obesum (Forssk.) Roem. & Schult. (Apocynaceae)

The complete chloroplast genome of medicinally important plant Adenium obseum (Forssk.) Roem. & Schult. (Apocynaceae) was sequenced. A total of 5,028,192,488 paired-end reads were obtained. One-hundred-and-twenty-seven unique coding genes including 96 protein-coding, 28 tRNA, and 3 rRNA genes were annotated. The length and GC content of the plastome were 154,437 bp (GenBank accession number MN765097) and 38.1%, respectively.

Molluscicidal activity of cardiac glycosides isolated from Adenium obesum

BACKGROUND

Terrestrial mollusks are one of most important agricultural pests worldwide. Natural phytochemicals have an extended history as a source of pesticides. This study was planned to isolate molluscicidal active compounds from the stems of Adenium obesum.

RESULTS

The benzene-soluble fraction of the hydroethanolic extract displayed the most potent molluscicidal activity against Monacha obstructa among different solvent fractions with a median lethal dose (LD₅₀ ) of 4.91 µg g^-1 body weight (bw). The bioactivity-guided chemical exploration of the benzene-soluble fraction led to the isolation of two known cardiac glycosides, cerberin and neriifolin which showed significant molluscicidal activity with LD₅₀ values of 5.39 and 4.3 µg g^-1 bw, respectively.

CONCLUSION

Isolation of the cardiac glycoside neriifolin from A. obesum and the molluscicidal activity of cerberin and neriifolin against terrestrial snails are reported for the first time. © 2019 Society of Chemical Industry.

Cytogenotoxic effects of Adenium obesum seeds extracts on breast cancer cells

The extracts prepared from various areal parts of the Adenium obesum (Forssk.) Roem. & Schult. (Family: Apocynaceae) including leaves, fruit and seeds ethanolic extracts and seed aqueous extract were evaluated against MCF-7 cells in order to investigate its potential of cytogenotoxicity and induction of apoptosis. The ethanolic seeds extract had comparatively higher cytotoxicity (IC₅₀ ∼ 337 µg/ml). Further, apoptosis and DNA damaging potential of seeds ethanolic extract was analyzed by applying multiple sub-lethal concentrations and durations. Flow cytometry results revealed that maximum percentage of early apoptosis (37%) and late apoptosis (35%) were observed after 12 h exposure in concentrations 200 µg/ml and 300 µg/ml, respectively. Similarly, the higher effect of extract in terms of DNA damage by alkaline comet assay was registered after 12 h treatment at concentrations 200 and 300 µg/mL. The calculated total damage score (TDS) for these concentrations were 614 and 617, respectively. The above findings indicate that A. obesum ethanolic seeds extracts has cytogenotoxic properties that could be further explored for the potential source of chemotherapeutic lead against cancer.

Isolation and characterization of antimicrobial compound from the stem-bark of the traditionally used medicinal plant Adenium obesum

BACKGROUND

Medicinal plants constitute a natural reservoir for medicines worldwide. They serve mainstream therapeutics and are central in folklore medicine. In case of Adenium obesum (Lav, Apocynaceae), indigenous people of Oman use it for the treatment of venereal diseases, wounds, skin diseases, headaches, muscle pain as well as joint pain; yet, the active ingredients have not been classified. To screened the antioxidant and antimicrobial activities of an identified compound that we isolated from the highest active chloroform extract.

METHODS

The antioxidant and antimicrobial activities of the extracts and the isolated compound were determined by diphenyl-1-picrylhydrazyl (DPPH) and disc diffusion methods. To characterize the compound, we used TLC, column, 1H-NMR, 13C-NMR, 2D-NMR, IR and MS.

RESULTS

The highest antioxidant activity was found in chloroform extract with EC50 value of 28.32 μg/ml followed by water, methanol, butanol, ethyl acetate and hexane extracts, their IC50 being 29.95, 39.17, 42.40, 43.20 and 57.00 μg/ml respectively. All crude extracts and pure compound displayed moderate antimicrobial activity against one Gram positive Staphylococcus aureus and three Gram negative Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris within growth inhibition range of 0-13 mm. The active metabolite was identified as 3,4-dihydroxycinnamic acid (R)-1-carboxy-2-(3,4-dihydroxyphenyl) ethyl ester which is a common plant ingredient known as rosmarinic acid.

CONCLUSION

The results indicate that walnut chloroform fraction may contain effective compounds with a broad spectrum of curative applications. This is the first report on isolation and characterization of a compound from chloroform crude extract of A. obesum.

Cytotoxic cardiac glycosides from the fruit (pods) of Adenium obesum (Forssk.) Roem. & Schult

Phytochemical investigation of methanolic extract of Adenium obesum led to the isolation of 42 (1-42) compounds belongs to cardiac glycosides, triterpenoids and steroids. The chemical structures of isolated compounds were elucidated by spectral techniques UV, IR, NMR and FAB MS. The cardiac glycosides were tested against three human cell lines, 3T3 (normal cells), HeLa (Human cervical cancer cell lines) and PC-3 (Human prostate cancer cell lines). The cardiac glycoside, honghelin (4), obeside B (5) and obeside C (6) showed significant effects against cell lines Hela, 3T3 and PC-3 compared to standard drug doxorubicin. Compounds 4, 5 and 6 exhibited very low IC₅₀ (μM) against the PC3 human cell line. 4 and 6 also showed least IC₅₀ against the HeLa human cell lines as compared to the standard drug doxorubicin whereas these three compounds showed effect on 3T3 cell line with high IC₅₀ values compared to drug cycloheximide.

Silver nanoparticles synthesized from Adenium obesum leaf extract induced DNA damage, apoptosis and autophagy via generation of reactive oxygen species

Silver nanoparticles (AgNPs) are an important class of nanomaterial used for a wide range of industrial and biomedical applications. Adenium obesum is a plant of the family Apocynaceae that is rich in toxic cardiac glycosides; however, there is scarce information on the anticancer potential of its AgNPs. We herein report the novel biosynthesis of AgNPs using aqueous leaf extract of A. obesum (AOAgNPs). The synthesis of AOAgNPs was monitored by color change and ultraviolet-visible spectroscopy (425 nm). It was further characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). The FTIR spectra for the AOAgNPs indicated the presence of terpenoids, long chain fatty acids, secondary amide derivatives and proteins that could be responsible for the reduction and capping of the formed AOAgNPs. X-ray diffraction confirmed the crystallinity of the AgNPs. The TEM images revealed mostly spherical particles in the size range of 10-30 nm. The biological properties of novel AOAgNPs were investigated on MCF-7 breast cancer cells. Cell viability was determined by the MTT assay. Generation of reactive oxygen species (ROS), DNA damage, induction of apoptosis and autophagy were assessed. A dose-dependent decrease in the cell viability was observed. The IC50 value was calculated as 217 μg/ml. Both qualitative and quantitative evaluation confirmed about a 2.5 fold increase in the generation of ROS at the highest concentration of 150 μg/ml. A significant (p<0.05) increase in the DNA damage evaluated by comet assay was evident. Flow cytometry revealed an increase in the apoptotic cells (24%) in the AOAgNPs treated group compared to the control. Acridine orange staining of acidic vesicles in exposed cells confirmed the induction of autophagy. These findings suggest that AOAgNPs increased the level of ROS resulting in heightened the DNA damage, apoptosis and autophagy in MCF-7 cells.