Efficacy of maturase K and rpL20 protein extracted from C. procera leaves on Anophelesstephensi

The present work is carried out to protein isolation, purification, and characterization from leaves, stem, and seed of C. procera and to evaluate the larvicidal potential on Anopheles stephensi. The whole protein was isolated using protein extraction buffer and precipitated by ammonium sulphate and larvicidal active protein was purified by the column chromatography. The homogeneity of larvicidal protein was confirmed by the SDS-PAGE. The identification of protein was done by the HPLC and LC-MS/ESI-MS. The crude protein from leaves showed 100% mortality of 3rd instar larvae of An. stephensi at the concentration of 5.5 mg/ml after 24 h of exposure. The crude protein from stem showed 25% mortality and no mortality observed was observed in seed protein. The leaves crude protein was further purified by ion exchange chromatography and eluted fractions were tested for larvicidal potential. The purified single protein fractions L2 and L3 from C. procera leaves showed 100% mortality at concentration of 0.06 mg/ml. The homogeneity of purified protein was confirmed by SDS-PAGE and two bands of 26 kDa and 15 kDa protein were observed. The peptide sequence "R.SQMLENSFLIENVMKR.L" was identified in the trypsin digested homogenous protein fraction L2 and "R.DRGSQKR.N" peptide sequence in L3 fraction by LC-MS/ESI-MS. The CprL2 peptide showed the sequence similarity with the protein maturase K and CprL3 peptide showed the sequence similarity with ribosomal protein L20 of C. procera. The conserved functional domain was also identified in both the CprL2 and CprL3 peptide. The identified proteins showed strong larvicidal efficacy at very low concentration. The identified proteins are novel and natural larvicidal agents against An. stephensi and hence can be used to control the malaria.

Network Pharmacology Approach to Identify the Calotropis Phytoconstituents' Potential Epileptic Targets and Evaluation of Molecular Docking, MD Simulation, and MM-PBSA Performance

Epilepsy originates from unusual electrical rhythm within brain cells, causes seizures. Calotropis species have been utilized to treat a wide spectrum of ailments since antiquity. Despite chemical and biological investigations, there have been minimal studies on their anticonvulsant activity, and the molecular targets of this plant constituents are unexplored. This study aimed to investigate the plausible epileptic targets of Calotropis phytoconstituents through network pharmacology, and to evaluate their binding strength and stability with the identified targets. In detail, 125 phytoconstituents of the Calotropis plant (C. procera and C. gigantea) were assessed for their drug-likeness (DL), blood-brain-barrier (BBB) permeability and oral bioavailability (OB). Network analysis revealed that targets PTGS2 and PPAR-γ were ranked first and fourth, respectively, among the top ten hub genes significantly linked with antiepileptic drug targets. Additionally, docking, molecular dynamic (MD) simulation, and Molecular Mechanics-Poisson-Boltzmann Surface Area (MM-PBSA) were employed to validate the compound-gene interactions. Docking studies suggested ergost-5-en-3-ol, stigmasterol and β-sitosterol exhibit stronger binding affinity and favorable interactions than co-crystallized ligands with both the targets. Furthermore, both MD simulations and MM-PBSA calculations substantiated the docking results. Combined data revealed that Calotropis phytoconstituents ergost-5-en-3-ol, stigmasterol, and β-sitosterol might be the best inhibitors of both PTGS2 and PPAR-γ.

Calotropis procera extract inhibits prostate cancer through regulation of autophagy

Current treatment options available for prostate cancer (PCa) patients have many adverse side effects and hence, new alternative therapies need to be explored. Anticancer potential of various phytochemicals derived from Calotropis procera has been studied in many cancers but no study has investigated the effect of leaf extract of C. procera on PCa cells. Hence, we investigated the effect of C. procera leaf extract (CPE) on cellular properties of androgen-independent PC-3 and androgen-sensitive 22Rv1 cells. A hydroalcoholic extract of C. procera was prepared and MTT assay was performed to study the effect of CPE on viability of PCa cells. The effect of CPE on cell division ability, migration capability and reactive oxygen species (ROS) production was studied using colony formation assay, wound-healing assay and 2',7'-dichlorodihydrofluorescein diacetate assay, respectively. Caspase activity assay and LDH assay were performed to study the involvement of apoptosis and necrosis in CPE-mediated cell death. Protein levels of cell cycle, antioxidant, autophagy and apoptosis markers were measured by western blot. The composition of CPE was identified using untargeted LC-MS analysis. Results showed that CPE decreased the viability of both the PCa cells, PC-3 and 22Rv1, in a dose- and time-dependent manner. Also, CPE significantly inhibited the colony-forming ability, migration and endogenous ROS production in both the cell lines. Furthermore, CPE significantly decreased NF-κB protein levels and increased the protein levels of the cell cycle inhibitor p27. A significant increase in expression of autophagy markers was observed in CPE-treated PC-3 cells while autophagy markers were downregulated in 22Rv1 cells after CPE exposure. Hence, it can be concluded that CPE inhibits PCa cell viability possibly by regulating the autophagy pathway and/or altering the ROS levels. Thus, CPE can be explored as a possible alternative therapeutic agent for PCa.

Phytochemical analysis, anti-inflammatory, antioxidant activity of Calotropis gigantea and its therapeutic applications

ETHNOPHARMACOLOGICAL RELEVANCE

Herbal remedies can be used to treat a variety of chronic inflammatory illnesses, like rheumatoid arthritis and leprosy. The plant Calotropis gigantea (C. gigantea) belongs to the family Apocynaceae. To treat numerous contagious diseases, C. gigantea is utilized alone or combine with certain medicinal herbs. Traditional Asian and African practitioners employed C. gigantea to treat a variety of inflammatory conditions like boils, rheumatoid arthritis, gout, leprosy and other disorders.

AIM OF THE STUDY

The goal of this study is to examine the anti-inflammatory and antioxidant activities of C. gigantea leaf extracts extracted using methanol, petroleum ether, and water.

MATERIALS AND METHODS

The leaf extracts of C. gigantea were obtained using the Soxhlet extraction technique. The phytoconstituents present in all three C. gigantea leaf extracts were confirmed by qualitative analysis, and the amounts of the alkaloids, flavonoids, terpenoids and phenols found in the extracts were quantified. C. gigantea crude extracts were subjected to a nitric oxide scavenging experiment to assess their free radical scavenging activities. Protein denaturation and proteinase inhibition assays were used to investigate the effectiveness of extracts to restrict denaturation of protein and to inhibit key enzymes responsible for tissue damage. Further, the membrane stabilization efficacy of plant extracts were examined by the heat-induced hemolysis method. The DPPH and FRAP experiments were performed to determine the antioxidant effectiveness of phytoconstituents extracted using different solvents. The GC-MS study of plant C. gigantea methanolic, aqueous and petroleum ether extracts displayed a broad range of compounds that possess beneficial therapeutic effects.

RESULTS

This study reveals that the methanolic extract of C. gigantea provides significantly more anti-inflammatory and antioxidant activity than other extracts.

CONCLUSION

Compared to the aqueous and petroleum ether extracts, the methanolic leaf extract of C. gigantea demonstrated greater in vitro anti-inflammatory and antioxidant properties.

Calotropis procera (Aiton) Dryand (Apocynaceae): State of the art of its uses and Applications

Calotropis procera (Aiton) Dryand (Apocynaceae), popularly known as milkweed, has been traditionally used to treat diseases particularly associated with gastric disorders, skin disease and inflammatory processes. The present study aimed to review the current scientific evidence regarding the pharmacological effects of C. procera extracted phytochemicals and possible research opportunities as complementary and alternative medicine. Scientific publications were searched in various electronic databases (PubMed, Scopus, Web of Science, Google Scholar, Springer, Wiley, and Mendeley) using the following search terms: Calotropis procera, medicinal plants, toxicity, phytochemical characterization, and biological effects. Collected data showed that cardenolides, steroid glycoside and flavonoids are the main classes of phytochemicals identified in C. procera latex and leaves. In addition, lignans, terpenes, coumarins, and phenolic acids have been reported. These metabolites have been correlated with their biological activities, including mainly antioxidant, anti-inflammatory, antitumoral, hypoglycemic, gastric protective, anti-microbial, insecticide, anti-fungal, anti-parasitic, among others. However, some of the studies were carried out with only a single dose or with a high dose not achievable under physiological conditions. Therefore, the validity of C. procera biological activity may be questionable. Not less important to highlight are the risks associated with its use and the possibility of accumulation of heavy metals that can be toxic. Furthermore, there are no clinical trials with C. procera to date. In conclusion, the need of bioassayguided isolation of bioactive compounds, bioavailability and efficacy, as well as pharmacological and toxicity studies, are needed using in vivo models and clinical trials in order to support the traditionally claimed health benefits.

Anti-inflammatory and antioxidant effect of methanol extract of latex of Calotropis procera in rat model of colorectal cancer

ETHNOPHARMACOLOGICAL RELEVANCE

Preparations derived from the plant Calotropis procera, have been used for medicinal purpose though the plant is known for its toxic effects. The aerial parts of the plant contain latex in plenty and have been found effective in treating disorders of gastrointestinal system and cancer.

AIM OF THE STUDY

This study evaluated the efficacy of C. procera dried latex extract prepared in methanol (MeDL) against inflammation and oxidative stress in experimental model of colorectal carcinoma (CRC).

MATERIALS AND METHODS

Two subcutaneous injections of chemical carcinogen, 1,2-dimethylhydrazine (DMH; 150 mg/kg) were given at an interval of one week to induce CRC in rats. The MeDL (50 and 150 mg/kg) and aspirin (60 mg/kg) were given daily and their effect was evaluated on markers of oxidative stress and inflammation after completion of 8 weeks following second injection of carcinogen. A comparison was made with normal and experimental control groups. The colon tissue levels of glutathione (GSH), thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), nitrite and myeloperoxidase (MPO) were determined. Enzyme-linked immunosorbent assay was performed to determine the levels of prostaglandin E₂ (PGE₂) and tumor necrosis factor-alpha (TNF-α) and immunohistochemical analysis was performed for IL-1β.

RESULTS

Induction of cancerous changes in the colon resulted in altered oxidative homeostasis as evident from a reduction in GSH level and SOD activity and rise in TBARS level when compared with normal rats. Elevated levels of nitrite, MPO, TNF-α, PGE₂ and immunoreactivity of IL-1β were also observed in these rats. The levels of these markers were normalized when the rats were treated with MeDL or anti-inflammatory drug, aspirin.

CONCLUSION

This study demonstrates that suppression of oxidative stress and inflammation contributes to the beneficial effect of MeDL in rat model of colon carcinogenesis.

Recombinant osmotin inclusion bodies from Calotropis procera produced in E. coli BL21(DE3) prevent acute inflammation in a mouse model of listeriosis

BACKGROUND

The osmotin from the medicinal plant Calotropis procera (CpOsm) has characteristics similar to adiponectin, a human protein with immunoregulatory actions.

PURPOSE

This study aimed to investigate whether recombinant osmotin inclusion bodies from C. procera (IB/rCpOsm) produced in E. coli BL21(DE3) can prevent infection-induced inflammation. A virulent strain of Listeria monocytogenes was used as an infection model.

METHODS

Cells of E. coli BL21(DE3) carrying the plasmid pET303-CpOsm were used to express the recombinant osmotin, which accumulated at reasonable levels as inclusion bodies (IB/rCpOsm). IB/rCpOsm were purified from induced cells and SDS-polyacrylamide gel electrophoresis followed by mass spectrometry analyses confirmed the identity of the major protein band (23 kDa apparent molecular mass) as CpOsm. Peritoneal macrophages (pMØ) from Swiss mice were cultured with IB/rCpOsm (1 or 10 µg/ml) in 96-well plates and then infected with L. monocytogenes. IB/rCpOsm (0.1, 1 or 10 mg/kg) was also administered intravenously to Swiss mice, which were then infected intraperitoneally with L. monocytogenes.

RESULTS

Pretreatment of the pMØ with IB/rCpOsm significantly increased cell viability after infection and reduced the intracellular bacterial load. The infiltration of neutrophils into the peritoneal cavity of mice pretreated with IB/rCpOsm at 10 mg/kg (but not 0.1 and 1 mg/kg) was reduced after infection. In these mice, the bacterial load was high in the peritoneal fluid and the liver, but histological damage was discrete. The treatments with IB/rCpOsm at 10 mg/kg significantly increased the expression of the anti-inflammatory cytokine IL-10.

CONCLUSION

This study shows that recombinant osmotin inclusion bodies from C. procera were bioactive and prompted anti-inflammatory actions at therapeutic dosages in the L. monocytogenes infection model.

Anti-migraine activity of freeze-dried latex obtained from Calotropis gigantea Linn

Migraine which is characterized by a pulsating headache affected an estimated population of 12% worldwide. Herbal products like latex derived from Calotropis gigantea R. Br. (Asclepiadaceae) are a representative intervention to treat migraine traditionally. However, post-harvesting stability issues of latex affect its biological potential. Freeze-drying has been successfully employed for the encapsulation of herbal bioactive compounds resulting in stable dried preparations. Latex derived from Calotropis gigantea (C. gigantea) was microencapsulated using chitosan by freeze-drying (FDCG) method and compared with sun ray-dried latex (ADCG). Current investigation was aimed to improve the shelf life of latex by freeze-drying microencapsulation technique and evaluation of its anti-migraine potential. Dried latex powders (ADCG and FDCG) were evaluated in terms of phenolic content, coloring strength, first-order kinetic, color parameters (L*, a*, b*, C*, and E*), moisture, water activity, solubility, and hygroscopicity. Additionally, apomorphine-induced climbing behavior, L-5-HTP-induced syndrome, and MK-801-induced hyperactivity were used to evaluate the anti-migraine potential of powdered latex. FDCG showed good physicochemical properties due to its higher concentration of phenolic and flavonoid contents. Moreover, FDCG significantly reduced the apomorphine-induced climbing behavior, L-5-HTP-induced syndrome, and MK-801-induced hyperactivity in a dose-dependent manner through an interaction of dopaminergic and serotonergic receptors. In conclusion, the method developed for shelf life improvement of latex offered maximum protection over a period of 10 weeks with retaining its natural biological potential; thus, it can be effectively utilized in the treatment or management of migraine. Anti-migraine effect of Calotropis gigantea freeze-dried latex by inhibition of dopamine and serotonin receptors (D1 and D2: dopamine receptors; 5-HT: serotonin receptors); yellow color represents serotonergic, and blue color indicates dopaminergic neurons.

Protective effect of methanol extract of latex of Calotropis procera in an experimental model of colorectal cancer

ETHNOPHARMACOLOGICAL RELEVANCE

The plant, Calotropis procera, has been used for treating various gastrointestinal disorders and cancer. Some of these medicinal properties have been attributed to the latex produced by the plant.

AIM OF THE STUDY

To evaluate the efficacy of methanol extract of air-dried latex (MeDL) of C. procera in the rat model of colorectal cancer (CRC).

MATERIALS AND METHODS

CRC was induced in the rats by 1,2-dimethylhydrazine (DMH) and the effect of MeDL was evaluated at two doses (50 and 150 mg/kg). MeDL and reference drug aspirin (60 mg/kg) were administered orally starting from 1 h before injecting DMH till 8 weeks after the second dose of DMH. The study also included experimental and normal control groups. Microscopic analysis was carried out to determine the count for aberrant crypt foci (ACF) and histology score whereas enzyme-linked immunosorbent assay and immunohistochemical analyses were performed for markers of carcinogenesis and angiogenesis. Other parameters that were evaluated include deoxyribonucleic acid (DNA) fragmentation, laddering, Bcl₂ and Bax immunoreactivity, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positivity.

RESULTS

Subcutaneous injection of DMH induced pre-neoplastic changes in the colon of rats with the appearance of ACF with multiple crypts (1-3, 4-6 or >6). In the experimental control group, total ACF count was 3.49 ± 0.23/cm of the colon length and the median histology score was 2.0 for architectural abnormalities, 2.0 for dilatation of crypts and 1.5 for hyperplasia/dysplasia against 1.0 for all the characteristics in normal rats. Oral administration of MeDL similar to aspirin, led to a reduction in ACF count and histology score of CRC concomitant with a decrease in the levels of markers of carcinogenesis - β-catenin and proliferating cell nuclear antigen (PCNA); markers of angiogenesis - matrix metallopeptidase-9 (MMP-9) and vascular endothelial growth factor (VEGF), and an increase in apoptotic DNA fragmentation.

CONCLUSION

MeDL confers protection in the rat model of CRC and the study suggests its therapeutic potential in this condition.

Antinociceptive effect of the hydroethanolic leaf extract of Calotropis procera (Ait) R. Br. (Apocynaceae): Possible involvement of glutamatergic, cytokines, opioidergic and adenosinergic pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Pain remains real and still a major problem in clinical medicine which requires new agents with improved efficacy for more therapeutic benefits. Plant sources can serve as a basis for the search for some novel drugs hence the analgesic effects of the hydroethanolic extract of Calotropis procera (CPE) which is widespread in Ghana and other tropical areas and used in folkloric medicine for painful and inflammatory conditions was evaluated.

MATERIALS AND METHODS

The analgesic properties of orally administered CPE at doses of 30, 100, and 300 mg/kg were evaluated in thermal (tail immersion), chemical (acetic acid-writhing, formalin-induced paw licking, glutamate-induced nociception) and mechanical (Randall-Selitto) tests for analgesia. The involvement of tumour necrosis factor-alpha (TNF-α), interleukin 1β (IL 1β), bradykinin, and prostaglandin E₂ (PGE₂) on the analgesic effects of CPE were also evaluated in hypernociception assays measuring mechanical pain thresholds.

RESULTS

The latency of tail withdrawal in the tail immersion test was significantly increased (p = 0.0001) while writhing induced by acetic acid was significantly reduced (p < 0.0001) on treatment with CPE (30-300 mg/kg). The extract also significantly inhibited both phase 1 and phase 2 nociceptive states induced by formalin comparable to morphine (p < 0.0001). Furthermore, the extract significantly attenuated hyper-nociception induced by TNF-α (p < 0.0001), interleukin 1β (p = 0.0102), bradykinin (p < 0.0001), and prostaglandin E₂ (p < 0.0001). Additionally, glutamate-induced paw licking was reduced significantly (p < 0.05). The antinociceptive effects exhibited by CPE (100 mg/kg) in the formalin test was reversed by systemic administration of naloxone (2 mg/kg) and theophylline (5 mg/kg) but not glibenclamide (8 mg/kg), granisetron (2 mg/kg), atropine (3 mg/kg), yohimbine (3 mg/kg, p.o.) nor nifedipine (10 mg/kg).

CONCLUSION

Overall, the hydroethanolic leaf extract of Calotropis procera possesses analgesic properties that is mediated possibly through the glutaminergic, opioidergic, and adenosinergic pathways.

In-vivo anti-plasmodial activity of phosphate buffer extract of Calotropis procera latex in mice infected with Plasmodium berghei

ETHNOPHARMACOLOGICAL RELEVANCE

Malaria is a global health problem with the greatest burden in sub-Saharan Africa (sSA). The resistance to available antimalarial agents necessitate for the development of new and safe drugs for which medicinal plants provides credible alternative sources for discovering new and cheap therapeutic agents. Calotropis procera is used in several folk or traditional medicines for the treatment of various diseases across different regions of the world. In Nigeria traditional medicine, C. procera latex is used either alone or in combination with other herbs to cure common diseases including malaria. In Malaka district (Indonesia), Calotropis gigantea (a member of Apocyanceae), is one of the most used herbs to treat malaria patient via the massage method.

AIM OF THE STUDY

This study aimed to evaluate the anti-plasmodial activity of phosphate buffer extract of Calotropis procera latex in mice infected with Plasmodium berghei.

MATERIALS AND METHODS

The plant's anti-plasmodial agent was extracted using 0.2 M-phosphate buffer (pH 7.0), followed by precipitation using acetone. 90 (ninety) mice were divided into three main groups of 30 (thirty) mice each, used for the curative, suppressive and prophylactic tests, respectively. The 30 (thirty) mice in each of the main groups were sub-divided into five groups of 6 (six) mice. The mice in the group 1, 2 and 3 (test groups) were made to receive graded doses of 25 mg/kg, 50 mg/kg and 75 mg/kg of the extract of C. procera latex intraperitoneally; group 4 (negative control group) received 0.2 ml of normal saline; while group 5 (positive control group) were administered with 5 mg/kg chloroquine. The phytochemical constituents of the plant and its intraperitoneal median lethal dose (LD₅₀) were also undertaken.

RESULTS

The freeze-dried acetone extract exhibited acute toxicity with median lethal dose (LD₅₀) of 745 mg/kg body weight in mice. The highest percentage parasite suppression (61.85%), percentage parasite cure (50.26%), and percentage parasite prophylaxis (65.47%), were obtained for the groups treated with 75 mg/kg bodyweight/day of the extract. The least percentage parasite suppression (44.74%), percentage parasite cure (35.21%), and percentage parasite prophylaxis (45.21%), were obtained for the groups treated with 25 mg/kg body weight of the extract. Also, a dose-dependent percentage parasite suppression (53.03%), percentage parasite cure (39.70%), and percentage parasite prophylaxis (49.82%) were obtained for the groups treated with 50 mg/kg body weight. This is comparable to the groups treated with standard chloroquine. The extract also produced a significant elevation in body weight of the animals for suppressive and curative tests. However, there were observable significant decreases in body weight of the animals in the case of prophylactic test.

CONCLUSION

This study showed that the phosphate buffer extract of C. procera latex possess anti-plasmodial activity. The results of this study can be used as a basis for further phytochemical investigations in the search for new and locally affordable antimalarial agents.

Calotropis gigantea stem bark extract induced apoptosis related to ROS and ATP production in colon cancer cells

Conventional chemotherapeutic agents for colorectal cancer (CRC) cause systemic side effects and eventually become less efficacious owing to the development of drug resistance in cancer cells. Therefore, new therapeutic regimens have focused on the use of natural products. The anticancer activity of several parts of Calotropis gigantea has been reported; however, the effects of its stem bark extract on inhibition of cancer cell proliferation have not yet been examined. In this study, the anticancer activity of C. gigantea stem bark extract, both alone and in combination with 5-fluorouracil (5-FU), was evaluated. A crude ethanolic extract was prepared from dry, powdered C. gigantea barks using 95% ethanol. This was then partitioned to obtain dichloromethane (CGDCM), ethyl acetate, and water fractions. Quantitative analysis of the constituent secondary metabolites and calotropin was performed. These fractions exhibited cytotoxicity in HCT116 and HT-29 cells, with CGDCM showing the highest potency in both the cell lines. A combination of CGDCM and 5-FU significantly enhanced the cytotoxic effect. Moreover, the resistance of normal fibroblast, HFF-1, cells to this combination demonstrated its safety in normal cells. The combination significantly enhanced apoptosis through the mitochondria-dependent pathway. Additionally, the combination reduced adenosine triphosphate production and increased the production of reactive oxygen species, demonstrating the mechanisms involved in the induction of apoptosis. Our results suggest that CGDCM is a promising anti-cancer agent and may enhance apoptosis induction by 5-FU in the treatment of CRC, while minimizing toxicity toward healthy cells.

Compositions and antimicrobial properties of binary ZnO-CuO nanocomposites encapsulated calcium and carbon from Calotropis gigantea targeted for skin pathogens

Calotropis gigantea (C. gigantea) extract with an ecofriendly nanotechnology approach could provide promising antimicrobial activity against skin pathogens. This study investigates the antimicrobial capability of green synthesized binary ZnO-CuO nanocomposites from C. gigantea against non-MDR (Staphylococcus aureus and Escherichia coli) and MDR (Klebsiella pneumoniae, Pseudomonas aeruginosa and methicillin-resistant S. aureus) skin pathogens. Scanning electron microscopy and transmission electron microscopy revealed the size and shape of B3Z1C sample. Results of X-ray powder diffraction, energy-dispersive spectroscopy, FTIR and UV-Vis spectroscopy analyses confirmed the presence of mixed nanoparticles (i.e., zinc oxide, copper oxide, carbon and calcium) and the stabilising phytochemical agents of plant (i.e., phenol and carbonyl). Antimicrobial results showed that carbon and calcium decorated binary ZnO-CuO nanocomposites with compositions of 75 wt% of ZnO and 25 wt% CuO (B3Z1C) was a strong bactericidal agent with the MBC/MIC ratio of ≤ 4 and ≤ 2 for non-MDR and MDR pathogens, respectively. A significant non-MDR zone of inhibitions were observed for BZC by Kirby-Bauer disc-diffusion test. Further time-kill observation revealed significant fourfold reduction in non-MDR pathogen viable count after 12 h study period. Further molecular studies are needed to explain the biocidal mechanism underlying B3Z1C potential.

Perspectives for the use of latex peptidases from Calotropis procera for control of inflammation derived from Salmonella infections

BACKGROUND

Anti-inflammatory properties have been attributed to latex proteins of the medicinal plant Calotropis procera.

PURPOSE

A mixture of cysteine peptidases (LPp2) from C. procera latex was investigated for control of inflammatory mediators and inflammation in a mouse model of Salmonella infection.

METHODS

LPp2 peptidase activity was confirmed by the BANA assay. Cytotoxicity assays were conducted with immortalized macrophages. Peritoneal macrophages (pMØ) from Swiss mice were stimulated with lipopolysaccharide (LPS) in 96-well plates and then cultured with nontoxic concentrations of LPp2. Swiss mice intravenously received LPp2 (10 mg/kg) and then were challenged intraperitoneally with virulent Salmonella enterica Ser. Typhimurium.

RESULTS

LPp2 was not toxic at dosages lower than 62.2 μg/mL. LPp2 treatments of pMØ stimulated with LPS impaired mRNA expression of pro-inflammatory cytokines IL-1β, TNF-α, IL-6 and IL-10. LPp2 increased the intracellular bacterial killing in infected pMØ. Mice given LPp2 had a lower number of leukocytes in the peritoneal cavity in comparison to control groups 6 h after infection. The bacterial burden and histological damage were widespread in target organs of mice receiving LPp2.

CONCLUSION

We conclude that LPp2 contains peptidases with strong anti-inflammatory properties, which may render mice more susceptible to early disseminated infection caused by Salmonella.

Essential Oil of Calotropis procera: Comparative Chemical Profiles, Antimicrobial Activity, and Allelopathic Potential on Weeds

Plants are considered green resources for thousands of bioactive compounds. Essential oils (EOs) are an important class of secondary compounds with various biological activities, including allelopathic and antimicrobial activities. Herein, the present study aimed to compare the chemical profiles of the EOs of the widely distributed medicinal plant Calotropis procera collected from Saudi Arabia and Egypt. In addition, this study also aimed to assess their allelopathic and antimicrobial activities. The EOs from Egyptian and Saudi ecospecies were extracted by hydrodistillation and analyzed via GC-MS. The correlation between the analyzed EOs and those published from Egypt, India, and Nigeria was assessed by principal component analysis (PCA) and agglomerative hierarchical clustering (AHC). The allelopathic activity of the extracted EOs was tested against two weeds (Bidens pilosa and Dactyloctenium aegyptium). Moreover, the EOs were tested for antimicrobial activity against seven bacterial and two fungal strains. Ninety compounds were identified from both ecospecies, where 76 compounds were recorded in Saudi ecospecies and 33 in the Egyptian one. Terpenes were recorded as the main components along with hydrocarbons, aromatics, and carotenoids. The sesquiterpenes (54.07%) were the most abundant component of EO of the Saudi sample, while the diterpenes (44.82%) represented the mains of the Egyptian one. Hinesol (13.50%), trans-chrysanthenyl acetate (12.33%), 1,4-trans-1,7-cis-acorenone (7.62%), phytol (8.73%), and myristicin (6.13%) were found as the major constituents of EO of the Saudi sample, while phytol (38.02%), n-docosane (6.86%), linoleic acid (6.36%), n-pentacosane (6.31%), and bicyclogermacrene (4.37%) represented the main compounds of the Egyptian one. It was evident that the EOs of both ecospecies had potent phytotoxic activity against the two tested weeds, while the EO of the Egyptian ecospecies was more effective, particularly on the weed D. aegyptium. Moreover, the EOs showed substantial antibacterial and antifungal activities. The present study revealed that the EOs of Egyptian and Saudi ecospecies were different in quality and quantity, which could be attributed to the variant environmental and climatic conditions. The EOs of both ecospecies showed significant allelopathic and antimicrobial activity; therefore, these EOs could be considered as potential green eco-friendly resources for weed and microbe control, considering that this plant is widely grown in arid habitats.

Triple-Negative Breast Cancer Cells Exhibit Differential Sensitivity to Cardenolides from Calotropis gigantea

Triple-negative breast cancers (TNBC) are aggressive and heterogeneous cancers that lack targeted therapies. We implemented a screening program to identify new leads for subgroups of TNBC using diverse cell lines with different molecular drivers. Through this program, we identified an extract from Calotropis gigantea that caused selective cytotoxicity in BT-549 cells as compared to four other TNBC cell lines. Bioassay-guided fractionation of the BT-549 selective extract yielded nine cardenolides responsible for the selective activity. These included eight known cardenolides and a new cardenolide glycoside. Structure-activity relationships among the cardenolides demonstrated a correlation between their relative potencies toward BT-549 cells and Na+/K+ ATPase inhibition. Calotropin, the compound with the highest degree of selectivity for BT-549 cells, increased intracellular Ca2+ in sensitive cells to a greater extent than in the resistant MDA-MB-231 cells. Further studies identified a second TNBC cell line, Hs578T, that is also highly sensitive to the cardenolides, and mechanistic studies were conducted to identify commonalities among the sensitive cell lines. Experiments showed that both cardenolide-sensitive cell lines expressed higher mRNA levels of the Na+/Ca2+ exchanger NCX1 than resistant TNBC cells. This suggests that NCX1 could be a biomarker to identify TNBC patients that might benefit from the clinical administration of a cardiac glycoside for anticancer indications.

Evaluation of the in vitro antileishmanial activities of bioactive guided fractionations of two medicinal plants

The organisms of the genus Leishmania are flagellated protozoan parasites and are the causative agents of leishmaniasis. This disease is a major health problem, especially in tropical countries. Currently, cutaneous leishmaniasis is treated by chemotherapy using pentavalent antimonials, but these drugs have serious organo-toxicity, drug resistance on several occasions, and low efficiency in controlling the infection. The present work is carried out to evaluate the in vitro antileishmanial activity of methanolic extracts and phytochemical fractions of two plants ethnobotanically used against leishmaniasis and skin infection, Calotropis procera and Rhazya stricta leaves against Leishmania major promastigote and amastigote stages and cytotoxicity against the Vero cell line. The leaves of C. procera and R. stricta were extracted with methanol and fractionated by petroleum ether, chloroform, ethyl acetate, n-butanol, and water. The methanolic extracts of the leaves of C. procera and R. stricta exhibited antileishmanial activity against L. major promastigotes with IC₅₀ values of 66.8 and 42.4 µg mL^-1, respectively. While their CC₅₀ 2.3 and 298 µg mL^-1 and their SI 0.03 and 7.03 respectively. However, the fractionations of the methanolic extract of C. procera leaves revealed antiparasitic activity against both L. major promastigote and amastigote stages in vitro, which significantly increased with polarity with the exception of n-butanol. Hence the best activity was revealed by the water fraction (IC₅₀ of 26.3 and 29.0 µg mL^-1) for the two stages. In conclusion, further phytochemical investigation should be performed for the C. procera water extract in terms of antileishmanial active ingredient isolation that may enhance the possibility of avoiding toxic substances and overcome the low SI (1.1 and 1.01).

Calosides A-F, Cardenolides from Calotropis gigantea and Their Cytotoxic Activity

Phytochemical analysis of the roots of Calotropis gigantea led to the isolation of six new cardenolide glycosides, calosides A-F (1-6), and five known cardenolides (7-11). The structures of 1-6 were elucidated based on NMR and ECD spectroscopic data interpretation. Caloside D (4) is the first naturally occurring example of a cardenolide containing a C-8/C-19 oxygen bridge. In turn, calosides E (5) and F (6) represent the first naturally occurring 3-epi-cannogenol diglycosides having potent cytotoxicity against the PANC-1 cell line (IC₅₀, 0.081 and 0.070 μM, respectively) and HeLa (IC₅₀, both 0.17 μM) cells, under normoglycemic conditions.

Acaricidal efficacy of Calotropis procera (Asclepiadaceae) and Taraxacum officinale (Asteraceae) against Rhipicephalus microplus from Mardan, Pakistan

Medicinal plants are used by traditional folk healers, modern physicians, and veterinarians as an alternative to conventional drugs to treat a wide range of disorders including parasitic diseases. Some compounds from these plants have been shown to have acaricidal activity and repel arthropods. The cattle tick Rhipicephalus microplus is one of the most destructive pests to the livestock industry in tropical and subtropical parts of the world. The potential to develop herbal acaricides to control R. microplus infestations is critical in maintaining cattle herd productivity, reducing economic losses, and curtailing the overuse of synthetic chemical acaricides. Calotropis procera, the apple of Sodom, and Taraxacum officinale, the common dandelion, were evaluated for acaricidal activity against R. microplus larvae and adults in vitro. Both plant species tested are common indigenous species of Pakistan where R. microplus infestations are widespread across livestock species including cattle, sheep, and goats. Whole-plant extracts derived from C. procera and T. officinale significantly reduced the index of egg laying (P < 0.01) and increased the percent inhibition of oviposition of adult female ticks at a concentration of 40 mg/mL when assessed by the adult immersion test (AIT). Calotropis procera and T. officinale treatments at the same concentration also resulted in larval mortality of 96.0% ± 0.57 and 96.7% ± 0.88, respectively, as measured using the larval packet test (LPT). An increasing range of extract concentrations was tested to determine the LD₅₀ and LD₉₀ for C. procera, 3.21 and 21.15 mg/mL, respectively, and T. officinale, 4.04 and 18.92 mg/mL, respectively. These results indicate that further studies are warranted to determine the relative contribution of individual phytochemicals from whole-plant extracts on acaricidal activity. This information will guide the design of further acaricidal efficacy tests using livestock infested with R. microplus.

Neurite outgrowth properties of Calotropis procera: In search for a neuroprotectant

In view of the well-documented medicinal properties of Calotropis procera (CP), the present study was designed to evaluate the neuroprotective effect of the extract. We have prepared a methanolic extract of Calotropis procera and screen varying concentration of CP (20, 30, 40, 50 and 70μg/ml) for the stimulatory potency on neurite outgrowth. The stimulatory effect of CP on neurite outgrowth was assessed in primary hippocampal neurons. Neurite lengths were measured using optika provison analysis software. Neuritogenesis was further analyzed by immunostaining by using specific neuronal marker β III-tubulin. The data show that neurite outgrowth from hippocampal neurons were significantly enhanced in the presence of CP (40μg/ml). The most stimulatory neurite outgrowth effects were appeared after 48hrs incubation of neurons with CP (40μg/ml). These data confirm that CP extract could promote invitro hippocampal neurite outgrowth in a dose-dependent manner. Our results indicate that CP can be used as a healthy dietary supplement for the cognitive functions of the brain.

Notch Inhibitors from Calotropis gigantea That Induce Neuronal Differentiation of Neural Stem Cells

Neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease occur due to loss of the structure and function of neurons. For the potential treatment of neurodegenerative diseases, accelerators of neuronal differentiation of neural stem cells (NSCs) have been focused on and a cell-based assay system for measuring Notch signaling pathway activity was constructed. Using this assay system, eight compounds isolated from Calotropis gigantea were identified as inhibitors of the Notch signaling pathway. Hes1 and Hes5 are target genes of the Notch signaling pathway, and compound 1, called uscharin, decreased the protein levels of Hes1 and Hes5 in assay cells and MEB5 cells (mouse NSCs). Furthermore, uscharin (1) enhanced the differentiation of MEB5 cells into neurons. The mechanism of uscharin (1) for the Notch signaling inhibitory activity would be acceleration of the degradation of the Notch intracellular domain (NICD) in the MEB5 cells.

Cardenolides from Calotropis gigantea as potent inhibitors of hypoxia-inducible factor-1 transcriptional activity

ETHNOPHARMACOLOGICAL RELEVANCE

Calotropis gigantea (L.) Dryand (Apocynaceae) is a medicinal plant native to southern China, India and Southeast Asia. It has been traditionally used for the treatment of several diseases including cancers in these countries.

AIM OF THE STUDY

This study aimed to isolate bioactive cardenolides from C. gigantea, to screen their hypoxia-inducible factor (HIF-) 1 inhibitory activity, and to analyze the structure-activity relationship (SAR).

MATERIALS AND METHODS

Isolation and purification of cardenolides from the latex and the fruits of C. gigantea were performed by using a series of separation techniques. Their structures were fully characterized by elucidating their NMR and HRMS data. The HIF-1 inhibitory activities of cardenolides were evaluated by using a T47D cell-based dual-luciferase reporter assay. The potent cardenolides were selected to further evaluate their dose-response manner. Cytotoxic effects of selected cardenolides were also examined against breast cancer cell line (MCF-7) and normal mammary epithelial cell line (MCF-10A) by MTT assay.

RESULTS

Among twenty isolated cardenolides, compounds 1, 3, 4, 6-8, 14 and 17 exhibited stronger HIF-1 inhibitory activities than that of digoxin, a well-known HIF-1 inhibitor (P<0.001). These eight cardenolides inhibited HIF-1 transcriptional activity in a dose-dependent manner with IC₅₀ values in nanomolar potency (21.8-64.9nM). An analysis of SAR revealed the great contributions of a β-configuration of the substituents at positions of C-2' and C-3', an aldehydic moiety on C-19, and the dioxane moiety between the aglycone and sugar parts of cardenolides to the HIF-1 inhibitory activity. In contrast, a hydroxyl group at any positions of C-15, C-16 and C-4' of cardenolides showed negative effects on suppressing HIF-1 transcriptional activity. In addition, these eight cardenolides also exhibited potent cytotoxic effects against human breast cancer cell MCF-7 (IC₅₀ values ranged from 30.5 to 68.8nM), but less toxic effects to human normal mammary epithelial cell MCF-10A (IC₅₀ values >20µM).

CONCLUSIONS

This is the first report of a comprehensive study of SAR on cardenolides from C. gigantea as HIF-1 inhibitors. Eight cardenolides (1, 3, 4, 6-8, 14 and 17) showed both potent HIF-1 inhibitory activity and strong cytotoxic effect against MCF-7 cancer cells in nanomolar level. The findings of these cardenolides provided important insights into the development of these potent HIF-1 inhibitors as anticancer drug.

First insights into the diversity and functional properties of chitinases of the latex of Calotropis procera

Chitinases (EC 3.2.1.14) found in the latex of Calotropis procera (Ait) R. Br. were studied. The proteins were homogeneously obtained after two ion exchange chromatography steps. Most proteins were identified individually in 15 spots on 2-D gel electrophoresis with isoelectric points ranging from 4.6 to 6.0 and molecular masses extending from 27 to 30 kDa. Additionally, 66 kDa proteins were identified as chitinases in SDS-PAGE. Their identities were further confirmed by mass spectrometry (MS) analysis of the tryptic digests of each spot and MS analysis of the non-digested proteins. Positive reaction for Schiff's reagent suggested the proteins are glycosylated. The chitinases exhibited high catalytic activity toward to colloidal chitin at pH 5.0, and this activity underwent decay in the presence of increasing amounts of reducing agent dithiothreitol. Spore germination and hyphae growth of two phytopathogenic fungi were inhibited only marginally by the chitinases but were affected differently. This suggested a complex relationship might exist between the specificity of the proteins toward the fungal species. The chitinases showed potent insecticidal activity against the Bruchidae Callosobruchus maculatus, drastically reducing survival, larval weight and adult emergence. It is concluded that closely related chitinases are present in the latex of C. procera, and the first experimental evidence suggests these proteins are involved more efficiently in defence strategies against insects rather than fungi.

Latex protein extracts from Calotropis procera with immunomodulatory properties protect against experimental infections with Listeria monocytogenes

BACKGROUND

The latex from the medicinal plant Calotropis procera is often used in folk medicine against infectious and inflammatory diseases.

PURPOSE

In this study, we investigate a protein fraction with immunomodulatory properties, named LPPI, against experimental infections, in vitro and in vivo, with a virulent strain of Listeria monocytogenes.

STUDY DESIGN

LPPI was exposed to cultured macrophages or Swiss mice and then challenged with L. monocytogenes.

METHODS

Peritoneal macrophages were obtained from Swiss mice, and cultured in 96-well microplates. Soluble latex proteins (LP) were subjected to fractionation by ion-exchange chromatography. The major peak (LPPI) was added into wells at 10 or 100µg/ml. Albumin (100µg/ml) was used for comparison between protein treatments. After incubation for 1h at 5% CO2/ 37°C, the supernatant was discarded and 0.2ml of L. monocytogenes overnight culture was added in the wells. Following 4h and 24h infection, the cytokine mRNA expression was evaluated as well as the number of intracellular colony forming units. Swiss mice (n=16) were injected intraperitoneally (i.p.) with LPPI (5 and 10mg/kg) while the control mice received albumin (10mg/kg) or LP (10mg/kg). After 24h, all animal groups were challenged with L. monocytogenes (10(6) CFU/ ml), also by i.p. route.

RESULTS

LPPI was not toxic to uninfected macrophages (pMØ) and significantly increased mRNA expression of TNF-α, IL-6, IL-1β and iNOS. Following infection, cell viability was reduced by 50% in albumin-treated pMØ (control); but only 17% in pMØ treated with LPPI at 100µg/ml. In this case, LPPI increased expression of TNF-α and IL-6 whereas the number of bacterial colony-forming units was reduced 100-fold in comparison to control groups. Swiss mice pretreated with LPPI showed dose-dependent survival rates that reached 80%, while mice that received albumin died 1-3 days after infection. After 24h infection, leukocyte migration to the infectious foci was high in LPPI-treated mice whereas the number of viable bacteria in the peritoneal fluid, liver and bloodstream were significantly reduced.

CONCLUSION

We conclude that LPPI present immunomodulatory properties that are beneficial for prevention of systemic bacterial infections caused by the intracellular bacteria L. monocytogenes.

Antioxidant and antiapoptotic activities of Calotropis procera latex on Catfish (Clarias gariepinus) exposed to toxic 4-nonylphenol

Calotropis procera L. is known as medicinal plant. The Phytochemical analyzes of its latex revealed that it possessed antioxidants, namely terpenes, phenolic compounds and cardenolides, flavonoids and saponins, while tannins, alkaloids and resin were absent in moderate to high concentration. In the present study, the role of latex of Calotropis procera as antioxidant and antiapoptotic was reported. To carry out this aim, fishes were exposed to 100 µg l(-1) 4-nonylphenol as chemical pollutant. The enzymes, superoxidase dismutase, catalase, acetlycholinstrase (AchE), glutathione s-transferase, cortisol, G6PDH) and apoptotic cells increased significantly (p<0.05) accompanied by irregular disturbance of (Na(+), K(+)) ions in the presence of 4-nonylphenol. On the other hand, these enzymes, ions, and apoptotic cells decreased normally and significantly (p<0.05) in the presence of latex. Total phenol content, total capacity antioxidant, reducing power decrease significantly (p<0.05) in the presence of 4-nonylphenol and increase normally in the presence of latex. Latex was used for the first time to protect catfish after 4-nonylphenol exposure. Our study confirms that crude latex of Calotropis procera possessed antioxidant and antiapoptotic activities against the toxicity of 4-Nonylphenol.

Impact of phenolic composition on hepatoprotective and antioxidant effects of four desert medicinal plants

BACKGROUND

Flavonoids and other polyphenols play a protective role in liver diseases and possess a high antioxidant capacity.

OBJECTIVE

To compare and evaluate the antioxidant and hepatotoprotective activities of 4 deserts plants, Fagonia indica Burm. f., Calotropis procera R.Br., Zygophylum hamiense Schweinf. and Salsola imbricata Forssk. in correlation to their composition especially their phenolic content.

METHODS

The influence of extracting solvent on total phenolic and flavonoidal contents was assessed spectrophotometrically. The flavonoid and other polyphenolic components of the methanol extracts were analyzed by RP-HPLC. DPPH radical scavenging potential of the different extracts was estimated. The hepatoprotective and antioxidant activities of the extracts against CCl4-induced hepatotoxicity in mice were evaluated.

RESULTS

The flavonol quercitrin and rosmarinic acid were major in the F. indica, C. procera and S. imbricata samples, while rutin prevailed in that of Z. hamiense. The ethanolic and methanolic extracts showed noticeable DPPH radical-scavenging activity as compared to ascorbic acid. Assessment of liver enzymes revealed that oral administration of the extracts did not show any evidence of hepatotoxicity. Moreover, protection against CCl4-induced liver damage was evident upon administration of three plants extracts namely, F. indica, C. procera and S. imbricata.

CONCLUSION

Overall, hepatotoxicity induced by CCl4 was effectively prevented by the three plants extracts through scavenging of free radicals and by boosting the antioxidant capacity of the liver. The protective effect of the plants could be attributed to their high quercitrin and rosmarinic acid contents.

Crystal structure of an antifungal osmotin-like protein from Calotropis procera and its effects on Fusarium solani spores, as revealed by atomic force microscopy: Insights into the mechanism of action

CpOsm is an antifungal osmotin/thaumatin-like protein purified from the latex of Calotropis procera. The protein is relatively thermostable and retains its antifungal activity over a wide pH range; therefore, it may be useful in the development of new antifungal drugs or transgenic crops with enhanced resistance to phytopathogenic fungi. To gain further insight into the mechanism of action of CpOsm, its three-dimensional structure was determined, and the effects of the protein on Fusarium solani spores were investigated by atomic force microscopy (AFM). The atomic structure of CpOsm was solved at a resolution of 1.61Å, and it contained 205 amino acid residues and 192 water molecules, with a final R-factor of 18.12% and an Rfree of 21.59%. The CpOsm structure belongs to the thaumatin superfamily fold and is characterized by three domains stabilized by eight disulfide bonds and a prominent charged cleft, which runs the length of the front side of the molecule. Similarly to other antifungal thaumatin-like proteins, the cleft of CpOsm is predominantly acidic. AFM images of F. solani spores treated with CpOsm resulted in striking morphological changes being induced by the protein. Spores treated with CpOsm were wrinkled, and the volume of these cells was reduced by approximately 80%. Treated cells were covered by a shell of CpOsm molecules, and the leakage of cytoplasmic content from these cells was also observed. Based on the structural features of CpOsm and the effects that the protein produces on F. solani spores, a possible mechanism of action is suggested and discussed.

Effectiveness and feasibility of methanol extracted latex of Calotropis procera as larvicide against dengue vectors of western Rajasthan, India

BACKGROUND & OBJECTIVES

Identification of novel effective larvicide from natural resources is essential to combat developing resistances, environmental concerns, residue problems and high cost of synthetic insecticides. Results of earlier laboratory findings have shown that Calotropis procera extracts showed larvicidal, ovicidal and refractory properties towards ovipositioning of dengue vectors; further, latex extracted with methanol was found to be more effective compared to crude latex. For testing efficacy and feasibility of extracted latex in field, the present study was undertaken in different settings of Jodhpur City, India against dengue vectors.

METHODS

Study areas were selected based on surveillance design for the control of dengue vectors. During the study period domestic and peri-domestic breeding containers were treated with methanol extracted latex and mortality was observed after 24 h as per WHO guidelines. Latex was manually collected from internodes of Calotropis procera and extracted using methanol (AR) grade.

RESULTS

Methanol extracted latex of C. procera was found effective and feasible larvicide against dengue vectors in the field conditions. Cement tanks, clay pots and coolers (breeding sites) were observed as key containers for the control of dengue transmission.

INTERPRETATION & CONCLUSION

Today environmental safety is considered to be very important. Herbal composition prepared by the extraction of latex of C. procera can be used as an alternative approach for the control of dengue vectors. This will reduce the dependence on expensive products and stimulate local efforts to enhance the public involvement.

Time lapse microscopy observation of cellular structural changes and image analysis of drug treated cancer cells to characterize the cellular heterogeneity

The effect of Calotropis gigantea latex (CGLX) on human mammary carcinoma cells is not well established. We present the results of this drug activity at total population and single cell level. CGLX inhibited the growth of MCF7 cancer cells at lower IC50 concentration (17 µL/mL). Microscopy of IC50 drug treated cells at 24 hr confirming the appearance of morphological characteristics of apoptotic and necrotic cells, associated with 70% of DNA damage. FACS analysis confirmed that, 10 and 20% of the disruption of cellular mitochondrial nature by at 24 and 48 h, respectively. Microscopic image analysis of total population level proved that MMP changes were statistically significant with P values. The cell to cell variation was confirmed by functional heterogeneity analysis which proves that CGLX was able to induce the apoptosis without the contribution of mitochondria. We conclude that CGLX inhibits cell proliferation, survival, and heterogeneity of pathways in human mammary carcinoma cells.

Calotroposides H-N, new cytotoxic oxypregnane oligoglycosides from the root bark of Calotropis procera

As a part of our continuing interest in identifying anticancer drug leads from natural sources, we have investigated the n-BuOH fraction of the root bark of Calotropis procera (Ait) R. Br. Seven new oxypregnane oligoglycosides: calotroposides H-N (1-7) were isolated and identified. Their structures were established on the basis of 1D and 2D NMR studies, HRMS, and GCMS spectral data. The in vitro growth inhibitory activity of the n-BuOH fraction and compounds 1-7 was evaluated against A549 non-small cell lung cancer (NSCLC), U373 glioblastoma (GBM), and PC-3 prostate cancer cell lines. Compounds 4 and 6 showed subnanomolar growth inhibition activity with IC50 ranging from 0.5 to 0.7μM against U373 glioblastoma (GBM) and PC-3 prostate cancer cell lines. These results provide further insight into the chemical diversity and biological activities of this class of compounds.

Calotropis procera mediated combustion synthesis of ZnAl2O4:Cr(3+) nanophosphors: structural and luminescence studies

ZnAl2O4:Cr(3+) nanophosphors were synthesized for the first time by a simple and environment friendly route using Calotropis procera milk latex as fuel. The structural and surface morphological studies were carried out using powder X-ray diffraction (PXRD), scanning electron microscopy and transmission electron microscopy techniques. The photoluminescence (PL) properties of ZnAl2O4:Cr(3+) as a function of dopant concentration and calcination temperature was studied in detail. The PXRD patterns and Rietveld confinement confirmed the cubic crystal system with space group Fd-3m. The crystallite size estimated from Scherrer's and W-H plots was found to be in the range of 16-26 nm. The PL spectrum shows an intense peak at ∼688 and ∼699 nm assigned to spin-forbidden (2)Eg→(4)A2g transition of Cr(3+) ions. The PL measurements for two excitations (∼410 and 527 nm) and with respect to calcination temperature indicated no significant change in the shape and position of emission peak except PL intensity. The CIE chromaticity coordinates lies well within the white region. Thermoluminescence (TL) studies revealed well resolved glow peak at ∼212°C with a small shoulder at 188 and 233°C. The glow peak intensity at ∼212°C increases linearly with γ-dose which suggest ZnAl2O4:Cr(3+) is suitable candidate for radiation dosimetric applications. The activation energy (E in eV), order of kinetics (b) and Frequency factor (s) were estimated using glow peak shape method.

Antibacterial and cytotoxic potential of silver nanoparticles synthesized using latex of Calotropis gigantea L

The present study aimed to synthesis silver nanoparticles (AgNPs) in a greener route using aqueous latex extract of Calotropis gigantea L. toward biomedical applications. Initially, synthesis of AgNPs was confirmed through UV-Vis spectroscopy which shows the surface plasmonic resonance peak (SPR) at 420 nm. Fourier transform infrared spectroscopy (FTIR) analysis provides clear evidence that protein fractions present in the latex extract act as reducing and stabilizing bio agents. Energy dispersive X-ray (EDAX) spectroscopy confirms the presence of silver as a major constituent element. X-ray diffractograms displays that the synthesized AgNPs were biphasic crystalline nature. Electron microscopic studies such as Field emission scanning electron microscopic (Fe-SEM) and Transmission electron microscope (TEM) reveals that synthesized AgNPs are spherical in shape with the size range between 5 and 30 nm. Further, crude latex aqueous extract and synthesized AgNPs were evaluated against different bacterial pathogens such as Bacillus cereus, Enterococci sp, Shigella sp, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus and Escherichia coli. Compared to the crude latex aqueous extract, biosynthesized AgNPs exhibits a remarkable antimicrobial activity. Likewise in vitro anticancer study manifests the cytotoxicity value of synthesized AgNPs against tested HeLa cells. The output of this study clearly suggesting that biosynthesized AgNPs using latex of C. gigantea can be used as promising nanomaterial for therapeutic application in context with nanodrug formulation.

Calotropis procera extract induces apoptosis and cell cycle arrest at G2/M phase in human skin melanoma (SK-MEL-2) cells

Calotropis procera (family: Asclepiadaceae) contains cardiac glycosides which are cytotoxic to cancer cells. The extracts of C. procera have been reported to be cytotoxic to many cancer cell lines and this is the first report against the human skin melanoma cells (SK-MEL-2). The SK-MEL-2 cells treated with C. procera methanolic extract (CPME) were analysed for growth inhibition and apoptosis. The exposure of phosphatidylserine in apoptotic SK-MEL-2 was analysed by using the Annexin-V FITC flow cytometry method. In CPME-treated SK-MEL-2 cells, 19.6% of apoptotic and 58.3% dead cells were observed. The 15.97% and 15.85% of early apoptotic cells were found at 20 μg/mL of the ouabain and paclitaxel, respectively. Active caspases, nuclear degradation confirmed apoptotic SK-MEL-2 cells in time- and dose-dependent manner. The cell cycle analysis shows that CPME treated cells halt at G2/M phase. Significant cytotoxic activity of CPME against SK-MEL-2 may be attributed to its high cardenolide content.

Two novel cardenolides from Calotropis procera

Two new cardenolides, named ischarin and ischaridin in addition to 10 known compounds, were isolated from Calotropis procera Ait. (Asclepiadaceae), growing wild in Jordan. Their structures were established mainly by the extensive application of one- and two-dimensional (1)H and (13)C-NMR spectroscopy.

Antibacterial activity of silver and zinc nanoparticles against Vibrio cholerae and enterotoxic Escherichia coli

Vibrio cholerae and enterotoxic Escherichia coli (ETEC) remain two dominant bacterial causes of severe secretory diarrhea and still a significant cause of death, especially in developing countries. In order to investigate new effective and inexpensive therapeutic approaches, we analyzed nanoparticles synthesized by a green approach using corresponding salt (silver or zinc nitrate) with aqueous extract of Caltropis procera fruit or leaves. We characterized the quantity and quality of nanoparticles by UV-visible wavelength scans and nanoparticle tracking analysis. Nanoparticles could be synthesized in reproducible yields of approximately 10(8) particles/ml with mode particles sizes of approx. 90-100 nm. Antibacterial activity against two pathogens was assessed by minimal inhibitory concentration assays and survival curves. Both pathogens exhibited similar resistance profiles with minimal inhibitory concentrations ranging between 5×10(5) and 10(7) particles/ml. Interestingly, zinc nanoparticles showed a slightly higher efficacy, but sublethal concentrations caused adverse effects and resulted in increased biofilm formation of V. cholerae. Using the expression levels of the outer membrane porin OmpT as an indicator for cAMP levels, our results suggest that zinc nanoparticles inhibit adenylyl cyclase activity. This consequently deceases the levels of this second messenger, which is a known inhibitor of biofilm formation. Finally, we demonstrated that a single oral administration of silver nanoparticles to infant mice colonized with V. cholerae or ETEC significantly reduces the colonization rates of the pathogens by 75- or 100-fold, respectively.

Antibacterial potential of Calotropis procera (flower) extract against various pathogens

Increased bacterial resistance towards commonly used antibiotics has become a debated issue all over the world in a last few decades. Due to this, consumer demand towards natural anti-microbial agents is increasing day by day. Natural anti-microbial agents have gained enormous attention as an alternative therapeutic agent in pharmaceutical industry. Current study is an effort to explore and identify a bactericidal potential of various solvent extracts of Calotropis procera flower. Flowers of C. procera were extracted with hexane, butanol, ethyl acetate and aqua to evaluate the antibacterial activity by agar well diffusion method against the various human pathogens. The microorganisms used in this study includes Salmonella typhi, Escherichia coli (O157:H7), Micrococcus luteus KIBGE-IB20 (Gen Bank accession: JQ250612) and methicillin resistant Staphylococcus aureus (MRSA) KIBGE-IB23 (Gen Bank accession: KC465400). Zones of inhibition were observed against all four pathogenic strains. Fraction soluble in hexane showed broad spectrum of inhibition against all the studied pathogens. However, fractions soluble in ethyl acetate inhibited the growth of E. coli, MRSA, and M. luteus. In case of butanol and aqueous extracts only growth of M. luteus was inhibited. Results revealed that the flower extracts of C. procera have a potential to be used as an antibacterial agent against these pathogenic organisms.

Pharmacological characterization of different fractions of Calotropis procera (Asclepiadaceae) in streptozotocin induced experimental model of diabetic neuropathy

ETHNOPHARMACOLOGICAL RELEVANCE

Calotropis procera (Ait.) R.Br. is one of an ancient traditional shrub, which has been used for the treatment of diabetes, pain and inflammation for thousands of years in India. The root extract of Calotropis procera has been widely used by the tribal׳s of district Udaipur, Rajasthan (India) for treatment of diabetes mellitus and its associated complications like diabetic neuropathy. The present study was performed to explore the protective effect of root, stem and leaf extracts of Calotropis procera in diabetes and diabetic neuropathy against tactile allodynia, mechanical hyperalgesia and thermal hyperalgesia in streptozotocin induced diabetic rats.

MATERIALS AND METHODS

Diabetes and peripheral neuropathy were induced in Wistar rats by injection of streptozotocin (45 mg/kg/intraperitoneally). The roots, stem and leaves of Calotropis procera were sequentially extracted with petroleum ether, chloroform, ethyl acetate and methanol. All the extracts were assessed by oral administration at 100 and 250 mg/kg in streptozotocin diabetic rats. The following compounds were used as positive controls: insulin NPH (1 IU/kg/day), metformin (500 mg/kg/day), glibenclamide (2.5 mg/kg/day) and a combination of acarbose (20 mg/kg/day) with methylcobalamine (500 µg/kg/day). In contrast, the streptozotocin induced untreated diabetic rats termed as negative control. Thermal hyperalgesia, mechanical hyperalgesia and tactile allodynia were evaluated in all groups of streptozotocin diabetic rats to assess the extent of neuropathy by Eddy׳s hot plate, tail immersion, Randall-Selitto and Von Frey hair tests. The basal nociceptive thresholds were assessed in week 4 of post streptozotocin injection. All groups received their treatment on a regular basis from 28 to 42 days following a confirmation of diabetic neuropathy. The nociceptive thresholds were assessed in all groups in week 5 and 6. The histopathology of pancreas and biochemical estimations of plasma insulin and glycosylated haemoglobin (HbA1C%) levels were also performed in week 6 of post streptozotocin injection.

RESULTS

The negative control rats developed diabetes and diabetic neuropathy after 6 week of streptozotocin administration distinguished by significant (p<0.01) hyperalgesia and tactile allodynia with enhanced HbA1C% level compared to normoglycemic rats. Chronic administration of root methanol, stem methanol and leaf ethyl-acetate extracts of Calotropis procera for 2 weeks at 100 and 250 mg/kg doses significantly (p<0.01) attenuated the diabetes induced mechanical hyperalgesia, thermal hyperalgesia, tactile allodynia and HbA1C% level in streptozotocin diabetic rats as compared to negative control rats. Further, the root methanol extract of Calotropis procera in 100mg/kg dose showed the regeneration capability of β cells in the histology of pancreas with significant (p<0.01) improvement in plasma insulin level in streptozotocin diabetic rats compared to negative control rats.

CONCLUSION

Root methanol extract of Calotropis procera (100mg/kg) has shown ameliorative effect in diabetic neuropathy which may be attributed by its multiple actions including potent hypoglycemic and antioxidant.

Potential effect of the medicinal plants Calotropis procera, Ficus elastica and Zingiber officinale against Schistosoma mansoni in mice

CONTEXT

Calotropis procera (Ait.) R. Br. (Asclepiadaceae), Ficus elastica Roxb. (Moraceae) and Zingiber officinale Roscoe (Zingiberaceae) have been traditionally used to treat many diseases.

OBJECTIVE

The antischistosomal activity of these plant extracts was evaluated against Schistosoma mansoni.

MATERIALS AND METHODS

Male mice exposed to 80 ± 10 cercariae per mouse were divided into two batches. The first was divided into five groups: (I) infected untreated, while groups from (II-V) were treated orally (500 mg/kg for three consecutive days) by aqueous stem latex and flowers of C. procera, latex of F. elastica and ether extract of Z. officinale, respectively. The second batch was divided into four comparable groups (except Z. officinale-treated group) similarly treated as the first batch in addition to the antacid ranitidine (30 mg/kg) 1 h before extract administration. Safety, worm recovery, tissues egg load and oogram pattern were assessed.

RESULTS

Calotropis procera latex and flower extracts are toxic (50-70% mortality) even in a small dose (250 mg/kg) before washing off their toxic rubber. Zingiber officinale extract insignificantly decrease (7.26%) S. mansoni worms. When toxic rubber was washed off and ranitidine was used, C. procera (stem latex and flowers) and F. elastica extracts revealed significant S. mansoni worm reductions by 45.31, 53.7 and 16.71%, respectively. Moreover, C. procera extracts produced significant reductions in tissue egg load (∼34-38.5%) and positively affected oogram pattern.

CONCLUSION

The present study may be useful to supplement information with regard to C. procera and F. elastica antischistosomal activity and provide a basis for further experimental trials.

Calotropis gigantiea (L.) R. Br (Apocynaceae): a phytochemical and pharmacological review

ETHNOPHARMACOLOGICAL RELEVANCE

Calotropis gigantiea (L.) R. Br (Apocynaceae) commonly called as "crown flower" or "giant milk weed" is a well-known weed to many cultures for treating various disorders related to central nervous system, skin diseases, digestive system, respiratory system, reproductive system etc. Indigenous groups made the plant as a part of their lives since they use the fruit fibre to make ropes, household items, for weaving clothes and flowers for garlands apart from usage for various indications. The study aims at far-reaching review on phytochemistry, pharmacological activities, ethnopharmacology, intellectual property transfer on pharmacological therapies, toxicity which aids to provide scientific evidence for the ethnobotanical claims and to identify gaps required to be conducted as a future research prerequisite.

MATERIALS AND METHODS

A systematic literature search was performed using different databases such as Scopus, Science direct, PubMed and Sciverse with no timeline limit set during the search. All the available abstracts and full text articles were included in the systematic review.

RESULTS

Most of the folkloric uses were validated by the scientific studies such as analgesic, anti-arthritic, anti-asthmatic, anti-bacterial, anti-convulsant, anti-pyretic, central nervous system disorders, contraceptive, anti-ulcer and wound healing. In addition other studies such as anti-diabetic, anti-diarrhoeal, anti-helminthic, anti-histamine, anti-inflammatory, anti-microbial, anti-oxidant, cardio-protective studies, cytotoxicity, hepatoprotectivity, fibrinolytic, mosquitocidal, nerve muscle activity, vasodilation and skeletal muscle activities were also reported for the plant. Isolated compounds such as calotropin, frugoside and 4'-O-β-D-glucopyranosyl frugoside were tested for the cytotoxicity efficacy against both human and rat cell lines out of which calotropin showed potent activity (IC50-15 ng/ml). However there were no clinical trials reported on the plant which is one of the major lacunas.

CONCLUSIONS

This review article explores the ethnopharmacological, pharmacological activities phytochemistry and intellectual rights of Cg which gives the evidence of a potent and commercial drug which up on further research leads to the most viable drug for variety of treatments. However there is further need for in-vivo studies and clinical trials on isolated phytoconstituents which will help to commercialise.

Cytotoxic cardenolides from the root bark of Calotropis gigantea

Six new cardenolides (1, 2 and 11-14), along with ten known ones, were isolated from the root bark of Calotropis gigantea. The structural determination was accomplished by the 1D- and 2D-NMR spectrum as well as ESIMS analysis. The isolated compounds were evaluated for their in vitro growth inhibitory activity against human A549 and Hela cell lines. The results suggested that some of these cardenolides (compounds 1, 6, and 8) displayed potent cytotoxicities.

Wound-healing and potential anti-keloidal properties of the latex of Calotropis procera (Aiton) Asclepiadaceae in rabbits

Calotropis Procera (CP) has been used in the management of toothache, fresh skin burns, gum bleeding as well as others to make it qualify as a medicinal plant. This study was designed to assess its wound-healing property in rabbits and its potentials for anti keloidal activity.Fresh latex of Calotropis were obtained and evaluated phytochemically. Fifteen male rabbits were used and four excisional wounds were created on each rabbit. The rabbits were divided into five groups of three each. Group 1 was the negative control and received no treatment. The wounds of group 2 animals were treated with 2mL of Calotropis latex; group 3 with 2mL honey; and group 4 with a mixture of 1ml honey and 1 mL of the latex. The animals in group 5 were given 2mg triamcinolone intramuscularly. All the groups had their wounds treated daily for 21 days. The wounds' diameters were measured on the day of wound creation, thereafter on days 7, 14 and 21 post wound creation. Biopsies of the wounds were taken on days 3 and 21 and viewed histologically. Phytochemical study of the latex revealed the presence of glycosides, tannins and alkaloids. The wounds were found to be significantly (p<0.05) reduced in groups treated with 50% latex in honey and triamcinolone, respectively, on day 7 post wound creation while there was a significant (p<0.05) reduction in wound surface area in all treated groups on days 14 and 21 post wound creation. Histological findings in untreated group showed thick bundle of collagen fibres some of which had broad based configurations, reminiscent of keloid. The group treated with 2mL of Calotropis latex revealed the presence of florid granulation tissues on day 3 while there was a marked reduction in quantity and size of collagen fibres on day 21 post wound creation which was comparable with what was seen for the triamcinolone-treated group.The general effect of Calotropis latex on wound-healing was noted. Likewise it's similarity to that of triamcinolone, an anti-keloidal agent; this makes it a probable candidate for future anti-keloidal study using a suitable model.

[Liposoluble constituents from the flowers of Calotropis gigantea and their antimicrobial activities]

OBJECTIVE

To study the liposoluble constituents from the flowers of Calotropis gigantea and their antimicrobial activities.

METHODS

The liposoluble constituents from the flowers of Calotropis gigantea were analyzed by GC-MS and their relative contents were determined by area normalization. Their antimicrobial activities against 2 pathogens were tested by agar disc diffusion method.

RESULTS

31 compounds were separated and identified, amounting to 85.14% of the total constituents. The liposoluble constituents from the flowers of Calotropis gigantea exhibited weak antimicrobial activities against Staphylococcus aureus and Canidia albicans.

CONCLUSION

The research result provides scientific foundation for exploitation and utilization of Calotropis gigantea.

Acetylcholinesterase from human erythrocytes membrane: a screen for evaluating the activity of some traditional plant extracts

The extraction of plant constituents is essential to isolate biologically active compounds and understanding their role in disease prevention, treatment and in knowing their toxic effects as well. However, meager information is available about the properties and biological activities of phytochemicals derived from certain plants found in Allahabad and adjoining areas. Keeping this information in view, we prepared aqueous extracts and determined their biochemical properties including their impact on the activity of human RBC's acetylcholinesterase (AChE). The UV—Visible spectrophotometric profiles of the aqueous extracts of different parts of the four plant species viz. Calotropis procera, Datura metal, Cannabis sativa, Argemone mexicana and Thevitia peruviana displayed two major peaks at 302 and 336 nm corresponding to the presence of different flavonoids in these preparations. These extracts indicated presence of protein in the range of 1.12 to 19.25mg/g wet weight of the plant tissues. The impact of different phytochemicals present in these extracts was studied on the activity of AChE isolated from human erythrocytes (RBCs). The extracts derived from Argemone mexicana and Datura metal exhibited strong AChE inhibitory potential, whereas others did not show significant inhibition even at higher concentrations. The results indicate that human RBC's can be used as a potential biomarker towards evaluation of the efficacy and toxic potential of varied plant extracts.

Molluscicidal activity of methomyl and cardenolide extracts from Calotropis procera and Adenium arabicum against the land snail Monacha cantiana

In this work, we have evaluated the molluscicidal activity of two cardenolide extracts from Adenium arabicum Balf f. [the benzene (B) and methanol (M) extracts], one cardenolide extract from Calotropis procera (Aiton) W.T. Aiton (extract C), and methomyl against the harmful land snail Monacha cantiana (Montagu). The contact LD₅₀ values for the above mentioned plant extracts were 12.62, 34.63, and 34.35 mg·kg⁻¹ of body weight, respectively, while the LD₅₀ for methomyl was 116.62 mg·kg⁻¹, that is, the plant extracts were 9.24, 3.37, and 3.4 times more toxic than methomyl. In addition, a simple colorimetric method, based on Kedde reagent, was modified to determine cardenolide concentrations in plant extracts. Thin layer chromatography analysis (TLC) showed several cardiac glycosidal compounds in each plant extract. The results proved that cardiac glycosides are promising candidate compounds that could be used to control land snails, or exploited to develop new, effective, and environmentally friendly molluscicides.

Laboratory observations on the larvicidal efficacy of three plant species against mosquito vectors of malaria, dengue/dengue hemorrhagic fever (DF/DHF) and lymphatic filariasis in the semi-arid desert

Comparative larvicidal efficacy of aqueous and organic solvent extracts from seeds, leaves and flowers of three desert plants viz. Calotropis procera (Aiton), Tephrosia purpurea (L.) Pers. and Prosopis juliflora (Sw.) DC. was evaluated against Anopheles stephensi (Liston), Aedes aegypti (Linnaeus) and Culex quinquefasciatus (Say). For this purpose larvae of all the three mosquito species were reared in the laboratory and studies carried out on late 3rd or early 4th instars using standard WHO technique. Based on concentration mortality data 24 and 48 hr LC50and LC90 values along with their 95% fiducial limits, regression equation, chi-square (chi2)/ heterogeneity of the response were determined by log probit regression analysis. Experiments were carried out with different solvent extracts of seeds of C. procera which revealed that methanol (24 hr LC50: 127.2, 194.8, 361.0) and acetone (229.9, 368.1,193.0 mg l(-1)) extracts were more effective with the three mosquito species, respectively. Petroleum ether extract was effective only on An. stephensi while aqueous extracts were not effective at all with any of the mosquito species (mortality < 10-30%). Tests carried out with methanol extracts of fresh leaves (24 hr LC50: 89.2, 171.2, 369.7) and flowers (24 hr LC50: 94.7,617.3, 1384.0 mg l-(-1)) of Calotropis showed that preparations from fresh parts were 2-3 times more effective as compared to the stored plant parts. Efficacy was less than 10-30% with both An. aegypti and Cx. quinquefasciatus while An. stephensi was still susceptible to extracts from both leaves and flowers even after two years of storage. The 24 hr LC50 values as observed for methanol extracts of seeds of T. purpurea and leaves of P. juliflora were 74.9, 63.2 and 47.0 and 96.2,128.1 and 118.8 mg l(-1) for the above three mosquito species, respectively. Experiments carried out up to 500 mg l-(1) with leaves (T. purpurea) and seeds (P. juliflora) extracts show only up to 10-30% mortality indicating that active larvicidal principle may be present only in the seeds of Tephrosia and leaves of Prosopis. In general, anophelines were found more susceptible than the culicines to the plant derived derivatives. More studies are being carried outon some other desert plants found in this arid region. The study would be of great importance while formulating vector control strategy based on alternative plant based insecticides in this semi-arid region.

Rapid identification of calotropagenin glycosides using high-performance liquid chromatography electrospray ionisation tandem mass spectrometry

INTRODUCTION

Cardiac glycosides in Calotropis procera have therapeutic use as inhibitors of Na⁺/K⁺-ATPase to regulate heart contractions. A large amount of research attention has been received by these compounds towards their identification and structural characterisation. In order to achieve rapid identification of cardiac glycosides in phytochemical extracts a liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed involving metal cationisation by post-column addition of alkali salts for the unambiguous determination of their molecular weights.

OBJECTIVE

Identification of cardiac glycosides in Calotropis procera leaf extract.

RESULTS

Calotropagenin and its 10 glycosides were unambiguously identified. The daughter ions at m/z 387, 369, 359, 351, 341 and 323 in their MS/MS spectra were attributed to the calotropagenin aglycone unit.

CONCLUSION

High performance liquid chromatography in combination with electrospray ionization tandem mass spectrometry involving metal cationisation by post column addition of alkali salts was successfully utilised for the rapid identification of calotropagenin glycosides/derivatives in Calotropis procera extract.

Protective effect of aqueous suspension of dried latex of Calotropis procera against oxidative stress and renal damage in diabetic rats

Calotropis species have been used in the traditional medicinal system for the treatment of diseases of the liver and abdomen. In view of the antioxidant and anti-hyperglycemic properties of an aqueous suspension obtained from the dried latex of Calotropis procera, the present study was carried out to evaluate its efficacy in affording protection against alloxan induced changes in rat kidney. A single intraperitoneal injection of alloxan (150 mg/kg) in rats produced hyperglycemia within 3 days and altered kidney functions over a period of 90 days. Daily oral administration of the aqueous suspension (100 and 400 mg/kg) in diabetic rats produced anti-hyperglycemic effect that was comparable to that of glibenclamide (10 mg/kg). Unlike glibenclamide, the aqueous suspension did not increase the serum insulin levels in diabetic rats. However, it produced a marked reduction in the levels of urinary glucose and protein and normalized the renal tissue levels of thiobarbituric acid-reactive substances (TBARS) and glutathione (GSH) in diabetic rats and the effect was comparable to that of glibenclamide. The protection afforded by the aqueous suspension was also evident from the histological analysis of the renal tissue. Our study shows that by exhibiting antioxidant and anti-hyperglycemic property the aqueous suspension of dried latex of C. procera affords protection against the complications associated with diabetes.

Laticifer proteins play a defensive role against hemibiotrophic and necrotrophic phytopathogens

Proteins from latex of Calotropis procera (CpLP), Plumeria rubra (PrLP), Carica candamarcensis (P1G10) and Euphorbia tirucalli (EtLP) were tested for antifungal activity against phytopathogens. CpLP and P1G10 inhibited each fungi analyzed. PrLP and EtLP did not exert inhibition. CpLP and P1G10 exhibited preferential inhibitory activity towards R. solani (IC₅₀ = 20.7 and 25.3 µg/ml, respectively). The inhibitory activity was lost after heat treatment or proteolysis, providing evidence for the involvement of proteins in the inhibitory effect. Treatment of CpLP or P1G10 with Dithiothreitol improved both, the endogenous proteolytic activity and the antifungal properties. Conversely, pre-treatment of CpLP or P1G10 with iodoacetamide drastically reduced endogenous proteolytic activities and partially abrogated antifungal activity. Similar results were observed when spores were challenged to germinate in the presence of laticifer proteins. The purified cysteine proteinase CMS2MS2 from Carica candamarcensis latex or papain (E.C. 3.4.22.2), a cysteine proteinase from latex of Carica papaya L., but not trypsin (EC 3.4.21.4) or chymotrypsin (EC 3.4.21.1), two serine proteases, replicated the results obtained with CpLP or P1G10, thus restricting the antifungal property to latex plant cysteine proteinases. CpLP, CMS2MS2 and papain induced production of reactive oxygen species in spores of F. solani, suggesting that inhibition could be linked to oxidative stress. Proteome analysis of CpLP by 2-D electrophoresis and MALDI-TOF-TOF confirmed the existence of various pathogenic-related proteins such as chitinases, peroxidases and osmotins. The results support that laticifer proteins are part of plant defense repertoire against phytopathogenic fungi.

Osmotin purified from the latex of Calotropis procera: biochemical characterization, biological activity and role in plant defense

A protein, similar to osmotin- and thaumatin-like proteins, was purified from Calotropis procera (Ait.) R.Br latex. The isolation procedure required two cation exchange chromatography steps on 50mM Na-acetate buffer (pH 5.0) CM-Sepharose Fast Flow and 25 mM Na-phosphate buffer (pH 6.0) Resource-S, respectively. The protein purity was confirmed by an unique N-terminal sequence [ATFTIRNNCPYTIWAAAVPGGGRRLNSGGTWTINVAPGTA]. The osmotin (CpOsm) appeared as a single band (20,100 Da) in sodium dodecyl sulfate-polyacrylamide gel electrophoresis and as two spots in two-dimensional electrophoresis (pI 8.9 and 9.1). Both polypeptides were further identified by mass spectrometry as two osmotin isoforms with molecular masses of 22,340 and 22,536 Da. The CpOsm exerted antifungal activity against Fusarium solani (IC₅₀=67.0 μg mL⁻¹), Neurospora sp. (IC₅₀=57.5 μg mL⁻¹) and Colletotrichum gloeosporioides (IC₅₀=32.1 μg mL⁻¹). However, this activity was lost when the protein was previously treated with a reducing agent (DTT, Dithiothreitol) suggesting the presence of disulfide bounds stabilizing the protein. The occurrence of osmotin in latex substantiates the defensive role of these fluids.

Glutaraldehyde-activated chitosan matrix for immobilization of a novel cysteine protease, procerain B

Proteases have several applications in the food industry. We report the immobilization of procerain B, a novel cysteine protease, on glutaraldehyde-activated chitosan beads through covalent attachment. Glutaraldehyde not only serves as a cross-linking agent but also links the procerain B on the surface of bead through primary amine group (either lysine side chain or N-terminal) by Schiff base linkage. Immobilized procerain B was characterized for optimum functional range and stability with respect to pH and temperature. The chitosan-immobilized procerain B has broad pH and thermal optima. The effects of substrate concentration and reusability of immobilized beads were also studied. It showed nearly 50% activity until the 10th use.