Crude Stem Extract Research Articles

Antioxidant Biomarkers from Vanda coerulea Stems Reduce Irradiated HaCaT PGE-2 Production as a Result of COX-2 Inhibition

BackgroundIn our investigations towards the isolation of potentially biologically active constituents from Orchidaceae, we carried out phytochemical and biological analyses of Vanda species. A preliminary biological screening revealed that Vanda coerulea (Griff. ex. Lindl) crude hydro-alcoholic stem extract displayed the best DPPH /•OH radical scavenging activity and in vitro inhibition of type 2 prostaglandin (PGE-2) release from UVB (60 mJ/cm2) irradiated HaCaT keratinocytes.Principal FindingsBio-guided fractionation and phytochemical analysis led to the isolation of five stilbenoids: imbricatin (1) methoxycoelonin (2) gigantol (3) flavidin (4) and coelonin (5). Stilbenoids (1–3) were the most concentrated in crude hydro-alcoholic stem extract and were considered as Vanda coerulea stem biomarkers. Dihydro-phenanthropyran (1) and dihydro-phenanthrene (2) displayed the best DPPH/•OH radical scavenging activities as well as HaCaT intracellular antioxidant properties (using DCFH-DA probe: IC50 8.8 µM and 9.4 µM, respectively) compared to bibenzyle (3) (IC50 20.6 µM). In turn, the latter showed a constant inhibition of PGE-2 production, stronger than stilbenoids (1) and (2) (IC50 12.2 µM and 19.3 µM, respectively). Western blot analysis revealed that stilbenoids (1–3) inhibited COX-2 expression at 23 µM. Interestingly, stilbenoids (1) and (2) but not (3) were able to inhibit human recombinant COX-2 activity.ConclusionsMajor antioxidant stilbenoids (1–3) from Vanda coerulea stems displayed an inhibition of UVB-induced COX-2 expression. Imbricatin (1) and methoxycoelonin (2) were also able to inhibit COX-2 activity in a concentration-dependent manner thereby reducing PGE-2 production from irradiated HaCaT cells. Our studies suggest that stilbenoids (1–3) could be potentially used for skin protection against the damage caused by UVB exposure.

In vitro Antibacterial, Cytotoxic and Antioxidant Activities of Plant Nephelium longan

The petroleum ether, chloroform and ethyl acetate fractions of ethanol extract of leaf and stem from the plant Nephelium longan (Fam-Sapindaceae) was subjected to antioxidant, antibacterial and cytotoxic activity. All the fractions showed potent antioxidant activity, of which the ethyl acetate and chloroform fraction of leaf demonstrated the strongest antioxidant activity with the IC50 value of 44.28 and 44.31 microg mL(-1), respectively. The petroleum ether extracts (500 microg disc(-1)) of leaf and stem of N. longan almost showed no activity against the tested pathogenic organisms except Escherichia coli. On the other hand, chloroform crude extracts of leaf and stem (500 microg disc(-1)) showed excellent antibacterial activity with the average zone of inhibition of 13-21 mm among the tested bacteria. Besides this, ethyl acetate crude extracts showed good activity against the growth of Sarcina lutea (20 mm), Vibrio mimicus (18 mm), Salmonella typhi (18 mm), E. coli (17 mm) and Staphylococcus aureus (14 mm). However, in the brine shrimp lethality bioassay, all the crude extracts of leaf and stem possessed considerable cytotoxic activity. It was evident that, the chloroform and ethyl acetate extracts of leaf and stem have significant cytotoxic potentials with the LC50 value of 8.802, 9.587, 9.248 and 10.45 microg mL(-1), respectively. Both the stem and leaf of the experimental plant have considerable antibacterial, cytotoxic and antioxidant properties which indicates that the plant have potent bioactive principles.

Assessment of antimicrobial activity of crude extracts of stem and root barks from Adansonia digitata (Bombacaceae) (African baobab)

This study seeks to validate the antimicrobial activity of crude extracts of stem and root barks from Adansonia digitata (Bombacaceae), investigate the minimum inhibitory concentrations (MICs) of the extracts and bioactive constituents present in the barks. Crude ethanolic and aqueous extracts of stem and root barks were evaluated for antimicrobial activities using agar-well method. Bioactive constituents were investigated using standard procedures for phytochemical analysis. The MICs were investigated using broth micro dilution method. The results showed that the extracts had significant antibacterial activity. The MICs of the plant extracts ranged from 6 to 1.5 mg/ml. Tannins, phlobatannins, terpenoids, cardiac glycosides and saponins were found to be present in the stem bark. Terpenoids only were found in the root bark. It is concluded that stem and root barks of A. digitata contain bioactive constituents which are responsible for antimicrobial activity of the crude extracts.

English

The root, stem and leaves of Vitellaria paradoxa, belonging to the Sapotaceae family and which have some ethnomedicinal applications were studied. Phytochemical screening of the plant parts reveals the presence of carbohydrates (free reducing sugars, ketoses, pentoses and starch), saponins, steroids, tannins and alkaloids. The antimicrobial screening of the crude methanol extract carried out in vitro on the following clinical isolates; Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pnuemoniae and Salmonella typhi showed that the crude methanol extracts had wider range of activity on these organisms than the petroleum ether extracts. The crude stem extracts inhibited the growth of P. aeruginosa, K. pneumoniae, B. cereus and S. typhi at concentration of 50 mg/ml while the leaf had a minimal inhibition concentration (MIC) of 70 mg/ml on S. aureus, E. coli and S. typhi. The root had an MIC of 60 mg/ml on S. aureus, E. coli, P. aeruginosa, K. pneumoniae and S. typhi. The MBC in all the cases were slightly higher than the MIC and was lowest in the stem extracts which indicates that the stem bark may contain the most active components.   Key words: Sapotaceae, Vitellaria paradoxa, antimicrobial activity, clinical isolates,in vitro.

Phytochemical and antimicrobial screening of the crude extracts from the root, stem bark and leaves of Vitellaria paradoxa (GAERTN. F)

The root, stem and leaves of Vitellaria paradoxa, belonging to the Sapotaceae family and which have some ethnomedicinal applications were studied. Phytochemical screening of the plant parts reveals the presence of carbohydrates (free reducing sugars, ketoses, pentoses and starch), saponins, steroids, tannins and alkaloids. The antimicrobial screening of the crude methanol extract carried out in vitro on the following clinical isolates; Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pnuemoniae and Salmonella typhi showed that the crude methanol extracts had wider range of activity on these organisms than the petroleum ether extracts. The crude stem extracts inhibited the growth of P. aeruginosa, K. pneumoniae, B. cereus and S. typhi at concentration of 50 mg/ml while the leaf had a minimal inhibition concentration (MIC) of 70 mg/ml on S. aureus, E. coli and S. typhi. The root had an MIC of 60 mg/ml on S. aureus, E. coli, P. aeruginosa, K. pneumoniae and S. typhi. The MBC in all the cases were slightly higher than the MIC and was lowest in the stem extracts which indicates that the stem bark may contain the most active components.

Laboratory evaluation of the toxic properties of forest anchomanes, Anchomanes difformis against pulse beetle Callosobruchus maculatus (Coleoptera: Bruchidae)

Abstract Laboratory experiments were carried out to investigate the efficacy of crude stem extracts of forest anchomanes, Anchomanes difformis (P. Beauv.) a plant occurring in West African forests, against the pulse beetle Callosobruchus maculatus (Fabricius). Crude stem extracts at 3% concentration showed high contact toxicity to adult beetles within 24 h after application, while it was moderately toxic to the beetles at the lowest (1%) concentration. At the highest application rate, the plant extract provided good protection to grains stored for 90 days. Grain viability and water absorption capacity were not affected by treatments with ethanol extracts of A. difformis. The significance of these findings is discussed in relation to biopesticide‐means of controlling cowpea bruchids.

Simple 1,4-benzoquinones with antibacterial activity from stems and leaves of Gunnera perpensa

From the dichloromethane extract of the leaves and stems of Gunnera perpensa two new, simple 1,4-benzoquinones and a known benzopyran-6-ol were isolated. From the methanol extract phytol was obtained. The two benzoquinones, 2-methyl-6-(-3-methyl-2-butenyl)benzo-1,4-quinone ( 1) and 3-hydroxy-2-methyl-5-(3-methyl-2-butenyl)benzo-1,4-quinone ( 2) and the benzopyran, 6-hydroxy-8-methyl-2,2-dimethyl-2H-benzopyran ( 3) were examined for antimicrobial properties together with the crude stem, leaf and root extracts. Minimum inhibitory concentration (MIC) assays were used to quantify antimicrobial activity and the MIC values for the crude extracts of stems, roots and leaves ranged between 100 μg and >16 mg/ml against the eight microorganisms investigated. Compound 1 showed significant antimicrobial activity with the most sensitive organism being Staphylococcus epidermidis with an MIC of 9.8 μg/ml. For compound 2, no activity was noted. Compound 3 exhibited good activity against the yeasts Cryptococcus neoformans (75 μg/ml) and Candida albicans (37.5 μg/ml).

An immunomodulator fromTinospora cordifolia with antioxidant activity in cell-free systems

Several plant products are known to exhibit immense medicinal value against human diseases. Our earlier studies showed that dry stem crude extract (DSCE) ofTinospora cordifolia contained a polyclonal B cell mitogen, G1-4A. DSCE as well as G1-4A also enhanced immune response in mice. In order to explore the possibility of using G1-4A/PPI (partially purified immunomodulator) to modulate radiation induced immunosuppression, the antioxidant effect of PPI from this plant was examined against reactive oxygen and nitrogen species (ROS/RNS), generated by photosensitization/peroxynitrite. Levels of lipid peroxidation products, superoxide dismutase (SOD) and catalase in liver/spleen homogenate from mouse were monitored. Photosensitization induced significant increase in thiobarbituric acid reactive substances (TBARS) in liver. The activities of SOD and catalase were reduced considerably. PPI, present during photosensitisation, prevented lipid peroxidation and restored the activities of both the enzymes. Likewise, oxidative damage induced by peroxynitrite was inhibited by PPI. The degradation of proteins due to photosensitization as assessed by SDS-PAGE was effectively reduced by simultaneous treatment with PPI during photosensitization. Selective inhibitors of ROS like mannitol, SOD, sodium azide and antioxidants, GSH and vitamin C brought about significant inhibition of formation of TBARS suggesting possible involvement of O2 •,•OH and1O2. Photosensitization in deuterated buffer enhanced formation of TBARS thus indicating generation of1O2. Thus, the action of PPI may be against oxidative damage through Type I and II photosensitization mechanisms. Therefore, the immunomodulator fromTinospora cordifolia may also be beneficial as an antioxidant.

Larvicidal Activity of Crude Aqueous Extracts of Solenostemma argel Against Mosquito Larvae

ABSTRACT Crude aqueous extracts of dried fruit pericarp, flower, root, and stem of Solenostemma argel (Del.) Hayne were tested for larvicidal activity against the third instar larvae of the mosquito Culex quinquefasciatus Say. Extract of the fruit pericarp was most effective with LC50 of 0.49 mg/ml at 24 h. The LC50 of crude aqueous extracts of flower, root and stem for mosquito larvae were 1.74 mg/ml, 3.02 mg/ml, and 3.98 mg/ml, respectively.

Antileishmanial activity of an indole alkaloid from Peschiera australis.

In this study, we show the leishmanicidal effects of a chloroform fraction (CLF) and a purified indole alkaloid obtained from crude stem extract of Peschiera australis against Leishmania amazonensis, a causative agent of cutaneous leishmaniasis in the New World. In a bioassay-guided chemical fractionation, the leishmanicidal activity in CLF completely and irreversibly inhibited promastigote growth. This fraction was also active against amastigotes in infected murine macrophages. Chemical analysis of CLF identified an iboga-type indole alkaloid coronaridine as one of its major compounds. Coronaridine showed potent antileishmanial activity, inhibiting promastigote and amastigote growth. Promastigotes and amastigotes treated with CLF or coronaridine showed pronounced alterations in their mitochondria as assessed by transmission electron microscopy.

Isolation and identification of the probing stimulants in the rice plant for the white-back planthopper, Sogatella furcifera (homoptera: delphacidae).

Adult females of the white-back planthopper, Sogatella furcifera, showed characteristic behavior of stylet sheath deposit on a parafilm membrane when fed on a 2% aqueous crude rice leaf and stem extract containing 15% sucrose. Subsequent bioassays revealed that the butanol-soluble fraction of the extract was highly active against the insects. When the butanol fraction was chromatographed on an ODS open column and eluted in sequence with a mixture of an increasing concentration of methanol in water, the 40 % methanol fraction was separated as the most active. A further bioassay of the HPLC components in the active fraction revealed that two major components (1 and 3) stimulated the high probing activity of the white-back planthopper only when they were combined. Of the active components, one component (3) was identified to be tricin 5-O-glucoside by spectroscopic analyses.

Removal of necrotic tissue with an ananain‐based enzyme‐debriding preparation

An enzymatic debriding preparation was formulated with purified enzyme derived from a crude pineapple stem extract. The primary component of this preparation was the sulfhydryl protease ananain which represented >/=85% of the proteolytic activity. The remaining proteolytic activity in the preparation was contributed by a co-purifying homologous cysteine protease comosain. Taken together these two proteases provided a protein purity of greater than 95% as judged by sodium dodecyl sulfate polyacrylamide gel electrophoresis. This ananain-based enzyme preparation exhibited both gelatinolytic and fibrinolytic activity in vitro. Ananain-based enzyme preparation was formulated in a hydrophilic cream vehicle at concentrations ranging from 115 to 260 U/gm vehicle. Ananain-based enzyme preparation formulated in this fashion is referred to as Vianain debriding agent. Vianain was applied to partial-thickness cutaneous burn wounds produced in the skin of domestic pigs. A maximum of two 4-hour applications of Vianain provided complete debridement of eschar from the partial-thickness burn wounds as judged by light and electron microscopic analyses of biopsy specimens harvested before and after debridement. Wounds debrided with Vianain exhibited more rapid reepithelialization as compared with wounds that were not debrided. Wounds on pigs that were hyperimmunized to ananain-based enzyme preparation before burning and debridement with Vianain exhibited a similar enhancement in reepithelialization as compared with wounds treated with vehicle alone. The capacity of Vianain to debride necrotic tissue was also evaluated in a guinea pig ischemic ulcer model. Full-thickness ischemic lesions were created on the back of guinea pigs. Vianain was applied to the hardened necrotic tissue for 6 hours per day for up to a maximum of 5 days. Complete debridement of these wounds was accomplished within 4 to 5 days. Treatment of ischemic cutaneous ulcerations in this animal model with two commercially available enzyme-debriding agents provided little or no debridement of the necrotic tissue. In vitro, Vianain treatment of surgically debrided human tissue samples, obtained from patients with burn injury or cutaneous ulcers, showed that the protease preparation was effective in rapidly digesting these necrotic tissues.

Evidence for the Existence of Ca2+/calmodulin-Dependent Protein Kinase IV Kinase Isoforms in Rat Brain

Calmodulin-dependent protein kinase IV (CaM-kinase IV), which plays crucial roles in the functioning of Ca2+ in the central nervous system and immune system, is markedly activated upon phosphorylation by the action of CaM-kinase IV kinase. Northern and Western blot analyses of CaM-kinase IV kinase showed relatively weak reactions in the rat cerebellum, where the activity of CaM-kinase IV kinase has been demonstrated to exist, indicating that CaM-kinase IV kinase isoforms distinct from the enzyme cloned from the cerebral cortex may exist in the cerebellum. When the crude extracts of rat cerebral cortex, brain stem, and cerebellum were immunotitrated with antibody against the cloned enzyme, only approximately 46, 56, and 25% of the enzyme activity of the respective extracts were immunoprecipitated. Thus, at least two distinct isoforms of CaM-kinase IV kinase appear to exist in the brain.

Acid Phosphatase Activity of Normal and Tumor Tissue of Tobacco Grown in Vitro and in Vivo

Tissue cultures of Nicotiana labacum consisting of green, albino and habituated (normal origin) and teratoma (tomorous origin) were grown under asceptic conditions for 6 to 8 weeks and their extracts were analyzed for phosphatase activity. Comparative enzyme analyses were also made on crude stem extracts of greenhouse-grown normal and tumor tissues of Nicotiana tabacum (var. Wisconsin) and a hybrid (N. glauca x N. langsdorffii).All the crude extracts showed acid phosphatase activity with a pH optimum at 5.8 to 6.0. The total protein content and enzyme acivity of teratoma tissue (tumor) was higher than that of green, albino or habituated tissue (normal). Similar increased levels were seen in tumor tissue grown in greenhouse in comparison with greenhouse-grown normal tissues. The crude extracts of each of the tissues did not exhibit any qualitative difference in specificity with the 5 different substrates tested; however, differences in the level of activity was observed.The effect of 4 different culture media was tested on the growth, protein content and acid phosphatase activity of habituated tobacco in tissue culture. Tissues growing in medium containing high salt concentrations showed higher activities than tissues grown in a basal control medium. From the results, it is suggested that although many factors like auxin and other growth factors can influence growth of habituated tobacco tissue, they need not necessarily affect this specific enzyme activity.

Factors affecting proteolytic activity of extracts from normal and tumour tissues of tobacco.

A SERIES of experiments were undertaken to establish the optimal conditions for extraction of soluble fractions containing proteolytic enzymes from normal and tumour (crown-gall) tissues of Nicotiana tabacum var. Wisconsin, and for assaying the proteolytic activity of these crude stem extracts. It was hoped that the results attained would expedite the selection of a single set of conditions for future extractions of crude plant material for the purpose of purifying the proteolytic principle.

Proteolytic activity of crude stem extracts from normal and tumour tissues of plants.

IN an effort to characterize more fully the tumorous tissue (crown-gall) induced in plants by Agrobacterium tumefaciens, the proteolytic content in the neoplastia tissues of several plants was investigated. Although a variety of enzymes have been found associated with crown-gall1, no reports are available concerning proteolytic activities of such tissue extracts. Recent findings of increased proteolytic activity in mammalian neoplastic tissues2,3 indicate a need for measuring the relative quantity of proteases in comparable plant tissues.