Abdul S. Shawl

ANTHELMINTIC ACTIVITY OF EXTRACTS OF ARTEMISIA ABSINTHIUM AGAINST OVINE NEMATODES

The increasing prevalence of anthelmintic resistant strains of helminths, drug residues in animal products and high cost of conventional anthelmintics has created an interest in studying medicinal plants as an alternative source of anthelmintics. Artemisia absinthium Linn. (Tethwen) is used traditionally by people as a vermifuge in addition to its other livestock uses. The objective of this study was to evaluate the anthelmintic efficacy of crude aqueous extracts (CAE) and crude ethanolic extracts (CEE) of the aerial parts of A. absinthium in comparison to albendazole against the gastrointestinal (GI) nematodes of sheep. To fulfill the objectives, the worm motility inhibition assay was utilized in order to investigate the direct effects of plant extracts on the survival of the adult nematodes under in vitro conditions and faecal egg count reduction assay to investigate the effects on faecal egg output of GI nematodes under in vivo conditions. Significant anthelmintic effects of CAE and CEE on live adult Haemonchus contortus worms (P < 0.005) were observed in terms of the paralysis and/or death of the worms at different hours post-treatment (PT), however, CEE were more efficacious than CAE. The oral administration of the extracts in sheep was associated with significant reduction in faecal egg output by the GI nematodes. The CEE was as effective as the reference drug-albendazole and demonstrated faecal egg count reduction (FECR) of 90.46% in sheep at 2.0 g kg(-1) body weight on day 15 PT followed by 82.85% FECR at 1.0 g kg(-1) bw on day 15 PT. The CAE showed less activity and resulted in maximum of 80.49% FECR at 2.0 g kg(-1)bw. Dosage had a significant (P < 0.05) influence on the anthelmintic efficacy of A. absinthium. The better activity of CEE can be attributed to the greater concentration of alcohol soluble active anthelmintic principle/s and a more rapid transcuticular absorption of the CEE into the body of the worms when compared with the CAE. The results of the present study suggest that A. absinthium extracts are a promising alternative to the commercially available anthelmintics for the treatment of GI nematodes of sheep.

Antistaphylococcal and biofilm inhibitory activities of acetyl-11-keto-β-boswellic acid from Boswellia serrata

BackgroundBoswellic acids are pentacyclic triterpenes, which are produced in plants belonging to the genus Boswellia. Boswellic acids appear in the resin exudates of the plant and it makes up 25-35% of the resin. β-boswellic acid, 11-keto-β-boswellic acid and acetyl-11-keto-β-boswellic acid have been implicated in apoptosis of cancer cells, particularly that of brain tumors and cells affected by leukemia or colon cancer. These molecules are also associated with potent antimicrobial activities. The present study describes the antimicrobial activities of boswellic acid molecules against 112 pathogenic bacterial isolates including ATCC strains. Acetyl-11-keto-β-boswellic acid (AKBA), which exhibited the most potent antibacterial activity, was further evaluated in time kill studies, postantibiotic effect (PAE) and biofilm susceptibility assay. The mechanism of action of AKBA was investigated by propidium iodide uptake, leakage of 260 and 280 nm absorbing material assays.ResultsAKBA was found to be the most active compound showing an MIC range of 2-8 μg/ml against the entire gram positive bacterial pathogens tested. It exhibited concentration dependent killing of Staphylococcus aureus ATCC 29213 up to 8 × MIC and also demonstrated postantibiotic effect (PAE) of 4.8 h at 2 × MIC. Furthermore, AKBA inhibited the formation of biofilms generated by S. aureus and Staphylococcus epidermidis and also reduced the preformed biofilms by these bacteria. Increased uptake of propidium iodide and leakage of 260 and 280 nm absorbing material by AKBA treated cells of S aureus indicating that the antibacterial mode of action of AKBA probably occurred via disruption of microbial membrane structure.ConclusionsThis study supported the potential use of AKBA in treating S. aureus infections. AKBA can be further exploited to evolve potential lead compounds in the discovery of new anti-Gram-positive and anti-biofilm agents.

Comparative studies and identification of camptothecin produced by an endophyte at shake flask and bioreactor

The fungus showing homology with Nodulisporium by 28S ribosomal gene sequencing, which has been discovered as an endophyte on medicinal plant Nothapodytes foetida, was found to produce 45 and 5.5 µg of camptothecin (CPT) per gram of mycelia at bioreactor and at shake flask, respectively, which was further quantified and characterised by various spectroscopic analyses.

Isolation, characterisation and antibacterial activity studies of coumarins from Rhododendron lepidotum Wall. ex G. Don, Ericaceae

Six coumarins daphnin (1), daphnetin (2), daphnetin glucoside (3), rhodonetin (4), rhodonin (5) and umbelliferone (6) were isolated from the methanolic extract of Rhododendron lepidotum Wall. ex G. Don, Ericaceae (aerial part). The compounds and their acetyl derivatives were screened for antibacterial activity against Staphylococcus aureus ATCC-29213, methicillin resistant Staphylococcus aureus ATCC-15187, Escherichia coli ATCC-8739, Pseudomonas aeruginosa ATCC-9027 by microdilution method as compared to the reference ciprofloxacin. Compound 2 displayed the best antibacterial activity with MIC 125 μg/mL against S. aureus ATCC-29213 and MRSA ATCC-15187 followed by 4 which exhibited the MIC value of 250 μg/mL against all the four tested strains. All molecules showed better antibacterial activity than their acyl derivatives.

Acylated flavonol glycosides from Epimedium elatum, a plant endemic to the Western Himalayas

Herba Epimedii is a well-known Botanical preparation used over long time in traditional Chinese medicine. The extracts and chemical constituents from Epimedium species are aphrodisiac as well as to treat many ailments. Chemical investigation of lonely species growing in Kashmir Himalaya Epimedium elatum was undertaken to evaluate its chemical profile. Two unusual substituted acylated flavonol glycosides named Elatoside A (1) and Elatoside B (2) have been isolated from the ethanolic extract of E. elatum along with 23 previously known ones (3-25). All isolates were evaluated for antimicrobial and PPAR-γ ligand binding activity, and some of them appeared to be modestly active.

Acetyl-11-keto-β-boswellic acid (AKBA); targeting oral cavity pathogens

BackgroundBoswellic acids mixture of triterpenic acids obtained from the oleo gum resin of Boswellia serrata and known for its effectiveness in the treatment of chronic inflammatory disease including peritumor edema. Boswellic acids have been extensively studied for a number of activities including anti inflammatory, antitumor, immunomodulatory, and inflammatory bowel diseases. The present study describes the antimicrobial activities of boswellic acid molecules against oral cavity pathogens. Acetyl-11-keto-β-boswellic acid (AKBA), which exhibited the most potent antibacterial activity, was further evaluated in time kill studies, mutation prevention frequency, postantibiotic effect (PAE) and biofilm susceptibility assay against oral cavity pathogens.FindingsAKBA exhibited an inhibitory effect on all the oral cavity pathogens tested (MIC of 2-4 μg/ml). It exhibited concentration dependent killing of Streptococcus mutans ATCC 25175 up to 8 × MIC and also prevented the emergence of mutants of S.mutans ATCC 25175 at 8× MIC. AKBA demonstrated postantibiotic effect (PAE) of 5.7 ± 0.1 h at 2 × MIC. Furthermore, AKBA inhibited the formation of biofilms generated by S.mutans and Actinomyces viscosus and also reduced the preformed biofilms by these bacteria.ConclusionsAKBA can be useful compound for the development of antibacterial agent against oral pathogens and it has great potential for use in mouthwash for preventing and treating oral infections.

New coumarin glycosides from Rhododendron lepidotum.

Two new coumarin glycosides, named Rhodonin (1) and Rhodonetin (2) were isolated from the aerial parts of Rhododendron lepidotum.

Molecular characterization and marker based chemotaxonomic studies of Podophyllum hexandrum Royle

Detailed chemical studies and RAPD analysis were done in different populations of Podophyllum hexandrum collected from high altitude regions of North Western Himalayas. Random amplified polymorphic DNA (RAPD) analysis revealed a high degree of genetic diversity among the 12 collected accessions, attributed to their geographical and climatic conditions. HPLC analysis also revealed variation in the concentration of two major marker compounds which lead to the identification of a chemotype. The study demonstrated that RAPD and chemical markers are very useful tools to compare the genetic relationship and pattern of variation among such prioritized and endangered medicinal plants.

New phenolics from the root of Scutellaria prostrata JACQ. ex BENTH.

Scutellariaprostrata (Lamiaceae), a perennial herb growing as a lonely species in Kashmir, Himalayas, was subjected to repetitive column and flash chromatographic isolation for its chemical documentation-cum-bioevaluation. The methanolic extract of S.prostrata afforded the isolation of ten compounds (1–10), including two new compounds – scutellapbiflavanone (1) and scutellaprostin M (2). The known compounds were found to be scutellarin (3), hispidulin-7-O-β-d-glucopyranoside (4), baicalin (5), wogonoside (6), scutellaprostin C (7), acetoside (8), martynoside (9) and scutellaric acid-3-O-β-d-glucopyranoside (10). Isolation of biflavonoids, phenolics and phenylethanoid compounds from S.prostrata seals a deal of chemotaxonomic importance of this particular species. The characterisation of the compounds was achieved by 1H, 13C, 1H–1H DFQ COSY, HMBC, HSQC, HMQC and ROESY NMR experiments. All the compounds were tested for antioxidant, antimicrobial and cytotoxic activities.

Chemical composition of the essential oils of Nepeta laevigata and Nepeta elliptica from India

The genus Nepeta (Lamiaceae), also called Glechoma and Cataria, is a multiregional genus and consists of about 250 species of perennial herbs distributed in central and southern parts of Europe, Asia, and the Middle East [1–3]. These plants are commonly known as catmint [4], and about 30 species occur in India. Many Nepeta species have been reported to be biologically active and are used in folk medicine because of their spasmodic, diuretic, antiseptic, antitussive, antiasthmatic, and febrifuge activities [5–9]. Several Nepeta species are also reported to reduce serum lipids and to possess anti-inflammatory effects [10, 11]. Most Nepeta species are rich in essential oils, and various biologically active iridoids/monoterpene nepetalactones have been reported in several Nepeta species possessing diverse biological activities, viz., feline attractant, canine attractant, insect repellant, arthropod defense [12, 13], antibacterial, antifungal, and antiviral activities [14]. N. laevigata and N. elliptica are distributed through Afghanistan, China, Nepal, Pakistan, and India. In India, the two plant species are largely confined to Himachal Pradesh, Jammu and Kashmir, and Uttar Pradesh. Nepeta laevigata, also known as Betonica laevigata, is a perennial aromatic herb that grows to a height of 80 cm, is white pubescent, and has petiole 2–12 mm and leaf blade ovate to triangular, while N. elliptica is a small ascending or flexuous herb, 30–60 cm high. Both N. laevigata and N. elliptica are used in traditional medicine. Nepeta laevigata, is reported to be used locally in fevers and for sore throat, while, as an infusion of the seeds, N. elliptica is used in dysentery. According to our finding, there is no report on the chemical compostion of the essential oil of N. laevigata and N. elliptica growing in J & K, India, so the aim of the present work was to compare the chemical composition of these two Nepeta species. The chemical constituents of the volatile oils were analyzed by capillary GC-FID and GC-MS. The components of the oils of the air-dried aerial parts of N. laevigata and N. elliptica are listed in Table 1 with their percentages and relative retention indices (RRI). The different chemical constituents of the essential oils are listed in order of their elution from an RTX-5 column. As shown, 24 components belonging to different class of compounds were identified in the oil of N. laevigata, making up 86.7% of the total oil. -Citronellol (16.5%), germacrene D (19.4%), -caryophyllene (10.8%), -bisabolol oxide B (12.4%), -bourbonene (4.5%), -humulene (3.5%), spathulenol (3.9%), and -bisabolol (5.3%) were the major ones. Other constituents such as 4a,7,7a-nepetalactone (2.0%), allo-aromadendrene (1.1%), and caryophyllene oxide (3.2%) were present in small amounts. In addition, some other constituents such as -pinene, 1,8-cineole, linalool, geraniol, citronellyl acetate, etc. were present in trace amounts. The essential oil composition is dominated by the presence of sesquiterpene hydrocarbons, oxygenated sesquiterpenes, and oxygenated monoterpenes constituting 40.9%, 25.1%, and 20.7%, respectively, of the total oil composition. Of the various nepetalactone isomers, viz., 4a,7,7a-nepetalactone, 4a,7,7a-nepetalactone, and 4a,7,7a-nepetalactone, which have been labeled as the biochemical markers of the Nepeta essential oils and are very useful in chemotaxonomic studies, only one nepetalactone isomer viz., 4a, 7, 7a-nepetalactone, as a minor constituent, was present in the essential oil of Nepeta laevigata. -Caryophyllene, which is one of the major constituents of the essential oil, has been reported in some Nepeta species such as N. depauperata [15], N. flavida [16], and N. nuda [17] as the major component. Likewise, germacrene-D, the other major constituent of the oil sample, has also been reported in various other Nepeta species such as Nepeta macrosiphon [18] and Nepeta sintensii [19]. In addition, the other major components such as -bourbonene and spathulenol have been reported in N.depauperata [15], N. macrosiphon [18], and N. sintensii [19].