Navneet Kishore

Alkaloids as potential anti-tubercular agents.

An increasing incidence of deaths due to tuberculosis and the known drawbacks of the current existing drugs including the emergence of multi drug-resistant strains have led to a renewed interest in the discovery of new anti-tubercular agents with novel modes of actions. The recent researches focused on natural products have shown a useful way to obtain a potentially rich source of drug candidates, where alkaloids have been found more effective. The present review focuses on current epidemiology of tuberculosis, synergy of the disease with HIV, current therapy, available molecular targets and, highlights why natural products especially alkaloids are so important. The review summarizes alkaloids found active against mycobacteria from the mid-1980s to late 2008 with special attention on the study of structure-activity relationship (SAR).

Are plants used for skin care in South Africa fully explored

ETHNOPHARMACOLOGICAL RELEVANCE South Africa is an important focal point of botanical diversity, and although many plant species have been used since ancient times in ethnomedicine, only a few species have hitherto been fully investigated scientifically. A large proportion of the South African population use traditional medicines for their physical and psychological health needs. Many medicinal plants have recently gained popularity as ingredient in cosmetic formulations based on their ethnomedicinal values and many cosmetic products sold in stores are of natural origin. The present review discusses the ethnopharmacological values, pharmacological and toxicological evidence of 117 plant species grown in South Africa, which are used traditionally for skin care purposes. Special focus was on their traditional use for many skin disorders in order to identify their therapeutic potential, the state of ethnopharmacological knowledge and special emphasis has been on areas which require further research. MATERIALS AND METHODS The information regarding all 117 plant species mentioned was extracted from Sci-Finder, Science direct, Medline and Google Scholar. All the available relevant data for medicinal plants was collated from literature review articles from the 19th century to early 2013. RESULTS The extracts from different parts of plants exhibited significant pharmacological properties, proving significant skin care potentials. Special emphasis was on those plant species which still need further exploration and these have been documented separately. CONCLUSIONS Despite the immense use of plants in ethnomedicine for skin care, limited research has been done on the activity of the crude extracts and very little on the active constituents. Consequently, almost 35 out of the 117 species are totally unexplored in the area of skin care. This investigation would be of interest to a broad readership including those researchers working in this field. The plant species namely: Greyia flanaganii, Sideroxylon inerme, Sclerocarya birrea, Calodendrum capense, Hyaenanche globosa, Harpephyllum caffrum, Ximenia americana, Leucosidea sericea Artemisia afra, and six Aloe species have been scientifically validated by our research group for skin hyperpigmentation problems.

Antidermatophytic action of the essential oil of Chenopodium ambrosioides and an ointment prepared from it

The essential oil from the leaves of Chenopodium ambrosioides exhibited antimycotic activity against the dermatophytes Trychophyton mentagrophytes and Microsporum audouinii, at a concentration of 50 ppm. Its nature was fungicidal and it exhibited a broad antimycotic spectrum against dermatophytes. The shelf‐life of chenopodium oil was found to be 360 days. The ointment of the oil prepared in petroleum jelly could control established ringworm infection in guinea‐pigs during preliminary animal trials.

Antimycotic activity of the essential oil of Artemisia nilagirica

During screening of essential oils isolated from leaves of 10 angiospermic taxa against dermatophytes Epidermophyton floccosum and Trichophyton violaceum, the essential oil of Artemisia nilagirica was found to possess complete antidermatophytic activity by the poisoned food technique. The minimum inhibitory concentration of the oil was found to be 200 ppm. It was fungistatic in nature and had a broad fungitoxic spectrum. An ointment of the essential oil prepared in polyethylene glycol showed pronounced efficacy as a herbal antifungal agent against dermatomycosis induced in guinea-pigs within 14 days of application. The oil was standardized on the basis of its different physico chemical properties, such as specific gravity, specific rotation, refractive index, acid value, saponification value, carbonyl percentage and phenolic content. Copyright

An antileishmanial prenyloxy-naphthoquinone from roots of Plumbago zeylanica

Leishmania donovani, an obligate intracellular parasite of genus Leishmania causes visceral leishmaniasis that affects millions of people worldwide, especially in the Indian subcontinent and East Africa. Generic pentavalent antimonials have been the mainstay for therapy in the endemic regions due to efficacy and cost effectiveness but the growing incidence of their resistance has seriously hampered their use. This study discloses strong in vitro antileishmanial activity of 2-methyl-5 -(3′-methyl-but-2′-enyloxy)-[1,4]naphthoquinone (1), a prenyloxy-naphthoquinone isolated and characterised from roots of the plant Plumbago zeylanica (family – Plumbaginaceae). The observed EC50 for the compound 1 against promastigote and amastigote forms of L. donovani was significantly (p < 0.001) lower than miltefosine, a reference drug. In context to limited treatment options and growing resistance for available drugs, compound 1 offers a greater prospect towards antileishmanial drug discovery and development.

An account of phytochemicals from Plumbago zeylanica (Family: Plumbaginaceae): A natural gift to human being #

The semi-climbing sub-shrub Plumbago zeylanica (family: Plumbaginaceae) is a widely accepted ethnomedicine around the world including India, Pakistan, Bangladesh, Sri Lanka, and Australia. The plant is credited with potential therapeutic properties including antiatherogenic, cardiotonic, hepatoprotective, and neuroprotective properties. The present review highlights the various medicinal and pharmacological aspects along with recent updates on phytochemical contents of the plant.

Natural products as leads to potential mosquitocides

Mosquitoes are the crucial vectors for a number of mosquito-borne infectious diseases i.e. dengue, yellow fever, chikungunya, malaria, Rift Valley fever, elephantiasis, Japanese Encephalitis, and Murray Valley encephalitis etc. Besides, they also transmit numerous arboviruses (arthropod-borne viruses) for example West Nile virus, Saint Louis encephalitis virus, Eastern equine encephalomyelitis virus, Everglades virus, Highlands J virus, and La Crosse Encephalitis virus. The emergence of widespread insecticide resistance and the potential environmental issues associated with some synthetic insecticides (such as DDT) has indicated that additional approaches to control the proliferation of mosquito population would be an urgent priority research. The present review highlights some natural product mosquitocides that are target-specific, biodegradable, environmentally safe, and botanicals in origin.

Cytotoxicity of syringin and 4-methoxycinnamyl alcohol isolated from Foeniculum vulgare on selected human cell lines

This study was carried out to determine the cytotoxic effect of seven plant extracts and the isolated compounds – syringin and 4-methoxycinnamyl alcohol – on cancerous and non-cancerous cells. The ethanol extract of Foeniculum vulgare was found to exhibit the most significant toxicity with an IC50 value of 19.97 μg/mL on HeLa cells. Bioassay-guided fractionation led to the isolation of two compounds, syringin (1) and 4-methoxycinnamyl alcohol (2). Both compounds showed toxicity against MCF-7, HeLa and DU145 cancer cell line. The results showed that compound 2 showed high toxicity against all the cancer cell lines with IC50 values of 14.24, 7.82 and 22.10 μg/mL, respectively. 4-Methoxycinnamyl alcohol also showed no apoptotic effect in cell cycle analysis after 48 h at a concentration of 10 μg/mL. However, DNA fragmentation study revealed that necrosis took place at a concentration of 10 μg/mL after 48 h exposure.

A new antifungal eudesmanolide glycoside isolated from Sphaeranthus indicus Linn. (Family Compositae)

Abstract A new antifungal eudesmanolide glycoside 11,13-dihydro-3-O-(β-digitoxopyranose)-7α-hydroxy eudasman-6,12-olide (2) in addition to known compounds 1 and 3, has been isolated from Sphaeranthus indicus Linn. Its structure was determined by spectral analysis (UV, IR, 1D and 2D NMR and mass spectrum).

Cytotoxicity of synthesized 1,4-naphthoquinone analogues on selected human cancer cell lines

In an effort to establish new candidates with enhanced anticancer activity of 5-hydroxy-7-methyl-1,4-naphthoquinone scaffold (7-methyljuglone) previously isolated from the root extract of Euclea natalensis, a series of 7-methyljuglone derivatives have been synthesized and assessed for cytotoxicity on selected human cancer lines. These compounds were screened in vitro for anticancer activity on MCF-7, HeLa, SNO and DU145 human cancer cell lines by MTT assay. Most of them exhibited significant toxicity on cancer cell lines with lower IC50 values. The most potent derivative (19) exhibited the toxicity on HeLa and DU145 cell lines with IC50 value of 5.3 and 6.8μM followed by compound (5) with IC50 value of 10.1 and 9.3μM, respectively. Structure-activity relationship reveals that the fluoro substituents at position C-8 while hydroxyl substituents at C-2 and C-5 positions played an important role in toxicity.