Kunja Bihari Satapathy

Physiological responses induced by chromium +6 toxicity to Cucumis sativus L. and Macrotyloma unifloroum Lam.

The aim of the present study was to examine the possible effect of Chromium (Cr 6+ ) stress on the rate of germination, growth, total chlorophyll, protein, and proline content in the seedling of Macrotyloma unifloroum Lam. and Cucumis sativus L. Upon exposure to graded levels of Cr +6 toxicity by using liquid culture medium. Seedling of both plants exhibited a gradual decline in the growth, total chlorophyll content, protein content along with enhanced proline content with increasing levels of Cr +6 . Rate of germination was 68% in case of Macrotyloma unifloroum Lam. whereas 1% in Cucumis sativus L. at 100 ppm of Cr +6 . The root and shoot growth showed a decline trend with the rise in concentrations (5 to 20 ppm) in both the plants. It was noticed that Macrotyloma unifloroum was less affected by Cr +6 in comparison to Cucumis sativus. The study of biochemical analysis revealed that the total chlorophyll and protein content of Macrotyloma unifloroum and Cucumis sativus were reduced gradually with the rise in concentration (5-20 ppm) and also time duration (7- 21days). A decrease in proline content was observed at lower concentrations (5 ppm) of Cr +6 whereas at higher concentrations (20 ppm) enhanced proline content was reported in both the species, but comparatively more in Cucumis sativus. The outcome of the present study indicates that the effect of hexavalent chromium (Cr +6 ) on

Evaluation of antimicrobial activity of different solvent extracts of Lawsonia inermis L. leaf against human pathogens

The development of drug resistance of pathogens, as well as the appearance of undesirable side effects of certain antibiotics has necessitated the search for new therapeutic agents from natural sources. Keeping this in view, the antimicrobial effect of Lawsonia inermis L. (Lythraceae) leaf extracts were examined using petroleum ether, methanol, and aqueous solvents and tested against 10 human pathogenic bacteria such as Escherichia coli, Bacillus subtilis, Bacillus circulans, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Salmonella typhi, Salmonella paratyphi, Streptococcus mitis, Proteus vulgaris and 6 fungi such as Aspergillus niger, Candida albicans, Candida tropicalis, Candida krusei, Fusarium oxysporum and Trychophyton mentagrophytes. Agar well diffusion method was adopted to test the susceptibility of the test microorganisms to the plant extracts while minimum inhibitory concentration (MIC) was determined using serial dilution of extracts. Petroleum ether extract of L. inermis leaf showed the highest antibacterial activity (zone of inhibition diameter in mm) against Salmonella typhi (40.11±0.01) followed by Salmonella paratyphi (26.03±0.06), Proteus vulgaris (19.03±0.06) and Staphylococcus aureus (14.13±0.0). Methanol extract of L. inermis leaf showed significantly higher activity against Streptococcus mitis, followed by Bacillus circulans, Proteus vulgaris (zone of inhibition diameter in mm was found to be 25.07±0.06, 23.03±0.05 and 22.07±0.06, respectively), but aqueous extract of L. inermis had higher inhibitory activity against the Salmonella typhi, Pseudomonas aeruginosa (26.06±0.05 and 19.06±0.05 mm zone of inhibition) than the rest of bacteria. Both methanol and petroleum ether leaf extract of L. inermis showed higher inhibitory activity against Candida krusei, Fusarium oxysporum, Trichophyton mentagrophytes (zone of inhibition diameter in mm was found to be 36.1±0.01, 36.07±0.06, 26.14±0.02, (M) and 35.06±0.03,31.08±0.02,24.08±0.02 (P), respectively) than Candida albicans and Candida tropicalis. Aqueous extract of L. inermis showed the inhibitory activity against Candida tropicalis, Candida krusei, Fusarium oxysporum, Trychophyton mentagrophytes (zone of inhibition diameter in mm was found to be 23.1±0.01, 23.07±0.06, 21.06±0.05, and 19.07±0.06, respectively) and least was found for Candida albicans, while the Aspergillus niger did not respond to any extract. Antibiotics such as Ampicillin, Ciprofloxacin, Streptomycin and Tetracycline used for bacteria and antifungals like Fluconazole, Terbinafine, Itraconazole, Chloramphenicol (0.5 mg/ml) were used as positive controls and compared with the plant extracts tested. Minimum inhibitory concentration was observed within the range from 6.25-50 mg/ml against all microbes. The results of the present study indicated that Lawsonia inermis L. leaf extracts can suitably be exploited for developing new antibiotics (herbal antibiotics) to overcome the increasing bacterial and fungal resistance to synthetic drugs.

Evaluation of in vitro antibacterial and antioxidant activities of Melia azedarach L. bark

The objective of the present investigation was to evaluate the antibacterial and antioxidant potential of n-hexane and methanolic extracts of Melia azedarach L. bark. The antibacterial potential of M. azedarach L. bark was tested against human pathogens causing diarrhoea and dysentery such as Shigella flexneri (MTCC- 9543), Salmonella enterica ser typhi (MTCC-733), Bacillus subtilis (MTCC-1305), Streptococcus mitis (MTCC- 2897), Klebsiella pneumoniae (MTCC-109) and Staphylococcus aureus (MTCC-1430) using agar well diffusion method. The results of the study revealed that n-hexane extract of bark sample was highly effective against Shigella flexneri whereas Streptococcus mitis, Staphylococcus aureus and Bacillus subtilis showed no response and other test pathogens under study responded moderately. It was observed that methanolic extract had high inhibition potential against Salmonella enterica ser typhi and Streptococcus mitis while moderate effect against other test bacteria. Studies on the antioxidant activity by DPPH scavenging method revealed significant antioxidant potential of n-hexane and methanolic extracts with IC50 value 84.37 and 66.79 respectively.

Studies on the antibacterial and antioxidant activities of Sonchus asper (L.) Hill and Seseli diffusum (Roxb. ex Sm.) Sant. & Wagh

Antioxidant and antimicrobial properties of various extracts from plants have recently been of great interest in both pharmaceutics and food industries, because of their possible use as natural additives which emerged from a growing tendency to replace synthetic antioxidants with natural ones. Sonchus asper (L.) Hill, and Seseli diffusum (Roxb. ex Sm.) Sant. & Wagh, were selected for the evaluation of their antibacterial and antioxidant activities against different disease-causing microorganisms such as Shigella flexneri, Micrococcus sp, Escherichia coli, and Staphylococcus aureus. The methanolic extract of Sonchus asper demonstrated more inhibitory activity against Staphylococcus aureus as compared to other plant extracts and pathogens where as the n-hexane extract of Sseseli diffusum exhibited highest antioxidant activity. The TLC study indicated that the n-hexane extract of Seseli diffusum resuted in more number of spots as compared to other solvents.