Melilotus indicus

Abstract: Soil infested with Chenopodium murale and amended with it were investigated to verify their allelopathic effects on seedling emergence and some growth and physiological parameters of five test species, Trifolium alexandrinum, Triticum aestivum, Melilotus indicus, lycopersicum esculentum and Cucumus sativus. The two types of soil exhibited phytotoxic effects on the seedling emergence of the test species. Growth and physiological parameters were significantly inhibited when the soil was amended with a high concentration of C. murale tissues. Soil amended with shoot tissue had more inhibitory effects than soil amended with root tissue, at the same concentration. M. indicus was more inhibited than the other species in relation to leaf area, dry matter, pigment, carbohydrates and protein contents.

Abstract: Medicago intertexta and Melilotus indicus, two wild leguminous herbs with different tolerance to salinity were investigated for NaCl-induced changes in the expression level of some Na(+) transporters. M. indicus plants grew well at NaCl concentration from 0 to 400 mM, whereas growth of M. intertexta plants was severely inhibited at NaCl concentrations higher than 100 mM. In M. intertexta, increasing NaCl in the growth media caused a strong increase in Na(+) content concomitant with a decrease in K(+) content in leaves and, above all, roots. In comparison, M. indicus plants cultivated in the presence of NaCl accumulated much less Na(+) in leaves and roots and no differences in K(+) content among plants grown in nutrient solution containing 100-400 mM NaCl were detected. The expression levels of four genes coding for NHX-type Na(+)/H(+) antiporters in the above two wild legumes were studied in plants cultivated under the different NaCl concentrations. Expression levels of the genes were higher in M. intertexta as compared with M. indicus plants. In M. intertexta, salt treatments increased MtNHX1, MtNHX3 and MtNHX4 transcript levels in leaves and roots. However, in M. indicus NaCl treatments only induced the expression of MtNHX1 in roots. Our data suggest that two different mechanisms, Na(+) avoidance or accumulation into cellular compartments, are developed by the two wild legumes to cope with salt stress, and that expression of NHX antiporters is linked to the accumulator phenotype.

Abstract: Melilotus indicus (Linn.) All. is a small herb distributed throughout Pakistan and has a number of ethnomedicinal uses. It is also consumed as a vegetable. In the present work, we are reporting the alpha-amylase and urease inhibitory activities of methanolic extract of M. indicus and its sub-fractions in different solvents. Both the methanolic extract and its fractions in chloroform, ethyl acetate, n-butanol and water showed remarkable inhibitory activities against alpha-amylase with the IC50 values being 1.29, 1.45, 1.07, 1.45 and 2.10 mg/mL respectively. The efficacy of the methanolic extract was comparable with that of acarbose (1.20 mg/mL), while the ethyl acetate fraction was more potent. The urease inhibitory activities of methanolic extract and chloroform, ethyl acetate, n-butanol and water fractions were more prominent with IC50 values being 0.95, 0.89, 1.53, 0.98 and 4.90 μg/mL respectively. The activity of methanolic extract was slightly higher than that of thiourea (0.97 μg/mL) which in turn was slightly higher than that of n-butanolic fraction. The chloroform fraction showed the highest anti-urease activity. All the plant samples showed enzyme inhibitory activity in a dose-dependent manner. Moreover, they were manifold more effective against urease than alpha-amylase. The combination of the plant extract with acarbose considerably increased the potency of the latter. The findings suggest that enzyme inhibitory activities of the vegetable M. indicus may have pharmacological significance against diabetes mellitus and gastrointestinal ulcers.