Effect of insulin and momordica charantia fruit juice extracts on glucose and ion transport in L6 rat muscle cell line

Momordica charantia fruit is traditionally used as a vegetable in the West Indies, the Indian subcontinent , Africa and South America and it is believed to have hypoglycaemic effects in both human and experimental diabetes. The effects of insulin and M. cizarantia extracts A and B on 3H D-glucose and on N-methylamino-cz-isobutyric acid ( 14C Me-AIB) uptake, as well as their effects on cation transport were investigated in L6 muscle cells. The results of this study have revealed that insulin can elicit marked and significant increases in both 3H D-glucose and "C Me-AIB uptake. On the other hand, extracts A and B of M. charantia in low concentrations (1, 5 and 10 jig/mI) had differential effects on 3H D-glucose and 14C Me-Am uptake during 1, 3 and 6 hr of incubation. The optimum effects on 3H D-glucose and Me-AIB uptake were achieved during 6 hr of incubation and the B extract seems to have a greater effect on both 3H D-glucose and 14C Me-AlE uptake compared to their respective controls. It is the perception that the extracts stimulate the PT 3-kinase signalling system, which is a similar system used by insulin. Any inhibition of 3H D-glucose and 14C Me-AIB that may be caused by the the exracts may be due in part to the presence of glucose in the extracts since exogenous glucose can also inhibit 3H D-glucose. The study has also revealed that insulin had a significant effect on the transport of sodium (Na) and potassium ( IC) in L6 muscle cells. Insulin caused a TV retention of K and increased efflux of Nat This may in turn have significant implications for glucose and amino acid uptake in muscle cells. Insulin also reduced calcium (Ca 2 ) efflux, although it was not significant. Likewise, the islet hormone had no significant effects on magnesium (Mg 2 ) transport. On the other hand, the different concentrations of A and B extracts had little or no effect on cation transport, with exception for sodium (Na t) and potassium (K) in which the extracts increase Na efflux and reduced the efflux of Kt. These results sugggest that the extracts may stimulate the activity of the Na-C ATP-ase pump. In conclusion, the results suggest that Al. charantia fruit extracts may play an important physiological role in regulating glucose , amino acid and cation transport in muscle cells. Further experiments are required to characterize the active ingredient (s) of the extracts and to investigate precisely the cellular mechanism of their hypoglycaemic effect. Furthermore these findings that are reported in this thesis may have implications in elucidating the therapeutic use of M. charantia in the management of diabetes mellitus.

Name dc:type.qualificationname

msc

Level dc:type.qualificationlevel

masters

Grantor dc:publisher.institution

University of Central Lancashire

Year dc:date.issued

2000

Author dc:creator

• Cummings, Emanuel F.

• C990 - Biological sciences not elsewhere classified

Language dc:language

en