In vitro evaluation of the antiglycation and antioxidant potential of the dietary supplement L-citrulline
Authors: Paulines Jessa Marielle U. , Lavilla Jr Charlie A. , Billacura Merell P. , Basalo Harmie L. , Okechukwu Patrick Nwabueze 
Published: September 2023

Diabetes mellitus (DM) represents a significant global public health concern. It is a metabolic condition characterized by abnormal glucose levels in the bloodstream, known as hyperglycemia. This condition arises due to irregular insulin secretion, defective insulin receptivity, or a combination of both factors. The primary contributors to diabetic complications are protein glycation and oxidative stress resulting from chronic hyperglycemia.

The aim. The increasing incidence of diabetes mellitus has prompted a quest for a novel, cost-effective, and efficacious medication. The objective of the study generally intends to explore and investigate the antiglycation and antioxidant potential of the dietary supplement L-Citrulline

Materials and methods. A two-reaction model system was carried out to study and monitor the inhibitory impact of the dietary supplement L-Citrulline against advanced glycation end products (AGEs) formation. This system involved the in vitro glucose bovine serum albumin (BSA-glucose assay) and methylglyoxal bovine serum albumin (BSA-MGO assay). The antioxidant activity of the supplement was assessed by measuring its capacity to chelate metal ions and scavenge reactive oxygen species. The iron chelating activity was evaluated through absorbance measurements, while fluorescence measurements were employed for the remaining assays.

Results. According to the findings of the antiglycation assays, it was observed that the dietary supplement L-Citrulline demonstrated inhibitory properties against the development of advanced glycation end products (AGEs) in the BSA-Glucose model at a concentration of 100 ppm. The degree of inhibition with respect to glycation was ascertained to be 52.19 ± 0.39 % through observation. The BSA-MGO model has exhibited inhibitory properties with an observed activity of 49.64 ± 0.27 % at 100ppm concentration with respect to glycation. On the other hand, the supplement demonstrates antioxidant characteristics through the chelation of Fe ions, leading to a percentage difference in activity of 68.58 ± 0.45 % compared to the control at 100 ppm. The utilization of Glucolypotoxixity (GLT) media during the reactive oxygen species assay yielded a significant rise of 173.48 ± 9.37 % in the reactive species levels compared to the control, with statistical significance. The addition of 10 mM dietary supplement L-Citrulline resulted in a noteworthy reduction of 98.42 ± 5.04 % in the escalation. Therefore, it can be deduced that utilizing L-Citrulline as a dietary supplement exhibits potential for its therapeutic applications in eliminating reactive oxygen species (ROS) within skeletal muscle cells.

Conclusion. The study results suggest that the dietary supplement L-Citrulline has demonstrated inhibitory capabilities against glycation at varying concentration levels. Furthermore, it was noted to exhibit significant efficacy in both sets of antioxidant tests. Therefore, the supplement exhibits potential in the treatment of diabetes mellitus