The regenerative and anti-inflammatory capability of Prosopis Glandulosa

[摘要] ENGLISH ABSTRACT: Introduction and aims: The use of herbal preparations for the treatment of various ailments has gained enormous prominence. The aim of this study was to evaluate the effects of a plant-derived product, consisting solely of dry-milled pods of the Prosopis glandulosa tree, on various altered metabolic demands placed on skeletal muscle. This study included the evaluation of (i) altered glucose uptake as a result of insulin resistance, (ii) exercise-induced fatigue and (iii) the inflammatory and regenerative process of skeletal muscle after a contusion injury, with particular attention paid to the infiltration of immune cells and the adaptation of regenerative markers. Methodology: P. glandulosa (100 mg/kg/day) mixed into jelly, was orally administered daily to rats for a period of 8-10 weeks. Aim 1: Rats were rendered insulin resistant after being on a high caloric diet for 16 weeks, where after half the animals underwent a 120 min intra-peritoneal glucose tolerance test. The rest were fasted, body weight and intra-peritoneal fat weight determined, sacrificed, blood collected for blood glucose- and insulin level determination and soleus muscles removed for insulin sensitivity determination. Aim 2: Soleus muscles were excised, weighed, measured and mounted for isometric force determination. Muscles were vertically placed in Krebs Henseleit buffer solution in a water-jacketed organ bath (25˚C). Twitch- and tetanic force production, contraction time, half-relaxation time, force-frequency relationship and fatigue were measured. Aim 3: The gastrocnemius muscle was injured by a contusion injury (mass-drop model) and left for 1-, 3 hours, 1- or 7 days before further experimentation commenced. Following the different time periods, the gastrocnemius muscles were removed, divided and stored either in liquid nitrogen or 4% formaldehyde. Immune cell infiltration was analyzed with immunohistochemistry (neutrophils - His48-positive; macrophages - F4/80-positive). ADAM12 (Western blotting) and desmin (immunohistochemistry) were used as markers to evaluate muscle regeneration. Results: Aim 1: P. glandulosa treatment had no effect on body- or fat mass. Treatment significantly decreased the elevated blood glucose levels observed in the obese rats. Aim 2: P. glandulosa treatment had: (i) no effect on muscle mass or optimal muscle length; (ii) no significant effect on muscle fatigue tolerance, as both treated and untreated groups fatigued at the same rate and (iii) P. glandulosa-treated rats generated significantly increased force when the muscle was stimulated to generate a single twitch and tetanus. This augmented effect disappeared after the fatigue protocol. Aim 3: Chronic P. glandulosa treatment as well as post-injury treatment led to a significant reduction in neutrophil infiltration into the injured area. Additionally, chronic P. glandulosa treatment significantly increased the expression of both ADAM12 (day 1) and desmin (day 7) after injury, indicating faster muscle regeneration. Conclusion: The data obtained from this study is novel, since there is no known literature on the effect of P. glandulosa on insulin resistance, force generation, fatigue tolerance or muscle recovery after injury. Given the current evidence, we conclude that P. glandulosa treatment might prove beneficial as supplement, aiding physical ability and assisting in the sooner recovery.

[发布机构] Stellenbosch University