Pretreatment with Fish Oil-Based Lipid Emulsion Modulates Muscle Leukocyte Chemotaxis in Murine Model of Sublethal Lower Limb Ischemia

Effects of n-3 polyunsaturated fatty acid supplementation on quadriceps weakness immediately after total knee arthroplasty: a pilot, randomized, open-label clinical trial

[Purpose] Severe quadriceps weakness immediately after total knee arthroplasty can be problematic. The n-3 long-chain polyunsaturated fatty acids have antioxidant and anti-inflammatory effects against ischemia-reperfusion injury, whereas n-6 long-chain polyunsaturated fatty acids exert pro-inflammatory effects, thereby promoting ischemia-reperfusion injury. [Participants and Methods] We explored the efficacy of preoperative n-3 long-chain polyunsaturated fatty acid supplementation against early quadriceps weakness among 20 patients scheduled for total knee arthroplasty (intervention group, n=10; control group, n=10). The intervention group received 645 mg of eicosapentaenoic acid) and 215 mg of docosahexaenoic acid daily for 30 days preoperatively. Serum eicosapentaenoic acid, docosahexaenoic acid, and arachidonic acid levels were measured preoperatively. We compared serum derivatives of reactive oxygen metabolites as oxidative stress biomarkers, knee circumference, thigh volume, knee pain during the quadriceps strength test, and quadriceps strength preoperatively and 4 days postoperatively to quantify the change. [Results] Preoperative n-3 long-chain polyunsaturated fatty acid supplementation significantly increased the (eicosapentaenoic acid+docosahexaenoic acid)/arachidonic acid ratio in the intervention group. A significantly lower increase in quadriceps weakness was exhibited in the intervention group than in the control group. However, changes in oxidative stress, knee/thigh swelling, and knee pain during strength testing did not significantly differ between the two groups. [Conclusion] Preoperative n-3 long-chain polyunsaturated fatty acid supplementation exhibited beneficial effects on quadriceps weakness immediately after total knee arthroplasty.

Tetrahydropalmatine induces the polarization of M1 macrophages to M2 to relieve limb ischemia-reperfusion-induced lung injury via inhibiting the TLR4/NF-κB/NLRP3 signaling pathway

Tetrahydropalmatine (THP) is the main component of the Chinese medicine Corydalis yanhusuo, which has been reported to alleviate limb ischemia-reperfusion-induced acute lung injury (LIR-ALI). This study aimed to investigate the mechanism underlying the effect of THP on relieving LIR-ALI. LIR-ALI model was established in rats with the presence or absence of THP pretreatment. Then, BEAS-2B cells and THP-1 macrophages were cocultured with rat serum from the Sham group and the Model group in the presence or absence of THP pretreatment. Subsequently, lung/body weight and lung wet/dry ratio of rats were calculated. Histological changes of lung tissues were observed by hematoxylin-eosin staining. Expression of CD86 and CD163 in lung tissues of rats was assessed by quantitative reverse transcription polymerase chain reaction, immunohistochemistry staining, and flow cytometry analysis. Levels of inflammatory cytokines were measured by enzyme linked immunosorbent assay. The expression of proteins related to toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB)/NLRP3 signaling was detected by western blot analysis. Results revealed that THP significantly relieved LIR-ALI in rats. Moreover, THP also reduced CD86 expression but elevated CD163 expression in lung tissues of rats with LIR-ALI. Furthermore, THP inhibited inflammation in serum and bronchoalveolar lavage fluid of rats with LIR-ALI and inactivated the TLR4/NF-κB/NLRP3 signaling in vivo. Additionally, coculture of serum from rats in the Model group also reduced viability, promoted inflammation, inactivated TLR4/NF-κB/NLRP3 expression in BEAS-2B cells and inhibited macrophage polarization, while these effects were all reversed by THP treatment. Collectively, THP could induce the polarization of M1 macrophage to M2 to suppress inflammation via inhibiting TLR4/NF-κB/NLRP3 signaling, thereby attenuating LIR-ALI.

Association between Preoperative Long-Chain Polyunsaturated Fatty Acids and Oxidative Stress Immediately after Total Knee Arthroplasty: A Pilot Study

Quadriceps muscle atrophy following total knee arthroplasty (TKA) can be caused by tourniquet-induced ischemia–reperfusion (IR) injury, which is often accompanied by oxidative stress and inflammatory responses. n-3 long-chain polyunsaturated fatty acids (LCPUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), exert antioxidant and anti-inflammatory effects against IR injury, whereas n-6 LCPUFAs, particularly arachidonic acid (AA), exhibit pro-inflammatory effects and promote IR injury. This study aimed to examine whether preoperative serum EPA + DHA levels and the (EPA + DHA)/AA ratio are associated with oxidative stress immediately after TKA. Fourteen eligible patients with knee osteoarthritis scheduled for unilateral TKA participated in this study. The levels of serum EPA, DHA, and AA were measured immediately before surgery. Derivatives of reactive oxygen metabolites (d-ROMs) were used as biomarkers for oxidative stress. The preoperative serum EPA + DHA levels and the (EPA + DHA)/AA ratio were found to be significantly negatively correlated with the serum d-ROM levels at 96 h after surgery, and the rate of increase in serum d-ROM levels between baseline and 96 h postoperatively. This study suggested the preoperative serum EPA + DHA levels and the (EPA + DHA)/AA ratio can be negatively associated with oxidative stress immediately after TKA.

Electro-Acupuncture on ST36 and SP6 Acupoints Ameliorates Lung Injury via Sciatic Nerve in a Rat Model of Limb Ischemia-Reperfusion

Introduction

Electro-acupuncture (EA) can significantly improve inflammatory response, but the specific mechanism is not clear. Limb ischemia-reperfusion (I/R) first produces inflammatory reactions in the lungs. In this study, EA on Zusanli (ST36) and Sanyinjiao (SP6) were used to explore the mechanism of improving tissue inflammation by sciatic nerve disconnection.

Material and Methods

A total of 56 male Sprague-Dawley rats were randomly divided into sham group, model group, EA group, SEA group, SNC+EA group, TNC+EA group and PNC+EA group. The sham groups were not given any treatment. Rats in the model group were treated with limb I/R without acupuncture intervention. In the EA group, ST36 and SP6 were given EA treatment for 30min before modeling. No electric current was given in the SEA group, and other operations were the same as those in the EA group. The SNC+EA group, TNC+EA group and PNC+EA group were respectively given sciatic nerve, tibial nerve or peroneal nerve amputation 72h before modeling, and the others were the same as the model group.

Results

Compared with the sham group, PaO2 and a/A ratios decreased significantly in the model group (P <0.05), while PA-aO2, RI, the ratio of wet to dry, lung injury value and inflammatory factor TNF-α, IL-1, IL-6, and MPO increased significantly (P <0.05). Compared with the model group, PaO2, a/A ratios increased significantly in the EA group (P <0.05), while PA-aO2, RI, the ratio of wet to dry lung, lung injury value, and TNF-α, IL-1, IL-6, and MPO decreased significantly (P <0.05). After transection of the sciatic nerve, the protective effect of EA disappeared. However, when the peroneal or tibial nerve was severed, EA continued to maintain the protective effect.

Conclusion

EA on ST36 and SP6 can alleviate lung injury caused by limb I/R through the sciatic nerve.

Association between serum n-3 polyunsaturated fatty acids and quadriceps weakness immediately after total knee arthroplasty

Objectives

Quadriceps weakness (QW) following total knee arthroplasty (TKA) can be elicited by tourniquet-induced ischaemia reperfusion (IR), which causes a vigorous acute inflammatory response. Dietary n-3 polyunsaturated fatty acids (PUFA) are important determinants of organ and tissue protection from IR. This study aimed to examine the association between serum n-3 PUFA levels and QW, knee pain, and knee swelling immediately after TKA.

Methods

A total of 32 patients who underwent unilateral TKA participated in this prospective study. On Postoperative Day 1, serum n-3 PUFA (eicosapentaenoic acid and docosahexaenoic acid) levels were measured. Preoperatively and on Postoperative Day 4, quadriceps strength, knee pain during quadriceps testing, and knee circumference were measured. QW, knee pain, and knee swelling were defined as changes in quadriceps strength, knee pain during quadriceps testing, and knee circumference, respectively, between the preoperative to the postoperative measurement.

Results

Mean serum n-3 PUFA levels were 192 μg/mL (standard deviation, 58 μg/mL) on Postoperative Day 1. All measured variables changed significantly between the preoperative and the postoperative measurement time-points (P <0.01). Quadriceps strength decreased from 1.2 to 0.4 Nm/kg (QW = −65%). Knee pain during quadriceps testing increased from 1.1 to 6.0 (knee pain = 4.0). Knee circumference increased from 40 to 44 cm (knee swelling = 10%). Multivariate analysis showed that lower serum n-3 PUFA levels were independently associated with an increased QW after adjusting for the Kellgren-Lawrence grade and the tourniquet time (P = 0.04). No significant relationship was observed between serum n-3 PUFA levels and knee pain or knee swelling.

Conclusion

Higher serum n-3 PUFA are independently associated with a lower increase in the QW immediately after TKA.