Renoprotective effect of Alpiniae oxyphyllae Fructus on ischemia/reperfusion-induced acute renal failure

Short-term Administration of Naringin Improves Renal Function in Renal Ischemia-reperfusion by Increasing Aquaporin-1 and Aquaporin-2 Levels

Background:

Since renal ischemia-reperfusion (I/R) can lead to a serious health problem, aquaporins have important roles in preventing negative changes in electrolyte-water balance. This study aimed to determine the effect of naringin treatment on renal function and AQP1 and AQP2 levels in the kidney cortex and medulla tissues in experimental renal I/R in rats.

Materials and Methods:

The study was carried out on 40 male Wistar-type rats, 8-12 weeks old. Experimental groups were formed as follows: 1) Control, 2) Sham+vehicle, 3) Renal (I/R)+vehicle, 4) Renal I/R+ Naringin (50mg/kg/day) (3 days of administration), and 5) Renal I/R+ Naringin( 100mg/kg/day) (3 days supplementation) group. First, the left kidney was removed by nephrectomy under general anesthesia, and then the right kidney was subjected to 45 minutes of ischemia and then 72 hours of reperfusion. Naringin was given to the experimental animals by an intraperitoneal route at the beginning of the reperfusion, after 24 and 48 hours. At the end of the experiments, first of all, blood samples were taken from the heart in animals under general anesthesia, and then the animals were killed by cervical dislocation, and kidney tissue samples were taken. Osmolarity in plasma and urine and plasma creatinine levels were evaluated. AQP1 and AQP2 levels were analyzed in the kidney cortex and medulla tissues by ELISA and PCR methods.

Results:

In kidney tissues, I/R led to a decrease in plasma and urinary osmolality, AQP1 and AQP2 levels in the cortex and medulla, and an increase in urea and creatinine levels (p < 0.001). However, naringin supplementation corrected the deterioration to a certain extent.

Conclusion:

The results of the study show that naringin supplementation at different doses, such as 50 or 100 mg/kg, may have protective effects on the deterioration of renal function caused by unilateral nephrectomy and I/R in rats.

Nootkatone Supplementation Attenuates Carbon Tetrachloride Exposure-Induced Nephrotoxicity in Mice

Nootkatone (NKT), a major ingredient of Alpinia oxyphylla, exhibited potential nephroprotective effects; however, the precise molecular mechanisms remain poorly understood. This study aimed to study the nephroprotective effects of NKT and the underlying mechanisms in a mouse model. Our results showed that NKT pretreatment at the doses of 5, 10, and 20 mg/kg per day for 7 days significantly attenuates carbon tetrachloride (CCl4)-induced increases of serum BUN and CRE and kidney pathology injury. NKT pretreatment also markedly inhibited oxidative stress, inflammatory response, and the activation of caspases-9 and -3 in kidneys of mice exposed to CCl4. Meanwhile, NKT pretreatment downregulated the expression of NOX4, IL-1β, IL-6, and TNF-α proteins and NO levels in the kidney tissues. Moreover, NKT pretreatment upregulated the expression of Nrf2 and HO-1 mRNAs, and downregulated the expression of NF-κB, IL-1β, IL-6, TNF-α, and iNOS mRNAs in the kidneys of mice, compared to those in the CCl4 alone treatment group. In conclusion, our results reveal that NKT supplementation could protect against CCl4 exposure-induced oxidative stress and inflammatory response in the kidneys by inhibiting NOX4 and NF-κB pathways and activating the Nrf2/HO-1 pathway. Our current study highlights the therapeutic application of NKT for kidney diseases.

Alpinia oxyphylla Miq extract reduces cerebral infarction by downregulating JNK-mediated TLR4/T3JAM- and ASK1-related inflammatory signaling in the acute phase of transient focal cerebral ischemia in rats

Background

Post-ischemic inflammation is a crucial component in stroke pathology in the early phase of cerebral ischemia–reperfusion (I/R) injury. Inflammation caused by microglia, astrocytes, and necrotic cells, produces pro-inflammatory mediators and exacerbates cerebral I/R injury. This study evaluated the effects of the Alpinia oxyphylla Miq [Yi Zhi Ren (YZR)] extract on cerebral infarction at 1 day after 90 min of transient middle cerebral artery occlusion (MCAo) and investigated the molecular mechanisms underlying the regulation of c-Jun N-terminal kinase (JNK)-mediated inflammatory cascades in the penumbral cortex. Rats were intraperitoneally injected with the YZR extract at the doses of 0.2 g/kg (YZR-0.2 g), 0.4 g/kg (YZR-0.4 g), or 0.8 g/kg (YZR-0.8 g) at MCAo onset.

Results

YZR-0.4 g and YZR-0.8 g treatments markedly reduced cerebral infarction, attenuated neurological deficits, and significantly downregulated the expression of phospho-apoptosis signal-regulating kinase 1 (p-ASK1)/ASK1, tumor necrosis factor receptor-associated factor 3 (TRAF3), TRAF3-interacting JNK-activating modulator (T3JAM), ionized calcium-binding adapter molecule 1 (Iba1), p-JNK/JNK, inducible nitric oxide synthase, cyclooxygenase-2, tumor necrosis factor-α, toll-like receptor 4 (TLR4), glial fibrillary acidic protein (GFAP), nuclear factor-kappa B (NF-κB), and interleukin-6 in the penumbral cortex at 1 day after reperfusion. SP600125 (SP), a selective JNK inhibitor, had the same effects. Furthermore, Iba1- and GFAP-positive cells were colocalized with TLR4, and colocalization of GFAP-positive cells was found with NF-κB in the nuclei.

Conclusion

YZR-0.4 g and YZR-0.8 g treatments exerted beneficial effects on cerebral ischemic injury by downregulating JNK-mediated signaling in the peri-infarct cortex. Moreover, the anti-infarction effects of YZR extract treatments were partially attributed to the downregulation of JNK-mediated TLR4/T3JAM- and ASK1-related inflammatory signaling pathways in the penumbral cortex at 1 day after reperfusion.

Effect of Alpina oxyphylla extract on streptozotocin-induced kidney injure via regulating TGF-β1 and MyD88

BACKGROUND

Abnormal renal metabolism is closely related to the development of chronic kidney disease. It is well known that renal inflammation plays an important role in the occurrence and development of tubulointerstitial damage in the renal tubules. The purpose of the experiment was to observe the bioactivity of Alpina oxyphylla extract (AOE) on renal injury in diabetic nephropathy (DN) rats induced by streptozotocin (STZ).

METHODS

Thirty male Wistar rats were randomly divided into five group (n = 6): (1) intact control (non-diabetic, ND); (2) intact diabetic (STZ), (3) diabetic rats treated with gliclazide 5 mg/kg (STZ-gli), (4) diabetic rats treated with AOE 400 mg/kg (AOE 400), (5) diabetic rats treated with AOE 800 mg/kg (AOE 800). The diabetic nephropathy rat model was established by single intraperitoneal injected 50 mg/kg STZ. Fasting blood glucose (FBG) and body weight was observed at 1、3、6 weeks. After 6 weeks, the renal function parameters of five groups and 24 h urinary protein were detected. Expression of transforming growth factor-beta1 (TGF-β1) and myeloid differentiation factor 88 (MyD88) were assessed by Western Blot.

RESULTS

The STZ group showed hyperglycemia, proteinuria, renal function damage, and the levels of 24 h urinary protein, fasting blood glucose (FBG), blood urea nitrogen (BUN), serum creatinine (Scr), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and interleukin-6 (IL-6) in the STZ group increased significantly compared with the ND group. The expression of TGF-β1 in STZ group was increase (p < 0.01), and the expression of MyD88 was significantly lower than in ND group (p < 0.05). The treatment of DN rats with AOE attenuated DN-associated in the serum biochemical index and the expression of TGF-β1.

CONCLUSIONS

AOE can effectively protect kidney tissues of diabetic nephropathy, and probably through regulating level of TGF-β1/MyD88.

Effect of Liuweibuqi capsules on CD4+CD25+Foxp3+ regulatory T cells, helper T cells and lung function in patients with stable chronic obstructive pulmonary disease complicated with lung Qi deficiency

Background

Chronic obstructive pulmonary disease (COPD) is predicted to become the fifth leading cause of disability and the third leading cause of death around the world by 2020. Though it is potentially treatable and preventable, evidence of brain structural alterations in COPD remains sparse and conflicting. We aim to investigate the effect of Liuweibuqi capsules on CD4⁺CD25⁺ Forkhead box protein 3⁺ (Foxp3⁺) regulatory T cells (Tregs), helper T cells (Th) and lung function in patients with stable COPD complicated with lung Qi deficiency.

Methods

COPD patients with lung Qi deficiency [458] were assigned into non-smoking COPD (NS-COPD), non-smoking control (NS-control), smoking COPD (S-COPD) and smoking control (S-control) groups, and healthy volunteers [245] into the non-smoking healthy (NSH) and smoking healthy (SH) groups. Levels of inflammatory cytokines were detected by Enzyme-linked immunoassay (ELISA). Contents of inflammatory cells, inflammatory marker, and CD4⁺CD25⁺Fox3⁺Tregs were measured by flow cytometry. FEV1/FVC (%) and FEV1 (%) were detected by pulmonary function test apparatus. Correlation between FEV1 (%) and Th1, Th2, Th17, Th1/Th2 or CD4⁺CD25⁺Fox3⁺Tregs was analyzed by Spearman rank correlation test. The related factors affecting treatment efficacy was assessed by logistic analysis.

Results

COPD patients and smoking people showed higher level of INF-γ, IL-4, IL-17, Th1, Th2, Th17 and Th1/Th2 but lower level of CD4⁺CD25⁺Fox3⁺Tregs. Liuweibuqi capsules could decrease level of inflammatory cells, cytokines, and markers (especially Th17 and IL-17), and increase level of CD4⁺CD25⁺Fox3⁺Tregs. FEV1 (%) negatively correlated with Th1, Th2, Th17 and Th1/Th2 but positively correlated with CD4⁺CD25⁺Fox3⁺Tregs, and smoking may strengthen their correlation, but Liuweibuqi capsules may weaker their correlation. Levels of inflammatory cytokines, cells, marker, CD4⁺CD25⁺Fox3⁺Tregs, FEV1/FVC (%), FEV1 (%), smoking and Liuweibuqi capsules are factors affecting efficacy.

Conclusions

Taken together, our data support the notion that smoking is an important factor to induce and aggravate COPD. Liuweibuqi capsules could stimulate proliferation of CD4⁺CD25⁺Fox3⁺Tregs and decrease Th17 expression to improve the lung function in stable COPD patients with lung Qi deficiency, and it had obvious efficacy for smoking COPD patients.

Natural medicines for acute renal failure: A review

Acute renal failure (ARF) is a life-threating disease with high mortality percentage. Two important mechanisms of ARF are inflammation and oxidative stress. Plants are rich source of antioxidant compounds and have a strong anti-inflammatory activity, so they may be useful for the treatment of ARF. Some herbal medicines are effective against different models of experimentally induced ARF such as cisplatin, gentamicin, glycerol, and ischemia-reperfusion injury. Some of these plants such as ginseng, black seed, ginger, garlic, grape, pomegranate, saffron, and green tea are so famous and are effective against various models of ARF. However, we found several articles examining the effectiveness of different plants for treating ARF. In the current article, we discussed plants and natural products that are effective in the treatment of ARF.

GATA2 regulates body water homeostasis through maintaining aquaporin 2 expression in renal collecting ducts

The transcription factor GATA2 plays pivotal roles in early renal development, but its distribution and physiological functions in adult kidney are largely unknown. We examined the GATA2 expression pattern in the adult kidney by tracing green fluorescent protein (GFP) fluorescence in Gata2(GFP/+) mice that recapitulate endogenous GATA2 expression and found a robust GFP expression specifically in the renal medulla. Upon purification of the GFP-positive cells, we found that collecting duct (CD)-specific markers, including aquaporin 2 (Aqp2), an important channel for water reabsorption from urine, were abundantly expressed. To address the physiological function of GATA2 in the CD cells, we generated renal tubular cell-specific Gata2-deficient mice (Gata2-CKO) by crossing Gata2 floxed mice with inducible Pax8-Cre mice. We found that the Gata2-CKO mice showed a significant decrease in Aqp2 expression. The Gata2-CKO mice exhibited high 24-h urine volume and low urine osmolality, two important signs of diabetes insipidus. We introduced biotin-tagged GATA2 into a mouse CD-derived cell line and conducted chromatin pulldown assays, which revealed direct GATA2 binding to conserved GATA motifs in the Aqp2 promoter region. A luciferase reporter assay using an Aqp2 promoter-reporter showed that GATA2 trans activates Aqp2 through the GATA motifs. These results demonstrate that GATA2 regulates the Aqp2 gene expression in CD cells and contributes to the maintenance of the body water homeostasis.