Combined Administration of Curcumin and Chondroitin Sulfate Alleviates Cartilage Injury and Inflammation via NF-κB Pathway in Knee Osteoarthritis Rats

Objective: Osteoarthritis (OA) is a degenerative chronic disease that most often occurs in the knee joint. Studies have shown that some food supplements, such as curcumin and chondroitin sulfate, are effective in treating knee osteoarthritis (KOA) by exhibiting different protective effects. In this study, we further investigated the combined therapeutic effects of curcumin and chondroitin sulfate on cartilage injury in rats with arthritis.

Methods: An experimental KOA model was induced by monosodium iodoacetate (MIA) in rats. All rats were randomly divided into five groups: Ctrl (control), model (saline), Cur (20 mg/kg curcumin in saline), CS (100 mg/kg chondroitin sulfate in saline), and CA (20 mg/kg curcumin and 100 mg/kg chondroitin sulfate in saline); drugs were given 2 weeks after MIA injection. The histomorphological changes of cartilage were observed by safranin fast green staining, H&E staining, and micro-CT scanning. Also, the levels of PGE2, TNF-α and IL-1β in the arthral fluid and serum were determined by the ELISA kits. The activities of SOD, CAT, COMP, MMP-3, and type II collagen were detected by biochemical kits. The expressions of TLR4, p-NF-κB, NF-κB, and COX-2 in cartilage were detected by Western blot.

Results: Data show that serum levels of IL-1β (p < 0.05), SOD (p < 0.0001), and MMP-3 (p < 0.001) were downregulated significantly in the CA group when compared to those in the model group. Meanwhile, obvious repair of cartilage with higher contains collagen II (p < 0.0001) could be observed in the CA group than the ones in Cur or CS group. In addition, significant downregulation of the expression of p-p65/p65 (p < 0.05) was found in the CA group.

Conclusion: Our findings showed that combined administration of curcumin and chondroitin sulfate could exert better repair for KOA in rat models. This may hold great promise for discovering potential drugs to treat KOA and may improve treatment options for it.

Monotropein alleviates secondary liver injury in chronic colitis by regulating TLR4/NF-κB signaling and NLRP3 inflammasome

Recently, it has reported that many inflammatory bowel disease (IBD) patients were contracted secondary liver injury. Monotropein (MON), an iridoid glycoside, is demonstrated to possess protective effects on acute colitis mice due to its anti-inflammatory activities. However, it was remained unknown whether MON could inhibit secondary liver injury caused by IBD. The aim of the present study was to investigate the protective roles and mechanisms of MON on secondary liver injury in chronic colitis mice model. In this study, 2% Dextran sodium sulfate (DSS) was used to induce mice model of chronic colitis. The results showed that MON attenuated DSS-induced hepatic pathological damage, liver parameters, infiltration of macrophages and cytokines levels. Furthermore, we found that MON attenuated liver injury through suppressing the activation of the toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signaling pathway and down-regulating the activity of NLRP3 (NOD-, LRR- and pyrin domain-containing 3) inflammasome. All the data indicated that MON may be an effective therapeutic reagent to attenuate secondary liver injury induced by chronic colitis.

Evaluation of toxicity studies of flavonoid fraction of Lithocarpus polystachyus Rehd in rodents

The aim of the study was to evaluate the safety of flavonoid fraction of Lithocarpus polystachyus Rehd (Sweet Tea-F, ST-F) in mice and rats through acute and sub-chronic toxicity studies respectively. For acute toxicity study, a single dose of 5000 mg/kg of ST-F was given orally to healthy KM mice. The mice were observed mortality and toxic symptoms for 24 h, then once a day up to 14 days. In the sub-chronic toxicity study, ST-F was administered orally at doses of 0, 70, 140, 560 mg/kg/day to rats for 26 weeks. Body weight and food intake were recorded weekly. Hematological, biochemical, coagulation and organ parameters were analyzed at the end of 26 weeks administration. Vital organs were evaluated by histopathology. In the acute toxicity study, ST-F caused neither significant toxic symptoms, nor mortality in mice. In sub-chronic toxicity study, daily oral administration of ST-F at the dose of 70 mg/kg resulted in a significant increase (P < 0.05) in the relative body weight at the 10-week, and the same situation brought at the dose of 140 mg/kg/day at the 22-week. Hematological and biochemical showed significant changes (P < 0.01 or P < 0.05) in WBC, GLU, ALP, AST and serum electrolytes levels at the dose of 560 mg/kg/day. The amount of RBC decreased significantly (P < 0.05) while the content of PLT slightly increased (P < 0.05) at the dose of 140 mg/kg/day. In additional, no obvious histological changes were observed in vital organs of ST-F treated animals compared to control group. The ST-F may be exit slight side effects at the dose of 560 mg/kg/day in rats. Thus, the overall results show that the no-observed adverse effect level (NOAEL) of ST-F was considered to be 140 mg/kg for male SD rats.

Immunomodulatory activities of phlorizin metabolites in lipopolysaccharide-stimulated RAW264.7 cells

The immunomodulatory effects of two new phlorizin metabolites, phloretin 4-O-β-d-glucuronide (1), 6-methoxyl-phloretin-2-O-β-d-glucuronide (2), together with phloretin-2-O-β-d-glucuronide (3) on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophage cells were determined. 1-3 (1-5μg/ml) significantly inhibited the production of NO (p<0.01). At the concentration of 5μg/ml, 2 and 3 further inhibited iNOS mRNA expression (p<0.01 or 0.05), and 1-3 inhibited iNOS protein expression (p<0.01). Conversely, they all promoted the proinflammatory cytokine TNF-α mRNA expression (p<0.01). For IL-10 mRNA, 1 and 3, which are main metabolism forms in rat plasma, obviously promoted its expression (p<0.01), while metabolite 2, which was only detected in rat urine, showed inhibitory activity, but 1-3 alone without LPS stimulation had no effect on the expression of both TNF-α and IL-10 mRNA expression. 1 further inhibited VEGF, CCL2 and CXCL1 mRNA expression at the concentration of 5-25μg/ml (p<0.01). These results indicated phloretin's metabolites with different structural forms showed different immunomodulatory activities.

Effect of Dendrobium officinale on D-galactose-induced aging mice

OBJECTIVE

To examine the effect of Dendrobium officinale (DO) on D-galactose-induced aging mice.

METHODS

Aging mice was induced by D-galactose at 0.125 g/kg for 10 weeks through subcutaneous injection except for the negative control group. After 10 days, according to complete random design, the aging modeling mice were randomized into 4 groups: aging control group (10 ML·kg-1·d-1) of distilled water), positive control group (vitamin B6 and ganodema lucidum tablets with a dose of 1 tablet/kg), DO-1 treatment group (DO juice with a dose of 1 g/kg), DO-2 treatment group (DO Polysaccharide with a dose of 0.32 g/kg), 14 mice in each group. All the animals were orally medicated daily for 9 weeks. Cognitive function assessment was performed using the maze test and step-down test. At the end of experiment, the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) levels in the serum, the SOD, GSH-Px and nitric oxide (NO) levels in the cerebrum, the SOD and catalase (CAT) levels in the liver, the SOD and NO levels in the heart, and the SOD level in the kidney, were determined using commercial kits. The spleen, liver, heart, cerebrum and kidney were excised for histological study.

RESULTS

Compared to aging control group, DO shortened the time of passing through the maze and prolong the step-down latency of aging mice (P <0.05 or P<0.01). DO markedly up-regulated serum levels of SOD, GSH-Px and T-AOC, and restored SOD levels in the heart, liver, kidney and cerebrum to normal status (P<0.05 or P<0.01). DO at the dose of 1 g/kg also signififi cantly improved the degree of spleen lesions (P<0.01).

CONCLUSIONS

DO had marked anti-aging effect on D-galactose-induced model of aging. The underlying mechanism could be related to modulation on antioxidation system and immune system. The results indicated that DO could potentially be used as natural drugs or functional foods for preventing aging.

Evaluation of the effects of the water-soluble total flavonoids from Isodon lophanthoides var.gerardianus (Benth.) H. Hara on apoptosis in HepG2 cell: Investigation of the most relevant mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

The water-soluble total flavonoids (WSTF) were extracted from Isodon lophanthoides var. gerardianus (Benth.) H. Hara, a common folk herbal medicine in China, which has been recorded by the "Chinese Pharmacopoeia" in 2015 and used for prevention and clinical treatment of common diseases of liver and gall for many years.

OBJECTIVE OF THE STUDY

The aim of this study is to evaluate the effects of WSTF on apoptosis in HepG2 cell and investigate the relevant mechanisms underlying.

MATERIALS AND METHODS

Cytotoxicity was evaluated in HepG2 cells (human hepatoma cell lines) using MTT assay. The influence of the WSTF on the intracellular reactive oxygen species (iROS) and the mitochondrial membrane potential were also determinated. We used flow cytometry analysis to detect the effects of WSTF on apoptosis, cell cycle. Then we applied RT-PCR for genetic expression of main effectors and western blot analysis for activation of main effectors involved in the potential apoptosis signaling pathways.

RESULTS

WSTF inhibited cell growth in HepG2 cells. Moreover, WSTF stimulates to increase amount of iROS, mitochondrial membrane potential, and the apoptotic relevant factors (cytochrome c, caspase-3) in HepG2 cells. WSTF could significantly induce apoptosis through downregulating apoptosis-antagonizing protein (Bcl-2, Survivin, mcl-1) and upregulating apoptosis-promoting proteins (Bax) and cell cycle G0/G1 arrest in HepG2 cells.

CONCLUSION

The results indicate that WSTF induces cell apoptosis through mitochondrial pathway in the HepG2 cells. Therefore, these studies suggest that WSTF could be used as a chemotherapeutic agent to treat hepatoma.

Sweet tea leaves extract improves leptin resistance in diet-induced obese rats

AIM OF THE STUDY

Dietary obesity is usually characterized by leptin resistance and abnormal lipid metabolism. Lithocarpus polystachyus Rehd.(Sweet Tea) leaf is a kind of Chinese folkloric medicine, and it has been widely used for obesity, diabetes, and hypertension in South China. The present study is aimed at investigating the pharmacological mechanism of the anti-hyperleptinaemia effects of Sweet Tea leaves extract in high fat diet-induced obese rats.

MATERIALS AND METHODS

We induced high fat diet obesity for 14 weeks to test the corrective effects of three ST doses (75, 150 and 300 mg/kg per day) for 8 weeks. At the end of the experiment, body weight, fasting blood glucose and serum lipids, superoxide dismutase (SOD), malondialdehyde (MDA), fasting serum insulin and leptin, C-reactive protein, adiponectin and resistin levels were measured, Homeostasis Model Assessment for Insulin Resistance (HOMA-IR) was also calculated. mRNA gene expression of PPARγ (peroxisome proliferator-activated receptor γ) and C/EBPα(CCAAT/enhancer-binding protein α) in epididymal adipose tissue of DIO control and experimental groups were evaluated.

RESULTS

Sweet Tea leaves extract could significantly decrease the levels of serum lipids, attenuate body weight gain and lower circulating leptin and insulin levels, ameliorate the state of oxidative stress, raise serum adiponectin, reduce circulating CRP and resistin levels, and depress the expression of PPARγ and C/EBPα in epididymal adipose tissue of obese rats.

CONCLUSION

The present findings suggest that ST can effectively attenuate the leptin resistance at least through anti-hyperlipidemic activity and thus has the therapeutic potential in treating hyperlipidemia and hyperleptinaemia related to dietary obesity.

The hypoglycemic activity of Lithocarpus polystachyus Rehd. leaves in the experimental hyperglycemic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Leaves of Lithocarpus polystachyus Rehd. are used for the treatment of disorders such as diabetes, hypertension, and epilepsy in folk medicine of South China. The possible antidiabetic effects of the leaves were investigated in experimental type 2 and type 1 diabetic rats.

MATERIALS AND METHODS

Type 2 diabetic rats received orally three different extracts of Lithocarpus polystachyus Rehd. leaves for 4 weeks (aqueous extract [ST-1], ethanol extract [ST-2], flavonoid-rich fraction [ST-3]). At the end of the experiment biochemical parameters were tested and livers and pancreases were excised for histological study. After the comparison of the pharmacological test results of the three extracts, the one which showed the best bioactivity was further studied to confirm its antidiabetes effect on both type 2 and type 1 diabetic rats.

RESULTS

Compared to ST-1 and ST-2, ST-3 had better effects on regulation of blood glucose, glycosylated serum protein, cholesterol, triglyceride, malondialdehyde, superoxide dismutase and attenuation of liver injury in type 2 diabetic rats (p<0.01 or p<0.05). ST-3 administration for four weeks also significantly reduced the fasting serum insulin and C-peptide level and improved the insulin tolerance (p<0.05). In type 1 diabetic rats, ST-3 supplement for three weeks caused significant reduction in fasting blood glucose, total cholesterol, triglyceride, urea nitrogen, creatinine and liver mass, along with significantly inhibiting the decline of insulin level compared to diabetic control (p<0.05 or p<0.01).

CONCLUSION

The flavonoid-rich fraction of Lithocarpus polystachyus Rehd. leaves (ST-3) had better beneficial effect than that of the ethanol or aqueous extract in experimental diabetic rats, which means that the bioactivity of the herbal leaves is probably due to the presence of flavonoids. The results also strongly suggest that the antidiabetic effect of ST-3 was possibly through multiple mechanisms of action including blood lipid and antioxidant mediation. The results indicated that the aqueous flavonoid-rich fraction of Lithocarpus polystachyus Rehd. leaves possessed significant protective activity in type 2 and type 1 diabetes.

Role of the interaction between puerarin and the erythrocyte membrane in puerarin-induced hemolysis

Adverse drug reactions (ADR), especially intravenous hemolysis, have largely limited the application of puerarin injections in clinics. This study investigated the underlying mechanisms of puerarin-induced hemolysis. Our results show that puerarin induced concentration-dependent and time-dependent hemolysis when human erythrocytes were incubated in saline solution with more than 2mM puerarin for over 2h. However, incubation in PBS or addition of 1mM of lidocaine to the saline solution completely abolished the hemolysis. Providing materials that could start ATP synthesis did not reverse the hemolysis, and puerarin did not affect Na(+)-K(+)-ATPase activity. In addition, puerarin (0.1-2mM) did not cause calcium influx or exhibited pro-oxidant activity in erythrocytes. Puerarin exhibited different influences on the membrane microviscosity of erythrocytes in saline and PBS. Moreover, 1mM lidocaine inhibited 8mM puerarin-induced reduction of membrane microviscosity in saline solution. SDS-PAGE analysis of membrane proteins revealed that 2mM puerarin treatment induced the appearance of several new protein bands but attenuated the expression of protein bands 2.1, 3, 4.1, 4.2 and 5. These results suggest that high concentrations of puerarin-induced hemolysis were associated with the changes of membrane lipids and of the composition of erythrocytes membrane proteins but not with ATP depletion, pro-oxidation and calcium influx. These changes could be related to the intercalation of amphiphilic puerarin at high concentration into the erythrocyte membrane in certain media, resulting in membrane disorganization and, eventually, cytolysis. Hence, in clinics, determining the optimal dose of puerarin is critical to avoid overdosing and ADR.

[Protective effect of Isodon lophanthoides on acute hepatic injury induced by D-galactosamine in rats]

OBJECTIVE

To study the protective effects of Isodon lophanthoides (ILVG) aqueous extract on acute hepatic injury induced by D-galactosamine (D-Gal) in rats.

METHODS

60 rats were divided into control group, model group, and low, middle, high dosage group, Bifendate group randomly. In test groups, rats received either ILVG aqueous extract (15, 7.5, 3.75 g/kg) or Bifendate (45 mg/kg) by gastric perfusion daily for 7 consecutive days. On the sixth day, D-Gal (550 mg/kg) was given to rats by oral administration. The levels of ALT, AST, ALP, TBA, T-Bil, TP and ALB in serum were analyzed. The weight of body, liver, spleen and thymus of each rat were measured. The hepatic glycogen content was analyzed individually. Liver tissue pathology was observed.

RESULTS

ILVG coud decrease the ALT, AST, ALP, TBA and T-Bil in serum, increase TP, ALB and hepatic glycogen content and restrain the enlargement of liver and the shrinkage of thymus, reduce necrosis in pathological observation.

CONCLUSION

ILVG aqueous extract possesses the effect on protecting on acute hepatic injury induced by D-Gal in rats, its effect is related to multifarious mechanism.