Linseed oil: an investigation of its antiarthritic activity in experimental models

Flaxseed Oil Alleviates Trimethyltin-Induced Cell Injury and Inhibits the Pro-Inflammatory Activation of Astrocytes in the Hippocampus of Female Rats

Exposure to the neurotoxin trimethyltin (TMT) selectively induces hippocampal neuronal injury and astrocyte activation accompanied with resultant neuroinflammation, which causes severe behavioral, cognitive, and memory impairment. A large body of evidence suggests that flaxseed oil (FSO), as one of the richest sources of essential omega-3 fatty acids, i.e., α-linolenic acids (ALA), displays neuroprotective properties. Here, we report the preventive effects of dietary FSO treatment in a rat model of TMT intoxication. The administration of FSO (1 mL/kg, orally) before and over the course of TMT intoxication (a single dose, 8 mg/kg, i.p.) reduced hippocampal cell death, prevented the activation of astrocytes, and inhibited their polarization toward a pro-inflammatory/neurotoxic phenotype. The underlying protective mechanism was delineated through the selective upregulation of BDNF and PI3K/Akt and the suppression of ERK activation in the hippocampus. Pretreatment with FSO reduced cell death and efficiently suppressed the expression of inflammatory molecules. These beneficial effects were accompanied by an increased intrahippocampal content of n-3 fatty acids. In vitro, ALA pretreatment prevented the TMT-induced polarization of cultured astrocytes towards the pro-inflammatory spectrum. Together, these findings support the beneficial neuroprotective properties of FSO/ALA against TMT-induced neurodegeneration and accompanied inflammation and hint at a promising preventive use of FSO in hippocampal degeneration and dysfunction.

A comprehensive review of the health benefits of flaxseed oil in relation to its chemical composition and comparison with other omega-3-rich oils

Flaxseed (Linum usitatissimum L) is an ancient perennial plant species regarded as a multipurpose plant owing to its richness in omega-3 polyunsaturated fatty acids (PUFA) including α-linolenic acid (ALA). The extensive biochemical analysis of flaxseed resulted in the identification of its bioactive, i.e., lignans with potential application in the improvement of human health. Flaxseed oil, fibers, and lignans exert potential health benefits including reduction of cardiovascular disease, atherosclerosis, diabetes, cancer, arthritis, osteoporosis, and autoimmune and neurological disorders that have led to the diversification of flaxseed plant applications. This comprehensive review focuses on flaxseed oil as the major product of flaxseed with emphasis on the interrelationship between its chemical composition and biological effects. Effects reviewed include antioxidant, anti-inflammatory, antimicrobial, anticancer, antiulcer, anti-osteoporotic, cardioprotective, metabolic, and neuroprotective. This study provides an overview of flaxseed oil effects with the reported action mechanisms related to its phytochemical composition and in comparison, to other PUFA-rich oils. This study presents the most updated and comprehensive review summarizing flaxseed oil's health benefits for the treatment of various diseases.

Unraveling the role of natural functional oils in modulating osteoarthritis related complications

Osteoarthritis (OA) is a common joint disease and has been studied extensively in recent years as no promising therapy available so far for its treatment and remains a great challenge for health care specialists. Although the identification of some major mechanisms that contribute to this disease suggests a plethora of bioactive agents in tackling the associated complications yet OA's pathophysiology is still poorly understood owing to complex mechanistic changes observed. Experimental research is now exploring a wide range of therapeutically effective agents in an effort to find a way to repair OA-related joint degeneration and halt it from getting worse. Data was acquired and reviewed from most relevant and recent studies. This review summarizes the studies that are currently available and focuses on how various unconventional functional oils affect osteoarthritis and the affected joint tissues. An analysis of the recent scientific literature allowed us to highlight the potential anti-arthritic properties of edible oils and their main constituents, which seems to suggest an interesting new potential therapeutic application. Due to eccentric nature of OA, it is necessary to concentrate initially on the management of symptoms. The evidence supporting functional oils chondroprotective potential is still accumulating, underpinning a global need for more sustainable natural sources of treatment. More clinical research that focuses on the consequences of long-term treatment, possible negative effects, and epigenetic implications is necessary to get optimistic results. However, different animal or clinical studies suggest that linolenic and linoleic fatty acids decreased chondrocyte oxidative stress, cartilage breakdown, and expression of inflammatory markers. Distinct fatty acids along with minor components of oils also reduced the generation of prostaglandins and decreased oxidative stress. Furthermore, the potential roles of the main components of edible oils and possible negative results (if any) are also reported. While no severe side effects have been reported for any edible oils. Overall, these studies identify and support the use of functional oils as an adjuvant therapy for the management of OA and as a means of symptomatic alleviation for OA patients. However, to prove the effectiveness or to draw precise conclusions, high-quality clinical trials are required.

Effects of Edible Oils with Different n-6/n-3 PUFA Ratios on Articular Cartilage Degeneration via Regulating the NF-κB Signaling Pathway

Osteoarthritis (OA), a common chronic disease, is characterized by articular cartilage degeneration and inflammation. Recent studies report that n-3 polyunsaturated fatty acids (PUFAs) exhibit protective effects against OA, while n-6 PUFAs are more likely to damage cartilage. However, the effects of edible oils with different n-6/n-3 PUFA ratios on OA are rarely reported. This study investigates the effect of linseed oil (LO), soybean oil (SO), and peanut oil (PO) on cartilage changes in mice joints following destabilization of the medial meniscus. We determined the n-6/n-3 PUFA ratios of LO, SO, and PO used in this experiment to be 1:3.85, 9.15:1, and 372.73:1, respectively. After 12 weeks of LO or SO feeding, OA mice showed increased cartilage thickness and decreased TNF-α in both the serum and cartilage, whereas no improvement was found in the PO group. This may be due to the fact that LO and SO optimized the fatty acid composition of articular cartilage. We further demonstrated that LO or SO activated GPR120 and attenuated EP4, which was followed by inhibition of the NFκB pathway and its downstream matrix-degrading enzymes: MMP13 and ADAMTS5. In conclusion, edible oils with low n-6/n-3 PUFA retard OA progression via inhibiting the NFκB pathway. This study provides a dietary guidance for OA patients.

A Review on Pharmacological and Clinical Aspects of Linum usitatissimum L

INTRODUCTION AND BACKGROUND

Linum usitatissimum L., known as common Flax or linseed, from the family Linnaceae, has long been cultivated in different nations due to its applications in medicine and industry. The present study aims to collect nearly all available information about chemical constituents of Flax, as well as pharmacological properties and confirmed clinical usages of it.

METHODS

We searched through databases such as Scopus and PubMed for relevant literature using the keywords: Linum usitatissimum, pharmacology and phytochemical from the beginning to 13 Aug 2017. Nearly 60 relevant papers, relating to a pharmacological and phytochemical constituent of L. usitatissimum were selected.

RESULTS AND DISCUSSION

According to our researches, various properties were attributed to L. usitatisimum including antioxidant, immunomodulatory, anti-inflammatory, antimicrobial, antiprotozoal, insecticidal, analgesic, anti-hyperlipidemia, anti-hyperglycemic, anti-tumor, wound healing and Feticidal activities. There were also many reports on disease prevention and healing properties of the flax. Diseases like: GI disorders, cardiovascular, urogenital, respiratory diseases and some neurological syndromes were mentioned to be treated by Flax. The application of Flax in drug formulations was also investigated.

CONCLUSION

Despite so much animal studies that have been accomplished, there have not been enough clinical trials done on pharmacological properties of L. usitatissimum. Therefore, this study could be considered as a concise and up to date overview for further facile studies and clinical trials over the valuable plant, L. usitatissimum.

Seeds

A wide variety of plant species provide edible seeds. Seeds are the dominant source of human calories and protein. The most important and popular seed food sources are cereals, followed by legumes and nuts. Their nutritional content of fiber, protein, and monounsaturated/polyunsaturated fats make them extremely nutritious. They are important additions to our daily food consumption. When consumed as part of a healthy diet, seeds can help reduce blood sugar, cholesterol, and blood pressure.

FM0807 decelerates experimental arthritis progression by inhibiting inflammatory responses and joint destruction via modulating NF-κB and MAPK pathways

Background: Rheumatoid arthritis (RA) is a chronic articular synovial inflammatory disease. The precise etiology underlying the pathogenesis of RA remains unknown. We aimed to investigate the inhibitory effect of curcumin analog FM0807 (curcumin salicylate monoester, 2-hydroxy-, 4-[(1E,6E)-7-(4-hydroxy-3-methoxyphenyl)-3,5-dioxo-1,6-heptadien-1-yl]-2-methoxyphenyl ester) on experimental RA and investigate its possible mechanisms of action.

Method: Rats with Freund’s complete adjuvant (FCA)-induced arthritis (AIA) were administered aspirin (0.1 mmol.kg⁻¹), curcumin (0.1 mmol.kg⁻¹), FM0807 (0.1, 0.2 mmol.kg⁻¹) and vehicle via gastric gavage, from days 7 to 21, once daily. The hind paw volume and arthritis index (AI) were measured, and radiographic and histological examinations were performed. Twenty-one days later, the animals were killed and left ankle joints were removed to measure protein expression of the elements of the nuclear factor κB (NF-κB) and mitogen-activated protein kinase (MAPK) pathway by Western blot analysis. The enzyme-linked immunosorbent assay (ELISA) was employed to measure synovial fluid levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, IL-1β and IL-10.

Results: Compared with AIA group, FM0807 reduced the AI and swelling of the injected hind paw in a dose-dependent manner, and inhibited increases in inflammatory cell infiltration, pannus formation and cartilage destruction. FM0807 also potently attenuated the increase in the expression of inflammatory factors TNF-α, IL-6 and IL-1β in synovial fluid, while IL-10 levels were also elevated. FM0807 significantly suppressed phosphorylation of extracellular-signal-regulated kinase (ERK) 1/2 (ERK1/2), c-Jun-N-terminal kinase (JNK) 1/2 (JNK1/2), p38MAPK, inhibitor of NF-κB kinase (IKK), IκB and NF-κB p65 protein, (all P<0.05), which displayed more potential effects compared with those of the aspirin and curcumin groups.

Conclusion: FM0807 exerts its therapeutic effects on RA by inhibiting cartilage degeneration. FM0807 treatment might be an effective therapeutic approach for RA.

Evaluation of the anti-arthritic activity of Cinnamomum cassia bark extract in experimental models

BACKGROUND

Cinnamomum cassia iswidely used as a traditional medicinal plant for the treatment of rheumatoid arthritis.

OBJECTIVE

The present study aimed to assess the anti-arthritic activity of C. cassia bark hydroalcoholic extract (CCHE) in different arthritic animal models.

METHODS

In formaldehyde model, sub-plantar administration of 0.1 ml of formaldehyde (2% v/v) into the right hind paws of Wistar albino rats on days 0 and 3. The rats were divided into six groups as follows: normal control, disease control, indomethacin group (3 mg/kg, p.o.) and three groups, treated with 50, 100 and 200 mg/kg CCHE (p.o.). Joint diameter was measured, and ankle joints were collected for MDA and GSH measurements. In complete Freund's adjuvant (CFA)-induced arthritis model, CFA was injected into the sub-plantar surface of the right hind paw in rats. Joint diameter was measured, and serum TNF-α and IL-1β were measured. Histopathological and immunohistochemical analyses were also performed.

RESULTS

CCHE treatment significantly (p < 0.01) reduced MDA levels and joint swelling in a concentration-dependent manner in rats with formaldehyde-induced arthritis, in which GSH levels were elevated (p < 0.01). In rats with CFA-induced arthritis, CCHE treatment significantly reduced joint swelling as well as IL-1β and TNF-α levels (p < 0.01). TNF-α receptor expression was decreased in rats treated with indomethacin or CCHE.

CONCLUSION

Based on these findings, it can be concluded that C. cassia possesses anti-arthritic properties.

A Topical Gel From Flax Seed Oil Compared With Hand Splint in Carpal Tunnel Syndrome: A Randomized Clinical Trial

This study compared the therapeutic effect of flax seed oil topical gel and hand splint in the treatment of carpal tunnel syndrome. This study was a randomized clinical trial. Forty-nine patients, 96 hands, with mild to moderate idiopathic carpal tunnel syndrome were divided into 2 groups randomly. One group was treated by topical gel and the other group by hand splint. Intensity of symptoms and function before and after intervention was measured via Boston Carpal Tunnel Questionnaire. After intervention, the ANCOVA showed a significant difference between the symptom and function scores of the 2 groups. In both cases, recovery was higher in the gel group (P < .001). The topical use of flax seed oil gel is more effective in the improvement of symptoms and function of patients with mild to moderate carpal tunnel syndrome as compared with hand splint, and it can be introduced as an effective treatment.

In vivo antiarthritic activity of Rosa centifolia L. flower extract

Introduction:

Rosa centifolia L. (Rosaceae) have been used for the treatment of joint pain and rheumatoid arthritis (RA) in the traditional system of medicine.

Aim:

In this study, the antiarthritic activity of the alcoholic extract from the floral parts of R. centifolia was investigated.

Materials and Methods:

The anti-inflammatory and antiarthritic activity of R. centifolia alcoholic extract (RCAE: 32, 64, and 128 mg/kg) was evaluated using the carrageenan-induced paw edema and complete Freund's adjuvant (CFA) induced arthritis model. Serum from arthritic rats was collected for the estimation of pro-inflammatory cytokine levels. Further, the safety of RCAE was evaluated in an acute and sub-acute (28-day) oral toxicity study.

Results:

RCAE (64 and 128 mg/kg) significantly (P < 0.01) inhibited carrageenan-induced paw edema at 1, 3, and 6 h post carrageenan challenge and demonstrated significant (P < 0.01) antiarthritic activity on days 3, 7, 14, and 21 day following CFA immunization. Further, RCAE (128 mg/kg) treatment also produced a significant (P < 0.01) decrease in circulating pro-inflammatory cytokine levels as compared with control. Further, no toxicologically significant treatment-related effects were observed in the oral sub-acute toxicity study conducted with the extract.

Conclusion:

The result of study demonstrates the antiarthritic activity of R. centifolia and validates its traditional use for the treatment of RA.

Effect of Linum usitatissimum L. (linseed) oil on mild and moderate carpal tunnel syndrome: a randomized, double-blind, placebo-controlled clinical trial

BACKGROUND

Carpal tunnel syndrome is known as the most common entrapment neuropathy. Conservative treatments cannot reduce the symptomatic severity satisfactorily; therefore, effectiveness of Linum usitatissimum L. (linseed) oil on carpal tunnel syndrome, as a complementary treatment, was evaluated in the current study. Linseed oil is a well-known preparation in Iranian traditional medicine and its analgesic, anti-inflammatory and anti-oxidative effects have been shown in previous studies.

METHODS

A randomized, double-blind, placebo-controlled clinical trial was conducted. One hundred patients (155 hands) with idiopathic mild to moderate carpal tunnel syndrome aged between 18 and 65 years old were randomized in two parallel groups. These two groups were treated during 4 weeks with topical placebo and linseed oil. In addition, a night wrist splint was prescribed for both groups. Symptomatic severity and functional status were measured using Boston Carpal Tunnel Questionnaire. In addition, median sensory nerve conduction velocity, motor distal latency, sensory distal latency and compound latency as electrodiagnostic parameters were measured at baseline and after the intervention period.

RESULTS

After the intervention, significant improvement was observed regarding Boston Carpal Tunnel Questionnaire symptomatic severity and functional status mean differences (p <0.001) in the linseed oil group compared with those in the placebo group. Also, regarding the mean differences of both groups, significant improvement of nerve conduction velocity of the median nerve was seen in the linseed oil group by a value of 2.38 m/sec (p < 0.05). However, motor distal latency and sensory distal latency of the median nerve showed no between-group significant changes (p = 0.14 for both items). Finally, compound latency was improved slightly in the case group, comparing mean differences between the groups (p <0.05). No significant adverse events were reported from using linseed oil.

CONCLUSIONS

It seems that linseed oil could be effective in the management of mild and moderate carpal tunnel syndrome, especially in improving the severity of symptoms and functional status. In addition, its effect on electerodiagnostic parameters, especially on the nerve conduction velocity, can be considered as a valuable point.

Ethnopharmacological in vitro studies on Austria's folk medicine--an unexplored lore in vitro anti-inflammatory activities of 71 Austrian traditional herbal drugs

ETHNOPHARMACOLOGICAL RELEVANCE

In Austria, like in most Western countries, knowledge about traditional medicinal plants is becoming scarce. Searching the literature concerning Austria's ethnomedicine reveals its scant scientific exploration. Aiming to substantiate the potential of medicinal plants traditionally used in Austria, 63 plant species or genera with claimed anti-inflammatory properties listed in the VOLKSMED database were assessed for their in vitro anti-inflammatory activity.

MATERIAL AND METHODS

71 herbal drugs from 63 plant species or genera were extracted using solvents of varying polarities and subsequently depleted from the bulk constituents, chlorophylls and tannins to avoid possible interferences with the assays. The obtained 257 extracts were assessed for their in vitro anti-inflammatory activity. The expression of the inflammatory mediators E-selectin and interleukin-8 (IL-8), induced by the inflammatory stimuli tumor necrosis factor alpha (TNF-α) and the bacterial product lipopolysaccharide (LPS) was measured in endothelial cells. The potential of the extracts to activate the nuclear factors PPARα and PPARγ and to inhibit TNF-α-induced activation of the nuclear factor-kappa B (NF-κB) in HEK293 cells was determined by luciferase reporter gene assays.

RESULTS

In total, extracts from 67 of the 71 assessed herbal drugs revealed anti-inflammatory activity in the applied in vitro test systems. Thereby, 30 could downregulate E-selectin or IL-8 gene expression, 28 were strong activators of PPARα or PPARγ (inducing activation of more than 2-fold at a concentration of 10µg/mL) and 21 evoked a strong inhibition of NF-κB (inhibition of more than 80% at 10µg/mL).

CONCLUSION

Our research supports the efficacy of herbal drugs reported in Austrian folk medicine used for ailments associated with inflammatory processes. Hence, an ethnopharmacological screening approach is a useful tool for the discovery of new drug leads.