The effects of carotenoids and retinoid on osteoclast formation in a co-culture of mouse bone-marrow cells and primary osteoblastic cells were examined. Carotenoids, such as β-carotene, canthaxanthin, and lycopene, inhibited the formation of tartrate-resistant acid phosphatase-positive, multinuclear osteoclast-like cells induced by either 1α, 25-dihydroxyvitamin D3, interleukin-1β, or parathyroid hormone in a concentration range from 100nM to 5μM. However, the carotenoids did not affect the osteoclast-like cell formation in the absence of bone-resorbing agents or the release of 45Ca from prelabeled fetal mouse calvaria at physiological concentrations. Retinoic acid (1nM-1μM) also suppressed osteoclast-like cell formation induced by the bone-resorbing agents described above. It was apparent that carotenoids and retinoic acid affected the proliferation and differentiation stage of osteoclast progenitor cells from the results of temporal addition of these compounds to the co-culture systems. These results suggest that a physiological concentration of carotenoids induces positive bone turnover by inhibiting osteoclast formation.
Oral submucous fibrosis (OSMF), a disease condition essentially found in Indians and southeast Asians has drawn attention mostly on the grounds of epidemiological and clinical manifestations, whereas the etiology is still uncertain. Since all OSMF patients are habitual chewers, it was thought ideal to experimentally induce OSMF in rats using betelnut extracts thereby establishing the toxic nature of betelnut. OSMF has been defined as a collagen disorder and the total collagen and collagen fractions in the different groups were analyzed. There was an increase in total collagen content and an increase in soluble fraction was also observed representing newly synthesized collagen. The group treated with panmasala, a commercial preparation available which is a combination of betelnut, tobacco, lime and spices showed no changes due to its chemopreventive efficacy. The importance of the results expected is that the causation and cure of many diseases involving collagen now lack a scientific basis. The results it is hoped would provide a means for classification of diseases at structural and molecular level so as to highlight a causal nexus between clinical expression of the disease and altered structural and compositional changes in OSMF.
Effect of naturally occurring sulphur-containing compounds such as diallyl sulphide (DAS), diallyl disulphide (DADS), and allyl methyl sulphide (AMS) on the inhibition of lung metastasis of B16F-10 melanoma cells was studied in C57BL/6 mice. Simultaneous administration of the compounds after tumor induction produced a significant reduction in tumor nodule formation (DAS 55%, DADS 90%, and AMS 54%). The effect was lower when the compounds were administered after tumor development, whereas prophylactic administration of the compounds did not have any effect on lung tumor nodule formation. Increased lung collagen hydroxyproline, serum sialic acid, and gamma glutamyl transpeptidase activity in the metastasized lungs of control animals was significantly reduced in the animals treated with the sulphur-containing compounds. Pathology of the lung tissue also correlated with the above findings. Our results are indicative of the antimetastatic activity of these sulphur-containing compounds.
A great deal of attention has been focused on the possible therapeutic implications of lipoic acid as a potent antioxidant. Lipoic acid serves as a vital cofactor for α-keto-acid dehydrogenase and is well known for its free radical-quenching effect. We evaluated the age-associated alterations in membrane-bound enzymes, glutathione and lipid peroxidation in young and aged rats in response to lipoate supplementation. In aged rats, the level of glutathione and the activities of membranebound enzymes were lower, whereas thiobarbituric acid reactive substances (a marker of free radical damage) were higher than those in the young rats. Intraperitoneal administration of lipoic acid to the aged rats led to a time-dependent reduction in lipid peroxidation and elevation in the activities of membrane-bound enzymes as well as in the level of glutathione. Our observations highlight the protective effect of lipoic acid in age-associated free radical-induced oxidative stress, thus proving its efficacy as a potent antioxidant.
To evaluate the effects of voluntary resistance exercise training on mitochondrial heme biosynthesis in the liver, we trained adult male Sprague-Dawley rats for 4 or 8 weeks to climb a wire-mesh tower (∅20cm×200cm), and then measured δ-aminolevulinic acid synthetase (ALAS) activity, the rate-limiting enzyme of heme synthesis, and cytochrome c content in their liver. The activity of citrate synthase in the skeletal muscle was also determined to establish whether the training protocol had any aerobic effect. Resistance training resulted in significant increases (p<0.05) in citrate synthase activities in gastrocnemius and forearm muscles, whereas ALAS activity and cytochrome c content in the liver of rats trained for 4 and 8 weeks were the same as those of corresponding sedentary rats. The relative weight of forearm muscle to body mass was significantly greater (p<0.05) in the training group than in the sedentary group. These results suggest that voluntary resistance exercise does not accelerate hepatic heme biosynthesis in spite of increasing aerobic capacity in the skeletal muscles.
The present investigation was performed to study the effect of Liv. 100, an ayurvedic herbal formulation, on the level of lipids in antabuse-using alcohol dependents. Liv. 100 was given to the patients at the dosage of 35mg/kg body wt for a period of 18 days. Antabuse-treated patients received antabuse at 4mg/kg body wt dosage for a period of 18 days. Fasting blood samples were collected before and after treatment of 18 days and used for the estimation of total lipids, total cholesterol, triglycerides, phospholipids, free fatty acids, free cholesterol, and ester cholesterol. The antabuse-receiving alcohol dependents treated with Liv. 100 showed significant decreases in the levels of total lipids, total cholesterol, triglycerides, free cholesterol, and ester cholesterol when compared with alcohol dependents receiving antabuse alone. The present study suggests the hypolipidemic effect of Liv. 100 in antabuse-using alcohol dependents.