Experimentally induced acute sinusitis and efficacy of vitamin A

Vitamin A and Wound Healing

Vitamin A is a general term for retinoids. Vitamin A deficiency leads to a variety of cutaneous manifestations. It also functions as a hormone through retinoic acid receptors altering the activity of multiple cell lines. Pancreatic vitamin A levels are critical for retinoid signaling and normal pancreatic control of glucose. Vitamin A deficiency is more common during infection, and supplementation reduces severe morbidity and mortality from infectious diseases. Vitamin A modulates activities at the cellular level and, via its interrelationship with hormones such as thyroid, insulin, and corticosteroids, has diffuse metabolic effects on the body. It plays an important role in all stages of wound healing. Vitamin A is known for its ability to stimulate epithelial growth, fibroblasts, granulation tissue, angiogenesis, collagen synthesis, epithelialization, and fibroplasia. Local (topical) and systemic supplementation with vitamin A has been proven to increase dermal collagen deposition. There are numerous animal studies and limited human studies regarding physiologic effect of vitamin A on acute or chronic wounds via systemic or topical administration. The most common use of vitamin A supplementation is to offset steroids' effect. When considering supplementation, the potential benefits must be weighed against the risk of harm. Vitamin A toxicity can be critical and even result in death. The evidence for supplementation with vitamin A is currently limited to expert opinion and is not backed up by rigorous trials. There is an acute need for therapeutic trials with vitamin A supplementations.

Phytosome complexed with chitosan for gingerol delivery in the treatment of respiratory infection: In vitro and in vivo evaluation

Respiratory infection is a viral spreading disease and a common issue, particularly in kids. The treatments are available but have so many limitations because the drawback of this disease is more morbidity and mortality in the severely immune compromised. Even, the phyto-constituent antibacterial drug Gingerol was selected to treat respiratory infection but it exhibits low bioavailability profile, less aqueous-solubility issue and most important is rapidly eliminated from the body. To overcome these problems, novel drug delivery (nanoparticle) based phytosome complexed with chitosan approach was implemented. In this research work, the phytosome (GP) was prepared by blending of gingerol with soya lecithin in organic solvent using anti-solvent precipitation technique and it was further loaded in the aqueous solution of chitosan to formulate the phytosome complexed with chitosan (GLPC). To optimize the formulations of gingerol, it was characterized for percentage yield, percentage entrapment efficiency, drug loading and particle size, physical compatibility studies etc. which demonstrated the confirmation of complex of GLPC with soya lecithin and chitosan. The % entrapment efficiency and % drug loading of GLPC was found (86.02 ± 0.18%, 08.26 ± 0.72%) and of GP (84.36 ± 0.42%, 08.05 ± 0.03%), respectively. The average particle size and zeta potential of GLPC and GP were 254.01 ± 0.05 nm (-13.11 mV), and 431.21 ± 0.90 nm (-17.53 mV), respectively which confirm the inhibition of particle aggregation by using chitosan in complex. The in vitro release rate of GP (86.03 ± 0.06%) was slower than GLPC (88.93 ± 0.33%) in pH 7.4 phosphate buffer up to 24 h by diffusion process (Korsmeyer Peppas model). The optimized GLPC and GP were shown irregular particle shapes & spherical and oval structures with smooth surface by SEM analysis. Furthermore, GLPC has shown the potent in vitro antioxidant activity, susceptible antibacterial activity and effective anti-inflammatory activity as compared to GP against stress, microbial infection and inflammation which were causable reason for the respiratory infections. GLPC has improved the significant bioavailability and also correlated the hematological values on rabbit blood against the incubation of microorganisms. Thus, the prepared nanoparticle based approach to deliver the gingerol, has the combined effect of chitosan and phytosome which shown better sustained-release profile and also prolonging the oral absorption rate of gingerol with effective antibacterial activity to treat respiratory infection.

The Effect of Dexpanthenol-Vitamin A (Nazalnem) on Silastic Splints After Nasal Septal Surgery

OBJECTIVE

To investigate the effect of dexpanthenol-vitamin A (Nazalnem) ointment applied to the surface of silastic splints with an airway immediately after nasal septal surgery on postoperative complaints and nasal mucosa function.

MATERIALS AND METHODS

The study enrolled 60 patients undergoing nasal septoplasty surgery. Group 1 (n = 30) received silastic splints with ointment containing dexpanthenol-vitamin A (Nazalnem), and Group 2 (n = 30), the control group, received silastic splints with vaseline. Of these patients, 2 patients from the Group 1 and 9 from the Group 2 were excluded.A thin layer of ointment was applied to the flat side of a silastic splint with an airway. The splints were removed on the second postoperative day. Patients were evaluated preoperatively and 1 and 2 weeks postoperatively using a visual analog scale and the Sino-Nasal Outcome test (SNOT-22). Mucociliary clearance (MCC) tests were performed at the same times.

RESULTS

Visual analog scale for nasal crusting, nasal congestion, and foul odor was better in Group 1 than in Group 2 both at 1 week and at 2 weeks postoperatively (P < 0.05).The SNOT scores were significantly lower in Group 1 than in Group 2 at 1 week (P < 0.01), but did not differ at 2 weeks postoperatively (P > 0.05).Postoperatively, the MCC were insignificant between the groups and within the groups at 1 and 2 weeks (P > 0.05).

CONCLUSION

Although Dexpanthenol-Vitamin A ointment had no direct effect on wound healing, it had significant effects on crusting, obstruction, and foul smell. However, silastic splints with dexpanthenol did not improve the MCC of the nose.

Protective effects of melatonin and selenium against apoptosis of olfactory sensory neurons: A rat model study

BACKGROUND

Selenium plays a role in the prevention of oxidative damage and has been linked to regulatory functions in cell growth, apoptosis, cell survival, and cytotoxicity. Melatonin has an antioxidant effect, which protects against a number of free radical species. Given its antioxidant properties, melatonin has been widely known to inhibit neuronal apoptosis. We examined the cytoprotective effects of melatonin and selenium in rat olfactory sensory neurons after rhinosinusitis by immunohistochemical evaluation of olfactory bulb mucosa.

METHODS

Rhinosinusitis was induced bilaterally in 24 animals. Twenty-four rats were randomly divided into three equal groups. The melatonin group was treated with intraperitoneal (i.p.) melatonin and ampicillin-sulbactam, the selenium group was treated with i.p. selenium and ampicillin-sulbactam, the antibiotic group was treated with i.p. ampicillin-sulbactam; all three groups were treated for 10 days. After a period of 10 days of treatment, the animals were killed for immunohistochemical analyses. All olfactory bulb mucosae were removed immediately.

RESULTS

No histochemical differences were found in the three groups. Terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling-positive cells were detected in each group. In the antibiotic group, the appearance of apoptotic cells was higher, whereas the number of apoptotic cells significantly decreased in the melatonin group. When compared with the selenium group, fewer terminal deoxynucleotidyl transferase 2'-deoxyuridine 5'-triphosphate nick end labeling-positive cells were observed in the melatonin group, which was not significant. In the antibiotic group, the cytoplasmic active caspase-3 and Bax immunostaining in the olfactory epithelium and glandular cells of stroma were higher when compared with the immunostaining in melatonin and selenium groups. Active caspase-3 and Bax immunostaining in the subepithelial stroma was dramatically reduced in the melatonin group. In contrast, the staining intensity and the number of Bcl-2 immunopositive cells were significantly increased in the melatonin group. In the selenium group, Bax and active caspase-3 were moderately immunopositive in the epithelium and subepithelial stroma. However, Bcl-2 immunostaining was more pronounced in the olfactory epithelium and some stromal cells.

CONCLUSION

Our results indicated the possibility that the supplementation of melatonin and selenium, two antioxidant agents for the treatments in the rhinosinusitis rat model, might be reduced or prevent anosmia.

Vitamin A supplementation in preschool children and risk of hearing loss as adolescents and young adults in rural Nepal: randomised trial cohort follow-up study

OBJECTIVE

To determine whether vitamin A supplementation administered in the preschool years can lower the risk of hearing loss in adolescence and adulthood.

DESIGN

Follow-up study of adolescents and young adults who, as preschool aged children in 1989, were enrolled into a cluster randomised, double blinded, placebo controlled trial of vitamin A supplementation.

SETTING

South central, rural Nepal.

PARTICIPANTS

2378 adolescents and young adults aged 14 to 23, representing 51% of those who finished the original trial and 71% of those living in the study area in 2006.

INTERVENTIONS

Every four months for 16 months preschool children were visited at home, given an oral 200,000 IU dose of vitamin A (half dose at age 1-11 months, quarter dose at <1 month) or placebo and the parents were queried about any childhood illnesses in the previous week, including purulent discharge from the ears.

MAIN OUTCOME MEASURES

Prevalence of mild or worse hearing loss (≥ 30 dB) in the most affected ear and tympanometric measures of middle ear function (peak height, ear canal volume, and gradient).

RESULTS

During the original trial, the prevalence of middle ear infection during the preschool years did not differ between the supplement groups. By adolescence and early adulthood, a non-significant 17% reduction in hearing loss occurred among those who had periodically received vitamin A compared with placebo as preschool aged children (odds ratio 0.83, 95% confidence interval 0.62 to 1.12). Among participants with any ear discharge in early childhood, vitamin A supplementation was associated with a reduced risk of hearing loss, by 42% (0.58, 0.37 to 0.92) compared with controls, after adjusting the confidence interval for the design effect of the original trial. Abnormal tympanometric peak height of the middle ear system was less likely among participants supplemented with vitamin A in childhood.

CONCLUSION

In undernourished settings, periodic, high dose vitamin A supplementation may reduce the risk of hearing loss associated with purulent ear infections in early childhood.

Activation of vocal fold healing with topical vitamin A in rabbits

CONCLUSION

The results suggest that vitamin A can prevent scar formation in the vocal fold after surgery.

OBJECTIVES

This study aimed to evaluate the effects of topically applied vitamin A on healing after vocal fold trauma.

MATERIALS AND METHODS

Vocal folds of 20 adult rabbits were traumatized unilaterally. Ten of them were treated with topical application of vitamin A and the others served as controls. All animals were sacrificed after 10 days. Vocal folds were resected for analysis by light microscopy.

RESULTS

The untreated vocal folds showed extensive deposition of collagen and fibroblast on light microscopy and vocal folds treated with vitamin A showed less deposition. There was a significant difference between the two groups according to the percentage of collagen and fibroblasts in the lamina propria (p<0.01).