Environmental implications and nanotechnological advances in octocrylene-enriched sunscreen formulations: A comprehensive review.

Ultraviolet (UV) radiation is a major contributor to skin aging, cancer, and other detrimental health effects. Sunscreens containing FDA-approved UV filters, like avobenzone, offer protection but suffer from photodegradation and potential phototoxicity. Encapsulation, antioxidants, and photostabilizers are strategies employed to combat these drawbacks. Octocrylene, an organic UV filter, utilizes nanotechnology to enhance sun protection factor (SPF). This review examines recent literature on octocrylene-enriched sunscreens, exploring the interplay between environmental impact, nanotechnological advancements, and clinical trial insights. A critical focus is placed on the environmental consequences of sunscreen use, particularly the potential hazards UV filters pose to marine ecosystems. Research in the Mediterranean Sea suggests bacterial sensitivity to these filters, raising concerns about their integration into the food chain. This review aims to guide researchers in developing effective strategies for photostabilization of UV filters. By combining encapsulation, photostabilizers, and antioxidants, researchers can potentially reduce phototoxic effects and contribute to developing more environmentally friendly sunscreens.

Drug Delivery Strategies for Avobenzone: A Case Study of Photostabilization.

Several developments and research methods are ongoing in drug technology and chemistry research to elicit effectiveness regarding the therapeutic activity of drugs along with photoprotection for their molecular integrity. The detrimental effect of UV light induces damaged cells and DNA, which leads to skin cancer and other phototoxic effects. The application of sunscreen shields to the skin is important, along with recommended UV filters. Avobenzone is widely used as a UVA filter for skin photoprotection in sunscreen formulations. However, keto-enol tautomerism propagates photodegradation into it, which further channelizes the phototoxic and photoirradiation effects, further limiting its use. Several approaches have been used to counter these issues, including encapsulation, antioxidants, photostabilizers, and quenchers. To seek the gold standard approach for photoprotection in photosensitive drugs, combinations of strategies have been implemented to identify effective and safe sunscreen agents. The stringent regulatory guidelines for sunscreen formulations, along with the availability of limited FDA-approved UV filters, have led many researchers to develop perfect photostabilization strategies for available photostable UV filters, such as avobenzone. From this perspective, the objective of the current review is to summarize the recent literature on drug delivery strategies implemented for the photostabilization of avobenzone that could be useful to frame industrially oriented potential strategies on a large scale to circumvent all possible photounstable issues of avobenzone.

Synthesis and biological screening of 2'-aryl/benzyl-2-aryl-4-methyl-4',5-bithiazolyls as possible anti-tubercular and antimicrobial agents.

A series of 2'-aryl/benzyl-2-aryl-4-methyl-4',5-bithiazolyl derivatives, 25-64 were synthesized and evaluated for inhibitory activity against Mycobacterium smegmatis MC(2) 155 strain and antimicrobial activities against four pathogenic bacteria Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Proteus vulgaris. Among them, compounds 40, 49, 50, and 54 exhibited moderate to good inhibition on the growth of the bacteria Mycobacterium smegmatis at the concentration of 30 µM. Compounds 26, 40, 44, 54 and 56 exhibited moderate to good antibacterial activity. Compound 5-(2'-(4-fluorobenzyl)thiazol-4'-yl)-2-(4-fluorophenyl)-4-methyl-thiazole (54) exhibited both antitubercular as well as antimicrobial activity against all tested strains.

Celiac axis compression: experience with 20 patients and a critical appraisal of the syndrome.

Twenty patients with celiac axis compression were treated surgically during a 5-year period. Fifteen remain asymptomatic, two are partially improved, two are unimproved, and one has been lost to follow-up. The main presenting symptom was upper abdominal pain--constant in some, intermittent in most--and the main diagnostic clue was a loud, localized systolic bruit in the midepigastrium. All had angiographic confirmation of the diagnosis. Ten had previous surgery (appendectomy, cholecystectomy, vagotomy, and pyloroplasty), without relief. The authenticity of celiac axis compression as a symptom-producing entity is difficult to establish objectively because the main treatable symptom is pain. However, eight of these patients gained weight, three have shown improvement in pancreatic function, and one of the unimproved patients still has an occluded celiac axis. A critical review of the literature of this controversial topic is included.

Autoimmune factors in African cirrhosis. Correlation with hepatitis B surface antigen and antibody.

Sera were tested for autoantibodies in 98 patients with cryptogenic cirrhosis in Uganda and results correlated with serological tests for hepatitis B surface antigen (HBs Ag) and antibody to HBs Ag (HBs Ab). Smooth muscle antibodies (SMA) were detected in 23 (24%) of the patients but there was no difference in the incidence of SMA between HBs Ag-positive and negative cases. Antinuclear antibodies (ANA) were detected in five cases; mitochondrial, gastric and thyroid antibodies were not found in any patient. Unlike other geographical locations autoimmune mechanisms appear to play little part in the progression of chronic liver disease in Uganda Africans. Hepatitis B surface antigen was present in 36 (37%) and HBs Ab in 47 (48%) of the patients. Although evidence for past exposure to hepatitis B virus (as shown by detection of HBs Ab) was present in at least 30 out of the 62 HBs Ag-negative cases, there was no greater incidence of autoantibodies in HBs Ag-negative patients with or without HBs Ab. Persistent infection with hepatitis B virus and continuing liver damage may be an important factor but these results do not favor a role for the virus in causing chronic liver disease by triggering off an autoimmune reaction.

Carnosinase activity of human gastrointestinal mucosa.

Carnosinase, the dipeptidase which hydrolyses carnosine and other histidine-containing dipeptides, was assayed in mucosal tissues of the human and of the rat gut. Kinetic properties of the intestinal enzyme were found to be similar to carnosinase of other animal tissues. Little or no activity was detected in human gastric or colonic mucosa, and the levels were lower in duodenal than jejunal mucosa. The distribution of carnosinase is similar to that of the disaccharidases. Mean carnosinase activity was 8-8 units/g weight in 15 patients with histologically normal mucosa compared with 5-7 units in five with villous atrophy. The enzyme levels increased with histological improvement of the mucosa in patients with coeliac disease on a gluten-free diet. Tolerance curves for carnosine and its constitutent amino acids showed malabsorption of the dipeptide in a patient with carnosinase deficiency. It is concluded that the intestinal mucosa has much less hydrolase activity for carnosine than for glycylglycine and other dipeptidases, and the relatively slow hydrolysis appears to be the rate-limiting step in the total absorptive process.

Hypothermia in the tropics. A review of 24 cases.

The clinical features in a series of 24 patients with hypothermia treated at Mulago Hospital, Kampala, are described. Hypothermia developed in all when the environmental temperature did not fall below 16 degrees. There was a preponderance of males; 14 of the 24 cases were over 50 years old. The most common predisposing factors were severe undernutrition or malnutrition with wasting and almost complete absence of subcutaneous fat, and anaemia present in over two thirds of the patients. Hypoglycaemia appeared to be the immediate precipitating factor in at least five patients. Acute pancreatitis was found in three of the four patients who died unexpectedly 2-7 days after recovery from hypothermia; focal pancreatitis and fat necrosis was also present in six other cases. It is concluded that hypothermia is not uncommon, and is a dangerous complication amongst patients with severe under- or malnutrition, and can occur even under "tropical" conditions, when the environmental temperature does not fall below 16 degrees.

Hepatitis-associated antigen and antibody in Uganda: correlation of serological testing with histopathology.

Histopathological findings in 91 Ugandan patients with cirrhosis were studied in relation to serological tests for the hepatitis-associated antigen (H.A.A.) and antibody (anti-H.A.A.). H.A.A. was present in 30 (32.9%) of the 91 patients as opposed to 7 (3.1%) out of 224 controls drawn from the same population (P<0.001). Younger subjects and males were more frequently positive. There was no difference in the presence of anti-H.A.A. between patients and controls. Correlation of the results of serological testing with histopathological features showed that macronodular ("posthepatitic," "postnecrotic") types of cirrhosis, which predominate in Uganda, were associated with the presence of H.A.A. but that the much less common micronodular ("nutritional," fatty, portal) type of cirrhosis was not. Evidence was found, on the other hand, for a direct role of alcoholism in the latter. Detailed histological analysis also showed two types of cellular change-liver cell swelling and dysplasia-to be associated with the presence of H.A.A. The data suggest an aetiological role for H.A.A. in most cases of cirrhosis in Uganda and these may be identified by histological criteria.

Dipeptidase deficiency and malabsorption of glycylglycine in disease states.

The activities of jejunal mucosal peptide hydrolases for glycylglycine, glycyl-L-leucine and L-leucylglycine, were assayed in 37 patients. Eight patients, four of whom had Crohn's disease, were found to have a marked reduction in the activity of glycylglycine dipeptidase and, to a lesser extent, of the other two hydrolases. Although absorption of glycine in the two groups was similar, there was malabsorption of glycylglycine in the patients with reduced dipeptidases as shown by a flat absorption curve. The importance of peptide hydrolases of small-intestinal mucosa in the final digestion of proteins, and the implications of peptidase deficiency in disease states is discussed. It is concluded that significant peptidase deficiency may occur even when the mucosa is otherwise histologically completely normal, similar to some states of disaccharidase deficiency described in recent years.