Polycyclic aromatic hydrocarbons in fish (fresh and dried) and public health in Nigeria: a systematic review

In Nigeria, environmental pollution linked with PAHs has been increasing, and PAHs in fish pose a threat to all, especially those that rely upon fish. This systematic review aimed at evaluating human health effect of PAHs concentration in dried and fresh fish in Nigeria. A systematic literature search was carried out on PubMed, MedLine, Web of Science and Science Direct, etc. From the total of 31 articles reviewed, 19 studies reported on fresh fish and 9 on dried fish. 54.8% of the selected research reported on high-level PAH accumulation in fresh fish. PAH contamination was mainly from petrogenic and pyrogenic sources. The major health outcomes from this study were cancer and non-carcinogenic risks, skin irritations, gastrointestinal, child deformities, respiratory disorders, emotional distresses, neurological and haematological effects. It is recommended that regulations be made to abate and monitor the environmental exposure of humans to PAHs to ameliorate the public health effects.

Persistent organic pollutants and heavy metals in Ghanaian environment: a systematic review of food safety implications

Advances in industrial and technological innovations have led to significant socio-economic benefits, but with overwhelming negative impacts on the environment. These impacts include the infiltration of organic contaminants into soil, water, and air, posing a threat to the environment and public health. Polybrominated diphenyl ethers (PBDEs), heavy metals, and polycyclic aromatic hydrocarbons (PAHs) are increasingly released as waste, endangering the environment. In countries like Ghana, where regulations are weakly enforced, industrial waste is released uncontrollably, posing threats to public health, environmental integrity, and food systems. This study systematically evaluated existing literature on PBDEs, heavy metals, PAHs, and organic contaminant exposure in Ghana and proposes a roadmap for achieving food safety and protecting the environment and human health. The research identified high mobility of specific heavy metals and risks associated with PBDEs and PAHs in sediments, dumpsites, and various food items. Unregulated dumping of electronic waste with PBDEs raised environmental concerns. An integrated approach is needed to address the multifaceted impact of organic pollutants on public health and ecosystems. Urgent implementation of effective environmental management strategies and regulatory measures is crucial. The study proposed short- to mid-term priorities emphasising the need to foster collaboration and implementing global measures. The mid- to long-term strategy includes a national information surveillance system, local monitoring capacity development, and integrating land contamination controls with food safety legislation. These measures would mitigate risks, ensure sustainable practices, and improve overall food safety management in Ghana, serving as a model for regions facing similar challenges with diverse pollutants.

Histopathological and biochemical assessments of Costus afer stem on alloxan-induced diabetic rats

BACKGROUND

In continuation of our study of the biological activity of the aqueous extract of Costus afer stem used in tradomedicare in Nigeria, this work has investigated the biochemical, nephroprotective, hepatoprotective and protective effects of aqueous extract of C. afer stem on alloxan-induced hyperglycaemic albino Wistar rats.

METHODS

Thirty male albino Wistar rats (150-200 g) were weight-matched into six groups of five rats each. Groups 1 and 2 were the normal (non-induced) and toxic (alloxan-induced) controls, respectively. Groups 3-6 were induced and treated with 1, 2 and 3 g/kg of the aqueous extract of C. afer stem and glibenclamide (5 mg/kg), respectively. Food and fluid intake, body weight, absolute and relative weight of organs (liver, pancreas, and kidneys) and biochemical parameters were measured.

RESULTS

There was a significant reduction in alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total bilirubin triglyceride, creatinine, urea and electrolyte when compared with toxic control group. The liver marker enzymes were restored in all the treated groups. The aqueous stem extract possessed hypoglycaemic effect and reversed the histopathological damage in alloxan-induced diabetic rats.

CONCLUSIONS

This study suggests that aqueous stem extract of C. afer possesses both hypoglycaemic and organ protective properties.

Morphological changes in the pancreas and glucose reduction of the aqueous extract of Costus afer leaf on alloxan-induced diabetic rats

BACKGROUND

Considering the antihyperglycemic and antioxidant activities of herbs, this study has evaluated the morphological changes, hypoglycemic effect, and comparative ameliorating effects of Costus afer Ker Gawl leaf and glibenclamide on pancreatic injury induced by alloxan.

METHODS

Thirty adult male albino rats that were divided into six groups of five weight-matched animals each were used in the study. Groups 1 and 2 served as controls, whereas groups 3-6 were alloxan-induced diabetic groups treated with different doses of the extract (375, 750, and 1125 mg/kg C. afer) and glibenclamide, respectively. The glucose level was measured daily, whereas the weight of the animal was monitored on a weekly basis for 21 days. The oral glucose tolerance test was measured on overnight fasted rats after glucose load at 0, 30, 60, 90, and 120 min. The histopathology of the pancreas was also investigated.

RESULTS

The phytoconstituents of C. afer Ker Gawl leaves include glycosides, tannins, saponins, terpenoid, phenolic compound, flavonoids, and alkaloids. Costus afer possessed significant hypoglycemic (p<0.05) effect and reversed the histopathologic damage of pancreases in alloxan-induced diabetic rats comparable to those of glibenclamide.

CONCLUSIONS

Costus afer leaves possess both antidiabetic and tissue protective properties on pancreases of investigated rats.

Acute and Cytotoxicity Studies of Aqueous and Ethanolic Leaf Extracts of Chromolaena odorata

Chromolaena odorata, a commonly used traditional remedy for different ailments, believed to be quite safe in terms of toxicity was evaluated for acute toxicity and cytotoxic potentials. Acute toxicity was done on albino Wistar rats using the Lorke method while brine shrimps were used to test for cytotoxicity. The results showed that the estimated LD50 for the aqueous and ethanolic extracts was 2154 and > 5000 mg kg(-1) body weight, respectively. Cytotoxicity to brine shrimps showed LC50 values of 324 and 392 ppm for aqueous and ethanolic extracts, respectively. These results indicate the relative non toxic nature of Chromolaena odorata extracts.

Cytological and biochemical studies during the progression of alloxan-induced diabetes and possible protection of an aqueous leaf extract of Costus afer

Some plants have proven efficacy in the management of diabetes mellitus, of which Costus afer is one. This study was designed to evaluate the cytological and biochemical properties, and comparative ameliorating effects, of an aqueous extract of Costus afer Ker Gawl. (Costaceae) leaf and glibenclamide (GBM), in liver, kidney, and pancreatic injury induced by alloxan. Thirty male albino rats were divided into six weight-matched groups. Group one served as the negative control (non-induced and non-treated, control), while groups 2-6 were alloxan-induced diabetic groups. Group 2 served as a positive control (induced and non-treated, IC), groups 3-5 were treated with different doses of the extract (375, 750, and 1,125 mg/kg body weight) and glibenclamide, respectively. Body weight, absolute and relative organ weights, food and fluid intake, levels of serum glucose and liver enzymes and kidney parameters were calculated and compared. Hepatocytes, renal tubules, and pancreatic cells of diabetic rats, in diabetic non-treated and treated rats were harvested and examined histopathologically. There was dose dependent amelioration on the injuries induced by alloxan on both hepatocytes, renal tubules, and pancreatic cells after treatment with Costus afer. The glucose level was reduced significantly in the Costus afer treated diabetic rats compared with the non-treated diabetic group. Costus afer leaves seem to be effective against diabetic cell injury induced in rat liver, kidney, and pancreas.

Effect of aqueous leaves extract of Costus afer Ker Gawl (Zingiberaceae) on the liver and kidney of male albino Wistar rat

BACKGROUND

The use of medicinal plants in Nigeria has significantly increased over recent years as it is easily accessible, cheap and the strong belief that herbal remedies are natural and therefore non toxic.

AIMS

This study aims to investigate the sub-chronic toxicity (28-day) of the aqueous extract of Costus afer Ker Gawl leaves on the liver and kidney of male albino Wistar rats.

MATERIALS AND METHODS

A total of 20 male albino Wistar rats (113-205 g) divided into four groups of five weight-matched animals each, were used for the study. Group 1 received standard feed and water ad libitium and served as the control. Group 2, 3 and 4 received 375, 750 and 1125 mg/kg of aqueous extract of C. afer leaves respectively. The animals were sacrificed under ether anesthesia and the organs were harvested, weighed and histopathological studies carried out. The effect of C. afer on the hepatic biomarkers aspartate aminotransferase (AST), alanine aminotransferase (ALT); alkaline phosphatase (ALP); triglyceride (TG); total bilirubin (TB); conjugated bilirubin (CB); albumin (ALB) and kidney biomarkers urea, creatinine, sodium, potassium and bicarbonate were investigated.

STATISTICAL ANALYSIS

Data were evaluated using Mann Whitney. If P ≤ 0.05 groups were considered to be significantly different.

RESULTS

C. afer contained alkaloids, saponins, flavonoids, anthraquinones, cardiac glycosides, terpenoids, phenolic compounds and tannins. The average body, organ, relative weights, feed and fluid intake showed no significant changes (P > 0.05) when compared to the control. The liver function tests (ALT, ALP, AST, CB, TB and ALB) showed significant differences (P < 0.05) in the test groups when compared with the control while TG showed no statistical difference (P > 0.05). The kidney function tests (urea, creatinine, sodium, potassium and bicarbonate) showed no significant differences (P > 0.05) in the test groups when compared to the control.

CONCLUSION

Costus afer may be hepatotoxic but non-toxic to the kidney.