Guidelines on Dosage Calculation and Stock Solution Preparation in Experimental Animals’ Studies

Dosage calculation and stock solution preparation in preclinical studies, involving the use of experimental animals are important in screening and development of new drugs. The present literature provides the basic principles and guidelines on dosage calculations and preparation of stock solution (with reference to crude plant extracts, sylimarin tablets, alloxan monohydrate as well as chemiron blood tonic) for experimental animal studies. Keywords: Dosage calculation, stock solution preparation, crude plant extract, sylimarin and chemiron blood tonic

Sub-chronic toxicity evaluation of Dryopteris filix-mas (L.) schott, leaf extract in albino rats

This study evaluated the acute and sub-chronic toxicities of ethanol leaf extract of Dryopteris filix-mas. Acute toxicity and phytochemical tests on ethanol leaf extract were determined. In sub-chronic toxicity test, animals were treated with 62.5, 125, 250 and 500 mg/kg of extract every day for 90 days. Blood samples were collected via retro-orbital puncture for baseline studies and at 31, 61 and 91st days for determination of hematological, kidney and liver function parameters. Liver and kidneys were harvested for histopathology analyses on 91st day. Also, a 28 day recovery study was carried out to determine reversibility in toxicological effects. Phytochemical screening revealed the presence of tannins, phenols, flavonoids, saponins, steroids, alkaloids, terpenoids, reducing sugar and cardiac glycosides. Acute toxicity test did not show toxicity or death at 5000 mg/kg. There was significant (p<0.005) reduction in white blood cell and lymphocyte counts, significant (p<0.05) increase in some liver and kidney biomarkers as well as alterations in liver and kidney histo-architecture on 91st days in animals that were treated with 250 and 500 mg/kg extract. However, toxicities observed on 91st day were reversible in recovery studies. The leaf extract of Dryopteris filix-mas may be hepatotoxic and nephrotoxic when used for long periods

Ficus Sycomorus L (Moraceae): A review on its Phytopharmacology and toxicity profile

Ficus Sycomorus (F. sycomorus), belonging to the family of moraceae, is an evergreen tree found in Nigeria and other parts of the world. It has several medicinal and culinary uses. This present review evaluated its traditional uses, phytochemical constituents, pharmacological and toxicological effects. From this evaluation, bioactivity guided isolation and purification of its promising extracts is recommended to facilitate the discovery and development of its lead molecules as alternative therapie

Acute Toxicity and Hypoglycemic Effect of a Polyherbal Formulation on Blood Glucose in Oral Glucose Tolerance Test (OGTT) and Alloxan-Induced Diabetic Rats

Madam F. Kayes Bitters® is an herbal formulation commonly used in Nigeria and some African countries in the management of diabetes mellitus and other diseases conditions. This study evaluated the in-vivo hypoglycaemic activity, as well as acute toxicity of the polyherbal formulation to provide its efficacy and safety. Healthy albino mice (20-30 g) and Sprague Dawley female rats (90-130 g) were used for this study. Acute toxicity study (LD50) of the herbal formulation was determined by methods originally described by Miller and Tainter in 1994. Following oral dosing with glucose (2 g/kg) in normal fasted animals, herbal formulation (HF) at various doses was administered and blood glucose levels at 30 minutes, 60 minutes, 90 minutes, and 120 minutes were taken and recorded. Diabetes was induced using alloxan 150 mg/kg and diabetic rats were given the HF at doses of 50, 100, and 200 mg/kg with glibenclamide 2.5 mg/kg used as standard drug treatment. Blood glucose level was determined on 1st day, 7th day, 14th and 21st day. The LD50 was greater than 5g/kg with oral administration. The oral glucose tolerance test showed that the group that received 100 mg/kg HF showed a significant reduction (p<0.05) in glucose level after 120 minutes when compared to the basal level of glucose recorded. All treated diabetic groups showed a significant decrease in glucose level on the 21st day. The herbal formulation of Hydrastis canadesis Aloe capensis, Echinacea angustifolia and honey exhibited a significant glucose-lowering activity in alloxan-induced diabetic rats

Antioxidant Activities of the Leaf Extract and Fractions of Dryopteris filix-mas (L.) Schott could be Attributed to The Abundance of Polyphenol Compounds

Dryopteris filix mas (D filix-mas) is wildly used in ethnomedicine for the management of rheumatoid arthritis, wounds and other diseases. We investigated the anti-oxidant activities of its leaf extract, and chromatographic fractions. The ethanol leaf extract was partitioned into four fractions; n-hexane, ethyl acetate, n-butanol and water. Ferric reducing anti-oxidant power (FRAP), 1, 1-diphenyl-2-picrylhydrazil (DPPH) and nitric oxide (NO) scavenging in vitro assays were carried out on the extract and fractions at 6.25, 12.5, 25, 50, 100, 200, 400 and 800 µg/mL. The most active fraction (ethyl acetate fraction) was further purified using chromatographic techniques to isolate its major compound whose structure was elucidated using ID nuclear magnetic resonance (NMR) and mass spectrometry. The ethyl acetate fraction produced the highest free radical scavenging activity among the other fractions. The fraction (VLC-E7) from which the bioactive compound, quercetin-3-O-αL-rhamnopyranoside, was isolated had the best FRAP and DPPH scavenging activities with EC50 and IC50 values of 88.81 ± 3.41 and 26.87 ± 0.24 respectively more than the ethyl acetate fraction. This study revealed that the polyphenol flavonoid, quercetin-3-O-αL-rhamnopyranoside could be responsible for antioxidant activity of ethno-medicinal property of D filix-mas leaf

Endophytes – untapped resources and pharmacological prospects against coronaviruses

Introduction and aim. Viral infections stand to be among the most devastating diseases globally. Though significant efforts have been made in research and drug development against viral infections, the search for safe, affordable and effective vaccines against the current ravaging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still on. This is because already approved vaccines still need improvement. This review draws the attention of researchers on the potentials of bioactive substances from endophytes against the novel coronaviruses. Material and methods. This assessment was made using references of articles published in English peer reviewed journals indexed in PubMed and Google Scholars databases up to June, 2022. The following key words were used; ‘coronaviruses’, ‘Endophytes’, ‘Endophytes and viral infections, ‘Endophytes and COVID-19, ‘SARS-CoV’. Analysis of the literature. In-silico, in-vitro and in-vivo studies revealed that natural compounds from endophytes showed antiviral activities against various human coronavirus, including HCoV 229E and a norovirus surrogate, the feline coronavirus FCV F9, COVID-19, Coronavirus 2 (SARS-CoV-2), SARSCoV-2 Mpro, among others. Conclusion. This finding calls for researchers to also focus on endophytes, as part of drugs development in the bid to finding possible solution in combating the devastating COVID-19, an emerging situation

Toxicological Evaluations of a Popular Polyherbal Remedy-STC30 in Wistar Rats

Background: There is a rising trend in the use of herbal stem cell remedies among the populace due to the belief that such remedies have all-encompassing health benefits, and without side effects. However, there is little or no scientific data reported on their safety profile. This study addressed the toxicological effects of STC-30, one of the popular polyherbal stem cell remedies used in several countries of the world including Nigeria, Ghana, Australia, among others. Methods: The acute toxicity test was carried out using Up and Down Procedure. For the sub-acute toxicity test, a total of 28 animals were used in four groups of seven each. The groups consisted of control, low dose (77.5 mg/kg), medium dose (155 mg/kg) and high dose (310 mg/kg). At the end of administration for 30-days, animals were sacrificed, and blood, kidneys and liver tissue samples were collected for hematological, biochemical and histopathological analyses. Results: Acute toxicity test revealed no obvious toxicity or death at 5000 mg/kg. There was no significant alteration (P>0.05) in body weight gain, feed and water intakes, relative organ weights, urea, sodium, potassium, chloride, total protein and albumin, malondialdehyde (MDA), and white blood cells. However, significant reductions (P<0.05) were noted in creatinine and aspartate aminotransferase (AST), hematocrit, hemoglobin, red blood cell and mean corpuscular hemoglobin only at high dose (doubled therapeutic dose) compared to the controls. There were no abnormal changes in liver, kidney and heart histology. Conclusion: Administration of STC-30 at the recommended dosage did not exert deleterious effects, but doubled therapeutic doses may be harmful to the red blood cells

Evaluation of Wound Healing Properties of Dryopteris filix-mas Leaf and Root Extracts on Albino Rats: Wound Healing Potentials of Dryopteris filix-mas on Albino Rats

Dryopteris filix-mas (D. filix-mas), belonging to the family of Dryopteridacea is a swampy fern that is popularly used by the Southern Nigerian dwellers in the treatment of wounds, hemorrhages, boil and other diseases. In order to authenticate its folkloric benefits in wounds, this study evaluated its wound healing activity using excision model. A total of fifty (50) Wistar rats were randomized into ten groups of five animals each. After creation of surface wounds, group 1 received paraffin base (control). Group 2 received Povidon iodine (standard). Groups 3, 4, 5 and 6 received 1.25, 2.5, 5 and 10% (w/w) of an ethanol leaf extract of D. filix-mas formulated with paraffin base respectively. Groups 7, 8, 9, 10 were treated with 1.25, 2.5, 5 and 10% (w/w) of ethanol root extract D. filix-mas formulated with paraffin base respectively. Treatments were topically applied to wounds once daily and healing rate was monitored every 3 days for 21 days. Wound swaps were taken on day 10th and day 20th for bacteria load determination. In-vitro antimicrobial activities of the leaf and root extract were tested against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli using agar-well diffusion method. Higher concentrations (5 and 10%) of the leaf and root extracts exhibited better wound healing activities more than lower concentrations. The leaf extract produced a better healing rate (wound contraction), antimicrobial activity and body weight regaining activities more than the root extract. This study validates the traditional use of D filix-mas in the treatment of wounds

Wound-healing Activity of the Aqueous Leaf Extract and Fractions of Ficus exasperata (Moraceae) and its Safety Evaluation on Albino Rats

Ficus exasperata have been reported to have wide applications in the treatment of many human diseases. However, its traditional use in the treatment of wounds has not been validated by any scientific study. Also, its safety in the management of chronic disease conditions requires attention. We evaluated the wound-healing activity of the aqueous extract and fractions of F. exasperata, as well as its safety after subchronic oral administration. Similar percentage of wound contraction was observed with 5% w/w extract ointment application and administration of cicatrin powder (standard) on the 4th day, while better contraction than the standard was recorded with higher concentrations of the extract ointment. Of all the fractions tested, significant (P<0.05) contraction was only noticed in chloroform fraction, though lower than that of the aqueous extract. The extract also showed concentration-dependent inhibition of all the tested microbial isolates. Extract administered up to 5000 mg/kg (single dose administration) did not cause any mortality after 24 h. Mortality was, however, recorded at 4000 mg/kg within the first 20 days of subchronic administration of the extract. Significant (P<0.05) increases in alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), and in particular, alkaline phosphatase (ALP) were observed at different doses and time periods. Pathological and histological changes were noticed in the liver and kidney on the 91st day of the study with 4000 mg/kg of the extract. Except for the significant (P<0.05) reduction in WBC on the 91st day, no other significant (P<0.05) changes were observed in other hematological parameters. The aqueous extract demonstrated better wound-healing activity than its fractions; however, the extract may not be safe at higher doses for subchronic oral administration, as may be the case in the management of chronic disease conditions

The Role of Medicinal Plants in Diabetes Mellitus and Oxidative Stress: A Review

Diabetes mellitus is an endocrinology disorder of great global concern. It results from an irregularity in the secretion or action of insulin. It is a metabolic condition characterized by chronic hyperglycemia. Oxidative stress plays a critical role in the pathophysiology of some diseases such as diabetes, aging, cancer, cardiovascular disease, as well as liver and lung diseases. Oxidative stress occurs due to an imbalance between radical generation and radical scavenging. One of the main mechanisms for the development of diabetes complications is via oxidative stress. Oxidative stress is a main upstream occurrence for diabetes complications as well as the development of insulin resistivity. Medicinal plants can be useful in the treatment of numerous diseases and some of their healthful effects are due to their antioxidant activity. Their antihyperglycemic effect is very much linked to their antioxidant potential. This review summarized the antidiabetic potential of some medicinal plants in animal models. There is a continuous need to explore the medicinal capability of herbal products with antioxidant effects in the management of diabetes mellitus