Subacute Oral Toxicity Research Articles

Single acute and repeated subacute toxicity evaluations of Annona atemoya leaf extract with in vitro anti-inflammatory potential

The nutraceutical and biological potential of Annona atemoya, a fruiting plant, has been reported. We and others have demonstrated that A. atemoya leaf extract (AAL) has various pharmacological properties, such as antioxidant, antimicrobial, and neuroprotective effects. However, knowledge about the safety and potential toxicity of AAL remains limited. We aimed to assess the potential toxicity of AAL using acute and repeated subacute oral toxicity tests in rats. In both acute and repeated subacute toxicity test, no AAL-related behavioral abnormalities or changes in mortality, food intake, body weight were observed up to a dosage of 2000 mg/kg, indicating that the median lethal dose of AAL is higher than 2000 mg/kg. In subacute toxicity tests, no significant changes in hematological and biochemical parameters, urinalysis results, and histopathological variables were observed. Therefore, the no-observed-adverse-effect level (NOAEL) of orally administered AAL was estimated to be 2000 mg/kg/day in male and female rats. We also examined the effect of AAL on the inflammatory reaction in lipopolysaccharide (LPS)-stimulated BV-2 cells. AAL treatment significantly inhibited the LPS-stimulated increases in the levels of nitric oxide (NO) and inflammatory cytokines, implying that AAL has an anti-inflammatory effect. Quality control analysis revealed that two marker compounds, rutin and isoquercitrin, were present at 27.570 and 4.322 mg/g, respectively, in a freeze-dried AAL sample and were completely eluted within 27 min. The extraction recovery was 99.47–103.80%, and the precision was ≤2.79%. Overall, these findings suggest the safety, anti-inflammatory activity, and standardization of AAL.

In silico, in vitro, and in vivo acute and sub-acute toxicity profiling of whole plant methanol extract of Equisetum diffusum D. Don from the sub-Himalayan West Bengal, India, having ethnobotanical uses

BackgroundEquisetum diffusum D. Don commonly known as ‘Himalayan horsetail’, has been traditionally used in the treatment of back pain, bone fracture and dislocation, and arthritis by various tribal communities of India. Our previous study confirmed the anti-inflammatory efficacy of the plant through in silico, in vitro, and in vivo model studies. Therefore, the current research is focused on safety dose evaluation for the first-time of the whole-plant methanol extract (EDME) of E. diffusum through appropriate in silico, in vitro, and in vivo approaches.MethodThe whole plant, along with its rhizomes, was collected, and the methanol extract was prepared. The in silico ADMET study was performed to predict the pharmacokinetics profile and toxicity of all the identified phyto-compounds of EDME previously screened by GC–MS study. In vitro cytotoxicity study of EDME was performed using two cell lines: kidney (HEK293) and liver (Huh7) cell lines. The in vivo toxicity study of EDME was validated by the acute toxicity (OECD 423, 2002) and sub-acute toxicity assays (OECD 407, 2008) in the Wistar Albino rat model.ResultsThe in silico ADMET study of all 47 bioactives predicted good pharmacokinetic and low toxicity profiles. In vitro cytotoxicity showed higher IC50 values of EDME viz., 672 ± 15.7 μg/mL and 1698 ± 6.54 μg/mL for both kidney (HEK293) and liver (Huh7) cell lines, respectively, which were considered as low-toxic. Based on acute oral toxicity, the LD50 value of the extract was considered “non-toxic” up to a feeding range of 2000 mg/kg of body weight. The regular consumption of the extract for an extended period (28 days) was also qualified as safe based on the body and organ weight, hematological, biochemical, and histoarchitecture results in the sub-acute toxicity assay.ConclusionThe detailed in silico, in vitro, in vivo (acute and sub-acute oral toxicity) studies gave us a new insight to the safety dose evaluation of Equisetum diffusum, which may serve as a reliable documentation for undertaking the experimental validation of the ethnobotanical uses of the plant which would help in the field of drug development for the treatment of inflammation related complications.

In-vivo and in-vitro toxicity evaluation of 2,3-dimethylquinoxaline: An antimicrobial found in a traditional herbal medicine.

2,3-dimethylquinoxaline (DMQ) is a broad-spectrum antimicrobial phytochemical. This study aims to assess its toxicological profile. In vitro studies conducted in appropriate cell cultures, included assessment of cardiotoxicity, nephrotoxicity, and hepatotoxicity. An in vivo study was conducted in mice to determine acute oral toxicity (AOT), and subacute oral toxicity (SAOT). Acute dermal toxicity (ADT) was conducted in rats. All in-vitro toxicity studies of DMQ had negative results at concentrations ≤100 μM except for a non-significant reduction in the ATP in human hepatocellular carcinoma cell culture. The median lethal dose of DMQ was higher than 2000 mg/kg. All animals survived the scheduled necropsy and none showed any alteration in clinical signs. Biochemistry analysis revealed a significant difference between the satellite and control groups, showing an increase in platelet counts and white blood cell counts by 99.8% and 188.8%, respectively. Histology revealed enlargement of renal corpuscles; hyperplasia of testosterone-secreting cells; and dilatation of coronaries and capillaries. The present data suggests an acceptable safety profile of DMQ in rodents except for thrombocytosis, leukocytosis, and histological changes in high doses that need further investigation.

Acute and subacute oral toxicity evaluation of Ayurvedic formulation Tapyadi loha in rats

Ayurveda is one of the oldest systems of traditional medicine that provides treatments for a wide range of acute and chronic health problems. It is a common myth amongst people that Ayurvedic drugs have no side effects, whereas the fact is that these drugs can cause adverse effects. Despite their wide use, the safety data of many Ayurvedic formulations are still unavailable. Tapyadi loha is an Ayurvedic formulation traditionally claimed for iron deficiency anemia in pregnant and non-pregnant patients. However, no scientific study has been conducted to evaluate its oral toxicity. Hence, the present study evaluated the acute and subacute oral toxicity of the Tapyadi loha according to the OECD test guidelines 425 and 407, respectively. Tapyadi loha did not cause mortality nor any signs of toxicity when given once orally at a dose of 2000 mg/kg. Subacute toxicity study showed no mortality as well as no behavioral, hematological, biochemical and histopathological abnormalities in rats treated with Tapyadi loha formulation at 250, 500 and 1000 mg/kg for 28 days. It is concluded that the Tapyadi loha is safe at a single dose of 2000 mg/kg and 28 days repeated dose of 1000 mg/kg by oral route in rats.

Safety profile determination of Benincasa hispida (Thunb.) cogn. Leaves extracts using toxicological and histopathological screening

BackgroundBenincasa hispida (Thunb.) cogn. commonly known as Winter gourd, is a very valuable herb belonging to the family Cucurbitaceae used in Chinese Traditional Medicine. B. Hispida is used in Chinese medicine for treating many conditions including urinary, mucolytic, and antipyretic problems. Many developing and developed countries have a common old myth about herbal medicines are known to be safe, but that is not totally correct. Materials and methodsThis stud focuses on the toxicological assessment of B. Hispida leaves. The OECD guideline 423 was used to conduct the acute oral toxicity test of BHELE. The limit test for BHELE at 2000 mg/kg and the behavioral study up to 14-days were conducted. BHELE at 500 mg/kg b. w. daily, 250 mg/kg b. w. daily, and 125 mg/kg b. w. per day were given to Wistar Rats for 28 days consecutively in a subacute oral toxicity test. ResultsThe limit dose (2000 mg/kg body weight) was not toxic and did not cause any mortality. There was no difference in body weight, relative organ weights, or the amount of water and food consumed during subacute oral toxicology study. The results of the hematological and serum biochemical analysis, as well as urine analyses revealed that BHELE consumption was not toxic. ConclusionAccording to our research, BHELE is safe and non-toxic for repeated oral administration at doses up to 500 mg/kg b. w.t.

A 90-day preclinical toxicological evaluation in rats of a highly purified and concentrated mulberry leaf extract.

Mulberry (genus Morus) leaves have long been used as a human food, especially in Asia, and animal feed. More recently, mulberry leaf extracts have been introduced as a convenient way to consume mulberry for non-nutritional functional effects. Reducose® 5% is an Morus alba leaf extract that has been highly purified and standardized to a content of 5 ± 0.5% 1-deoxynojirimycin, a naturally present polyhydroxylated piperidine alkaloid analog of D-glucose. This extract has previously been evaluated in acute and subacute (28-day) oral toxicity studies in which no adverse effects of the test item were observed in mice or rats, respectively. Due to continued and growing interest in the extract in multinational markets, we have now further investigated potential toxic effects in subchronic (90-day) oral toxicity study in male and female Han:WIST rats. The test item was administered at doses of 850, 1700, and 2550 mg/kg bw/day, and did not cause adverse effects in clinical signs, body weight development, clinical pathology, gross pathology, or histopathology in comparison to the vehicle-control group. The no-observed-adverse-effect-level was determined to be 2550 mg/kg bw/day. These results add to the existing body of both preclinical and clinical work relevant to the safety of the extract and of interest to regulators in various global markets.

Acute, subacute, repeat dose toxicity and safety studies of BiosimCovex (COVID-19 Nosode) in animal model

Introduction: BiosimCovex, a coronavirus nosode’s biological preparation was sourced from preclinical samples. The study needs to investigate the acute, subacute oral toxicity of different homeopathic drugs. The acute, subacute, repeat dose toxicity and safety testing of this newly developed nosode were conducted as per the OECD and New Drug and Clinical Trial (NDCT 19) rules. Material and methods In acute, subacute, repeat dose toxicity study, the homeopathic drug was administered orally at body weight, and animals were observed for toxic symptoms for 14 days. The study design consisted of 10 animals (05 males and 05 females) in acute mice and rats, 48 animals (24 males and 24 females) in subacute/repeat dose rats, and 24 (12 males/12 females) in repeat dose rabbit studies. Results Results indicate that in the acute and subacute studies of the rat and mice, no mortalities or clinical signs were found. The body weight and body weight gain in rats were normal and decreased in mice in the acute study. The feed consumption was normal for rats and mice. In male rabbits’ body weight was decreased and in other groups body weight gain observed was normal. The clinical signs were found to be normal in rats and rabbits. Histopathology results reveal that the BiosimCovex has not produced any major reactive and toxic changes in all the systemic organs when administered by an oral route up to a high dose. Conclusion No toxicity was documented using acute, subacute, and repeat dose studies using BiosimCovex, a coronavirus nosode.

Acute and subacute toxicological evaluation of the ethanol leaf extract of Morus mesozygia stapf. (Moraceae) in rodents

Ethnopharmacological relevanceTraditionally, the Morus mesozygia tree leaf has been used to manage maladies such as peptic ulcer, hyperglycemia, dermatitis, rheumatism, stomach-ache, arthritis, cough, malignancies, and malaria in parts of Africa. Aim of the studyThe study aimed to evaluate the potential of ethanol leaf extract of Morus mesozygia (EEMm) to induce toxicity by employing both acute and sub-acute oral toxicity experimental models. Material and methodsThe extract's cytotoxicity was studied using brine shrimps (Artemia salina) lethality assay (BSLA), while in the acute toxicity test, male and female mice were administered a single oral dose of EEMm (2000 mg/kg). Male and female Wistar rats received repeated doses of 100 or 500 mg/kg EEMm orally for 28 days in the sub-acute toxicity experiment. The phytochemical analysis of EEMm was done using the HPLC. ResultsThe BSLA revealed a moderate cytotoxic potential of the extract, with an LC50 of 567.13 ± 0.27 μg/mL. All the animals survived the acute toxicity test, with no significant changes in the relative organ weights, suggesting that LD50 is greater than 2000 mg/kg. The animal weights did not vary significantly in the sub-acute toxicity test neither were the alterations in biochemical and hematological tests pronounced, although the histoarchitectures of the kidney, liver and spleen indicated slight anomalies in the evaluated animals. The HPLC analysis revealed the presence of quercetin, ferulic acid, rutin, caffeic acid, morin and gallic acid. ConclusionsEthanol leaf extract of Morus mesozygia demonstrated a safe toxicity profile in rodents, supporting its broad folkloric use in African ethnomedicine.

Biochemical and toxicity evaluation of Retama sphaerocarpa extracts and in-silico investigation of phenolic compounds as potential inhibitors against HPV16 E6 oncoprotein

Cervical cancer is a type of cancer which affects the cervix cells. The conventional treatments for cervical cancer including surgery, chemotherapy, and radiotherapy are only effective in premature stages and less effective in late stages of this tumor. Therefore, the therapeutic strategies based on biologically active substances from plants are needed to develop for the treatment of cervical cancer. The aim of the present study was to assess in vivo toxicity, hematological and biochemical blood parameters in Wistar rats fed Retama sphaerocarpa aqueous leaf extract (RS-AE), as well as to perform in silico molecular docking studies and dynamic simulation of phenolic compounds against HPV16 oncoprotein E6 in order to identify potential inhibitors. RS-AE was found not to induce acute or sub-acute oral toxicity or significant alterations in hematological and biochemical blood parameters in Wistar rats. A total of 11 phenolic compounds were identified in RS-AE, including dihydrodaidzein glucuronide, chrysoperiol pentoside, genistin and vitexin, which turned out to have the highest binding affinity to HPV16 oncoprotein E6. Based on these results, these RS-AE phenolic compounds could be used as natural drugs against the HPV16 E6 oncoprotein.

Safety assessment of Acori Tatarinowii Rhizoma: acute and subacute oral toxicity.

Introduction: Acori Tatarinowii Rhizoma (ATR) is a well-known traditional Chinese medicine that is used for treating neuropathic diseases. However, there is little information about the safety of ATR. Methods: The present study evaluated the acute and subacute oral toxicity of a water extract of ATR in Institute of Cancer Research (ICR) mice. In acute trials, a single administration of extract at a dose 5,000mg/kg body weight led to no clinical signs of toxicity or mortality, indicating that the lethal dose (LD50) exceeded 5,000mg/kg. A subacute toxicity test was done using daily doses of 1,250, 2,500, and 5,000mg/kg of the ATR extract for 28days, which did not show any adverse clinical symptoms or mortality. However, the male renal organ index and urea level in mice given 5,000mg/kg was obviously abnormal, which was consistent with pathological results and suggested that this dose might cause kidney injury. Results: Doses of ATR lower than 2,500mg/kg could be regarded as safe, although the potential cumulative effects of long-term use of high doses of ATR need to be considered. Discussion: The study highlights the function of ATR in reducing blood lipids and provides a new idea for its widespread clinical use in the future.

Safety assessment of Wuzhuyu decoction extract: acute and subacute oral toxicity studies in rats

Wuzhuyu decoction (WZYD) is a well-known classic traditional Chinese medicine prescription and has been widely used to treat headache, nausea, vomiting, insomnia, etc. However, little published information is available about its safety. Our aim was to investigate the acute and subacute oral toxicity of WZYD extract in rats following the technical guidelines from China’s National Medical Products Administration (NMPA) for single and repeated doses toxicity studies of drugs. Acute oral toxicity was assessed in rats via oral administration of WZYD extract at 4 g/kg three times within a day followed by a 14-day observation period. To evaluate the subacute toxicity, rats were orally administered with WZYD extract at doses of 0, 0.44, 1.33, and 4 g/kg for 28 days. The items examined included clinical signs, body weight, food consumption, hematological and biochemical parameters, bone marrow smear, organ index, and histopathology. After the rats were administered with 12 g/kg (3 × 4 g/kg) WZYD extract, no mortality and toxic effects were observed during the observation period. In the subacute toxicity study, WZYD extract did not cause any significant treatment-related abnormality in each examined item of rats, so the no observed adverse effect level (NOAEL) of WZYD extract for 28 days orally administered to rats is considered to be 4 g/kg, which is approximately 80-fold of its clinical proposed dosage.

Subacute Oral Toxicity Studies of Pankajakasthuri Orthoherb Tablets Formulated for Managing Pain and Inflammation of Joints

Objectives The objective of this investigation was to assess the subacute oral toxicity of the Pankajakasthuri Orthoherb Tablets, a polyherbal formulation used to manage pain and inflammation due to various pathological reasons, including osteoarthrosis, polyarthritis, rheumatoid arthritis, and other chronic degenerative disorders. Materials and Methods The subacute toxicity studies of Pankajakasthuri Orthoherb Tablets were conducted using Wistar albino rats of both sexes, according to Organization for Economic Cooperation and Development-approved procedures. In this study, rats were orally administered Pankajakasthuri Orthoherb Tablets daily at doses of 250, 500, and 1000 mg/kg body weight for 28 days. Throughout the study period, general behavior, mortality, and adverse effects were recorded. Body weight, selected hematological and clinical chemistry parameters were determined at the end of the investigation period. Finally, histopathological analysis was performed to determine whether the study drug was inducing any alternations in the vital organs. Results Daily administration of Pankajakasthuri Orthoherb Tablets for a continuous 28 days did not record any major toxicity indications. Additionally, no significant variation in food and water consumption, body weight, relative organs and hematology and clinical chemistry parameters was recorded in both sexes compared to the control. Histopathological investigation of the vital organs also revealed normal architecture, which suggests no morphological alterations after the administration of Pankajakasthuri Orthoherb Tablets. Conclusion The outcomes of this investigation confirmed that Pankajakasthuri Orthoherb Tablets did not have the potential to induce toxicity signs in the experimental rats. The No observed Adverse Effect Level (NOAEL) for female and male rats of Pankajakasthuri Orthoherb Tablets under these experimental conditions was 500 mg/kg body weight. Based on the NOAEL, the human equivalent dose of the Pankajakasthuri Orthoherb Tablet was calculated at 5.195 g/day.

In vivo oral toxicity and antioxidant capacity of Nothofagus antarctica (G.Forst.) oerst (ñire) leaves

ABSTRACT Nothofagus antarctica (NA) is a native tree of Patagonia. Since ancient times, NA leaves were used in infusions for medical and food purposes, but there are no deep insights on its toxicity. The aim of this work was to assess the safety and antioxidant activity of NA leaves infusion. Mice were used to determine acute and subacute oral toxicity. Total polyphenols, flavonoids and the antioxidant activity of the infusion were assessed, as well as the antioxidant activity in biological samples. Toxicity tests revealed no death or signs of toxicity. No significant differences in biochemical parameters/histological structure were registered. NA infusion exhibited a high content of polyphenols and flavonoids, contributing to its remarkably antioxidant activity. The periodic administration of NA infusion could increase the antioxidant capacity in mice at intestinal level. The results support the safe of consuming NA leaves infusion and suggest their contribution for modulating the intestinal oxidative stress.

Toxicological Evaluation of a Polyherbal Formulation (18KHT01) and Validation of UPLC-DAD Method for Quality Control.

Background: 18KHT01 is a novel synergistic composition of Quercus acutissima, Camellia sinensis, Geranium thunbergii, and a small portion of Citrus limon. Our previous report demonstrated that the 18KHT01 exhibits potent antiobesity effects, with synergistic antioxidant, antiadipogenic, and antiobesity activities in diet-induced obese mice. This study explores the toxicity profile and quality control parameters of the 18KHT01 formulation. Methods: Broad-spectrum acute and subacute oral toxicity studies were performed using male and female ICR mice. In order to simultaneous analysis of the 18KHT01 formulation, an ultraperformance liquid chromatography coupled with a diode array detector (UPLC-DAD) method was developed and validated using six marker compounds. Results: Acute oral toxicity evaluation of 18KHT01, administered at single high doses of 2, 2.5, 3, and 5 g/kg, identified 2 g/kg as the no-observed adverse effect level (NOAEL). The LD50 (50% lethal dose) and LD100 (100% lethal dose) of 18KHT01 for male ICR mice were 3.99 and 7.77 g/kg, and those for the female mice were 2.94 and 4.70 g/kg, respectively. In addition, a 30-day repeated dose oral subacute toxicity evaluation indicated that 18KHT01 is safe below 500 mg/kg/day for long-term administration in ICR mice of either sex. UPLC-DAD method validation revealed that each calibration curve for the marker compounds showed good linearity, as well as the validation parameters such as precision, specificity, and accuracy met the acceptance criteria. Conclusion: The present study evidenced the toxicological profile of 18KHT01 polyherbal formulation in mice as well as developed a simple, rapid, and accurate chromatographic method for quality control.

Evaluation of acute and subacute oral toxicity induced by ethanol extract of Boletus griseipurpureus Corner in male mice: Blood parameters and histopathological studies

Evaluation of acute and subacute oral toxicity induced by ethanol extract of Boletus griseipurpureus Corner in male mice: Blood parameters and histopathological studies

Acute and sub-acute toxicity study of anti-obesity herbal granules in Sprague Dawley rats.

Toxicological studies are essential for developing novel medications in pharmaceutical industries including ayurvedic preparation. Hence, the present study is aimed to evaluate acute and 28-days repeated dose oral toxicity of anti-obesity polyherbal granules (PHG) in Sprague Dawley rats by OECD guidelines No 425 and 407, respectively. In an acute oral toxicity study, a single dose of 2 g/kg PHG was administered to rats and mortality, body weight, and clinical observations were noted for fourteen days. However, in the subacute oral toxicity study, the PHG was administered orally at doses of 0.3, 0.5 and 1 g/kg daily for 28 days to rats. Food intake and body weight were recorded weekly. On the 29th day, rats were sacrificed and subjected to haematological, biochemical, urine, necropsy, and histopathological analysis. In an acute oral toxicity study, no treatment-related, mortality, behavioral changes, and toxicity were found throughout fourteen days. Likewise, in the sub-acute toxicity study, no mortality and toxic effects were found in haematology, biochemical, urine, necropsy and histopathological analysis in rats for 28 days of treatment with PHG. Based on these results, the LD50 of PHG was found to be greater than 2 g/kg and the no-observed-adverse-effect level (NOAEL) of PHG for rats was found to be 0.5 g/kg/day. Thus, anti-obesity polyherbal granules showed a good safety profile in animal studies and can be considered an important agent for the clinical management of obesity.

In silico, in vitro and in vivo safety assessment of three Limosilactobacillus mucosae strains for probiotic candidates

Previous studies indicated that Limosilactobacillus mucosae had a good ability to regulate lipid metabolism, however, there was limited research on its safety. In this study, we assessed the safety of three L. mucosae strains including genotypes and phenotype, subacute oral toxicity test, and their influences on immunosuppressed mice. The results showed that there were no virulence genes or genetic islands with clear pathogenicity in the genomes of L. mucosae DCC1HL5, FZJTZ26M3, and GD16M9. All three strains were resistant to chloramphenicol, additionally, DCC1HL5 was resistant to kanamycin and tetracycline, but the possibility of horizontal transfer of their resistance genes was relatively low. L. mucosae DCC1HL5, FZJTZ26M3, and GD16M9 did not produce biogenic amine, and α-hemolysis was found. The results of the 28-day subacute oral toxicity test showed that 109 CFU of each strain did not cause significant abnormalities in various aspects such as body weight, organ indexes, histopathology, hematological parameters, fasting blood glucose, serum lipids, liver parameters, and intestinal inflammation in both healthy and immunosuppressed mice. Therefore, L. mucosae DCC1HL5, FZJTZ26M3, and GD16M9 have the potential for safe application in functional foods.

Subacute Toxicity of Microgranulated Myrmecodia platytyrea Aqueous Tuber Extract (gMPAE)

Introduction: Myrmecodia platytyrea, locally known as ‘Sarang Semut’, is an epiphytic plant native to Asia and the Asia Pacific. The tubers were traditionally used to manage cancer, hyperuricemia, and coronary heart diseases. Scientifically, the aqueous tuber extract has potential pharmacological benefits, including anti-cancer, anti-diabetic, and anti-inflammatory properties. Since the extract had no acute or subacute toxic effects, it might be used as a supplement to reduce inflammation and improve physiological functioning with better bioavailability than conventional preparations. This study aims to investigate the subacute toxicity of the microgranulated aqueous extract of M. platytyrea tuber (gMPAE). Methods: The formulation of the microgranules was established and analysed using a scanning electron microscope (SEM). The subacute oral toxicity study was carried out. The female nulliparous and non-pregnant ICR mice were divided into three groups (n=5), a group treated with normal saline (control group), a group treated with a placebo (blank microgranules), and a group treated with gMPAE, orally once daily for 28 days. Results: The gMPAE was produced using a spray-dry method and displayed microparticles with irregular shapes typical for spray-dried formulations. The sub-acute toxicity study showed no physical or behavioural changes in both placebo or gMPAE-treated mice compared to the control mice, with no mortality observed after 28 days of treatment and no signs of delayed occurrence of toxic effects 14 days post-treatment. Conclusion: Standardised spray-dried microgranules of M. platytyrea tuber aqueous extract were successfully developed to enhance the extract’s efficacy and are safe to be used as health supplements.

Acute and sub-acute oral toxicity assessment of the methanol root extract of Olax subscorpioidea Oliv. (Olacaceae) in mice and rats

Olax subscorpioidea Oliv. is an important medicinal plant included in African traditional anticancer medicines. Little information about its safety and toxicity appears in the literature. This study thus aimed at evaluating the safety of its methanol root extract orally administered in laboratory animals. Fourier Transform Infrared (FTIR) spectrophotometric analysis of O. subscorpioidea extract was conducted. For acute toxicity, methods within the Organization for Economic Co-operation and Development (OECD) guidelines were used, with slight modifications. A single female mouse was orally administered a dose of 2,000 mg/kg body weight of O. subscorpioidea methanol root extract and was monitored for at least 24 h for any signs of toxicity or death. An additional four mice (n = 4, 2/sex) were similarly treated. Another female mouse was orally administered 5,000 mg/kg body weight and observed for at least 24 h. Additional four mice were similarly treated. For sub-acute toxicity, the extract was administered daily to Wistar rats for 21 days at 250 mg/kg, 500 mg/kg, and 1,000 mg/kg. General behaviours changes, haematological, biochemical, and histological examinations on rats’ organs were performed. The FTIR spectrum showed no peaks in the 2220–2260 cm−1 region, suggesting that no cyanide groups were present in the extract. A single oral dose at both 2000 mg/kg and 5000 mg/kg did not induce any signs of toxicity or mortality, indicating an oral median lethal dose (LD50) >5000 mg/kg. When compared to the controls, dose-dependent changes were observed in the red blood cells, haemoglobin and haematocrit levels at 500 mg/kg and 1000 mg/kg (p<0.05). Histopathological examinations showed severe vascular congestion in the liver, and interstitial congestion and haemorrhage with moderate glomerular damage in the kidney. This study showed O. subscorpioidea root's methanol extract as non-toxic in acute administration, but with potential for toxicity in sub-acute oral administration.

Pharmacognostic characterization, wound healing and toxicity assessment of the stem bark of Xylia evansii Hutch (Leguminosae)

Xylia evansii is widely used in traditional medicine to stop bleeding gums and treat wounds. This study was undertaken to assess the wound healing activity and toxicity profile of the stem bark methanol extract of X. evansii (XES). Wound healing activity was determined by the dermal excision model in rats. The free radical scavenging capacity, antioxidant activity, total phenolic and flavonoid contents were evaluated by the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, total antioxidant capacity (TAC), aluminum chloride colorimetric and Folin Ciocalteu methods respectively. Acute and sub-acute oral toxicity assessment was performed following the Organization for Economic Co-operation and Development guidelines. Significant (p < 0.05) dose-dependent wound healing effect, similar to that of 1 % silver sulphadiazine was elicit by the 10, 15 and 20 %w/w XES ointments. The highest effect was demonstrated by XES 20 %w/w which resulted in 98.3 % wound surface closure by day 9 of treatment (p < 0.0001). The total phenolic and flavonoid contents were determined to be 381.2 ± 12.57 mg/g gallic acid equivalent (GAE) and 460 ± 29.07 mg/g quercetin equivalent respectively. XES exhibited remarkable free radical scavenging effect (IC50 = 68.13 ± 1.87 μg/mL) and had a total antioxidant capacity of 279.2 ± 32.08 mg/g GAE. The LD50 of XES was estimated to be > 5000 mg/kg. In sub-acute toxicity, 28 days treatment with XES (250, 500, 1000 mg/kg body weight) did not result in any significant (p > 0.05) change in the body weight or weight of the heart, lung, spleen, liver and kidneys. The haematological and biochemical profiles of XES-treated rats were not significantly (p > 0.05) affected after 4-weeks treatment with XES, except for platelet count which increased significantly (p < 0.0001) in a non-dose-dependent manner. Histopathological examination did not reveal any toxic effect to liver cells, however at 1000 mg/kg XES, slight abnormalities were identified in the glomeruli. Microscopy of the powdered stem bark displayed calcium oxalate crystals, pitted vessels and lignified fibres. Tannins, flavonoids, coumarins, saponins, triterpenes and alkaloids were identified in the bark. This is the first report on the wound healing potential and safety profile of X. evansii, giving scientific credence to its use in traditional medicine.