Acute and subchronic oral toxicity assessments of Combretum micranthum (Combretaceae) in Wistar rats.

BACKGROUND: Combretum micranthum (CM) (Combretaceae) is widely used in traditional medicine throughout West Africa for the treatment of diabetes, hypertension, inflammation, malaria and liver ailments. In our recent research we demonstrated that CM has nephroprotective potentials in diabetes mellitus, hypertension and renal disorders. However, to the best of our knowledge, no systematic study concerning its toxicity profile has been reported. AIM OF THE STUDY: The study carried out to evaluates the potential toxicity of the hydroalcoholic extract from leaves of the CM, through the method of acute and sub-chronic oral administration in rats. MATERIALS AND METHODS: During the acute toxicity study, male and female rats were orally administrated with CM extract at single doses of 5000 mg/kg (n = 5/group/sex). Abnormal behaviour, toxic symptoms, weight, and death were observed for 14 consecutive days to assess the acute toxicity. For sub-chronic toxicity study, the extract was administered orally at doses of 500 and 1000 mg/kg (n = 5/group/sex) daily to Wistar rats for 28 days. The general behaviour and body weight of the rats was observed daily. A biochemical, haematological, macroscopical and histopathological examinations of several organs were conducted at the end of the treatment period. The CM extract was subjected to Fourier transform infrared spectrophotometric examination in order to detect the presence or absence of cyanide toxic compounds. RESULTS: The absence of absorbance peaks between the 2220-2260 cm-1 region of FT-IR spectrum of CM, indicating the absence of cyanide groups. This suggested that the CM extract may not contain toxic substances. During the acute toxicity test, no mortality or adverse effects were noted at the dose of 5000 mg/kg. In the subchronic study, the CM extract induced no mortality or treatment-related adverse effects with regard to body weight, general behaviour, relative organ weights, hematological, and biochemical parameters. Histopathological examination of vital organs showed normal architecture suggesting no morphological alterations. CONCLUSION: The present study revealed that oral administration of CM extract for 28 days, at dosage up to 1000 mg/kg did not induce toxicological damage in rats. From acute toxicity study, the median lethal dose (LD50) of the extract was estimated to be more than 5000 mg/kg.

Nephroprotective activity of Combretum micranthum G. Don in cisplatin induced nephrotoxicity in rats: In-vitro, in-vivo and in-silico experiments.

Nephrotoxicity is known to be a major complication during cisplatin chemotherapy in cancer patients. In the present study, the protective effect of a hydroalcoholic extract of Combretum micranthum (CM) against cisplatin (CP)-induced renal damage was evaluated using in-vitro human embryonic kidney (HEK)-293 cells and in-vivo experiments. Further, in-silico molecular docking and dynamic experiments were carried out with bioactive compounds of the title plant against nuclear factor kappa B (NF-κB) and soluble epoxide hydrolase (sEH). Incubation of HEK-293 cells with cisplatin resulted in a significant increase in cell death with changes in normal cellular morphology. Co-treatment of HEK-293 cells with CP and CM extract at varying concentrations resulted in significant enhancement of cell growth compared to CP treatment indicating the cytoprotective activity of CM with an EC50 8.136 µg/mL. In vivo nephroprotective activity was evaluated by administering CM (200 and 400 mg/kg, p.o) to rats for 10 days followed by single intraperitonial injection of CP (7.5 mg/kg) on the 5th day of the experiment. Nephrotoxicity induced by CP was apparent by elevated levels of serum and urine kidney function markers, transaminases, oxidative stress markers and histopathological alterations in kidney. Pre-treatment with CM normalized the renal function at both the doses by ameliorating the CP-induced renal damage markers, oxidative stress and histopathological variations. In-silico studies showed that, out of the thirty bioactive compounds, isovitexin and gallic acid exhibited a higher docking score of -22.467, -21.167 kcal/mol against NF-κB. Cianidanol and epicatechin exhibited a higher docking score of -14.234, -14.209 kcal/mol against sEH. The protective effect of CM extract in CP-induced nephrotoxicity might be attributed to its antioxidant, anti-inflammatory activity by inhibiting NF-κB and sEH upregulation.

Bioactive phenolic fraction of Citrus maxima abate lipopolysaccharide-induced sickness behaviour and anorexia in mice: In-silico molecular docking and dynamic studies of biomarkers against NF-κB.

Sickness behaviour, fever, anxiety, anorexia and depression are interrelated phenomena. The citrus fruit peels offering significant low-cost nutritional dietary supplements due to its rejuvenating biological activities. The present study was undertaken to explore the beneficial effect of enriched phenolic fraction of peel (PFMC) in lipopolysaccharide (LPS)-induced sickness behaviour and anorexia in mice. Further, the HPTLC estimation of hesperidin, total phenolic and flavonoid content in PFMC were carried out. In silico molecular docking and dynamic studies of bioactive compounds against NF-κB (1NFK) were also performed. The amount of hesperidin was found to be 55.33 mg/g of PFCM as per the proposed HPTLC method. Total phenolic and flavonoid content was found to be 71 mg of gallic acid/g and 58.1 mg of quercetin/g of PFCM. The single dose of LPS (400 µg/kg, i.p) treatment exhibited significant reduction in food, water intake and behavioural tests and tissue GSH, whereas significantly higher levels of tissue LPO and plasma IL-6 levels compared to normal control. Pre-treatment of PFCM (100 and 200 mg/kg, i.p) and dexamethasone (1 mg/kg, i.p) showed significantly altered the LPS-induced behavioural, anorexia and biochemical parameters. The bioactive compounds such as hesperidin, naringenine, naringin and dexamethasone showed docking score of -22.49, -21.99, -16.43 and -11.12 respectively against NF-κB (1NFK). Among tested bioactive compounds, naringin clearly exhibited higher inhibiting property on target protein structure. The protective effect of PFCM in LPS-induced anorexia and sickness behaviour is due to its antioxidant, anti-inflammatory and appetizing activities, inhibiting IL-6 and NF-κB.