Acute and Subchronic Toxicity Studies on the Aqueous Extract of the Plant Mixture (Bidens pilosa and Cymbopogon citratus Aerial Parts) in Rat Model.

Bidens pilosa (B. pilosa) and Cymbopogon citratus (C. citratus) are plants used individually or in combination in the traditional treatment of several ailments such as cardiovascular disorders. In order to valorise their traditional use, a toxicological study was conducted on the aqueous extract of the mixture of aerial parts of B. pilosa and C. citratus. The acute and subchronic toxicity studies were conducted according to the OECD 425 and 407 guidelines. Regarding the acute study, the aqueous extract of the mixture of B. pilosa and C. citratus 50 : 50 (2000 and 5000 mg/kg) was administered once to rats of both sexes. In the subchronic study, the aqueous extract of the mixture of B. pilosa and C. citratus (200, 400 and 800 mg/kg) was administered once daily to rats for 28 days. The aqueous extract of the mixture of B. pilosa and C. citratus (2000 and 5000 mg/kg) did not cause death and did not induce any apparent sign of toxicity during the 14 days of observation. The DL50 of the extract is therefore greater than 5000 mg/kg. Taken daily for 28 days, the extract had no significant effect on selected parameters (creatinine, AST, ALT, urea, and uric acid) of renal and hepatic function, as well as on the number of some blood cells. However, the aqueous extract of the mixture of B. pilosa and C. citratus (200 and 400 mg/kg) caused a significant (p < 0.05; p < 0.001, respectively) decrease in creatinine levels in male rats as compared to normal control animals. In females, the aqueous extract of the mixture of B. pilosa and C. citratus (200 and 400 mg/kg) resulted in a significant (p < 0.05) increase in total cholesterol levels as compared to normal control animals. The study showed that the aqueous extract of the mixture of B. pilosa and C. citratus has a low toxicity and does not cause any injury to the liver, kidney, lungs, or spleen.

Estrogenic and Antioxidant Activities of Pterocarpus soyauxii (Fabaceae) Heartwood Aqueous Extract in Bilateral Oophorectomized Wistar Rat.

Phytoestrogens are used to ease postmenopausal symptoms, a property probably due to estrogenic and antioxidant effects. Pterocarpus soyauxii (P. soyauxii) is empirically used in Cameroon to treat among others primary and secondary amenorrhea. The aim of this study is to evaluate estrogenic and antioxidant activities of P. soyauxii heartwood aqueous extract in bilateral oophorectomized Wistar rats. Firstly, a characterization of the extract was carried out. For that, flavonoids, phenols, and tannins levels in P. soyauxii extract were evaluated by colorimetric assays and UHPLC-MS analysis was realized. In vitro antioxidant analysis of P. soyauxii was conducted using DPPH, ABTS, and FRAP assays. Secondly, 2 sets of pharmacologic tests were carried out. The results revealed that P. soyauxii aqueous extract contains, respectively, 229.42 ± 3.62 mg EAG/g, 63.42 ± 2.16 mg EQ/g, and 27.88 ± 0.23 mg ETA/g of polyphenols, flavonoids, and tannins. UHPLC-MS enabled identifying seven components including mono(2-ethylhexyl) phthalate, cembrene, 3',5'-dimethoxy-4-stilbenol, and linoleic acid. DPPH, ABTS, and FRAP assays revealed that P. soyauxii extract possessed a high antioxidant activity with IC50 value of 730.20 µg/mL, 892.90 µg/mL, and 765.75 mEAG/g of extract, respectively. In the uterotrophic assay, P. soyauxii extract induced significant increase of fresh uterine weight, uterine and vaginal epithelial size, and mammary glands differentiation compared to Ovx control. In the postmenopausal model, compared to the sham control, vagina and uterine dystrophies were observed in Ovx rats treated with distilled water. P. soyauxii aqueous extract expressed estrogenic-like effects on vagina and did not affect uterine epithelial height compared with vehicle groups. On the back of these vaginotrophic effects, the extract displayed antiatherogenic properties by reducing (p < 0.001) AI and LDL cholesterol level as compared to Ovx control group. The extract at 200 mg/kg significantly prevented the increase of MDA (p < 0.01) level and decreased nitrites (p < 0.001) and GSH (p < 0.01) levels compared to Ovx rats. These beneficial effects are related at least in part to the presence of compound such as mono(2-ethylhexyl) phthalate, 3',5'-dimethoxy-4-stilbenol, and linoleic acid. Overall, P. soyauxii aqueous extract exhibits estrogenic and antioxidant effects which can inhibit postmenopausal symptoms by providing vaginal stratification, improving lipid profile and insulin sensitivity, and reducing oxidative stress without side effects on the endometrium and mammary gland in 84-day Ovx rats.

Nymphaea lotus Linn. (Nymphaeaceae) Alleviates Sexual Disability in L-NAME Hypertensive Male Rats.

Hypertension (HT) is a risk factor for erectile dysfunction (ED). This study aimed to evaluate the suppressive effect of Nymphaea lotus (N. lotus) on erectile dysfunction induced by NO deficiency in rat. 40 male rats equally divided into 4 groups received an oral treatment with 10 mg/kg/day of L-NAME, a NO blocker, during 4 weeks. Control group composed of 10 male rats received only distilled water (10 mL/kg). Thereafter oral treatments with N. lotus (75 and 200 mg/kg/day) and losartan (10 mg/kg/day) started and continued concomitantly with L-NAME in 3 groups for 4 additional weeks. Normal and negative controls received only distilled water. Sexual behaviour, orientation activities, anxiety, and penile histomorphology were evaluated at the end of treatment. L-NAME administration elevated significantly the blood pressure in male rats and decreased the copulatory rate by enhancing intromission latency and decreasing the numbers of intromission and ejaculation. However, the sexual motivation remains unaltered by chronic NO blockage suggesting that L-NAME induces penile dysfunction mainly by peripheral mechanisms. L-NAME chronic intake also induced anxiety, 4 weeks of N. lotus cotreatment prevented inhibitory effects of L-NAME on male sexual behaviour by shortening mainly ejaculation latency and postejaculatory interval while losartan does not. Losartan proved to be a more effective drug to decrease the blood pressure compared to the plant extract. Effectively, Nymphea lotus was able to reverse totally at 75 mg/kg the increment of hemodynamic parameters and the histological damage and exhibit anxiolytic-like effects in hypertensive male rats. Nymphaea lotus uses NO pathway to facilitate sexual responses at central and peripheral levels and can have a double medicinal use, against anxiety and erectile dysfunction.

Safety assessment of the aqueous extract of the flowers of Nymphaea lotus Linn (Nymphaeaceae): Acute, neuro- and subchronic oral toxicity studies in albinos Wistar rats.

Background Nymphaea lotus Linn (N. lotus) is a medicinal plant widely used in Cameroon popular medicine, to treat neuropsychiatric conditions, male sexual disorders or as food supplement. However, scientific data on the pharmacotoxic profile of this plant are not available. The safety of N. lotus was assessed in acute, neuro- and subchronic toxicity studies by following the OECD guidelines. Effectively, no data have been published until now in regard to its safety on the nervous system. Methods Aqueous extract of N. lotus at doses of 200, 400 and 600 mg/kg body weight (BW) was evaluated for nitrites contents and orally administered to rats daily for 28 days (5 male, 5 female per group). The control group received distilled water (10 mL/kg) and a satellite group was used to observe reversal effects. Neurotoxicity of the plant was determined using open field test for motor coordination, ataxia and gait analysis. Clinical signs and state of livelihood were recorded during the 24 h, then for 28 days of treatments. At the end of 28-day period, animals were anesthetized and decapitated. The whole brain was homogenized for neurobiochemical analysis. Blood samples were collected with or without anticoagulant for hematological examinations and serum analysis. Specimens of liver, kidney, testis, ovaries, and brain were fixed in 10 % formalin and processed for histopathological examinations. Results Our findings indicate dose-dependent elevation of nitrites contents in the flowers aqueous extract of N. lotus. Acute toxicity study revealed no signs of toxicity neither at the dose 2,000 mg/kg nor at 5,000 mg/kg. Thus the LD50 value of aqueous extract of N. lotus flowers is superior to 5,000 mg/kg. The repeated administration of N. lotus during 28 days, induced no signs of neurobehavioral changes in male, but female rats exhibited dose-dependent response in the open field test, suggesting sex and dose-relative psychotropic effects of N. lotus. The evaluation of neurobiochemistry revealed consistent rise of brain cholesterol by 44.05 %; 158.10 % and 147.62 % respectively in male rats treated with the doses of 200, 400 and 600 mg/kg. In female rats, these levels were significantly increased (p<0.001) only at the dose of 600 mg/kg compared to control. This trend persisted after 14 days withdrawal. Brain potassium and calcium concentrations were increased in all rats compared to their respective control receiving distilled water, suggesting transmembrane current stabilizing properties of brain cells by our extract. Further, serum biochemical analysis demonstrated that 28-day administration of N. lotus flowers increased depending on the dose and sex, the levels of serum urea, proteins, creatinine and bilirubin and reduced γ-glutamyltransferase (GGT) and alkaline phosphatase (ALP) activities. These results suggest liver alterations that are endowed by lower liver relative weight and histology damages observed in female rats treated with the dose of 600 mg/kg of our extract. We also observed a rise in the low-density lipoprotein (LDL) fraction and AI of male rats undergoing N. lotus treatment. In female rats, the latter remains unaltered, confirming the dose- and sex-dependent response of our extract. The levels of white blood cells (WBC) and granulocytes were higher in male irrespective to their control, revealing stimulatory properties of the male hematopoietic system. Such variations (sex- and dose-dependent) are without biological relevance for the majority of the biochemical parameters evaluated, indicating a wide margin of safety for the traditional use of N. lotus. The alkaloids, nitrites and phytosterols contained in N. lotus flowers extract may probably account for its neuroprotective, anti-oxidant, and immunoboosting properties. Conclusions N. lotus do not possesses neurotoxicity but is able to induce behavioral changes in rats. Therefore, the application of this plant as either drug or supplementary food should be carefully considered.