Immunomodulatory effects of epiphytic Loranthus micranthus leaf extracts collected from two host plants: Psidium guajava and Parkia biglobosa.

BACKGROUND: Immunological abnormalities are implicated in the pathogenesis of many chronic diseases. Due to the drug-related adverse effects of currently available orthodox immunomodulators, natural immunomodulators are being looked upon as potential agents to replace them in therapeutic regimens. This research aimed to investigate the immunomodulatory potential of L. micranthus extracts epiphytic on Psidium guajava (LMPGE) and Parkia biglobosa (LMPBE). METHODS: Phytochemical screening and acute toxicity testing were carried out to identify the phytoconstituents and safety profiles of the extracts. The extracts' innate and adaptive immunomodulatory potentials were determined in experimental animals using in vivo leucocyte mobilization, delayed-type hypersensitivity (DTH) response, hemagglutination antibody titre, and cyclophosphamide-induced myelosuppression models. Levamisole was used as the standard drug throughout the study. RESULTS: Compared to LMPBE, LMPGE contained significantly (p <  0.05) more tannins, cyanogenic glycosides, saponins, reducing sugars, glycosides, flavonoids, and alkaloids. Furthermore, the groups treated with the extracts had a significant (p <  0.05) increase in the total number of leucocytes, neutrophils, basophils, and antibody titers relative to the untreated control. In the same way, the treatment raised TLC in cyclophosphamide-intoxicated rats, with 250 mg/kg b. w. of LMPGE and LMPBE recording 9712.50 ± 178.00 and 8000.00 ± 105.00 ×  109 /L, respectively, compared to 3425.00 ± 2 5.00 × 109 /L in the untreated group. Overall, LMPGE was more effective. CONCLUSIONS: The findings from this study suggest that L. micranthus epiphytic in Psidium guajava and Parkia biglobosa has possible immune stimulating potential.

FTO gene expression in diet-induced obesity is downregulated by Solanum fruit supplementation.

The Fat Mass and Obesity-associated (FTO) gene has been shown to play an important role in developing obesity, manifesting in traits such as increased body mass index, increased waist-to-hip ratio, and the distribution of adipose tissues, which increases the susceptibility to various metabolic syndromes. In this study, we evaluated the impact of fruit-based diets of Solanum melongena (SMF) and Solanum aethiopicum fruits (SAF) on the FTO gene expression levels in a high-fat diet (HFD)-induced obese animals. Our results showed that the mRNA level of the FTO gene was downregulated in the hypothalamus, and white and brown adipose tissue following three and six weeks of treatment with SMF- and SAF-based diets in the HFD-induced obese animals. Additionally, the Solanum fruit supplementation exhibited a curative effect on obesity-associated abrasions on the white adipose tissue (WAT), hypothalamus, and liver. Our findings collectively suggest the anti-obesity potential of SMF and SAF via the downregulation of the FTO gene.

Flavonoid-rich fraction of Lasianthera africana leaves alleviates hepatotoxicity induced by carbon tetrachloride in Wistar rats.

Lasianthera africana P. Beauv. (Icacinaceae) is a good source of natural antioxidants, having the potential to protect against oxidative stress-related diseases and complications. This study investigated the antioxidant, hepatoprotective and curative effects of flavonoid-rich fraction of L. africana leaves (LAFRF) against carbon tetrachloride-induced hepatotoxicity in Wistar rats. Phytochemical, nutrient content, and in vitro antioxidant activity of LAFRF were determined by standard methods. Fifty Wistar rats were randomized into 10 groups (n = 5). Groups 1 and 2 served as normal and CCl4 controls, respectively. Groups 3A-6A constituted the protective study while groups 3B-6B represented the curative study. The effects of LAFRF at 3, 10, and 30 mg/kg body weight (b.w.) on lipid peroxidation, antioxidant status, liver enzymes activities, and histology of CCl4-intoxicated rats were assessed. LAFRF total flavonoids (281.05 ± 7.44 mg QE/g), indicated LD50 above 5000 mg/kg b.w., and scavenged ABTS*+ with an IC50 of 5.05 ± 0.00 µg/mL relative to butylated hydroxytoluene (4.16 ± 0.00 µg/mL), and a concentration-dependent increase in total antioxidant capacity. Carbon tetrachloride (1 mL/kg) triggered significant (p < 0.05) increases in malonedialdehyde concentration (2.67 ± 0.21 mg/mL), with a corresponding decline in antioxidant status, and increases in alkaline phosphatase, alanine and aspartate aminotransferase activities (68.00 ± 9.59 IU/L, 79.60 ± 5.03 IU/L and 81.80 ± 3.96 IU/L), respectively. LAFRF significantly (p < 0.05) lowered lipid peroxidation levels, liver enzyme activities, increased antioxidant status, and improved hepatic histo-architecture of pre- and post LAFRF-treated rats. This demonstrates its high antioxidative, hepatoprotective and curative effects, indicating its potential for future drug development.

High resolution UPLC-PDA-QTOF-ESI-MS/MS analysis of the flavonoid-rich fraction of Lasianthera africana leaves, and in vivo evaluation of its renal and cardiac function effects.

Lasianthera africana P. Beauv. (Icacinaceae) is a traditional Nigerian medicinal plant used for treatment of ulcers, diarrhea, parasitic infections and diabetes. This study was aimed at characterizing the bioactive principles extractable from the flavonoid-rich fraction of L. africana leaves (LAFRF), and to evaluate its effects on renal and cardiac functions. Isolation, and purification of the LAFRF was achieved using standard methods. The in vitro antioxidant activity was evaluated on DPPH∗ and ferric reducing antioxidant potential (FRAP). The total flavonoids (281.05 ± 7.44 mg QE/g), were identified, structurally characterized and quantified using high resolution ultra-performance liquid chromatography, in tandem with quadrupole-time-of-flight electrospray ionization mass spectrometer (UPLC-PDA-QTOF-ESI-MS/MS). Fifty Wistar rats of both sexes (110-130 g), were distributed into 10 groups (n = 5). Groups 1 and 2 served as the normal and CCl4 controls respectively. Groups 3A-6B constituted the preventive and curative studies. The effects of the LAFRF at 3, 10, and 30 mg/kg body weight on urea and creatinine concentrations, lactate dehydrogenase (LDH), and creatine kinase (CK) activities of CCl4-intoxicated rats were assessed. The LAFRF displayed remarkable in vitro antioxidant property by scavenging the DPPH∗, with an IC50 of 5.40 ± 0.00 µg/ml which is more potent than the scavenging activity of the ascorbic acid (IC50 of 7.18 ± 0.00 µg/ml), and also effectively reduced Fe3+ to Fe2+ when compared to gallic acid. The UPLC-PDA-QTOF-ESI-MS/MS fingerprint of the LAFRF indicated presence of quercetin (758983.6 mg/kg), rutin (17540.4 mg/kg), luteolin (126524.3 mg/kg), isorhamnetin (197949.0 mg/kg), and other non-phenolic compounds. The LAFRF significantly (p < 0.05) improved renal function, and normalized cardiac enzyme activities in vivo. The ability of the LAFRF to scavenge the DPPH and Fe3+ radicals, improve renal and cardiac functions following CCl4 intoxication shows its potential in the development of alternative therapy for combating oxidative stress-related complications.

Antioxidant properties and membrane stabilization effects of methanol extract of Mucuna pruriens leaves on normal and sickle erythrocytes.

This study was aimed at investigating the antioxidant properties and membrane stabilization effects of Mucuna pruriens leaves on sickle erythrocyte as a possible means of sickle cell disease management. Pulverized plant material was extracted with methanol, filtered and concentrated at reduced pressure with a rotary evaporator. Phytochemical analysis and antioxidant studies of the extract were carried out using standard methods. Blood samples of volunteer sickle cell patients and healthy individuals used in the study were collected from the University of Nigeria Medical Centre and University campus community, Nsukka respectively. The genotypes of the individuals were confirmed by cellulose acetate paper electrophoresis. Water induced haemolysis of human red blood cell was used to assess membrane stabilization of the erythrocytes. Phytochemical result of the extract showed the presence of alkaloids, flavonoids, tannins, proteins, terpenoids, saponins, cardiac glycosides and anthraquinones. Antioxidant vitamins C and E were present in concentrations of 495.36 mg/100 g and 101.03 mg/100 g respectively. The percentage (%) scavenging activity of the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and hydroxyl radical by the extract was significant. The extract exhibited membrane stabilization on both normal and sickle erythrocytes. The percentage (%) inhibition of haemolysis by the extract in both normal and sickle erythrocytes at different concentrations of 100, 200, 400, 600 and 800 µg/ml were significant and concentration dependent. We conclude that M. pruriens leaves have antioxidant properties and erythrocyte membrane stabilizing potentials and could be recommended for use in the management of patients with sickle cell anaemia.