The Danger of Long-Term Use of Rauwolfia vomitoria Afzel. (Apocynaceae) Aqueous Root Back Extract for Benign Prostatic Hyperplasia.

Abstract

Rauwolfia vomitoria has recently been reported as a promising phytomedicine for benign prostatic hyperplasia (BPH). It has a wide range of therapeutic advantages intermingled with diverse controversies of toxicities, necessitating the need to proceed on a long-term investigation to determine the safety of R. vomitoria. The study is aimed at determining the subchronic toxicity of R. vomitoria. Rats were randomised into four (4) groups, which included the normal control group (C), R. vomitoria root bark aqueous extract (RVRAE), low dose (LD, 10 mg/kg bwt.), medium dose (MD, 25 mg/kg bwt.) and high dose (HD, 50 mg/kg bwt.). The experimental set-up included daily administration of plant extracts for a period of 90 days. Relative organ weights, haematological and renal function revealed no significant differences across the treatment groups. However, for liver function, whilst most liver analytes remained unchanged, a significant increase in alkaline phosphatase (ALP) was observed across treatment groups. C and LD values were C = 144.2 ± 29.3 and LD = 246.4 ± 66.9 (IU) (p = 0.008). Total bile acids (TBAs) reduced in a dose-dependent manner; C = 27.9 ± 7.6, LD = 19.0 ± 5.5, MD = 18.6 ± 4.3, HD = 116.8 ± 16.8  μmol/L. The most prominent significant value among others occurred between the C and HD groups (p = 0.004). Absolute and relative organ weights of lungs decreased in a dose-dependent manner. However, only the absolute organ weight was significant (p < 0.05) with values of C = 2.13 ± 0.12, LD = 1.81 ± 0.05, MD = 1.77 ± 0.15, HD = 0.62 ± 0.17 g. PSA levels in the study did not show significant differences (p > 0.05). However, a decline was observed with the high dose group. No significant histopathological alterations were observed in the kidneys, confirming the absence of renal toxicity. However, some histoarchitecture alterations were observed in the liver and lungs, which require further investigation. The safety of the root bark extract remains doubtful, with the lungs and the liver adversely affected even at lower doses of 10 mg/kg bwt.